914 V8 cooling, overheating issues Options

[John2kx]

Howard,

I run a Renegade cooling system and have had overheating issues along the way. Most were due to problems caused by myself. I'll post some pics of my system and be glad to share what I have learned the last year and a half.

First pic is of water sender location. I actually run two gauges. The two brass fittings are my temperature monitor points. Since the water from pump is routed into block, to heads and then to intake prior to moving back to radiator, the intake is the preferred location of sender.

John

[John2kx]

This is the thermostat of choice from what I have used. Note the 1/8" bleed hole. This will allow removal of air when filling system as well as protect water pump impeller from damage while thermostat is closed. Note: I drill three of these 1/8" holes in mine and use a 180F. Available through Jeggs or Summit.

http://photos.groups.yahoo.com/group/pors-...rc=gr%26.view=t



John

[rick 918-S]

Your link isn't working. Just post the pictures you big tease!

[steve@ottosvenice.com]

Frist thing is to make sure All of the air is out of the system Raise the front of the car up about 18 inches the run the motor and open your bleeder valve on the Rad . this will allow any air pockets to move up to the rad avd be removed. Steve

[John2kx]

Howard,

A more detailed description of your temperature readings would be helpful.

-Are you seeing 240 while on the road above 40 mph? Or does the temp. creep up in traffic and then never come below 240 after getting back to cruise mode?

-What size is your inlet/outlet holes for radiator? A picture would be helpful here.

-How do you bleed air from cooling system? Where is petcock located?

-Do you have a recovery tank? Is the level in tank always the same when car has sat overnight? (looking for a leak here, ie, headgasket, intake etc.)

-Have you tried running both fans continuiously from warm up (170F) and left on during a hot lap? (trying to see if your system is playing catchup)

-How are your water hoses routed? (under car, through longs.)

-Any kinks in hose? Inlet to water pump is a common area.

John

[steve@ottosvenice.com]

Front tank and Rad

[steve@ottosvenice.com]

We are building a Beach Boys Monterey this is a 5.0 Ford built to 400hp that is going in it. Steve

[BIGKAT_83]

Sure looks like alot of obstacles to overcome to use that Ford engine.

Bob

[BIGKAT_83]

This is the thermostat of choice from what I have used. Note the 1/8" bleed hole. This will allow removal of air when filling system as well as protect water pump impeller from damage while thermostat is closed. Note: I drill three of these 1/8" holes in mine and use a 180F. Available through Jeggs or Summit.



t/s.http://photos.groups.yahoo.com/group/pors-chev/vwp?.dir=/66+912+V-8&.src=gr&.dnm=HighFlowTstat.gif&.view=t&.done=http%3a//photos.groups.yahoo.com/group/pors-chev/lst%3f%26.dir=/66%2b912%2bV-8%26.src=gr%26.view=t

John

John is this the photo you wanted.

Bob (IMG:style_emoticons/default/unsure.gif)

[John2kx]

Bob,

That's the one, thanks!

John

[John2kx]

Howard,

Here's the link to a thread I forgot about. You should learn something from the info here.

http://www.914world.com/bbs2/index.php?act...thermostat&st=0

John

[Howard]

To all and John especially. Wouldn't have even considered another 914 without this site. The info is invaluable.

Read all the stuff on the link (it should probably be nailed as the start of a V8 sub board). Purged bubbles, took it for a blast, then let it idle for 5 minutes. Shut down and let it cook for another 5. Using a candy themometer, took Zora's temp. Dash gauge says 245, top of radiator petcock 179, expansion tank 195. Engine does not even feel especially hot to the touch. Think I may be getting a bare metal reading.

Two sensors..see below. What is all that plumbing? BTW, has two fans blowing down from engine hatch opening. Keeps dipstick from getting too hot (IMG:style_emoticons/default/smile.gif) but just noise besides that. Do we think it does any good?

Hope these post OK.

914-8

[John2kx]

Howard,

Your pics posted fine. Some took a long stare to figure out what I was looking at........suggest in the future starting with a overview of area your trying to pin and then zooming in a bit for the next shot.

Good news! Your cooling system looks better than most I've seen that weren't designed by RH.

1. I only notice one fan up front and thought you mentioned one (of two) staying on all the time and the second was manually controlled. Am I missing something here? I would like to understand for sure what turns your front fan on. Trace the wiring from fan motor. You should see power source and if supplied with a thermo switch mounted in radiator, a second set of wires from this switch to fan motor or to a relay or similar device that connects back to fan motor.

2. I think you have a source of air entering your system the way things are configured. The expansion tank mounted in left rear of engine bay is a good fill point, holds lots of water and is mounted higher than radiator and intake.......all good. What I see wrong here is that if you fill that tank full when car is cold, as water temperature rises and expands, there is no place for excess to go but out overflow line. I see no overflow tank and it appears overflow line discharges to ground. What you want is a tank for the water to discharge into and then as water temperature cools (contracts) a vacuum is started that will suck water from overflow tank back into expansion tank. Without overflow tank, when vacuum occurs, you will suck air back into system everytime you run through a heat/cool cycle. I believe for less than $10 you can fix this problem. Note: I usually see about 1 qt. of water added to my overflow tank when car is hot.

I'll attach a pic of how Renegade (RH) makes this happen. The small fill port acts just like your large expansion tank. The plastic tank is the overflow collection point. Note: overflow tank is mounted as high as possible and close to expansion tank to eliminate air pockets from enter cooling system.

I don't think the fans mounted to engine bay help. They can't hurt and are already mounted. Up to you if you want to remove them.

Sensors: the picture was dark but what I see is tapped into a oil source near distributor. I have something similar but use a single sensor with two outputs. One for oil pressure gage, the second goes to idiot light. Look at front of intake (either side of thermostat housing) for water temperature sensors.

I would not put much faith in measuring exterior of radiator, thermostat housing, hoses etc. when trying to determine true water temperature. My experience with a $175 infared gun measuring these points proved useless. To prevent risk of damaging that new engine, I'd advise a second method of reading true water temperature.........buy another gage.

You should have found how to bleed system of air from previous posts. This is often overlooked by most but a important part of procedure to ensure air is removed.

John

[John2kx]

The attached pic should show how air is kept out of system on my car when water contracts. Device with radiator cap would serve as your expansion tank. Plastic tank is overflow tank and the part missing in your system. Clear plastic hose is connected at bottom of overflow tank. Black hose is overflow line which discharges overboard.........I have yet to have that happen yet.

BTW, Scott at RH advises against radiator caps with the spring release handle. He does recommend using a 16 lb. cap with his system.

Hose routing: I failed to identify yours but would need better pics to do so. I recommend starting at your water pump. The one large hose there is suction side from radiator. From discharge of water pump, you will see flow to front of block, thermostat housing is outlet back to radiator. To and from expansion tank should make better sense after learning the basics. Hope I answered all your questions.

John

[Howard]

John, as you said this is kind of like private emailing back and forth but agree group could benefit.

PO says 2 radiators in tandem. Haven't had front cover off but can hear one fan in front of radiator (s) that can be manually activated, no thermo switch found. Second fan behind radiator runs when ignition is hot, no switch there.

Will do the 2nd tank ASAP. Good idea. Can it be mounted as high as current tank or do we need gravity feed? Thing has not cooked over anyway, so really expect bad gauge/sender.

Sensors..goes to show you how much of a mechanic I am. Will keep looking for sender. There are elec tabs on radiator, but not hooked up nor wires present.

Temp check. Stuck thermo in expansion tank coolant and open radiator petcock. It's digital and pretty much instant.

Can you get me out at the National???

[Howard]

Guess I should have waited for the picture. (IMG:style_emoticons/default/laugh.gif)

New cap on list for tomorrow. Say, why don't you just fly out here? I'll buy (IMG:style_emoticons/default/rolleyes.gif)

[John2kx]

Will do the 2nd tank ASAP. Good idea. Can it be mounted as high as current tank or do we need gravity feed? Thing has not cooked over anyway, so really expect bad gauge/sender.


Temp check. Stuck thermo in expansion tank coolant and open radiator petcock. It's digital and pretty much instant.

Can you get me out at the National???

Overflow tank should be mounted as high as possible. You don't need gravity since vacuum will pull the water back into system..........you just don't want a really long run or 2+ feet elevation difference between the two tanks. The plastic tank you saw in my picture can be purchased at many local auto part stores. Comes with mounting device, cap and hoses for less than $10. There are usually two sizes available.

If you removed your radiator cap shortly after engine temperature read 260F and measured water temp. in expansion tank with a good gage, I would point at your water gage too.

I have seen high temperatures without boilover.

How many tickets do you need : )

John

[Howard]

How many tickets do you need : ) (IMG:style_emoticons/default/mueba.gif)

John, we have to work on this communication thing. I don't want tickets, get me a starting time (IMG:style_emoticons/default/cool.gif). Watching golf is like watching sex. The pros may be better but I'd just as soon stumble through it myself (IMG:style_emoticons/default/beerchug.gif)

OK, now where were we. Here's the water pump. Looked all over engine top for any other wires and finally found temp sensor (pic to follow).

[Howard]

OK, this can't be right. Temp sensor nestled between exhaust ports? No shit it's hot! Is this a normal location? Looked around thermo housing, no wires there and pulling this turned of the gauge.

[Howard]

oops! can't seem to add picture