[tomaszek]

SO i've read as much as i can and done everything recommended like you all suggested.

New cooling system, divider plate is super tight, new 3 core rad. all new hoses, working stat, 70 water/30 glycol. adjusted timing and carb. shroud fan at correct location.

350 professionally built when i got the car, bored over 0.030, pretty much stock, mild cam.

run great at idle, gets up to 190 , and if i drive stays there, so airflow issue. well i have a 7 blade fan , shroud is tight . I even put electric fans to kick on at 190.

but stopped, creeps up and hits about 220 on gauge (never ever overflows-never) and then sputters out and by 225 engine locks up. no turning over. Weird that i had never had coolant overflowing. (new 14lb rad cap)

cools down, starts do problem? vaopr lock? but if so the engine is still getting too hot so I don't think that matters? What am I missing. I flushed the heck out of teh colling system when all apart, so i think that is as efficient as I can get it, and the fan and shroud is as good as i can get.

I am thinking about the 600CFM holley. Should i jet up or down? I have no idea what i ended up with. ANy help is appeciated. it;s not lean as of now via vaccum gauge..

I hate to mess with the carb it runs so good. maybe valve adjustment?

exhaust leak?

thanks
keith

[Chris65LeMans]

Do you mean that it won't even crank after it dies? Sounds like an electrical problem to me.

Have you verified these temps with a laser thermometer?

[OCMDGTO]

1 Why are you using 70water/30AF? I have always used 50/50 here in Md but it only gets to single digits rarely. I just looked on my AF jug and it recommends 50/50 unless you are at the north pole and then it is 70AF/30water
2 How old is your water pump?
3 Any hose collapse?

[tomaszek]

Right. No hose collapse. New water pump. I think I used a cast. But if I didn't I got the divider plate wicked close. I am using more water bc water has more cooling efficiency than glycol. But yes when it dies around 220 ish. It will not crank over. I assumed things get hot and just tighten up so much it expands and locks up. New battery. I have an hei and was wondering if something inside gets hot and something shorts out? When running system is charging at 13. 9 v. I am going to wrap the small section of gas hose with heat shield but not sure it's vapor lock. I have an infrared gun. Exactly where should I be shooting it. Near gooseneck ? Or near the manifold where the temp sending units screws in.

[hectore3]

Are you using modern pump gas? Because with the ethanol added it can boil in a little as 100 degrees. Add some race gas when the tank gets near empty and re-evaluate.

[DOC]

will the engine turn over with a breaker bar and socket on the front crankshaft when hot?

[tomaszek]

It's a pretty non mod 35o. Pump gas should be fine but I've tried different octane. No difference. It's by no means a race engine. I'll have to try turn the engine when hot at crank. What will that tell me so I'll know what where trying to narrow down? Thanks for the advise so far guys.

[DOC]

If it wont turn mechanically something is getting too hot and creating a tight interferance fit. verses just hot electrical components. Doubtful, but always need to check.....

["QUICK-SILVER"]

I bought a chevelle many years ago that did this. It had a new completely rebuilt 350. Pistons ended up being too tight in it. Heated up worse at idle till pistons finally swelled and stuck in the cylinders.

Hope it's not your problem
Clay

[Chris65LeMans]

Originally Posted by tomaszek

Right. No hose collapse. New water pump. I think I used a cast. But if I didn't I got the divider plate wicked close. I am using more water bc water has more cooling efficiency than glycol. But yes when it dies around 220 ish. It will not crank over. I assumed things get hot and just tighten up so much it expands and locks up. New battery. I have an hei and was wondering if something inside gets hot and something shorts out? When running system is charging at 13. 9 v. I am going to wrap the small section of gas hose with heat shield but not sure it's vapor lock. I have an infrared gun. Exactly where should I be shooting it. Near gooseneck ? Or near the manifold where the temp sending units screws in.

If you crank the key and nothing happens, it ain't vapor lock.

When I check my gauge, I want to see if it's telling me the right number, so I hit the temp sending unit with it.

With my gauge, 195=195, but a 250 reading is really 230. Something I have to remind myself on long freeway runs in the summer.

[tomaszek]

I think it's distributor related. So I was thinking to buy a recurve kit and play around with that. I need help with that. I am buying a new timing light since I melted mine. Any starting points will be helpful. I have initial at 12 right now and the adjustable advance canister at 14. I will try the turning of the engine by hand tommorrow and get the dist number so you can help me buy the correct spring curve kit Thanks. I am on a mission now.

[tom s]

As Chris has done,have you checked how accurate you gage is?If you don't have a laser temp gun get one.With it you can see what the actual temp is right at the place where it's minted.You can also see hot spots on the engine,how much drop in temp from where the hot water goes in and what it is where it's goes back to the engine.Tom

[tomaszek]

I do have a temp gun. I did check temp a while ago on the new rad. When at 180 it was hot at top and it did cool when it returned back to engine. But once it got to like 210 ish the rad starting to become the same temp at top inlet and the bottom out back to block. So it's like once it hits 210 220 it's too late. The engine is about to cut out and sputter and stall. I can check around the block for hot spots. And will record at various spots. Ill take temps at.180 and record at that time. I'm so frustrated. I spent tons of time re doing the cooling system but to no change. So in my mind I'm done with the cooling system. Mentally at least. Ahhh

[tom s]

My 350 auto radiator always has about a 25 degree drop even with the 455 that is in my 69 now.Have rechecked the timing to be sure the dizzy has not slipped?If not tight they will retard them selves and cause the engine to run hot.Just reaching!Tom

[tomaszek]

Unfortunately I have checked like 100 times. I took off the cap and the delco remy had stamped

Delco remy 2089c21

Does anyone know if this is just the standard gym hei. Trying to find the spring kit. I am trying to attach a pic.

[Chris65LeMans]

You said that your car won't even crank after it dies - that's the first problem I'd try to solve. I don't know enough about the electrical side to make suggestions, but I'm sure it has nothing to do with your springs or advance.

[NeighborsComplaint]

You're saying the engine overheats so severely that it seizes up (mechanically locks up) until it cools down and operating clearances are restored? If the motor won't turn over with a jump, it is seized from overheating. You can confirm this by pulling the plugs when it quits and see if the motor turns over with a breaker bar and a socket on the balancer bolt.

Does the engine ping (detonation from overheating) just before it quits? Listen for it as it is a precursor to overheating.

Is your upper radiator hose cool to the touch when this happens? If so, you have a stuck thermostat and are overheating. Change your thermostat and hope you haven't stuck pistons or bearings,

Does your lower radiator hose collapse when the car is at operating temperature? This can cause engine coolant starvation. Your lower hose should have a coil spring inside it to prevent it from collapsing.

[tomaszek]

So no the Engine hoses are all springed inside, they are super hot, stat was tested before i put it in, and i've tried this with the stat removed, no difference.

When it gets too hot it simply kinda sputters and hick ups a few times and cuts out . No pinging at all. I haven't tried the breaker bar yet, i will. But the starter won't crank. but as soon as it's back down to say 200ish, it'll crank over and will start back up.

I took off the dist cap ,and everything looks fine, so i don't see much there.

My gut tells me timing (which is now at 12) or the carb holley 600cfm but i adjusted the heck out of that with a vaccumm gague and even fattened it up with the idle mixture screws just to see, but no difference. Plugs look perfect, nice and dry and brown.

I sprayed around the carb looking for a vacuum leak, none to be found.

Oil is clean, i see no evidence of water or antifreeze....

But i;ve locked this up about 10-15 times on accident and on purpose. at Some point I worry about the heads. But as of now seems to be fine.


I just don't get the not cranking over when it overheats. Any chance the HEI gets too hot and some component opens up or shorts out? Still doesn't explain why it gets that hot in the first place.

how about the valves, posibble need adjusting, not letting hot exhaust out? they sound fine?

[Greg Reid]

Sounds like it could be too tight as said above. That may be causing the overheating AND the resultant seizing.

350 professionally built when i got the car, bored over 0.030, pretty much stock, mild cam.

Have you ever owned this engine when it was NOT having this problem? If so, that would indicate that it was built properly and something else is happening.

[GT182]

E10 fuel could also make it run hot. As soon as you can find a gas station that sells gas with no E10 in it, try a tank full of a 50 50 mix. I'm not saying it's the full cause of your overheating, but it could be a part of it. Maybe they're putting E15 in the tanks and no one knows about it. If it's E15, cars older than 2012 will not run with it.

I know that with my 66 GTO if I run 100LL or C9 [96 octane] VR-1 Racing fuel it does run cooler.