Engine stalls after rebuild. Please Help!
Thread Starter
Instructor
Joined: Aug 2021
Posts: 200
Likes: 34
From: Niceville FL
Engine stalls after rebuild. Please Help!
This is my first ever engine rebuild on my 77' 350. I replaced nearly everything including all the bearings, camshaft, new roller rockers, push rods, lifters, crankshaft, piston rings, and every gasket.
I put it all back together, primed the oil, and today I went to start it for the first time. It took a bit to get it running initially, I'm guessing the fuel just had to make its way through the line that I replaced. This is where it starts to get weird, Watch the videos I've included, it'll show what's happening. Basically, after almost 45 min of trying it wont stay running. It will start fairly consistently, but it will always die even at high rpms. Oil pressure looks good at about 35-38, I'm using conventional 10-30. My gas is new, and my coolant is full. The only smoke I saw was after it began to warm up my paint was being cooked.
Videos:
My best guess is the fuel is clogging as the filter is dirty, but I cant be sure. I have no idea what I'm doing. Any help is appreciated.
I put it all back together, primed the oil, and today I went to start it for the first time. It took a bit to get it running initially, I'm guessing the fuel just had to make its way through the line that I replaced. This is where it starts to get weird, Watch the videos I've included, it'll show what's happening. Basically, after almost 45 min of trying it wont stay running. It will start fairly consistently, but it will always die even at high rpms. Oil pressure looks good at about 35-38, I'm using conventional 10-30. My gas is new, and my coolant is full. The only smoke I saw was after it began to warm up my paint was being cooked.
Videos:
My best guess is the fuel is clogging as the filter is dirty, but I cant be sure. I have no idea what I'm doing. Any help is appreciated.
Le Mans Master
Joined: Jun 2019
Posts: 7,649
Likes: 2,466
From: Indiana
If thats a new cam I think you have to use high zinc oil and break it in right away..
i would not crank anymore until you stop recheck everything like timing, fuel delivery etc..
others will have better advice..
it needs tostart and run high rpm 2000 ish for 20 minutes from what i read..
i would not crank anymore until you stop recheck everything like timing, fuel delivery etc..
others will have better advice..
it needs tostart and run high rpm 2000 ish for 20 minutes from what i read..
Thread Starter
Instructor
Joined: Aug 2021
Posts: 200
Likes: 34
From: Niceville FL
Nothing was changed on the carb but the fuel line, it was only sitting about a month. Timing is set as best as I could get it just by turning the distributor w/o my timing gun, It wont stay on long enough to get good initial timing, but I still did my best. Should I try using a gun?
Appreciate the ideas!
Appreciate the ideas!
Thread Starter
Instructor
Joined: Aug 2021
Posts: 200
Likes: 34
From: Niceville FL
How necessary do you think high zinc oil is? I've seen it thrown around a few times, but from most of what I've been told is that conventional is better at least for setting the rings.
Melting Slicks
Joined: Mar 2010
Posts: 2,268
Likes: 374
From: Randolph nj
Its VERY important to use a high zinc oil at break in ,, joe gibbs driven break in oil is very good
was assembly lube used when you put the motor together
I hate to say this but you better get some zinc in that motor sooner them later
was assembly lube used when you put the motor together
I hate to say this but you better get some zinc in that motor sooner them later
Corvette Stories
The Best of Corvette for Corvette Enthusiasts
How Much Horsepower Every Corvette Engine "LOST" in 1972
Joe Kucinski
Top 10 DOs and DON'Ts for Protecting Your Convertible Top!
Michael S. Palmer
Top 10 Most Explosive Corvettes Ever Made: Power-to-Weight Ratio Ranked!
Joe Kucinski
150 hp to 1,250 hp: Every Corvette Generation Compared by the Specs That Matter
Joe Kucinski
8 Coolest Corvette Pace Cars (and Replicas) of All Time
Verdad Gallardo
Top 10 Corvette Engines RANKED by Peak Torque (70+ Years of Muscle!)
Joe Kucinski
Corvette ZR1X Will Be Pacing the Indy 500, And Could Probably Race, Too!
Verdad Gallardo
Top 10 Corvettes Coming to Mecum Indy 2026!
Brett Foote
Top 10 C9 Corvette MUST-HAVES to Fix These C8 Generation Flaws!
Michael S. Palmer
Melting Slicks
Joined: Nov 2006
Posts: 3,400
Likes: 1,813
From: Apple Valley, MN
First, as others have warned, drain the oil and put in some proper break-in oil.
Second, read up on how to static time an engine and also look at all of your vacuum lines on the engine and ensure they are connected properly. Make sure the plug wires are all properly connected.
Go slowly and deliberately, understand what you are doing and why you are doing it when troubleshooting.
Second, read up on how to static time an engine and also look at all of your vacuum lines on the engine and ensure they are connected properly. Make sure the plug wires are all properly connected.
Go slowly and deliberately, understand what you are doing and why you are doing it when troubleshooting.
Le Mans Master
Joined: Aug 2017
Posts: 8,336
Likes: 2,810
From: Cool Northern Michigan
How necessary is Zinc in the oil you ask?
How necessary is ATF in your transmission to function correctly?
That is the first thing a cam company will ask for warranty claims is, was Zinc introduced.
As far as "seating the rings" that is where synthetic oil is frowned upon.
Not the conventional, not Zinc oils.
How necessary is ATF in your transmission to function correctly?
That is the first thing a cam company will ask for warranty claims is, was Zinc introduced.
As far as "seating the rings" that is where synthetic oil is frowned upon.
Not the conventional, not Zinc oils.
Burning Brakes
Joined: Aug 2007
Posts: 897
Likes: 245
From: Green Valley Ca
If your using a flat tappet camshaft, you needed the motor to start immediately and run around 2000 rpm for 20 minutes. To break in the camshaft you should have use oil with zinc additive.
In my opinion your startup problems, and your choice of oil, you could experience possible camshaft damage.
In my opinion your startup problems, and your choice of oil, you could experience possible camshaft damage.
Thread Starter
Instructor
Joined: Aug 2021
Posts: 200
Likes: 34
From: Niceville FL
Going to get High Zinc oil today. How long should I leave it in before changing it?
I did use assembly lube on everything when putting it together too, as well as priming the oil pump, it should never have run dry.
I did use assembly lube on everything when putting it together too, as well as priming the oil pump, it should never have run dry.
Is my vette stock?? HAHA
Joined: Oct 2015
Posts: 20,183
Likes: 9,317
From: Im not allowed to tell you
2020 C3 of the Year Finalist - Modified
2020 Corvette of the Year Finalist (performance mods)
2019 C3 of Year Winner (performance mods)
2016 C3 of Year Finalist
I run mine for about 500 miles, not very long as the engine is having metal as the rings seat and parts mate to each other. It will tend to get your filter dirtier faster. No sense in taking any chances in starving a new engine
Burning Brakes
Joined: Dec 2017
Posts: 1,043
Likes: 414
2023 C3 of the Year Finalist - Modified
I personally break in the cam, then do 15 or so 1/2 to 3/4 throttle pulls in 2nd gear to seat the rings.
change out the oil and call it good.
Melting Slicks
Joined: Mar 2010
Posts: 2,268
Likes: 374
From: Randolph nj
I don’t think he’s screwed he should just put the recommended break in oil and run the car and see what happens ,,, he has no other choice at this point but I would not ruin his day by telling him he’s screwed … let be optimistic and see how this plays out …. I’m saying he will be ok .. I have seen worse situations …
Thread Starter
Instructor
Joined: Aug 2021
Posts: 200
Likes: 34
From: Niceville FL
Bought some zinc oil today and put it in. Thinking about it now, I think 45 min is an over exaggeration. It just felt long because I was nervous. I don't think it ever ran dry of oil either. It was also never running longer than 10-15 seconds at a time. I doubt it would have caused any major damage, that just doesn't make sense to me. How would I know if there is damage without looking at the lifters? I don't really want to pull off the intake manifold again.
Thread Starter
Instructor
Joined: Aug 2021
Posts: 200
Likes: 34
From: Niceville FL
Update: I put the high zinc oil in, made sure to get it flowing by spinning the oil pump for a bit. I also replaced the fuel line and filter so its no longer kinked. I tried starting it again. It seems better, but starts pulsing then dies again. I'm thinking it may be a carb issue.
Le Mans Master
Joined: Aug 2017
Posts: 8,336
Likes: 2,810
From: Cool Northern Michigan
You pulled the dizzy to prime the oil pump. So, it's just a matter of getting the timing right to stay running.
Meanwhile, crank down the idle speed screw.
Times like this, you want the distributor clamp just snug enough not to move, but loose enough it can be forced to move by hand.
Meanwhile, crank down the idle speed screw.
Times like this, you want the distributor clamp just snug enough not to move, but loose enough it can be forced to move by hand.