Overheating Issues, Perplexed

[jwd]

Originally Posted by elmariachi

Also, I bought this car turn-key minus from a guy that had put 1500 miles on it from new with an all-aluminum 482 KC Pond engine. He says he had zero cooling issues. I am running that same radiator and even using his hoses.

To me, that narrows it down to your engine. What it is in particular, I don't know, but it's not your cooling system. You can improve the cooling system and that may help it compensate but it doesn't address the root of the problem.
I have the same car, same cooling system except I'm running a Windsor motor (I know, big difference) and I can drive my car all day in traffic with 90+ temps. and never go over 185F. The fan will only come on if after a long run, I let it idle for about 5 in the driveway and then the temp. drops right back down.
Like you said, many Hurricane owners run big blocks with no problems. I would be looking for the problem instead of treating the symptoms.

Jim

[elmariachi]

Originally Posted by jwd

To me, that narrows it down to your engine. Jim

When the dyno shop did the break-in run and dyno pulls, the engine was plumbed with an electric water pump and a controlled/cooled water supply. After they were done on the dyno they changed the oil, bolted on my new Edelbrock waterpump, and plumbed in a heavy duty racing radiator with a large electric fan. We then ran it for 20 minutes checking for leaks and it never went over 180*F. When I got it home and bolted it into the go-kart, I then put 20+ miles on it running around the subdivision before mounting the body and it never got above 180*F. Then I mounted the body and it started idling hot. No way its the engine.

EDIT>> Every engine will run hot and eventually melt down if its not cooled. By laying a second pusher fan in the nose I can hold the temps to 195, and that's still leaving two full corners of the radiator without direct airflow. So I am not sure at that point I am any different than any other properly cooled Cobra: Cooling system is discharging engine heat and keeping the engine cool enough to operate at idle and roadspeed.

[jwd]

Originally Posted by elmariachi

No way its the engine.

Then my question would be "Why did Brad not have the problem you are having and the only thing changed was the motor (to a smaller one with less HP)?" Just doesn't make sense.

Jim

[elmariachi]

Originally Posted by jwd

Then my question would be "Why did Brad not have the problem you are having and the only thing changed was the motor (to a smaller one with less HP)?" Just doesn't make sense.

Jim

Fair question and I agree, which is why I posted this thread. Maybe his aluminum engine and heads were just within the capabilities of this fan and radiator, coupled with a much less harsh environment in Michigan versus Texas. In other words, maybe the cast iron engine and heads, coupled with the temps here, are a tad too much for the cooling system.

I am not arguing against there being something wrong with the engine, but I have far more data supporting an airflow/cooling system capacity issue than I do an internal engine issue. The engine was properly tested, machined and rebuilt and it performed flawlessly on the dyno. There are no combustion gases in the coolant, no coolant in the oil, I was present when the head gaskets were mounted, so on and so forth. It warms up normally. Oil pressure and temps are good and no matter how hard I run it, it stays cool. I ran the piss out of it yesterday afternoon and it was 95*F here with 50% humidity. It never got over 85*C while moving.

[Wayne Maybury]

Originally Posted by elmariachi

When I got it home and bolted it into the go-kart, I then put 20+ miles on it running around the subdivision before mounting the body and it never got above 180*F. Then I mounted the body and it started idling hot. No way its the engine.
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I have been following this thread from the beginning and I am amazed at how thorough and diligent you have been at trying to solve this problem. I know that this is a crazy idea and involves a lot of work but if you cannot find the problem to your 100% satisfaction, why don't you remove the body and see what happens? I also think the problem may be the engine, not the cooling system. By taking the body off, you can see if it still runs hot once and for all.

Wayne

[elmariachi]

Originally Posted by Wayne Maybury

I also think the problem may be the engine, not the cooling system. By taking the body off, you can see if it still runs hot once and for all.Wayne

The car is presently painted Lamborghini Titanium with silver stripes. All along it has been my plan to repaint it to a more original color. That's been a "Fall 2009" event and my preference would be to not pull the body until then. I have a bigger fan and shroud coming and even if all we are doing is masking the problem, I may live with it until the fall so that I only have to remove the body one more time. But let's go down this path for the sake of discussion...

If I pull the body and it still overheats, then what is wrong? What about the engine >>specifically<< could be causing this?

[CobraEd]

Retarded timing and/or lean mixture at idle.


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[elmariachi]

Originally Posted by CobraEd

Retarded timing and/or lean mixture at idle.
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We've already been there some pages back (not expecting everyone to read every post in this massive thread.) Offline to this thread I have worked on timing and mixture with CC member "Patrick." We started out at the dyno settings of 20* base + 18* advance (which is where it was before mounting the body.) We then went to 18+18 and we are presently at 16* initial + 21* advance for a total of 37*, all in my 3200 rpm. It does seem to idle bit cooler now than it did at 20+18. Certainly idling cleaner and not so gassy.

I also have Don Gould's Word doc entitled "4 Seconds Flat" and he advises 24* initial + 10* advance via his 10* MSD bushing, which I have lying here on my desk but haven't tried. His whole argument around FE timing is not in line with what is recommended by people on this forum, but I am trying to approach this one step at a time.

After lots of road testing and using a vacuum gauge I am 1.75 turns out on the primary and 2 turns out on the secondary, Mighty Demon 750 Annular. Plugs look great and it runs and transitions great. Car starts time after time, no strain/knocking/pinging or backfires.