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-   -   Installing Yella Terra UL's...got question? (https://ls1tech.com/forums/generation-iii-internal-engine/996731-installing-yella-terra-uls-got-question.html)

porsche914ls6 Oct 4, 2008 02:37 PM

Installing Yella Terra UL's...got question?
 
My 1.7 Yella Terra UL roller rockers came with Allen headed bolts and no washers that fit under the head of the bolts like the stock ones. Can I run the stock rocker bolts with the washers or should I use the allen headed ones w/out washers that came with my set? I slipped a stock bolt through and checked if there is any difference in range of motion and there is no difference as far as I can see...so I'm pretty sure the stock bolts will work fine. The instructions make no mention of slipping a washer under the head of the rocker bolts. Seems weird to not run washers under the head of the bolt. Any body know what's best? Also, I've been using red locktite on the bolt threads...are you?

Thanks

vettenuts Oct 4, 2008 03:55 PM

The rockers come with shims, you need to check the wipe first. Once you do that, the Allen head bolts are fine without washers. I think you will find the machined diameter under the bolt head is too small for a washer. Also, I don't remember a washer under the stock bolt, although there is a flange under the bolt head. You can also use the stock bolts if they fit through the hole in the rocker shaft if you want. YT only recently included bolts as there were some interference problems with the stock bolts and the hole in the shaft.

porsche914ls6 Oct 4, 2008 08:13 PM

I checked the wipe and it is noticably inward toward the intake. To get the geometry correct I'll need to adjust the height of the rocker by shortening or raising the pedistal with a shim. In this case, I believe I actually need to machine a small bit of material off the pedistal...does that sound correct? I hope I have this backwards in my mind...because I'd much rather drop the provided shims in and be done with it.

Thanks,

Bill

vettenuts Oct 5, 2008 08:06 AM

No, you need to raise the pedestal. Start with the shims and work from there. I found that the shims were not thick enough for my setup and figured out a thickness and then bought new shims.

As you raise the rocker, the wipe pattern will move to the exhaust port side of the head.

porsche914ls6 Oct 5, 2008 10:50 AM

I'm glad all I'll need is thicker shims. Thanks

vettenuts Oct 5, 2008 06:25 PM

I used washers and played with the thickness until I got the correct pattern, then I ordered shims from McMaster-Carr. I can look up the diameters if you want, they were SAE but very close to metric.

porsche914ls6 Oct 5, 2008 07:38 PM

Looks like I'll be doing the same thing you did. Playing araound with washers until the desired thickness is found and I'm getting a nice centrally located wipe. Then check for proper pushrod length. I appreciate your advice (again).

voda1 Aug 24, 2009 10:37 AM


Originally Posted by vettenuts (Post 10226975)
The rockers come with shims, you need to check the wipe first. Once you do that, the Allen head bolts are fine without washers. I think you will find the machined diameter under the bolt head is too small for a washer. Also, I don't remember a washer under the stock bolt, although there is a flange under the bolt head. You can also use the stock bolts if they fit through the hole in the rocker shaft if you want. YT only recently included bolts as there were some interference problems with the stock bolts and the hole in the shaft.

Anyone have the YT special bolts? 4 pair of mine took stock bolt, the other 4 pair need smaller size. Need ASAP!


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