Wolftrk99

iTrader: (5)

Looking at #7, it is the shortest run of exhaust, in theory with stock manifolds(which should mean less backpressure), it also has the pcv tube in the valve cover directly over it, which could if you have a leaking valve stem seal also pull extra air in..... Actually the back two cylinders have the shortest run to dump the exhaust, but iirc 7 is slightly shorter, granted with headers that should be fixed by the longer primaries.... Add to that the theories of all excess intake air and silt in the fuel rail and there are numerous issues with 7!!!

Wouldnt the quicker exit of exhaust also lead to less exhaust gas being sucked back in when the valves open?

LPCWS6

I can't speak for the OP but I'm not going to over think it. IMO those problems are probably due to a bad tune more than anything else.

Ken in AZ

Sorry - I just meant to be careful in the tune and NicD will be aware of anything. Didn't mean to derail the thread.

Back on track tho - Fixed a nasty exhaust leak that was in front of the B1 O2 sensor - I could tell it made a difference in drive-ability and idle. things were much happier.

I must have popped something tonight - thinking a valve spring or a rocker. Hoping it's nothing too bad - engine runs well and idels nice - just sounds like a sewing machine after I did a blast on the freeway.

I did try my hand at tuning tonight since I could feel some flat spots in the tune after switching the manifold. Knowing that the Timing was dialed in I didn't mess with it at all and only fattened up the tune a bit and raised the rev limit by 200rpm since it appeared to be shifting early at 6600 instead of the 6800 it was supposed to.

I'm guessing my cam is to blame since it's right at the max .660" limit for the springs. I didn't get a spec from my machine shop on the installed height of the springs but after doing some reading it appears they might really be only a .650" spring.

Anywho - tear into it this week and see what happened - ordering the new cam for sure within the month should have it all back together. If anything serious has to be done more than what I'm expecting I'll be pulling the heads and having WCCH work their magic on them.

I'll keep y'all posted

Ken in AZ

Sorry - I have other threads going on about the build and I've neglected this one.

I'm going to try and get to a dyno this next couple of weeks or so if all goes well. I switched cams to a BTR STG 3 400ci cam that is 239/254 .624/.595 114+5

I don't think I had the preload adjusted correctly with the last cam - I only had it at 1/4 turn preload on the adjuster nut. I went with a half turn with the new cam and the valvetrain noise is nearly completely gone as compared to before.

I also switched to Speed Density and Swapped the factory L92 intake.

I also swapped out the Dana 60 with 5.13's for a 14bolt with 4.10's and a trutrac.

I'm going to pull the trans Friday and try to fix the "no reverse" problem I have too and then try to get to a dyno after that. I may switch to the ported L92 intake again as well since I feel I have my tuning problems situated.

Keep you posted.

NVR MISS

darkirish63

iTrader: (5)

Thread is 3 years old..