85 Monte Carlo SS build

[JCzNova]

It just makes me think it is off because you said it comes from both sides.

That is what has me scratching my head...

Chris, you did your own pushrod measurements correct? After the stuff that happened at that shop before, everything they touch would be in question now.

[firebird_1995]

Lol thanks man. Ive never had this many problems with a build. Its very frustrating and demoralizing.

[popo8]

And that just makes me think that its gotta be something right in front of u, and its gonna make u laugh....hopefully.

Co-Owner/Admin @ LTXtech.com

[popo8]

@JCZNova

and I were discussing this and we decided that you needed some motivation.... and there is only one man out there that can motivate with his eliquent speech.

[firebird_1995]

That is what has me scratching my head...

Chris, you did your own pushrod measurements correct? After the stuff that happened at that shop before, everything they touch would be in question now.

Yes, and stock length were fine.


Let's talk theory.... sometimes understanding what it takes for an event to take place helps me consider other possibilities.

What does it take to make a backfire in the exhaust? We need an air/fuel mixture, and an ignition source. As for ignition source, a spark plug firing while an exhaust valve is open? Maybe due to spark jumping arc from a nearby wire? A hot surface in the exhaust? Getting a/f into the exhaust, either the exhaust valve is leaking or hung open and an unburnt mixture is getting into the header. Maybe some fuel is getting by during the overlap period? Any other ideas?

[firebird_1995]

@JCZNova

and I were discussing this and we decided that you needed some motivation.... and there is only one man out there that can motivate with his eliquent speech.

Lol thanks guys. I'm going to get my head out of my ass and start getting serious with this. Got way too much money and time invested into it to stop now.

[JCzNova]

Yes, and stock length were fine.


Let's talk theory.... sometimes understanding what it takes for an event to take place helps me consider other possibilities.

What does it take to make a backfire in the exhaust? We need an air/fuel mixture, and an ignition source. As for ignition source, a spark plug firing while an exhaust valve is open? Maybe due to spark jumping arc from a nearby wire? A hot surface in the exhaust? Getting a/f into the exhaust, either the exhaust valve is leaking or hung open and an unburnt mixture is getting into the header. Maybe some fuel is getting by during the overlap period? Any other ideas?

So by theory, if you pulled the valve covers and ran it, you think it would back fire up through the exhaust valve? Or would you be able to hear an abnormality of the valve hanging open?

More head scratching...

[firebird_1995]

By "valve leaking" I mean leaking past the seat, although I suppose it could leak past the guides too.


I've heard of guys shooting the valves with a timing light while the pickup is on that cylinders spark plug wire. That might be an option to see if there is anything odd going on.

[JPack]

Back fire and pop out exhaust is a timing issue. Valve is open on exhaust when cylinder is firing. Does it do it random with steady rpm or is it doing it with the rpm like when it should be firing? I highly doubt it is fuel related. If it does it steadily with steady rpm it is either the timing, or valves not seating.

[popo8]

Lol thanks guys. I'm going to get my head out of my ass and start getting serious with this. Got way too much money and time invested into it to stop now.

IT WORKED!!!

Co-Owner/Admin @ LTXtech.com