This is a 454, with a solid flat tappet. Engine fired up and the first shot :hurray: . Sounded great so I was keeping it at 2500 rpms then I started to noitce smoke coming from the header collector where it seals, also noticed smoke from the mufflers where they seal to the exhaust pipe. This is my third breakin and this never happened before, could something major be happening?? I had 80 lbs of oil pressure but the temp did shoot up to 220. Please help??

P.S. This was built by a shop, not by me.

Smoke is normal during break-in. How were the headers looking?

The headers looked fine, not glowing or anything. For the first 30 to 60 seconds they smoked because I had my dirty hands all over them but then they stopped. Then about 2 minutes later is when I noticed the smoke that must be coming from the inside!! I'm thinking that something must be leaking out of the cyl head and into the exhaust. What do you guys think? Should I try to run it again?

That seems kind of stange. Never heard of it before. Usually people just cant get them started lol.

That seems kind of stange. Never heard of it before. Usually people just cant get them started lol.

Tell me about it...when it fired on the first try I thought I was home free. Maybe there is nothing wrong but I want to make sure before I run it again.

Maybe they spilled oil or something into the headers without realizing it. I would call the shop and do what they say, if something happens they should really replace it since they built it and you do what they tell you.

Maybe they spilled oil or something into the headers without realizing it. I would call the shop and do what they say, if something happens they should really replace it since they built it and you do what they tell you.

The shop built the engine but I installed it, the headers were in my basement while the engine was out. What scares me is that I had no smoke for a couple of minutes then all of a sudden it was smoking from every seal in the exhaust. Maybe it took that long for the rest of the exhaust to heat up and burn off the condensation that was built up?

That could be it or something similar

Is it smoking out the exhaust or on the exhaust. one side or both sides..I had one smoke on the driver side due to the oil pressure sending unit leaking where it bolts to the block.. And it does take 3 or so minute for it to heat up to burn all the oil off. If it sounds good,getting good oil psi, run it for another 5min see if it burns if off,,,,,Ohh check your oil and make sure you not loosing a lot in a short period of time..Hope you get it.

UPDATE!!! Ran it again for about 5 minutes and NO SMOKE! Dam temp keeps shooting up to 220 so I shut it down. I'll try to run it again after it cools down. Thanks for all your help guys.

Mist the radiator with water from a garden hose.

Put a large fan in front of car pointing at radiator.. It helps !!!

my guess is the coolant system could possibly be air bound or its just running hot cause its a fresh motor and it needs to seat in, you dont notice the coolant level droping in the radiator??? or is their a decent amount of white smoke coming from the tailpipe?

I don't think the coolant is airlocked because I filled the system without the thermostat installed and I know it's circulating (sp?). I have a brass radiator and a flex-a-lite dual fan that's probably not adequate for the engine. Anyway, I think I'll try a box fan and see what happens.

Could it be it takes a few for the rings to fully seat?
I know on my old 396 when I first fired it, it smoked for about 5-10 minutes then nothing, the guy that helped me install it said it was from the rings needing to seat. Always had good oil pressure and never had a single issue after that.

Or did you squirt oil into the spark plug holes before you fired it?

Just my 2 cents.

Put a large fan in front of car pointing at radiator.. It helps !!!
Yeah...that's what I've done. Fresh motors are tight and create more heat. A large fan in front of the radiator helps.

When it's hot, does it still roll over easily with the starter? If it doesn't, I'd think about an inspection before going any further. Been there, done that. Ended up doing a complete rebuild on an 800 mile engine that was machine shop built. :rolleyes:

Put a large fan in front of car pointing at radiator.. It helps !!!

Exactly. Set it on a flat surface like a bench (which is what I did) right in front of the grill blowing into the rad. Also, leave the cap off while your running it to allow the air someplace to bleed out. Sometimes, i will leave the heat on and wait until i start getting heat which is a good sign the air is gone or close too it.

It is also best to have a buddy outiside of the car looking all over under the hood for leaks and anything else that might not look right. Its hard to do from the drivers seat. I actually let my brother operate the pedal instead while I kept an eye on the motor during break in. He is not much of a car guy but he sure loved the fact that he got to take control of the engine. Plus, its a job that is pretty much straight forward that anyone can do. If I had him look for any misshaps, I dont think he would have really understood the circumstances of an engine that is getting broken in the first time. Knowing what to keep an eye out for, glowing headers, smoking or leaking gasket, melting hoses or plug wires, etc. He did it perfect when he operated the throttle.

if there's no thermostat in the engine stop right there and put one in. Chevys are not meant to be run without a thermostat.

Also need to check your ignition timing, it shoulf be at around 40 at 2500 during breakin. If it's retarded it will heat up, maybe turn the headers red hot.

[QUOTE=Tom Mobley]if there's no thermostat in the engine stop right there and put one in. Chevys are not meant to be run without a thermostat.

Also need to check your ignition timing, it shoulf be at around 40 at 2500 during breakin. If it's retarded it will heat up, maybe turn the headers red hot.[/QUOTE

Make sure your trans lines are not leaking onto the header and causing smoke, because that is what happened too me. The fluid was only slightly dripping on the collector and then burning off, so there was none hitting the ground, which puzzled me until I got up underneath the car and saw it puking myself. Also check your fluid level again because if there is air in your cooling system the liquid in the system will quickly turn to steam, thus dradtically increasing your temp. Just my two cents!!! GOOD LUCK..

Could it be it takes a few for the rings to fully seat?
I know on my old 396 when I first fired it, it smoked for about 5-10 minutes then nothing, the guy that helped me install it said it was from the rings needing to seat. Always had good oil pressure and never had a single issue after that.

Or did you squirt oil into the spark plug holes before you fired it?

Just my 2 cents.
I second that motion

You'll definitely need at least one box fan. Think about it, you're running the motor at 2500 rpm in a stationary car! There's no air being forced through the rad from the car moving and you have only the small rad fans that are meant to cool at idle. I run two box fans during cam break-ins and have the hose on standby...

Those box fans will help keep her cool but misting that radiator will do a better job. I usually mist the radiator and keep the temp down around 170-190 or so.

Your smoke could have been oil/water in the headers, mufflers and/or pipes. If your motor is making more horsepower than before it will make more heat and will overheat if you had a marginal cooling system before.

Thanks everyone, I talked to the engine builder yesterday and he said the smoke was from oil that he used to coat the cylinder walls. The last engine I broke in didn't smoke like that so were assuming the previous builder assembled it dry :sad: . I did try the fan on the last go around and it did help a little, I think the fan was pretty weak as well. Again, thanks to all who posted.