Overheating Issues, Perplexed

[coinop101]

My 427 side oiler runs best between 190 - 210 F . Also installed
1- Edelbrock hi flow Rad. Pump
2- Hi Flow Thermostate
3 Like 90 % anti freeze / coolent
4- 2800 CFM puller fan .
5- Flushed Radiator
6- Removed rear hood gasket to allow heat to excape .
Big blocks do run hot .
Peter

[razerwire]

Something to think about also, my bennett car has stainless steel headers with full polish stainless side exhaust, there is a lot of radiant heat in engine bay and off side pipes , cools off quicker than steel exhaust when shut down, but I can feel heat in foot boxes and side of car when running. Motor is 427 f.e. 1965 block and heads, cast iron, runs 185 to 190 degrees. The csx car has HPC coated headers and side pipes. The finish is ruff almost like velcro. The reason is to cut under hood and side exhaust temp. The dry sump tank is in right fender above exhaust and even with shield and heat barrier ,coating was needed to keep from overheating oil. Motor is 468 f.e. Kroyer/Shelby block and heads, 670 h.p. , runs 80 degrees c. You can feel the diff in under hood and side exhaust temp. You would have to work real hard to burn leg, there is that much diff. The Bennett car you don't want to get close to for 10 to 15 min after shut down.

[elmariachi]

The restrictor testing has begun. The largest of the 3 in the kit is installed. I drove it tonight and it behaved just as before, cool down the road, temps rising to 90-95C at average timed red lights, then up to 100C sitting in the driveway idling. I'll install the smallest restrictor tomorrow eve.

I do want to mention that as a result of the tuning and timing last week, the overall time to temp rise at lights and when idling is slower than before, but I still fear that if I were to let it sit and idle it would eventually melt down. Not going to try it to find out.

[edwhite7]

I noticed in the original post you stated that you had the bypass hose installed. I had this exact problem and it went away after I plugged the bypass and started running water wetter. I am sure others will disagree but I am convinced that the engine is to far from the radiator and the pump will bypass rather than pump through the radiator at idle. I also drilled some 1/8 holes in the thermostat to help it bleed air through the system and installed an overflow tank.

[elmariachi]

Originally Posted by edwhite7

I noticed in the original post you stated that you had the bypass hose installed. I had this exact problem and it went away after I plugged the bypass and started running water wetter. I am sure others will disagree but I am convinced that the engine is to far from the radiator and the pump will bypass rather than pump through the radiator at idle. I also drilled some 1/8 holes in the thermostat to help it bleed air through the system and installed an overflow tank.

I have tried the t-stat holes, no dice. But the notion of the bypass allowing water to recirc is interesting. Are you saying that the bypass is keeping water from being pumped into the expansion tank and on into the radiator?

[CHANMADD]

Originally Posted by edwhite7

I noticed in the original post you stated that you had the bypass hose installed. I had this exact problem and it went away after I plugged the bypass and started running water wetter. I am sure others will disagree but I am convinced that the engine is to far from the radiator and the pump will bypass rather than pump through the radiator at idle. I also drilled some 1/8 holes in the thermostat to help it bleed air through the system and installed an overflow tank.

I would go with this answer as the solution!!

[edwhite7]

For me the holes were just to keep air from collecting behind the t-stat. It is designed to sense water and air can cause the temp to go way high before it finally opens. After it opens it can then regulate normally. This tends to happen in cars with t-stats mounted at the top of the system, they collect air. I believe that the bypass is keeping the water from being pumped through the expansion tank and then the radiator. It is just to far and easier to bypass. I am sure that there is a good reason for the bypass but my car will overheat in traffic with it connected. If I sat more than two or three minutes at idle I would turn the heater on and after it passed 220 F I would have to shut it off and leave the fans running. I would bump it over without starting to get new water into the heads until the temps came down. Those were the days, water wetter made a big difference and now I never think about it. The car has been on the road more than 20 years and has never overheated.
I originally cut through the existing hose and worked it off without removing the pump. I was able to slip some hose caps on and clamp them with worm clamps. After I was convinced that it worked I removed the pump and plugged the ports with some pipe plugs.

[undy]

El,

Do me a favor, get a volt meter and read your puller fan voltage at the fan relay outlet or fan motor (better) with the engine up to temp, at idle with the usual accessories on. Take a new reading with the headlights on too. Let me know what you find.

The highest CFM puller fan will pull like poop if it's run in an extreme under-voltage condition. The "typical" replica wiring harness is marginal at best for hi-amp fans (inadequate conductor sizes). Also, a lot of alternators struggle to put out 10 to 15 amps at idle.

I think you'll end up discovering the only way you're going to improve things is raising the air CFM across the "full face" of the radiator at idle. Your "tight to the radiator" shroud isn't helping things either.

Dave

[danc30]

I still say nix the glycol. Go with straight water and a bottle of water wetter. Mine runs about 15-20 degrees cooler like this.

Water cools a lot better than glycol........

Dan

[vector1]

http://www.stewartcomponents.com/Tech_Tips.htm

[elmariachi]

Shroud was already removed. I'll check the voltage again and reply back later this eve, but it was 13.1 when I checked last weekend. Dan, I had already drained the coolant/water mix and gone with straight distilled and water wetter as you mentioned on the Hurricane forum. I was hopeful, but alas, no change.

[ERA Chas]

El,
My So acts exactly as yours before your testing: T'stat opens at 180, temps while moving remain 180-190 (6000+ RPM) slowly inching up to 210+ standing still. I once saw 227 waiting at an accident scene a mile from my house. I'm lucky the brass tank held together. This has been the case for 17 years and I've lived with it and driven accordingly.
I have replaced the orig ERA copper/brass with their Griffen ally rad. (10 or so years ago) The most notable effect was that it heated slightly more slowly and cooled much more quickly. I have the EDE HV pump.
I realize now because of your thread, that my March pulleys are probably the cause of both our problems because the WP and crank are almost the same diameter. Actually the WP is larger than the crank. So it's not overdriven.
If I found that were the case I'd probably change the WP pulley, but again I don't parade the car and have no imminent need to do that. I also know Houston is generally much hotter than LI.
I think your biggest improvement (it's all relative) will be the pulley change and no shroud. (I never tried one)
Everything else suggested is either an incremental improvement or none at all.
We're all pulling for ya so keep up your fine work.

[mr0077]

El, on the pulley issue...when I was putting my motor together I went over to a place on the northeast side of Houston called Best American Core (I think) and got a set of pulleys off a 361 or 391 truck motor (I think they are the same) and used them for dyno work. They must have been a 50% overdrive ratio (driving the water pump faster). Unfortunately I threw them away, but point is, they were cheap and all you want to do is find out if that is part of the problem. BTW, I ended up using some underdrive March pulleys with no overheating problems, so my set-up is of no help in diagnosing yours...keep us posted on the progress!

[ERA Chas]

Wow.

[razerwire]

Update on previous post, coming back from car show last night I slowed way down when getting close to my house because I don't want to upset neighbors anyway I pulled into garage up on the lift and let the csx car idle for a few min. 80 degree c and reached down and tapped the exhaust pipe with my hand , was not that hot. HPC coating will lower underhood temp. which in turn will help cooling system do its job. If you have not finished your exhaust you may want to look into coating.

[elmariachi]

Originally Posted by razerwire

HPC coating will lower underhood temp. which in turn will help cooling system do its job. If you have not finished your exhaust you may want to look into coating.

Headers and sidepipes are all ceramic coated. Sidepipes are mild to the touch within 10 minutes of shutdown and cool within 20. IR gun says they are at 175 when idling and headers are at 300.

[Jamo]

Been reading and watching this thread...

I live in Fresno...we'll match or exceed anything Houston or Florida thinks is hot or humid. I can run the 482 high lift thumper in stop and go in mid-summer with nary a problem. More than a few folks watched at a SAAC in fontana a few years ago while I let the tin can idle for an hour to charge a dead battery...on hot cement after running a full session in July...and it never got past 85C. I run a Spal to pull, and two original style pushers in front from Shelby (which are more show as far as I'm concerned...replacing the air they block). I run 50W racing oil with a cooler, and it barely gets above 120C. Yes, the aluminum block does help...but doesn't account for all that much given its state of tune. The headers were coated two years ago (for looks)...no difference from when they weren't before that. 160F thermostat, Edlebrock water pump, March pulleys.

If you haven't already...run straight water with a bottle of Water Wetter. Using more coolant is going in the wrong direction. Water is the best coolant, and the WW provides all the lubrication you need and makes the water a bit slimey to flow better.

On what basis do I suggest this? Autocrosser for over 30 years...where we haul ass for 1-2 minutes and then idle for 10-15 waiting for the next run, in the summer on hot cement. EVERYONE dumps the coolant and runs straight water, with a bit of WW in the last decade or so when it came out.

My other basis...as a farmer's kid. We always ran straight water in the trucks as we idled them along in the field to pick up grapes, etc.

{Edit...I went back and saw you did the full water replacement. Good, it's just Mustang's suggestion about running 100% coolant kept knawing at me. }

Other typical precautions, of course...burp and reburp the system to insure there are no air pockets, check the air flow, dump the undersized pulleys and get the thermostat down to 160...get the water flowing sooner (biblically-speaking, heat begats heat), timing, etc.

I know you tried just about all of this. As you yourself have mentioned, it's difficult to only do one thing at a time to see what works. Lots of good stuff on this thread...all of it valid, but heat issues (like electrical) can be tough to resolve at times.

Given everything you've reported on...especially how the temp drops a bit when you give it some gas when it idles...I'd think about a bigger radiator, assuming no flow issues with the passages or pump.

[767Jockey]

El,
That double puller fan you mentioned sounds promising. While the extra CFM it pulls can't hurt, I am more interested in the additional area of the radiator that it forces into use, much like a big puller with a properly designed shroud would do. I remain convinced that your problem is in the radiator size and shroud design. The problem got worse when you blocked more of the radiator with the faulty shroud. It should get better when you call more of the radiator into proper use. This seems to be the only change you've made that had any documentable difference to the problem. This is certainly the road I would go down. Best of luck.

[elmariachi]

Originally Posted by Jamo

I live in Fresno...we'll match or exceed anything Houston or Florida thinks is hot or humid.

I think I can win that bet.

Originally Posted by Jamo

Other typical precautions, of course...burp and reburp the system to insure there are no air pockets, check the air flow, dump the undersized pulleys and get the thermostat down to 160...get the water flowing sooner (biblically-speaking, heat begats heat), timing, etc.

Given everything you've reported on...especially how the temp drops a bit when you give it some gas when it idles...I'd think about a bigger radiator, assuming no flow issues with the passages or pump.

I tried the 160*, made no difference. The engine will eventually surpass 160 and then 180, so the only purpose the t-stat is providing is to determine the running temp down the road. When I had a 190F in it, it ran 190 down the road. I have a 180 in it now and it runs 180* down the road.

Jamo, I assume you have the Fluidyne in your car? After looking at one in a local car this past weekend, there is no comparison between it and this PRC in my car. Though its 1.5" narrower, the Fluidyne is much thicker in the core and the tanks. So that's my ace in the hole. But I am going to start with the smaller water pump pulley, then play with the fans. I also borrowed a big honkin' shop fan that looks like a Pratt & Whitney radial engine and see what happens when I add it. Probably won't get to do all this until the weekend.

Originally Posted by 767Jockey

El, It should get better when you call more of the radiator into proper use. This seems to be the only change you've made that had any documentable difference to the problem. This is certainly the road I would go down. Best of luck.

I have no doubt that if I can locate a deep enough shroud that it will make a big difference. The difference in temps between where the fan is drawing air through the fins near the center and out near the corners where there is no draw is 20*F. So if a properly shrouded high cfm fan, coupled with a larger capacity radiator, added to a smaller water pump pulley doesn't do the trick, then I am moving to Colorado. I hate Houston, so I needed a good excuse anyway.

For those that asked, the 3600 cfm Zirgo fan I now have is showing 13.1 volts at the wiring entering the fan motor, versus 13.6 at the back of the alternator at idle.

[Jac Mac]

Try hooking a couple of portable w/shop extractor fans with ducting into the engine compartment while its idleing, if the additional removal of hot air from up high in the engine compartment is enough to stabilise the temp then you know its airflow. As I mentioned earlier you might need a couple of smaller fans mounted in the wheel/header bays to acheive this. The Daytonas & Flip Top have the ideal situation in this regard, virtually none of their rad heat goes thru engine bay.