Hi!
Someone hawing experience from roller rocker arms to fit the trickflow heads,the stock or some aftermarkets dont seemes to fit very well.
I have tryed compcams 1.6 ratio alu lifters and on the intake side the rollertip on the arm like roll over the center of the valvetop,on the exhaust it is a little better but not perfect.
There must be very bad pressure if you run like that insted of hitting the center of the valve top.
If someone haveing done some mods on these heads let me now.
Thanks

 

Sounds like maybe you don't have the right length pushrods. Where the rocker contacts the stem isn't as important as how far it moves across the stem though.

 

Well there are experience makanic who told me that it doesnt matter what length of the pushrods are if the rockerarm dont hit the right spot at the valve,even whith lash caps its not ok and safe to run whith the rollertip over the edge he says.
And why is it different on intake then on exhaust?
Thanks
Anders

 

the geometry of the arms is controlled by the pushrod, if it is going off then of the valve stem, you need the correct sized pushrod.

See this acrticle from Comp Cams, on the geomitry of this stuff. If your mechanic say's its the rockers, he is an idiot.

http://www.compcams.com/Technical/Products/Pushrods/

 

Is it running over the edge, or over the center?

 

Just a little bit over the center.

 

Hi!
If you could imagine a number 4 in the picture at max lift you now what i mean.

 

Hey Firebird Sweden,

Your pushrods are the problem as others mentioned. I encountered the same problem when I had a mustang. I purchased trickflow twisted wedge o-ringed heads and got a set of crane pushrods because Summit was out of the Trickflow pushrods and they told me this is a substitute brand. I also purchased new roller rockers, lifters, cam, etc. About 6-8 months later I had a bad valve tap. I checked everything out, removed the springs and noticed slop in several valve guides. I called a tech rep at Summit and he told me that I should have never used the Crane pushrods becuase they were too short. I got new valveguides and purchased the correct pushrods and if ran excellent! If the roller doesn't sit in the correct spot on the top of the valve then you have a geometry problem = pushrod length. You will eventually get uneven wear in the valve guides.

Like the other person said...talk to a different mechanic!

 

Ok
Maybe its me having problem to explain the problem,i will attache a photo of the valve,you can see the difference betwen intake and exhaust valve,is that right to be an 1,6mm difference?

 

I still think you could fix it with the right pushrods.

Which heads are those? They look like a twisted wedge head, I didn't think trickflow made TW heads for chevy's.

You might also call trick flow. It could be that those heads were designed to use a 1.5 on the intake, and 1.6 exaust, with custom lenght pushrods.

 

Changing the rocker ratio changes the distance from the pushrod cup to the fulcrum on the rocker, not the distance from the stud to the valve on the head.

 

Yes you are right that chould not make any different,still why are they not equal.
Yes they are twisted wedge head.
I have give trick flow a mail but they have not answer yet.

 

they do make twisted wedge heads for chevy, i just got rid of a set. i had used +.100 longer pushrods on my motor, and had comp cam pro magnum 1.6 rr's, it was hard to get the valve last set right cuz one would always ccome lose, but after a few tried it was ok..

 

Ok
so you used 7.300 pushrods?

 

no, 7.900, 7.800 was stock...

 

7.2 stock roller cam
7.8 stock flat tappet


and tell your mechanic that pushrod lengths do matter

 

Ok
This is the aswer from trick flow.

The difference is where the rocker stud hole is drilled in the trunion. On
the intake rocker it is drilled a little off center