Motor ran well after initial fire up. Broke cam in as one should (flat tappet). Plenty of oil pressure. One of the plug wires melted on headers last night so I tucked car away for the evening and resumed repair this morning.

Again motor started up immeditiatly but this time made a slight "popping" or backfired through TB. Shut motor down. Then fired back up and adjdusted TPS for the hell of it. Seemed to eliminate issue. Then about 2 mins later I notice a slight "ticking, tocking, knocking" whatever you want to call it from the #8 cylinder. At this point the popping through the TB comes back. My nieghbor comes over to say hi and throw his 2 cents in. "Maybe it a bent pushrod or valve" he says. So I pull off valve cover and look. Crank motor over with covers off but there was too much oil spitting everywhere to listen for long. Then I noticed that those 2 springs were not seated in the bosses like the others on the head. With a big screwdriver we manage to put them in to place. Easy fix. put all back together and turned over again. No luck its still there. So I remove everything again and this time take the roller tip rocker arms off and pull out 2 pushrods to check for straightness. Neither one looks off.

I really don't want to pull the head if I don't have to. What is my next best step?

BTW my fuel pressure based on the guage I added to my HSR rails is reading low. Maybe 35 psi. The new tune program I installed is set up for 30lb injectors. Maybe this has something to do with the popping? The engine and headers also feel really hot. I had the same headers on my lb9 and they never got this hot. It wouldn't shock me if I am dealing with 2 or 3 seperate issues.

 

That's a tough one, by any chance did you look at the plug with the melted wire?

 

No but it was the same wire as the cylinder in question. Ill go pull it right now.

 

 

Here is a shot of 2 and 4 for reference

 

How does the gap look? Sometims they can be fouled and it can be hard to tell. I would try a few new plugs and make sure the wires are making good contact on both ends.

 

So are you suggesting that the knocking noise is just a misfire?

 

Forget the plugs for the moment, here's a wtf!

How were a couple of springs not seated? Was there an error when you assembled the valvetrain?

I should imagine this would have some consequences for valvetrain geometry and cam break-in. Did you re-check the lifter pre-load when you re-seated the springs?

 

If the gap was closed on the cylinder with the burnt wire then you could have an internal problem.

 

Gaps were all similar. I pulled all plugs today. Would you say these were "carbon fouled". I do think I should run a colder plug. I was running the Accel 574s 's but just ordered the 276s's tonight. Possibly I was hearing alot of detonation or preignition. I'll check the base timing and make sure I have some nice fresh 93 Octane since the car has been sitting for about 6 months.

 

That's what I was thinking and if new plugs don't help then I would check the push rods for that cylinder to make sure they didn't get bent for some reason.

 

Just as a precaution I would run a compression test on that cylinder primarily and a couple of others for reference.