Streetracer361

My car has a misfire and I have tried everything. Just thought I would try to tighten the pushrods. By the way I have a cam and it makes a lot of valve train noise. Does anyone know what the valve train torque would be?

bsf

iTrader: (7)

I do not really understand your question. Rocker arms bolt torque spec is 22ft-lb for LS1's.

Streetracer361

the car is misfiren when idealing but when its at 1000rpms, it doesnt miss. The valves make a lot of noise thats why I was asking.

vettenuts

iTrader: (4)

Pushrod's preload the lifters. If yours is making a "lot of noise", they don't sound like the correct length. Did you measure your pushrod length requirement with the new setup? Tightening the rocker will only result in broken rocker bolts or stripped threads if they are already tightened to specification.

Streetracer361

They were installed at MTI and their suppost to be currect size for the cam. 224/224-581/581-112 for a m6 speed car. I dont think that their tight, it sound like a lot of valve train nosie. I check the headers and its not them.

snake charmer

iTrader: (118)

take the valve covers off and check the rockers and see if one is loose . then you could take on off and check the pushrod length . then let us know .

btw you did right usually a lose header bolt is to blame for valvetrain noise .

DaveX

They get torqued to 22 ft lbs. You can't go any tighter. If one or more came loose it could make alot of noise so it's not a bad idea to check them. But use a torque wrench. Aside from that it's usually either the wrong length pushrods (most likely cause) or a collapsed lifter, or bad/fluctuating oil pressure.

Streetracer361

thanks guy im going to pull the valve cover and check that first. then check the length on the pushrods. let you all know what I find. By the way what is the right size on the pushrods lenght for this cam.

DaveX

Hard to say, if you have stock heads and stock thickness gaskets, you can just measure the base circle of the new cam compared to the old cam, take half the difference and add it to the stock pushrod length. But you won't be able to measure it since it's already installed. I'm going to guess 7.425 if you have stock heads. You can also use a pushrod length checker, but it's been my experience that these are very hard to use accurately with the hydraulic lifters. See what length is in there, you most likely need to go a little longer to quiet it down.

DONAIMIAN

iTrader: (18)

Before you start taking **** apart.

Is it a true missfire that you can feel, or is it just a flashing SES light?

Streetracer361

Its a true missfire. I put it on a computer and it shows misfires on all, but it goes away at 1100 rpms (idail 900). It has a lot of valve train noise, almost like a header leak but its not.