Good morning everyone. I am in the process of upgrading my oil system. This is on my dedicated track 914. The upgrades include remote oil cooler, accusump, and CB Maxi oil pump.
In my research for installing the accusump it seems like there are two places that are recommended, in the cooler return line with a check valve and direct to the block. I did not want to use the sandwich plate adapter so I opted for the block option. Simpler with less seals to fail.
As I looked into the workings of the type IV oil system I found a potential problem with both these locations; the oil relief valve on the front of the engine. VW used this valve to bypass the cooler when the oil is thick. But this also means the cooler is bypassed when the oil pressure is high. Does the use of an oil accumulator negate the oil cooler system by maintaining oil pressure?
While on the straights the pump could potentially make 50-60 psi of oil pressure. (the 30mm pump that was in the engine produces those pressures much of a 20 min session) At those oil pressures the cooler will be bypassed based on what I know of the relief valve (bypassing cooler at 60psi, partially open at 35 psi, and sealed at 12psi). The accusump will also build up to that pressure. When I go to brakes and the revs drop the accusump will start pushing back and keep the pressure up till the differential is corrected. If I am back on to the next straight in that time then the pump starts building the pressure again.
Options:
1. Am I making a mountain out of a mole hill? Leave it alone.
2. Plug that relief valve so it stays closed and let the oil cooler thermostat bypass the oil when its cold. This is a pre 76 case so there is the secondary relief valve by cylinder 1. Might be able just to invert the piston so the bypass grove is below the bypass passages.
3. There is also the high pressure pistons sold by pelican parts and others. Does this just shift the bypass window to a higher pressure range?
I would love to hear people's thoughts on this.
Miguel
QUOTE(Seabird @ May 19 2014, 09:53 AM) 
1. Am I making a mountain out of a mole hill? Leave it alone.
I think this is one of the problems that hasn't been truly solved yet, so no, not making a mountain out of a molehill.
QUOTE
2. Plug that relief valve so it stays closed and let the oil cooler thermostat bypass the oil when its cold. This is a pre 76 case so there is the secondary relief valve by cylinder 1. Might be able just to invert the piston so the bypass grove is below the bypass passages.
You can't run the engine without some kind of relief valve in the oil circuit.
Full pressure produced by the pump with cold oil will pop galley plugs.
An adjustable pressure relief valve mounted on the side of the block, with a short hose going back to the sump, would take care of it.
QUOTE
3. There is also the high pressure pistons sold by pelican parts and others. Does this just shift the bypass window to a higher pressure range?
That's exactly what it does.
Chris,
Seems like you and I are the only ones actually interested in the subject.
BTW motor is back in and I'll be mounting the cooler later this week. I order the high pressure kit from PP yesterday. Going to be in Daytona for a Chumps race this weekend so get her running before next week is not going to happen.
Miguel
Seems like you and I are the only ones actually interested in the subject.
BTW motor is back in and I'll be mounting the cooler later this week. I order the high pressure kit from PP yesterday. Going to be in Daytona for a Chumps race this weekend so get her running before next week is not going to happen.
Miguel
QUOTE(Seabird @ May 20 2014, 11:32 AM)
Chris,
Seems like you and I are the only ones actually interested in the subject.
BTW motor is back in and I'll be mounting the cooler later this week. I order the high pressure kit from PP yesterday. Going to be in Daytona for a Chumps race this weekend so get her running before next week is not going to happen.
Miguel
Not the only ones:
The bottom "T" line is to the Accusump.
Click to view attachment
Click to view attachment
QUOTE(Seabird @ May 20 2014, 10:32 AM)
Chris,
Seems like you and I are the only ones actually interested in the subject.
BTW motor is back in and I'll be mounting the cooler later this week. I order the high pressure kit from PP yesterday. Going to be in Daytona for a Chumps race this weekend so get her running before next week is not going to happen.
Miguel
New motor?
Oh, are you driving in Chump?
Thanks for jumping in Randal! I was just 
at folks 
I guess I could have been clearer with my original post. Where the accusump input is isn't the problem; its the oil relief valve that acts to bypass the cooling loop. Oil pressure above 35psi will essentially cut the flow to the cooler. Hot oil goes directly to your crank and gets hotter.
An accusump works as an oil pressure dampener. If the oil pressure stays above 35 psi the cooler never gets a chance to cool the oil. At some point viscosity gets critically thin and then it starts passing through the cooler. But this might be to late; the oil might already be burnt or below a healthy viscosity.
Its apparently a common problem when using a 30mm pump. I had no I idea at the time but my first trip to the track with my 914 resulted in this. After a 20 min session on track, driving through the pits my oil pressure warning light would come on at idle. I had to keep the revs up just to maintain 10-15 psi! A little stressful. When I checked my oil the dipstick looked completely dry!! It was so thin it would not cling to the dip stick. I freaked out and added 3qts to the motor. When I checked again after a few minutes the dipstick showed 3qts high! I had to drain off the excess oil which was black after just one session (it was new oil with zero miles before the session.)
I am just piecing the puzzle together now that I am researching the inner workings of the oiling system. (914 noob here
)
And no my oil temp gauge was not functioning. An issue that is being resolved currently.
There is a thread on the Samba from a while back that covers the high pressure pump issue well. Its for VW 1600 motors but their oiling system and the type IV are very similar. Check it out here >>> Duel relief oiling system
I have since swapped out the 30mm pump for a 26mm pump. But I am worried that the accusump will cause the same issue.
Hopefully I was a little clearer this time.
Regards,
Miguel
at folks I guess I could have been clearer with my original post. Where the accusump input is isn't the problem; its the oil relief valve that acts to bypass the cooling loop. Oil pressure above 35psi will essentially cut the flow to the cooler. Hot oil goes directly to your crank and gets hotter.
An accusump works as an oil pressure dampener. If the oil pressure stays above 35 psi the cooler never gets a chance to cool the oil. At some point viscosity gets critically thin and then it starts passing through the cooler. But this might be to late; the oil might already be burnt or below a healthy viscosity.
Its apparently a common problem when using a 30mm pump. I had no I idea at the time but my first trip to the track with my 914 resulted in this. After a 20 min session on track, driving through the pits my oil pressure warning light would come on at idle. I had to keep the revs up just to maintain 10-15 psi! A little stressful. When I checked my oil the dipstick looked completely dry!! It was so thin it would not cling to the dip stick. I freaked out and added 3qts to the motor. When I checked again after a few minutes the dipstick showed 3qts high! I had to drain off the excess oil which was black after just one session (it was new oil with zero miles before the session.)
I am just piecing the puzzle together now that I am researching the inner workings of the oiling system. (914 noob here
) And no my oil temp gauge was not functioning. An issue that is being resolved currently.
There is a thread on the Samba from a while back that covers the high pressure pump issue well. Its for VW 1600 motors but their oiling system and the type IV are very similar. Check it out here >>> Duel relief oiling system
I have since swapped out the 30mm pump for a 26mm pump. But I am worried that the accusump will cause the same issue.
Hopefully I was a little clearer this time.
Regards,
Miguel
QUOTE(Jetsetsurfshop @ May 20 2014, 11:55 AM)
New motor?
Oh, are you driving in Chump?
Same motor. Had to drop it to tap the galley for the accusump. I bought a remote cooler kit from Chris and wanted to update and check a few things before going back out with it. Turns out there is an 86b cam in it. Apparently that's a cool cam. Once I finish the job I'll put together a little write up for it.
No not driving this weekend. My last experience with Chump put me off the organization. Hopefully this weekend will make me feel better about them. The race I attended was basically a 25hr demolition derby. It was crazy. They actually red flagged the race at 8am to yell at all the drivers. "Stop hitting each other or we will end the race" was the short of it.
My e30 buddies built an e30 for Chump. I have been working with them on it and this will be its first race. If it looks sane maybe I'll run a few races with them.
Miguel
QUOTE(Seabird @ May 20 2014, 01:24 PM)
Thanks for jumping in Randal! I was just
at folks I guess I could have been clearer with my original post. Where the accusump input is isn't the problem; its the oil relief valve that acts to bypass the cooling loop. Oil pressure above 35psi will essentially cut the flow to the cooler. Hot oil goes directly to your crank and gets hotter.
An accusump works as an oil pressure dampener. If the oil pressure stays above 35 psi the cooler never gets a chance to cool the oil. At some point viscosity gets critically thin and then it starts passing through the cooler. But this might be to late; the oil might already be burnt or below a healthy viscosity.
Its apparently a common problem when using a 30mm pump. I had no I idea at the time but my first trip to the track with my 914 resulted in this. After a 20 min session on track, driving through the pits my oil pressure warning light would come on at idle. I had to keep the revs up just to maintain 10-15 psi! A little stressful. When I checked my oil the dipstick looked completely dry!! It was so thin it would not cling to the dip stick. I freaked out and added 3qts to the motor. When I checked again after a few minutes the dipstick showed 3qts high! I had to drain off the excess oil which was black after just one session (it was new oil with zero miles before the session.)
I am just piecing the puzzle together now that I am researching the inner workings of the oiling system. (914 noob here
) And no my oil temp gauge was not functioning. An issue that is being resolved currently.
There is a thread on the Samba from a while back that covers the high pressure pump issue well. Its for VW 1600 motors but their oiling system and the type IV are very similar. Check it out here >>> Duel relief oiling system
I have since swapped out the 30mm pump for a 26mm pump. But I am worried that the accusump will cause the same issue.
Hopefully I was a little clearer this time.
Regards,
Miguel
That link has excellent documentation.
Hey Miguel,
I don't have much to offer regarding the cooler, etc. unfortunately. But I will be at Daytona this weekend. I'll be racing with the gunmetal grey Mustang. Come by and say "hi" when you get a chance!
What does your e30 look like? I drove one at Sebring last year - those things are bulletproof, easy to drive and pretty quick. I was very impressed, other than the loose seat bolts and shock bolt that fell out going through turn 1. Stupid guys prepping the car - needless to say I won't be racing with them ever again.
I don't have much to offer regarding the cooler, etc. unfortunately. But I will be at Daytona this weekend. I'll be racing with the gunmetal grey Mustang. Come by and say "hi" when you get a chance!
What does your e30 look like? I drove one at Sebring last year - those things are bulletproof, easy to drive and pretty quick. I was very impressed, other than the loose seat bolts and shock bolt that fell out going through turn 1. Stupid guys prepping the car - needless to say I won't be racing with them ever again.
Ill look for you George. Look for a PM from me with contact info.
Condor Speed Shop and MAD Motorsports are the two teams that I work/hang out with. You wont be able to miss the MAD trailer; its a 53' car hauler with MAD vinyl all over it.
Here is the car:
Condor Speed Shop and MAD Motorsports are the two teams that I work/hang out with. You wont be able to miss the MAD trailer; its a 53' car hauler with MAD vinyl all over it.
Here is the car:
Ok so if I follow this right, I either already have the booster kit in or need it.
I will run just under 35 psi at around 220 degree at 60 mph. After several hours of this it has climbed to 260 degrees when I stopped to eat and let it cool down.
So I might be ahead of the game to add the booster kit and already plan on adding another oil cooler for additional cooling.
I will run just under 35 psi at around 220 degree at 60 mph. After several hours of this it has climbed to 260 degrees when I stopped to eat and let it cool down.
So I might be ahead of the game to add the booster kit and already plan on adding another oil cooler for additional cooling.
I've been doing a little noodling on this, and even machined into a crankcase to see inside the relief bore.
I'll post pics when I have an opportunity.
One interesting bit of evidence is a wear pattern in the bore from the spring which shows where the piston resided most of the time.
It was typically being pushed down by the oil pressure far enough to expose the cooler bypass opening.
Simply increasing the pressure resistance by using a longer piston/spring only moves the problem to a higher pressure but does nothing to solve the basic problem of oil bypassing the cooler at operating rpm.
However, there appears to be a simple "drop-in" solution which I can test in the next week or two.
My solution replaces the pressure relief piston and spring, but not with just a different piston/spring.
I plan to make a sleeve which blocks off the cooler bypass circuit, but not the sump return circuit.
The sleeve will hold a smaller diameter piston/spring designed to bypass anything more than about 60psi back to the sump.
That way the cooler will always get oil flow but never see pressure above 60psi.
I'll post pics when I have an opportunity.
One interesting bit of evidence is a wear pattern in the bore from the spring which shows where the piston resided most of the time.
It was typically being pushed down by the oil pressure far enough to expose the cooler bypass opening.
Simply increasing the pressure resistance by using a longer piston/spring only moves the problem to a higher pressure but does nothing to solve the basic problem of oil bypassing the cooler at operating rpm.
However, there appears to be a simple "drop-in" solution which I can test in the next week or two.
My solution replaces the pressure relief piston and spring, but not with just a different piston/spring.
I plan to make a sleeve which blocks off the cooler bypass circuit, but not the sump return circuit.
The sleeve will hold a smaller diameter piston/spring designed to bypass anything more than about 60psi back to the sump.
That way the cooler will always get oil flow but never see pressure above 60psi.
You are not the only one interested:
http://www.914world.com/bbs2/index.php?showtopic=217063
And:
http://www.914world.com/bbs2/index.php?sho...oler&st=240
By running the oil cooler off of the oil filter bracket, I dont have the issue with it being bypassed at higher pressures.
I am also planning on running an accusump, just havent gotten to it yet.
http://www.914world.com/bbs2/index.php?showtopic=217063
And:
http://www.914world.com/bbs2/index.php?sho...oler&st=240
By running the oil cooler off of the oil filter bracket, I dont have the issue with it being bypassed at higher pressures.
I am also planning on running an accusump, just havent gotten to it yet.
QUOTE(stugray @ May 22 2014, 10:33 AM)
You are not the only one interested:
http://www.914world.com/bbs2/index.php?showtopic=217063
And:
http://www.914world.com/bbs2/index.php?sho...oler&st=240
By running the oil cooler off of the oil filter bracket, I dont have the issue with it being bypassed at higher pressures.
I am also planning on running an accusump, just havent gotten to it yet.
Your right Stugray, the sandwich plate adapter solves the problem of the cooler bypass. Once I eliminated the sandwich plate from possible solutions I might use I did not spend much energy on its functionality.
I have read the second thread but for some reason the first one had not come up in my searching. I did a quick read through and am going to give it a more through read through when I have a free moment this afternoon.
Thanks for chiming in.
Miguel
QUOTE(Racer Chris @ May 22 2014, 08:34 AM)
I've been doing a little noodling on this, and even machined into a crankcase to see inside the relief bore.
I'll post pics when I have an opportunity.
One interesting bit of evidence is a wear pattern in the bore from the spring which shows where the piston resided most of the time.
It was typically being pushed down by the oil pressure far enough to expose the cooler bypass opening.
Simply increasing the pressure resistance by using a longer piston/spring only moves the problem to a higher pressure but does nothing to solve the basic problem of oil bypassing the cooler at operating rpm.
However, there appears to be a simple "drop-in" solution which I can test in the next week or two.
My solution replaces the pressure relief piston and spring, but not with just a different piston/spring.
I plan to make a sleeve which blocks off the cooler bypass circuit, but not the sump return circuit.
The sleeve will hold a smaller diameter piston/spring designed to bypass anything more than about 60psi back to the sump.
That way the cooler will always get oil flow but never see pressure above 60psi.
Great Chris! Let us know how it goes. Put me down for one when you get it worked out.
Miguel
Here's a little visual aid:
Relief valve components installed.
Click to view attachment
Notice the wear from the spring.
Click to view attachment
Relief piston in the closed position.
Click to view attachment
Relief piston positioned where spring marks begin. Shows cooler bypass open.
Click to view attachment
Click to view attachment
Relief valve components installed.
Click to view attachment
Notice the wear from the spring.
Click to view attachment
Relief piston in the closed position.
Click to view attachment
Relief piston positioned where spring marks begin. Shows cooler bypass open.
Click to view attachment
Click to view attachment
Here's my prototype pressure relief which eliminates the cooler bypass.
The opening pressure is estimated at 60 psi. Fine tuning may be necessary, and is done by varying the piston length to change spring preload.
Added features not shown include an o-ring seal at the top, and a screw to retain the spring.
The head of the screw will double as an alignment feature so the bypass holes line up correctly. (weld build-up visible was intended as the alignment feature)
Click to view attachment
Click to view attachment
Click to view attachment
The opening pressure is estimated at 60 psi. Fine tuning may be necessary, and is done by varying the piston length to change spring preload.
Added features not shown include an o-ring seal at the top, and a screw to retain the spring.
The head of the screw will double as an alignment feature so the bypass holes line up correctly. (weld build-up visible was intended as the alignment feature)
Click to view attachment
Click to view attachment
Click to view attachment
I think we have a winner here!
We just ran the first test in an engine and the results are exactly what I had hoped for.
We just ran the first test in an engine and the results are exactly what I had hoped for.
QUOTE(Seabird @ May 21 2014, 07:38 AM)
Ill look for you George. Look for a PM from me with contact info.
Condor Speed Shop and MAD Motorsports are the two teams that I work/hang out with. You wont be able to miss the MAD trailer; its a 53' car hauler with MAD vinyl all over it.
Here is the car:
Get in the car for Chump @ Sebring! George will be Driving, I will be Driving!
Of course you will be driving for 2nd Place!
I just might.
Though this should get its own OT topic I'll give a short blurb here. We finished 6th at Daytona, two of our drivers had never been on the track before, and one of our drivers developed a fever while driving his stint. Had it not been for two silly penalties we would have been in the hunt for 1st place (15 min worth of penalties at sub 2:30 laps makes up the 6 lap differential at the end.) GRRRR.
Not bad for a team and car's first race! We are quite ecstatic to say the least!
Also I got to meet the George, the PaintedMan; which was cool.
OT race report over.
Mean while back on the 914 front I am excited for Chris's new solution to the oil cooler bypass issue! A week and a half away from getting to test it! Man its going to be hot at Sebring too!
Regards,
Miguel
Though this should get its own OT topic I'll give a short blurb here. We finished 6th at Daytona, two of our drivers had never been on the track before, and one of our drivers developed a fever while driving his stint. Had it not been for two silly penalties we would have been in the hunt for 1st place (15 min worth of penalties at sub 2:30 laps makes up the 6 lap differential at the end.) GRRRR.
Not bad for a team and car's first race! We are quite ecstatic to say the least!
Also I got to meet the George, the PaintedMan; which was cool.
OT race report over.
Mean while back on the 914 front I am excited for Chris's new solution to the oil cooler bypass issue! A week and a half away from getting to test it! Man its going to be hot at Sebring too!
Regards,
Miguel
QUOTE(Seabird @ May 28 2014, 01:43 PM)
I just might.
Though this should get its own OT topic I'll give a short blurb here. We finished 6th at Daytona, two of our drivers had never been on the track before, and one of our drivers developed a fever while driving his stint. Had it not been for two silly penalties we would have been in the hunt for 1st place (15 min worth of penalties at sub 2:30 laps makes up the 6 lap differential at the end.) GRRRR.
Not bad for a team and car's first race! We are quite ecstatic to say the least!
Also I got to meet the George, the PaintedMan; which was cool.
OT race report over.
Mean while back on the 914 front I am excited for Chris's new solution to the oil cooler bypass issue! A week and a half away from getting to test it! Man its going to be hot at Sebring too!
Regards,
Miguel
Spoke with Chris today about this prototype for a bit. I'll block off some space next to my trailer for you. I'm track support for my dad on Sunday and will be able to help you out too. Looking forward to checking out the new components. Are you getting there Saturday night or Sunday morning?
Shane
QUOTE(Jetsetsurfshop @ May 28 2014, 03:45 PM)
Spoke with Chris today about this prototype for a bit. I'll block off some space next to my trailer for you. I'm track support for my dad on Sunday and will be able to help you out too. Looking forward to checking out the new components. Are you getting there Saturday night or Sunday morning?
Shane
Should be there Saturday by 5 or so.
Just finished the accusump tonight. Finishing the cooler install is next.
So much to do so little time.
Miguel
Well, get on it!! 
See you there.
Shane
See you there.
Shane
QUOTE(Jetsetsurfshop @ May 29 2014, 05:31 PM)
Well, get on it!!
See you there.
Shane
Cooler installed!
[/quote]
Cooler installed!
[/quote]
Miguel
Let us know how this works out for you. When I installed my Tangerine Racing street headers, it moved most of the plumbing to the drivers side. I thought this location would be perfect. When I didn't see much improvement, I realized that I was probably picking up a lot of engine heat from the impeller. I moved the cooler higher and added a NACA duct on the right side rocker panel. Not sure how effective that is yet, but Foley has used that position with positive results, he says.
I have a feeling that all the talk about rear mounted coolers being inadequate has more to do with this cooler bypass circuit than anything else. Between accusumps and high pressure pumps I think most track type iv's have been shooting themselves in their proverbial feet.
Thanks to Chris we might have a solution on our hands here.
Next weekend will be a good test of this. We shall see
Miguel
Thanks to Chris we might have a solution on our hands here.
Next weekend will be a good test of this. We shall see
Miguel
Hey Miguel,
What was you track temps at the last event?
Shane
What was you track temps at the last event?
Shane
I think he said he didn't have an oil temp gauge installed before?
The new vdo gauge and the old sender were a mis-match so I had no data. It was wicked hot though. Swapped the sender last night so we will have data this time.
Hey Miguel,
Did you install a pull-thru fan? I wonder what will happen at idle? What will the oil temps do?
Just a concern with eliminating the stock cooler. We will know soon enough...
Shane
Did you install a pull-thru fan? I wonder what will happen at idle? What will the oil temps do?
Just a concern with eliminating the stock cooler. We will know soon enough...
Shane
No puller fan. It's a race car, it should not have to idle too much once it gets up to temp.
Some racer friends came over last night and we got a bunch of the car buttoned up. Today after work another friend came over with his scales and we corner weighted the car. 2166 with my full figure in the drivers seat. 50.2% cross 51.8% rear. Pretty happy with those numbers. That's puts me pretty close, weight wise to where I need to be for HSR.
Went through the whole accusump priming routine. Filled up the oil sump. Added extra for the cooler and fird it up. I let it idle for 10 mins and it did not break 150. With some higher revs I was able to get the gauge to approach 170. Did that for a little while and gave up on getting it to heat up. The cooler was warm to the touch and the gauge was reading, works for me.
I still have a few details to sort out but the bulk of the work is done. Will be ready for next Sunday in no time
Some racer friends came over last night and we got a bunch of the car buttoned up. Today after work another friend came over with his scales and we corner weighted the car. 2166 with my full figure in the drivers seat. 50.2% cross 51.8% rear. Pretty happy with those numbers. That's puts me pretty close, weight wise to where I need to be for HSR.
Went through the whole accusump priming routine. Filled up the oil sump. Added extra for the cooler and fird it up. I let it idle for 10 mins and it did not break 150. With some higher revs I was able to get the gauge to approach 170. Did that for a little while and gave up on getting it to heat up. The cooler was warm to the touch and the gauge was reading, works for me.
I still have a few details to sort out but the bulk of the work is done. Will be ready for next Sunday in no time
QUOTE(Jetsetsurfshop @ May 31 2014, 12:36 PM)
Hey Miguel,
Did you install a pull-thru fan? I wonder what will happen at idle? What will the oil temps do?
Just a concern with eliminating the stock cooler. We will know soon enough...
Shane
The stock cooler doesn't work for shit at idle anyway.
A remote cooler will radiate more heat without air flowing thru it than the stock one does at 900 rpm engine speed.
A fan on the cooler will impede airflow when driving at high speeds.
QUOTE(Racer Chris @ Jun 1 2014, 08:58 PM)
QUOTE(Jetsetsurfshop @ May 31 2014, 12:36 PM)
Hey Miguel,
Did you install a pull-thru fan? I wonder what will happen at idle? What will the oil temps do?
Just a concern with eliminating the stock cooler. We will know soon enough...
Shane
The stock cooler doesn't work for shit at idle anyway.
A remote cooler will radiate more heat without air flowing thru it than the stock one does at 900 rpm engine speed.
A fan on the cooler will impede airflow when driving at high speeds.
Good to know about the stock cooler.
Plan on selling the factory oil cooler delete system yet? Don't see a price listed on the website.
Shane
QUOTE(Seabird @ May 19 2014, 07:53 AM)
Good morning everyone. I am in the process of upgrading my oil system. This is on my dedicated track 914. The upgrades include remote oil cooler, accusump, and CB Maxi oil pump.
In my research for installing the accusump it seems like there are two places that are recommended, in the cooler return line with a check valve and direct to the block. I did not want to use the sandwich plate adapter so I opted for the block option. Simpler with less seals to fail.
As I looked into the workings of the type IV oil system I found a potential problem with both these locations; the oil relief valve on the front of the engine. VW used this valve to bypass the cooler when the oil is thick. But this also means the cooler is bypassed when the oil pressure is high. Does the use of an oil accumulator negate the oil cooler system by maintaining oil pressure?
While on the straights the pump could potentially make 50-60 psi of oil pressure. (the 30mm pump that was in the engine produces those pressures much of a 20 min session) At those oil pressures the cooler will be bypassed based on what I know of the relief valve (bypassing cooler at 60psi, partially open at 35 psi, and sealed at 12psi). The accusump will also build up to that pressure. When I go to brakes and the revs drop the accusump will start pushing back and keep the pressure up till the differential is corrected. If I am back on to the next straight in that time then the pump starts building the pressure again.
Options:
1. Am I making a mountain out of a mole hill? Leave it alone.
2. Plug that relief valve so it stays closed and let the oil cooler thermostat bypass the oil when its cold. This is a pre 76 case so there is the secondary relief valve by cylinder 1. Might be able just to invert the piston so the bypass grove is below the bypass passages.
3. There is also the high pressure pistons sold by pelican parts and others. Does this just shift the bypass window to a higher pressure range?
I would love to hear people's thoughts on this.
Miguel
Part of the problem could be from using the 40 year old check valve springs if you haven't already changed them out.
A spring will relax over time through thousands of heat cycles. I can only assume that an old spring now has the modulus of elasticity of silly putty.
In fact having a spring as part of a check valve for any high temp fluyid system is a bad idea anyway. The hotter the spring gets the looser it gets (the spring constant is a function of temperature). The only way to reduce this thermal effect is to get a spring made from inconel or titanium which will have flatter thermal response curves.
Plus buying a new sping may not be any better since it may have a lower modulus than an OEM spring.
The spring equation is very simple. Spring force = spring constant x deflection
You can check several springs aginst each other with a simple jig fixture where you can apply the same vertical load to each spring. The spring with the least deflection under the same load has the highest spring rate. The higher the spring rate, the higher the allowed cracking pressure...
Bill
Bill, your words were prophetic!
Got to Sebring Saturday afternoon. Found Shane in the usual spot on the paddock. And began to unpack. Registration and Tech with Chin was a breeze. We were set for a nice day at the track. Little did we know there were gremlins laying in wait for us.
The long and short of temperatures was with the distraction of what was to come with oil pressures we got very little data on the cooling and the cooler bypass blank off kit. Between the rusty relief valve that was in the motor when purchased and a still unknown oil pressure issue I was not able to enjoy even half a session. We will try again in two weeks though so stay posted.
Sunday morning after the drivers meeting there was an open track warm up session which I was going to use to get in the grove before my evaluation session (first time running with Chin.) I could not even complete a warm up lap before my oil pressure dropped to the floor!!
As I idled in and through the pits pressure came back. 65-70 psi at idle. I thought maybe there was an air pocket in the cooler circuit and now its gone; head out and keep an eye on it. Nope, I got as far as Bishops Bend this time and the pressure disappeared. Idled in and hoped I did not do any serious damage.
A discussion among the friends on hand and we decided to check the pressure relief spring assembly. What we found was shocking to say the least.
Yep that is a rusty and scored piston and spring. If you have not inspected your oil pressure relief system in a while now is the time.
Our best guess of what was happening was that with the high oil pressures the engine was making the relief valve was fully extending and getting jammed open. A little jostling around and it would release. I had a new Weltmister high pressure kit on hand so that was swapped in. Ran a session with the fresh Weltmister piston and the rusty spring. Started to see ugly pressure drops after a few laps so I returned to the pits.
At this point we decided to test out the Foley blank off sleeve and piston. Very nice fit and finish. (I did not photograph it but I'll pull it out in the next day or two and post a picture here.) Ran a few more laps before the oil pressure light came on. At this point we were starting to suspect something else was causing the pressure drop off issue. The oil was hot but not hot enough to cause the massive pressure losses so soon.
For the four session we played around with some shrouding to block off hot exhaust wash from the headers entering the cooler. No significant change to oil temps. Pressure drop caused me to come in after 11 mins on track
Fifth and final session I decided to take it easy take a Sunday drive; it had not blown up yet might as well relax a bit and enjoy what was left of the day. More of the same. Got 16 mins in this time.
A big thanks to Shane and my friend Mike for coming out and lending a hand!! As usual Chris Foley's support and advice has been wonderful.
We have a few areas were I am going to look for the problems. Hopefully the gremlin will get sorted for the next track weekend. Stay tuned.
Miguel
Got to Sebring Saturday afternoon. Found Shane in the usual spot on the paddock. And began to unpack. Registration and Tech with Chin was a breeze. We were set for a nice day at the track. Little did we know there were gremlins laying in wait for us.
The long and short of temperatures was with the distraction of what was to come with oil pressures we got very little data on the cooling and the cooler bypass blank off kit. Between the rusty relief valve that was in the motor when purchased and a still unknown oil pressure issue I was not able to enjoy even half a session. We will try again in two weeks though so stay posted.
Sunday morning after the drivers meeting there was an open track warm up session which I was going to use to get in the grove before my evaluation session (first time running with Chin.) I could not even complete a warm up lap before my oil pressure dropped to the floor!!
As I idled in and through the pits pressure came back. 65-70 psi at idle. I thought maybe there was an air pocket in the cooler circuit and now its gone; head out and keep an eye on it. Nope, I got as far as Bishops Bend this time and the pressure disappeared. Idled in and hoped I did not do any serious damage.
A discussion among the friends on hand and we decided to check the pressure relief spring assembly. What we found was shocking to say the least.
Yep that is a rusty and scored piston and spring. If you have not inspected your oil pressure relief system in a while now is the time.
Our best guess of what was happening was that with the high oil pressures the engine was making the relief valve was fully extending and getting jammed open. A little jostling around and it would release. I had a new Weltmister high pressure kit on hand so that was swapped in. Ran a session with the fresh Weltmister piston and the rusty spring. Started to see ugly pressure drops after a few laps so I returned to the pits.
At this point we decided to test out the Foley blank off sleeve and piston. Very nice fit and finish. (I did not photograph it but I'll pull it out in the next day or two and post a picture here.) Ran a few more laps before the oil pressure light came on. At this point we were starting to suspect something else was causing the pressure drop off issue. The oil was hot but not hot enough to cause the massive pressure losses so soon.
For the four session we played around with some shrouding to block off hot exhaust wash from the headers entering the cooler. No significant change to oil temps. Pressure drop caused me to come in after 11 mins on track
Fifth and final session I decided to take it easy take a Sunday drive; it had not blown up yet might as well relax a bit and enjoy what was left of the day. More of the same. Got 16 mins in this time.
A big thanks to Shane and my friend Mike for coming out and lending a hand!! As usual Chris Foley's support and advice has been wonderful.
We have a few areas were I am going to look for the problems. Hopefully the gremlin will get sorted for the next track weekend. Stay tuned.
Miguel
This was my first time at the track with a completely new oiling system in 1997.
Click to view attachment
We drove 7 hours so I could hang out under the car all weekend.
At least I had the sense to rent garage space in advance, so it wasn't unpleasant, just discouraging.
Click to view attachment
We drove 7 hours so I could hang out under the car all weekend.
At least I had the sense to rent garage space in advance, so it wasn't unpleasant, just discouraging.
I wish I could of been more help. Managing my Dad all day was a bigger challenge then I thought.
How did Warren's test go?
(pics of 914s in the paddock where they belong )
How did Warren's test go?
(pics of 914s in the paddock where they belong
)
Nice pic. Looks like we had a private test day at Sebring.
Miguel
Miguel
QUOTE(Jetsetsurfshop @ Jun 10 2014, 05:51 PM)
I wish I could of been more help. Managing my Dad all day was a bigger challenge then I thought.
How did Warren's test go?
(pics of 914s in the paddock where they belong
)Not done testing yet. This last weekend was very hot, so I got some good baseline numbers. Installed the Foley valve yesterday, with the longer piston. (He sent me two) The outside air temp was pretty cool 55-60, so it took awhile to warm up. Once warm, I did not see a lot of difference in the numbers from testing with the old valve. I will put the shorter piston in tomorrow and see what happens. Playing golf today.
QUOTE(ww914 @ Jun 12 2014, 07:46 AM)
QUOTE(Jetsetsurfshop @ Jun 10 2014, 05:51 PM)
I wish I could of been more help. Managing my Dad all day was a bigger challenge then I thought.
How did Warren's test go?
(pics of 914s in the paddock where they belong
)Not done testing yet. This last weekend was very hot, so I got some good baseline numbers. Installed the Foley valve yesterday, with the longer piston. (He sent me two) The outside air temp was pretty cool 55-60, so it took awhile to warm up. Once warm, I did not see a lot of difference in the numbers from testing with the old valve. I will put the shorter piston in tomorrow and see what happens. Playing golf today.
I'm not certain yet but, based on my brief test, I think the shorter piston opens at a high enough pressure and the longer piston may be too much except for high revving engines.
Track Test Report:
Was back up at Sebring this weekend with my 914 facing the grueling heat of central Florida in June. Surface temp of the track was upwards of 127 deg F when I measured it at mid day after one of my sessions. It was hot.
The cooler and pressure relief kits did their jobs well.
First thing I need to mention is the error in my VDO gauge. At the end of a 25 minute session the gauge was indicating 260 degree oil temp. As soon as I arrived in my pit I measure temperatures in several locations, oil cooler fins, tuna can, crank case sump (aluminum), and oil filter. Not a single one of these approached 260*. The closest reading was found on the cooler and the oil filter and they read 220*. That's a 40 degree error, on a new gauge!!
Temps were as follows:
oil cooler 215-220 depending where it was measured
Tuna can 180
Crank case 190
Oil filter 220
The oil pressure issues I was having were solved and were probably due to installer error in setting the acussump pre-charge.
While making changes and tweaks to the oiling system I closed off the top portion of the oil cooler box and added a scoop to the bottom to try and avoid picking up exhaust wash. Additionally I added a fresh air duct from the fan in the front valance to the cooler box.
The difference between the current set up and how Chris supplies the kit on track really only came down to how quickly the oil came up to its peak temp of 220. Without the extras the temp would come up to 220 within 3-4 laps and with the extras it would take 5-6 laps. If 220 is the ideal operating temp, which some folks promote, then the extra work was in vain.
I like that I can get a little extra cooling while idling back to my pit stall.
Throughout the session I was checking my oil pressure. Better than 50 psi was observed from the start of the session till the end. Only at idle rpms while heading back to the pits did the pressures drop. With the block off sleeve in place I am certain that all the oil running through the galleys first went through the cooler.
I am very happy with the results. If I end up with a bigger motor or a 6 I may have to swap to a front mount cooler. But if it could handle a 25 min session at Sebring in June I think it can handle just about anything its going to see with me at the wheel.
I was only able to run a session an a half as I developed a fuel starvation problem on Saturday afternoon. So now there is a new problem to address but at the least I have an oiling system that is up too par. Thanks Chris!!
Miguel
Was back up at Sebring this weekend with my 914 facing the grueling heat of central Florida in June. Surface temp of the track was upwards of 127 deg F when I measured it at mid day after one of my sessions. It was hot.
The cooler and pressure relief kits did their jobs well.
First thing I need to mention is the error in my VDO gauge. At the end of a 25 minute session the gauge was indicating 260 degree oil temp. As soon as I arrived in my pit I measure temperatures in several locations, oil cooler fins, tuna can, crank case sump (aluminum), and oil filter. Not a single one of these approached 260*. The closest reading was found on the cooler and the oil filter and they read 220*. That's a 40 degree error, on a new gauge!!
Temps were as follows:
oil cooler 215-220 depending where it was measured
Tuna can 180
Crank case 190
Oil filter 220
The oil pressure issues I was having were solved and were probably due to installer error in setting the acussump pre-charge.
While making changes and tweaks to the oiling system I closed off the top portion of the oil cooler box and added a scoop to the bottom to try and avoid picking up exhaust wash. Additionally I added a fresh air duct from the fan in the front valance to the cooler box.
The difference between the current set up and how Chris supplies the kit on track really only came down to how quickly the oil came up to its peak temp of 220. Without the extras the temp would come up to 220 within 3-4 laps and with the extras it would take 5-6 laps. If 220 is the ideal operating temp, which some folks promote, then the extra work was in vain.
I like that I can get a little extra cooling while idling back to my pit stall.
Throughout the session I was checking my oil pressure. Better than 50 psi was observed from the start of the session till the end. Only at idle rpms while heading back to the pits did the pressures drop. With the block off sleeve in place I am certain that all the oil running through the galleys first went through the cooler.
I am very happy with the results. If I end up with a bigger motor or a 6 I may have to swap to a front mount cooler. But if it could handle a 25 min session at Sebring in June I think it can handle just about anything its going to see with me at the wheel.
I was only able to run a session an a half as I developed a fuel starvation problem on Saturday afternoon. So now there is a new problem to address but at the least I have an oiling system that is up too par. Thanks Chris!!
Miguel
Miguel. The numbers when exposed to oil usually show higher. The dipstick gauges take a reading very close to the stock senders and usually show numbers close to the gauges unfortunately.
I think the mass of the case and insulation qualities skews the numbers some.
It's worth borrowing a dipstick gauge to confirm
I think the mass of the case and insulation qualities skews the numbers some.
It's worth borrowing a dipstick gauge to confirm
QUOTE(brant @ Jun 24 2014, 08:52 AM)
Miguel. The numbers when exposed to oil usually show higher. The dipstick gauges take a reading very close to the stock senders and usually show numbers close to the gauges unfortunately.
I think the mass of the case and insulation qualities skews the numbers some.
It's worth borrowing a dipstick gauge to confirm
Yep, I am with you on that. I thought the filter would be the closest externally measurable location given the thinness of the steel wall.
Chris and I discussed removing the sender and testing it in a pot of boiling water to verify the actual error. Next time I do an oil change I will work this into my evening. Not really interested in dumping $50 of fresh oil at the moment.
Thanks for the input though!
Miguel
I would tend to agree. Though VDO gauges are notoriously inaccurate in all forms, your oil temps probably were higher than 220, though perhaps not 260.
The point of the fins, sump, filter, etc being exposed to air is that they should always be cooler than the oil. The principles behind heat transfer dictate that the object (fluid) with higher heat gives off that energy to the next surrounding object.
I would definitely be curious to see the difference with a dipstick thermometer though. Does anyone still make those new?
Glad you're figuring things out though Miguel. The work that you and Chris have put in is something that we're all benefiting from for sure.
The point of the fins, sump, filter, etc being exposed to air is that they should always be cooler than the oil. The principles behind heat transfer dictate that the object (fluid) with higher heat gives off that energy to the next surrounding object.
I would definitely be curious to see the difference with a dipstick thermometer though. Does anyone still make those new?
Glad you're figuring things out though Miguel. The work that you and Chris have put in is something that we're all benefiting from for sure.
QUOTE(ThePaintedMan @ Jun 24 2014, 10:09 AM)
I would definitely be curious to see the difference with a dipstick thermometer though. Does anyone still make those new?
I guess I could put the thermal wire that came with my voltmeter down the dipstick tube. Or safety wire it to the dipstick tube. Whats the consensus on that?
Are the VDO generally off by a constant or a scalar error? Might even be a quadratic!! If I fall victim to a Diff Equ flashback just revive me with a shot of Jack and a can of PBIR. It always seemed to work in College or at least got me drunk....
I digress. Further testing has been requested and I will happy provide.
Miguel
I think they are still available new.
Manley? Brand or something
Manley? Brand or something
QUOTE(brant @ Jun 24 2014, 11:12 AM)
I think they are still available new.
Manley? Brand or something
Yeppers Mainely
At the bottom $50
I ran 240-250 in the afternoon sessions. Did an extra cool down lap and got back to 230 before the pits. It was hot out there, wow!
If the sessions were any longer, a front cooler would be the answer.
I see a cool 914 in the background in post #41. (behind the ugly dually)
If the sessions were any longer, a front cooler would be the answer.
I see a cool 914 in the background in post #41. (behind the ugly dually)
QUOTE(Jetsetsurfshop @ Jun 24 2014, 03:10 PM)
I ran 240-250 in the afternoon sessions. Did an extra cool down lap and got back to 230 before the pits. It was hot out there, wow!
If the sessions were any longer, a front cooler would be the answer.
I see a cool 914 in the background in post #41. (behind the ugly dually)
Yeah
I picked that one for you.So you think we could see a heat soaking issue where eventually the cooler can't keep up?
Miguel
QUOTE(Seabird @ Jun 25 2014, 07:33 AM)
So you think we could see a heat soaking issue where eventually the cooler can't keep up?
Miguel
Miguel,
I think that's always been the consensus with any aircooled engine. Since oil becomes the primary fluid involved with heat transfer, and is less thermally efficient than water, you see a longer "lag" in temperatures. I.e., it takes longer to heat up than water, but also is harder to cool back down once hot.
There are some that suggest that increasing the *volume* of oil in the engine helps with this, but in my admittedly small knowledge of fluid dynamics, that would essentially only delay the eventual point that you described - where the cooler simply can't keep up with the temps.
Which is why everyone just ends up going to a bigger cooler, or making the existing cooler work more efficiently (exposing it to cooler air, faster air, etc).
I may not belong in this conversation since I'm not an engineer, but this is my understanding of the challenges of aircooled engines. Please kick me out if I'm over my head.
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