i got everything wired and cranked it over today . the headers got real hot real quick. i had put high temp. exhaust paint on them and that started burning off. i then let it sit for a while, then checked the antifeeze and some smoke came out of the radiator, but it was full of antifreeze. it was kinda running a little ruff, but not bad. also, i only ran it for about 2 or 3 minutes. the heater hoses were hot and the hose for the cooling line going to the back of the heads was hot. any ideas on what i should check....timing....the temp sensor appearently isn't working, so not sure how hot it really got. i'm going to try and fix that one tonight. thanks, jimmy

LT1s do not run as cool as some of the older small blocks do. My '97 is always around 95-100*C (200-215*F) and thats well within normal operating temps.

Don't worry about the header paint burning off - 99% of those 'high heat exhaust paints' do. Almost none of them work, especially on EFI engines where the headers will get hotter than on a carb'd engine anyway. Worry if the headers start to glow red though - thats a sign of a problem with ignition timing or fuel delivery. If they don't glow, don't worry about them.

Heater hoses should get hot. They have engine coolant running through them - and because of the way they are routed around the engine, the coolant will be the hottest in the heater hoses.

Was it smoke coming from the rad when you had the cap off? Or was it just steam? Steam is not unusual. Especially in an engine like the LT1, which is designed to run on the warm side of normal engine operating temps anyway.

You should get a mechanical water temp guage and read the engine temp off that. They are more accurate the than the guages on your dash, and they are only like $15 anyway.

If your headers are getting stupid hot, I would look into your timing. I have seen headers turn cherry red due to too much advance.

Something to think about.

thanks Air_Adam and nelapse,
i'll get a mechanical water temp gauge and try that out....i'm pretty sure it was steam...and i'll check into the timing. it's just unusual for me to see an engine get that hot that quick. i wasn't worried about the exhaust paint...just the fact that the paint started melting off within a short amount of time. i'll let you all know how this goes, but i'll probably not work on it again until next weekend.
thanks

when I first started up my engine the smoke was rolling off the headers like you'd never seen within 5 minutes. looked like someone was pouring oil directly on the them from all the paint burning off. shop probably looked like it was on fire from the outside. I wouldn't worry about it too much.


with the correct thermostat, these engines heat up to operating temp fast.

Actually, unless you go into the PCM and change the timing you can't get it wrong on the motor. The LT1's usually run about 44* full advance, around 20 or so at idle stock.

That is the way it is suppose to work with TPI too. You are only suppose to change the timing by using the ECM. However, people still screw with the distributor though.

No, with the TPI you change the timing by turning the distributor, you just have to unplug the advance wire coming from the ECM before adjusting. With the LT1, there is no adjustment, it bolts in one place and doesn't move at all.

actually, my optispark is a MSD...you can adjust it +/- 7 degrees on the optispark. i'll still check the timing, just to be safe. thanks for the replys.

Umm....I hate to say this but apparently alot of guys have had problems with them coming apart, I was going to get one but decided against it from all of the problems I've heard.

You are right about the LTx but I do not agree with you with the TPI, just because you can change timing that way does not mean it is the right or correct way to do it.

How else are you supposed to change it? Burn a chip every time you want to?

You pull the EST (tan/blackstripe wire) which bypasses the advance the ECM puts in the dist and then adjust the base timing to what it is supposed to be. If you look at the underhood label on the car, it tells you how to adjust the timing.

Here's a partial picture of the emissions label under the hood of my GTA

yeah, i've heard good and bad things about them. just figured i would give it a shot and let MSD know what i think about it.

A factory LT1 ignition is not adjustable. You cannot just loosen off a clamp and twist it, like you can (and are supposed to) with a Tune Port engine. The LT1 relies 100% on the computer to set the ignition timing. I can't remember off hand, but I'd be willing to bet my '97 LT1 car that there is not even a timing mark on the balancer (especially considering there is nowhere to put it - the outer edge of the balancer has a belt on it).

The Tune Port engines are adjustable, and they are supposed to be. Thats why the emissions label has a specification for initial timing (0*, 6*, 8*, whatever it might be) and the LT1 cars do not.

But, back to the original question - put that mechanical guage on there and run it for awhile and see how warm it runs. The LT1 are warm running engines, so expect something between 210-220* to be its 'stable' normal operating range. Its perfectly normal and safe. The fans on my LT1 and on my 3rdgen turn on around 230*, for what its worth, too.

My fans used to turn on at 230, they now turn on at 200 and turn off at 190, car seems to run much better cool. With it being a '93 model, I'm not for sure what kind of monitoring software you can get to see where the ECM is turning on the fans at.

already a step ahead....it gets in the 100's here every summer, and 110 degrees is not uncommon to see a few times a year. so, i put in a 160* stat and had the fans programmed at 180*