twisted wedge head problem?

[tcmustang]

using twisted wedge heads, 1.7 rr's, they sent me 6.7" push rods trying to start motor, only getting back fires and rough idle. Confirmed timing, found TDC with dial indicator set based timing at 10 degrees, using 70mm TB, 73mm Mass Air, didnot touch cam.
Could push rods be too long?
thanks!

 

[tcmustang]

anybody???

 

[Joes95GT]

Those pushrods are ~.50" too long. I've never messed with TFS stuff, so you may need a longer pushrod, but 6.7 inches seems way too long.

Joe

 

[Grn92LX]

6.7" is what you need. Timing is off or rockers set too tight..

 

[zenboy99]

Most people suggest going with a 6.75" pushrod, Trick Flow recomends the 6.7", but I'm sure thats not the problem. Are you sure you have everything hooked up correctly? vacuum lines, electrical connections, etc.

 

[94stang-lover]

i'm sorry to say that but i had the same thing when i start building my engine and i had back fire to and the problem was that i got 8 bended valves cos they were hitting the pistons coz the 1.7 rr's are pushing the valve way down and the push rods ur using are longer than u suppose to use. i took my heads to a machine shop and did a valve job and a ported them and install 1.6 rr's and they are running good now . anyway if u can take off the heads and check the valve if they are ok or not. and i'lll check the push rods coz i think they are longer than u suppose to use

 

[tcmustang]

i'm sorry to say that but i had the same thing when i start building my engine and i had back fire to and the problem was that i got 8 bended valves cos they were hitting the pistons coz the 1.7 rr's are pushing the valve way down and the push rods ur using are longer than u suppose to use. i took my heads to a machine shop and did a valve job and a ported them and install 1.6 rr's and they are running good now . anyway if u can take off the heads and check the valve if they are ok or not. and i'lll check the push rods coz i think they are longer than u suppose to use

Thanks, I was afraid about the 1.7 and the longer push rods. I guess i'll pull the heads tomorrow. This is a 95 GT for a friend. I have a 94 cobra and we routed the vaccum hoses like my cobra. But this is NOT a vaccum prob, I have had bent valves on a pair of gt40 iron heads 10 yrs ago, similar symptoms.

 

[jwalker]

I have TW heads and use the 6.75 push rods with 1.7 rockers. I have stock pistons. No problems here.

Maybe the distibutor is 180 degrees out.

 

[tcmustang]

I have TW heads and use the 6.75 push rods with 1.7 rockers. I have stock pistons. No problems here.

Maybe the distibutor is 180 degrees out.

We checked the distributer,no help, but just talked to the trick flow tech guy, he e-mailed me instructions for adjusting the valves for the 1.7 rr. that are a little diff form the normal procedure for valve adjustment. Am going to put air in each cyl. with the valves closed to double check that I don't have a bent valve, then try this new procedure for adjustment.