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Thu Sep 13, 2007 10:38 pm

From what I read I think my geometry is Ok? My head is spinning. What do you guys think? FK8 cam Steve Tims Stage 2 heads with .075 thick lash caps. See pics and let me know. Thanks
Zero lift

Half lift

Full lift

Fri Sep 14, 2007 6:51 am

Any suggestions before I cut my pushrods?

Fri Sep 14, 2007 9:41 am

I'd want to be further up on the pad. Color the pad (part that contacts the lash cap) with a sharpie marker, then reinstall and rotate the engine one full revolution. Pull the rockers off and check the pad, if geometry is correct the sharpie should have worn off the center on the pad. Shim until the line is the center...

Fri Sep 14, 2007 4:16 pm

This may illustrate the above post.

Fri Sep 14, 2007 4:18 pm

I'll give it a shot. Thanks

Fri Sep 14, 2007 4:20 pm

Would you recommend shimming with lash caps or try to just remove my lash caps and see what I come up with?

Fri Sep 14, 2007 5:16 pm

jammer729 wrote: Would you recommend shimming with lash caps or try to just remove my lash caps and see what I come up with?

You're going to want lash caps with those rockers, you can get ones thinner than .075".

Sat Sep 15, 2007 8:43 am

I just ain't having any luck. I tried.030, .060 then .120 shims. see pic at half lift with .120 shims and my .075 lash caps. It gets slightly more to the center of the pad but higher on the lash cap with more shims and also they wipe off more of an area (ink) the higher I go also. I did try no shims and no lash cap and that seemed the best but I really want to use lash caps cause the pad was a bit high on the valve stem. I keep going back to what I started with it has the smallest area marked off. Here is a better pic and also a pic of the lifter and lash cap.
Half lift

Rub mark on lifter

Rub mark on lash cap

.120 shims with .075 lash caps at half lift

Sun Sep 16, 2007 7:09 am

I think the only way to get it better would be to have shorter valves? Not an option though. Seems the further away you shim the higher up the pad rides on the lash cap due to the valve being on an angle? It keeps getting closer to the rocker shaft. Let me know what you think.

Sun Sep 16, 2007 7:41 am

I could be wrong but it is my understanding that some manufacturers have mounting blocks and the holes in the shaft offset on some ratio rockers.

It seems like you may need a longer pushrod. If the pushrod is in line with your adjuster at 1/2 lift you should be close.

Here is a post from Don Pauter from another forum;

Max,
There are three different shafts available, one with zero offset and two with offsets from approx. 3mm(1.3/1.4) to 4mm(1.5) which do you have? From your description of the problem you require further offset shafts.

Keylime5,
Your situation must be opposite if you switched to a 1.4 shaft, with less offset than a 1.5,the roller tip would have increased high of center on the valve tip. A word of caution, in most cases broken rockers are an indication of severe loss of control, if left unresolved a dropped valve may be in your future.

I'm not quite sure whats up with after market heads but we/they have run the table in terms of shaft offsets. the zero offset shafts were developed exclusively for use with the 910 head however we are often obliged to exchange shafts due to offset problems similar to those above. Valve length plays a critical role in positioning but I feel there must be other changes during production to account for the wide variations required to accommodate some makes.

I urge anyone with similar problems with our products to contact us directly for assistance, also refer to our web site for complete instructions on rocker arm setup.

D P

Sun Sep 16, 2007 6:42 pm

Ok how is this? I have .060 shims with the lash caps? I think its either this or no shims see above pics. I like the way the rocker is at half lift with the .060 shims but I likre the way the pad wear is on the no shims.Please help
Half lift

Rub on lifter pad

Rub on lash cap

Tue Apr 28, 2009 3:47 pm

I ended up using the .060 shims as shown in the last set of pics and I drove it hard like it should, reved it to 7500 rpms and ran it down the track a few times and no problems with the valves or rockers nearlt 2 years latter.

Thu May 07, 2009 3:12 am

thanks for the update;-)