New engine, popping under boost??

[farmtruc]

i would suspect a cracked plug....
but keep us updated on your results since you've taken it apart...
x2 on quik, i would do a .030 or so

I forgot to mention, I did change plugs, but it's getting a new set just incase.

got it all apart and back together again. Just need to get in two plugs and the coils, then let it warm up and top everything off.

i regapped to .030 this time. Thought the smaller gap might cure it, but it didn't. I'm running msd coils just to see if it helps.

I'll keep you updated,
thanks for the feedback.


hey, btw, i did notice something. some of the cylinders had black residue outside of the cylinder bore, like the combustion/explosion escaped pass the head gasket sealing ring. I guess like a head gasket leak.

[ducky]

I know this is a shot in the dark, but maybe if this doesnt work try regapping to .035. I had some bad popping with my plugs gapped at .030. FWIW

[Bagged93gmc]

maybe your head is warped causing it to leak outside the chambers?

[GasGuzzler]

At least we won't know what fixed it since have the engine was replaced all at once.....

[farmtruc]

Shotgun approach worked hahah!

I can rule out plugs because I did in fact change those, that's a lot easier than heads I guess.

I installed the same wires and coils.

The only difference are the heads, now I'm upset!

Here's the story; I sent off some perfect condition heads to a shop, I changed my mind and requested my heads be sent back, when I got my heads back, they had been in the vat machine, cleaned and different valves were in there.
I was told they "cleaned them up".

I was always doubting that because the heads I sent off were in perfect condition, came off a running turbocharged truck (with only a few miles on it) and there wouldn't be any reason to clean them up.

I think I got some heads that were sitting in the corner.

So, if the problem are the heads, bent valve, bad seat, etc, what do you think?
Springs are brand new, I put them in there.

let me know,
allen

[GasGuzzler]

So, if they are the heads, bent valve, bad seat, etc, what do you think?

One of those. Now put them back on and let's do a leak down to find out.

If you have a short block lying around and a beernight you could try them on that. You can also turn the head over with the chambers sitting up and the deck level and pour some solvent in the chambers and look for the valve that drains into the head. This will show a leaking seat. Take that valve out and then check it for straightness. If it's straight, the seat or valve job is the problem.

[farmtruc]

One of those. Now put them back on and let's do a leak down to find out.

... This will show a leaking seat. Take that valve out and then check it for straightness. If it's straight, the seat or valve job is the problem.

Ok, I just tore the engine down and I'm going to reinstall the heads to do a leak down, LOL yeah right!

I can turn them upside down and fill the chamber, that's about all the time I have.
I'll just sent them off to the machine shop, have them shaved, reworked, valve job and new valves put in them.
Oh well.

[ChevyLee]

Ok, I just tore the engine down and I'm going to reinstall the heads to do a leak down, LOL yeah right!

I can turn them upside down and fill the chamber, that's about all the time I have.
I'll just sent them off to the machine shop, have them shaved, reworked, valve job and new valves put in them.
Oh well.

JR the guy who does the head work up here is freakin awesome. PM jon or kurt an they will get you his info.

[GasGuzzler]

Ok, I just tore the engine down and I'm going to reinstall the heads to do a leak down, LOL yeah right!

That was a joke

Did you try the solvent test?

[ChevyLee]

Sounds like scum to me.. its everywhere