I was seeing what I thought to be rather high oil temps on my street/track 305 Chevy powered 914. About 220 degrees-spikes to 240. Now that I installed a new 350, I've added an external oil cooler with thermostatic fan to help the situation, but have not hammered the car yet as we are still breaking it in.

What oil temps are the other V8 guys seeing? I haven't found it necessary to put an external cooler on the wife's street car, but I believe I am pushing it with the track car. My only frame of reference in an old A1 GTI that used to see this same range.

Any feedback?

David Lee in Houston, TX

Probably most of us V8 owners don't monitor our oil temp. I believe 220F is normal for most small block Chevys like 350s. High oil temps could be caused by insufficient bearing clearances. Oil temp goes way up with bearing clearances less than .0020". There's a 50% temp increase with clearance reduced to .0015".

I dont run one on mine so it must never get very high I would have to agree with Guy on the bearings. Mine is just a street cruiser so I dont really worry about the oil temp, just the water temp.

Hmmm.....maybe someone with a track car will see this and respond? As you indicate, the street guys are not really worried about it. I do run a coolant temp gauge on the street car, but no oil temp gauge. On the track car, I monitor oil pressure, oil temp, water temp at the head(odd bank) and mixture. I am just looking for a baseline so that I can keep an eye on it.

Even the guys that drive their street cars (V8s) hard, don't seem to worry about oil temp. Am I paranoid?

David Lee

I dont know about paranoid, but I have always had the attitude that "Ignorance is bliss"

David

I suppose you're already running a high volume Melling oil pump, which would definitely be recommended with an external cooler. What's your oil pressure and water temp running when hot? Don't racers usually run around 60 psi? Where's your temp sender located? Maybe it's picking up hot oil splash? Are you running a stock oil pan? What kind of rpms were you running when you had the spikes?

Get rid of that crappy dino oil and throw some Mobil 1 in the pan. If it spikes to 240 and then backs down quickly I wouldn't worry about it. The synthetic can take that without breaking down. There is no reason for a high volumn pump. All that does is waste HP driving the damn thing and make timing variations worse. It can also lead to oil pump driveshaft failure. You new oil cooler should handle the job fine.

Guy, I am running a Melling high volume pump. The oil sender is in the pan. I use a Canton baffled and trap doored road racing pan. (7 quart) The sender is under the oil at all times. It is not in the "splash zone". The pressure take off is at the top of the block for the idiot light and the side of the block near the oil filter housing for the pressure gauge sender.

I don't think that I have a problem as I now have 60psi at full gate when hot and 20 psi at idel when hot. (My wifes street car V8, runs about 70psi at speed and 30 psi when fully hot. She has no cooler. They have the same tolerences on the bearings when built, but I have a wilder cam, valves and heads on the track car) I am weighing the value of the oil cooler. I mounted one with this new motor, but may be able to do without it. It uses a Mocal sandwich adapter and seems to effect pressure, but not too much. I guess I just need to run an event with it and one without to see the true difference.

David Lee

Hey man

How about a pic of this sweat ride of yours...

In my summer here, seeing 220 is not a panic...I never seen over 250 without some problems...somewhere.
But there are so many factures involved with oil vrs coolant specs

QUOTE

but I have a wilder cam, valves and heads on the track car

What kind of Hp are we talking about ? I'm interested anything over 300Hp gets a oil cooler at my shop, with a t-stat.
Tight tolerences will give you an overall overheat condition, usually followed with extreme pre-ignition = bad . Don't ask how I know.... Laffing Pontiac 400 stage 2- dynoed at 486hp... I don't think this is your case here .
What I look for on Hi output motors is not only the high end specs, but the split. I am just guessing here but heres a few thoughts your way

Overall cooling
Heat transfer, oil to coolant.
Heat tranfer , motor to oil/coolant.

I suspect your oiltemps are a real concern, I am uncomfartable, with your hot oil pressures...I donno, if it was mine I wouldn't be satisfied with it, from a new motor. I don't think the problem is mechanical as much as the temps are breaking down your oil. High Volume Pumps are a must and yours is a great choice ! Are you using a t-stat for coolant or wide open?.
If you bring down your overall temps I would expect a real improvement everywhere. My chums 450Hp daily driver 76 Blazer 4X4, run a 160 tstat, full coollers. with no probs in 90+ temps. Oil will heatup faster then coolant and after 2?? deg it will start to climb at a higher rate then coolant, at what temp it starts, you would have to research at little, I would be guessing.
Depending on your estimated Hp you might have to go with Aluminum heads - with hi compression motors, combustion chambers temps rise big time. They also help removing heat.

So if it was mine I would start at the beginning.
Motor output, head temp...
Heat transfer from motor to liquids
Heat transfer from liquids to coolers
Heat transfer from coolers to air (out)

You might just have to find a week link and tweek it, but it sounds to me like you are on the ball....
There is a member mesix that probably has more experience then me, and he a HP guy, maybe he will chime in.
But then again I write so slow there probly was 100 responses by the time I hit Send

Keep me informed
Later
Joe

Oil temps on Chris Julians car (mine isnt monitored) where very high at the wcc track day.

Brad even said that all his v8 cars had high oil temps and needed an oil cooler for the track.

Before I go on the track again (even autox) I am going to put an oil cooler on it.

Nice phat B&M unit. Maybe even a fan.

Andrew

Joe, I thank you for your lengthy reply. My motor has less than 5 hours on it now. It is a 350 (40 over late block) with 292 non roller cam, hydr lifters, larger stainless intake and exhaust valves in early cast heads and roller tip rockers. It is built to produce 360 hp, but I have not yet dynoed the unit. I take great care in selecting proven parts and always work on the conservative side. The entire engine has ARP hardware and the Canton road race pan and matching pickup was chosen for the G loads I will see on the track. I run a 4160 Holley with Eldebrock Performer manifold. Basic....and simple to get right. Also at this time I run a HEI with very conservative advance numbers.

Your points are all good ones, but not overlooked by me on this project. I use the RH radiator setup with a 160 degree high flow thermostat and this keeps the water temp at about 190 on a hot day. (remember, I am in Houston....it is 100 today on my side of town) I can see spikes of about 205 on the track, but it cools back down when I pull off. This is an autocross, DE and time trial car that never sees more than about 5 laps at a time.

I still have not seen a reply with some hard numbers. Does anyone monitor their oil temps on a V8 car? There seem to be a number of people looking the other way on this topic. You might be suprised to see the results if you check your temps, even on a street only car.

I suspect that my Mocal thermostatic sandwich plate is hurting my flow a bit and effecting the oil pressure readings. I will pull it out today and do a radius job on the inlet and outlet ports. That has helped me a bit on another project.

I feel that your idea of anything over 300 hp needing an oil cooler is a fair one, but if your temps are under control, why bother? 220-240 is not unheard of when running SCCA IT VW GTIs, but I am inexperienced with V8s. My Solo I Mini Cooper used to see 225 degrees on the track, but never went any higher. Maybe someone will chime in with real numbers from their cars.

To answer your request for pictures........I will hold off on sharing these until the MUSR 7 pics are in. I prefer to show in race mode rather than those in the driveway.

David Lee

David I have not tracked my car but I do have a oil temp. gauge. The highest I seen the oil get to on a mid 90 degree day was 230/240. This was after running with Atlanta traffic on I-75 at 95 to 100 mph for 35 miles. The water temp stayed right at 190 with a 180 thermostat. Everything I've read says to look for about a 40 degree rise from the water temp.

Bob

Brad said he saw 250 when he rode in Chris's car.

Maybe he said higher... I wish he would respond. But he's at a better place now.


Hopefully that helps...

Andrew

Real numbers.............thanks Bob and Andrew. 250 is ugly, but 230-240 is in line with what I am seeing on the oil side, although my water temp has been a bit higher than 180-190. I think I will ditch the 50/50 mix and try straight water with Water Wetter. DLee

How much oil are you running in the pan? If you are running more than five quarts you need to drain some oil. Not only will that help HP it will also drop your oil temps. Just because you can put seven quarts of oil in the pan doesn't mean you need to. All that does it take longer to get up to operating temp. The Chevy oiling system is not junk like the Fords.

A stock blueprinted Z28 oil pump will pump 9gal of oil per minute. The loosest engines I have seen running wetsump systems only required 8gpm. Now why do you feel that your engine needs more oil volume? All you are doing is wasteing HP and creating heat.

Also the safe rule for oil pressure is 10psi/1000rpms. That is the old standby. The new rules are 10psi/100HP. I would stick to the old rule for your street motor.

Oil temps should be reaching 230deg. That is a comfortable oil temp for a race car. I would also go to synthetic after you finish your break in. If the temps spike to over 260 you should be worried but you will be safe up until that point in limited stints.

Brett, thank you for the reply. I am concerned not about volume but temperature. The Canton road race pan that I run is designed for 7 quarts and not 5. It is baffled, trap doored and also has kick outs on both sides. Canton does not recommend running less than 7 and with the extra volume in the oil cooler lines and in the cooler, I think that it would be a mistake to tun only 5.

Thank you for your advise on the temp. I am seeing peaks at no more than 240, so I feel that I am in good shape.

I have no problems in warming up the extra two quarts of oil before my runs. My Mocal sandwich plate also uses a wax element type thermostat similar to the 911 unit to assure that oil is not making the loop before it is 180 degrees.

I also like the synthetics and after another 5 hours or so of running time I will be making the change. DLee

Your good then I wouldn't worry about it until it becomes and problem.

QUOTE (Brett W @ Jul 3 2005, 01:51 PM)

How much oil are you running in the pan? If you are running more than five quarts you need to drain some oil. Not only will that help HP it will also drop your oil temps. Just because you can put seven quarts of oil in the pan doesn't mean you need to. All that does it take longer to get up to operating temp. The Chevy oiling system is not junk like the Fords.

Brett,

If this is for a track car, then I would strongly caution against your recommendation. Most Chevy roadracers run more oil, rather than less, to curb starvation in the corners.

DLee,

A good roadrace add-on is an Accusump. It will give you that extra insurance against a cornering induced sudden drop in oil pressure that will surely damage a motor in a heartbeat. If you're confident with your existing Canton pan, then great. I would however, keep a close eye on your oil pressure guage at your first track day just to be sure you're covered.

I will talk to Terry Stewart. He owns the 500HP 383 914 (a track car with license plates!) seen at the '05 WCC. He installed an oil cooler with fan. He's had it on the track a number of times, so he's sure to know the temps he was running. BTW, he added an Accusump after finding his roadrace pan wasn't enough, and even then he had some minor issues. I advised he add an extra quart of oil, and his problems disappeared.

Andy

The pan design will determine how low he can run the oil level. Many people buy these deep sump pans and then fill them up with oil. The purpose of the deep sump is to move the oil level away from the crankshaft to cut down on windage. If this pan is designed properly he should not need to run the maximum amount of oil. I just built a pan for another engine with kickouts and trap doors and some other tricks but even with all that the oil level is still a little high when running 5 quarts. If the pan manufacture says that the pan should use 7 quarts then, unless you have the pan off, then use the manufactures reccomendation. If you have the pan off then you can experiment.

I agree the accusump is a vital addition to a road race motor.

Andy, the Accusump was a great addition to my road race Mini as it also doubled as a pre oiler. At this point I don't want to throw products at the car if not needed. This is also still a streetable car. I still drive it on the street when I want to have a little fun. The Petty bar prevents passengers from riding, but that is just a well. They aren't very comfortable. If someone wants to get a feel for a V8 914, we just take my wifes car for a spin.

I ran the same Canton pan (which also has a windage tray Brett) on my 305 and had no oiling issues even under high G loads. 7 quarts of oil did the trick. Temps were a little high, so I added a cooler when I went to the 350 with more HP. The 305 had 285HP and now I have gone to 360HP. I have a test and tune coming up, so I will let you know how I do. To be honest, I am prepping for the track event at the MUSR 7. I am not a real competative guy, but it sure would be nice to be the fastest 914 at the event. I will report back on how I do. DLee

Ok David: I'm getting some of the details:

-305 Chev @ 360 HP
-Canton Road Race Pan
-Melling pump
All are the right things to do so far.

Questions:
-Are you ROAD RACING or slaloming the car?
(there is a BIG DIFF in time @ G-loading between a parking lot and a road course....as you know)
-what are you using to generate the High-G's?
I am on 315/35 ZR 17 YOKO A032R rear + 255/40ZR17
on the front (11" & 9.5" rims)and must be corner at 1.0G+ at low speeds and maybe more when the rear wind kicks in at higher speeds. If you are a modest set of wheels & tires, you won't be pushing the oil as hard sideways and will NOT run into the problems I have.

If you are not out on the "nut fringe" as I am, you just may be good with where you are!

Best,

Terry Stewart

Terry, the details are correct apart from I have have just gone from a 305 with 285 HP to a new 350 with 360 HP. I am running 225s on the front on 7" Fuchs and 255s on the back with 8" Fuchs. Tires at this time are Goodyear Eagle GSCS tires (Corvette Solo I tires). The car is used for fun street, autocross and Solo I type road events. High speed, but low lap count. DLee