[fastfreddynz]

thankyou both for the help!!!

i started with the howard 7.850 rods, then to a stock set 7.800 both to long,so i got hold of a ajustable one, 7.750 seams to be the best, so ill go order a set tomora,

thx!
nathan

[Awesome Bill]

he could run as tight as .010".010" and not have a bit of problem. A good starting point s .020/.020"cold and it will be .022-.024 hot. He is most likely under cammed anyway. TL cam s are pretty hot right now and if he has the time to dyno this most likely the lash I gave him will produce more power. We always start on the tight side with dyno testing and go as much as .020 loose. Very seldom do we find more power loose unless the cam is waaaaaay to big!

[lun40119]

Oh, my bad, I though that we were talking about the rocker arm pattern, not the lash. I thought you meant under .020 for the pattern on the valve. sorry bout that.

[want-a-be]

spoke out of turn with out reading what was said on the first page.

Don

[lun40119]

Originally Posted by Awesome Bill

Start with .020/.020" intake and exhaust, the cam your using will be solid for sure if your springs are really large and have over 125lbs of seat pressure. Always use oil. Make sure you take some black magic marker, color the tip of the valve, install the rocker and run a pattern. The pattern should be no wider than .020" and dead center if possible. It does not really matter if it dead center but the narrower the pattern the more power you will make. Start with this.

Actually I did read it correctly............

[lun40119]

Mine is wider than that with the shaft stuff......................

[fastfreddynz]

thx guys.
so how does one get such a thin line? i get that a longer rod will bring the line to low,and a shorter rod to high on the valve stem,but dont have any idea of why or how to get a thin lie acoss it?
nathan

[lun40119]

Proper rocker arm geometry creates the thin line......there are guys that can put it into words better than I can, but I was always taught, it is the trunnion height. When you set up shafts, you set the trunion height, and then measure the pushrod. Pushrod length is an outcome of proper stand height.





I remember when talking to Bill, or Don, I didn't think that the shafts could really be that much better. They were right, there is no comparison. Money well spent, will use shafts, in my wifey's motor too.

[Awesome Bill]

Getting back to geometry, the pattern should be like the one pictured on Jake's valve for ideal conditions. Getting proper geometry also gets you the most valve lift. If its wide, your wrong, if its narrow and thin but not in the center, the trunion seat in the shaft system is to far forward or if it is thin and to the outside of the valve its is got the rocker center to far down or towards the valve. Also, height of valves will move this around. A plus .200" valve in a conventional head will cause the pattern to be on the exhaust side of the valve. Either way, dead center just means the rocker company and the correct valve length is used. We have found some engines to be .200" short and way down on power. When corrected the engine will just free right up with power.

[Awesome Bill]

Originally Posted by fastfreddynz

thx guys.
so how does one get such a thin line? i get that a longer rod will bring the line to low,and a shorter rod to high on the valve stem,but dont have any idea of why or how to get a thin lie acoss it?
nathan

check the next to last post. I never use a shorter than 7.900 push rod with and flat tappet cam and aftermarket head. I think your way out of the ball park. The pattern has to come clean and thin like Jake's picture or your not getting the proper lift. Do it again and slow down. I use the actual valve spring with push rods we have until its perfect. Sometimes not all push rods are the same. Half are .025 " to .050" longer with different companies valves and actual tip heights.