I just swapped in a 400 horse carbed motor. When i had the stock 350 TPI, it never overheated. Upon searching this site, I've read both that the stock radiator is plenty, and that i need a better radiator. It will warm up fine to 180, then sit there for a couple minutes, then continue climbing, so I figure the thermostat must be working, or it wouldn't wait to go past 180. It never had the lower air dam on it before and ran fine, but i'm guessing the higher power motor just needs that little extra. That's where I plan on starting, just wondering if there are any other words of wisdom. I've triple checked timing and oil level, so i'm figuring start with the air dam, if that doesn't fix it, guess I'll get the radiator everyone talks about in the sticky, and if that doesn't work, another higher flowing water pump. Does that make sense?

 

yea i hear ya on the over heating. i have had everything go wrong with mine over heating. as long as you have 2 fans blowing in the right direction that will help a lot. try swaping a 160 thermo in that will help as well. i got a brand new radiator at advance auto for 100 bucks and the car has never run cooler. a higher flowing pump wont hurt but i think the big thing is having good fans. are your fans manual turn on fans or activated by the temp sensor.

 

i installed a griffin radiator and it caused an overheating problem because they require more airflow.

 

I still have the stock dual fan setup, controlled by a toggle switch for the moment. That was going to be my last thing to change. I've read of people having luck swapping to fans from an LS1.

 

i was also temped to remove the thermostat and see how that would do, but then people say that coolant won't stay in the radiator long enough to cool down.

 

Ok, I just made the 5 mile drive to work. It got up to 180 right as I hit the parking lot. I let it idle for a good 5 minutes and the temp stayed steady. Kinda makes me figure it would be the fact that I don't have an air dam since it would seem to only overheat while driving. Didn't have time to let it idle much longer to really check it cause I'm about out of gas.

 

yea that is a good thing to not let it idle with the price of gas.

 

well i bought an air dam. Hopefully it will be here by the end of the week so i can figure out if i need to buy anything else.

 

ahhhhhh that is your problem. the air dam is the major part of the cooling system i must have missed that you didnt have one. yea with out that dam the engine will over heat real quick

 

Just weird that it never had a problem until the motor swap. With the stock motor, it didn't overheat at all, even without the air dam. I've also heard taking out the A/C condensor lets more air pass around the side of the radiator instead of through it. not sure how true that is, but maybe that is the little extra airflow loss, combined with the lack of an air dam it needed to overheat.

 

yea for sure. if you dont use the A/C pull all that crap out. it helps with cooling and weight. also it makes it easyer to work on everything. but if you still use the A/C i would not touch anything to be on the safe side.

 

Ok, just throwing this out there. Could part of the overheating be to me being an idiot and having the vacuum advance hooked up to the wrong port on the edelbrock carb? I just realized I had it hooked to the constant vacuum instead of the timed vacuum port. I'm sure that was screwing with my timing. Perhaps I should have quadruple checked? I'm sure I'll have to recheck everything after work since i adjusted everything to the wrong port.

 

yea that is out of my knowledge i dont know carbs i am TPI so i cant help there

 

yes, if the timing is wrong it will certainly cause it to overheat, and using the wrong vacuum port for the advance is a common mistake.

 

Well it does seem to be running around 170 now, unless i get on it a little bit, that's even without the air dam. I got the air dam today, so that is still going on. My timing is still off though. Don't know much about setting it and was reading many different ways, with and without vacuum connected. Right now, i'm running 10 degrees advanced at idle, but mechanical only goes up to 28 degrees at 3000 RPM, If I'm correct, it should be around 32-36 mechanical without vacuum hooked up. What is the vacuum advance supposed to add? I read somewhere it should add another 12-15, but i never adjusted mine out of the box and it was adding about 25. I pulled it back down to 13, is that good?

 

I'm not familiar with the specs on your particular engine build, but the few that I worked with called for a little less advance at idle than what you've stated. If this is the problem, 4 degrees would not affect performance off idle, but may be throwing the total advance "curve" into less than desirable territory.