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Re: Thinner Valve Tappets

PostPosted: Tue Jun 08, 2021 9:47 am
by tonyabacus
Does anyone have a link to Rohan’s XP’s spreadsheet please

Re: Thinner Valve Tappets

PostPosted: Fri Jun 11, 2021 6:25 am
by rgh0
Big valve std dimensions.pdf
(23.19 KiB) Downloaded 69 times

Hi Tony
Is this what you were looking for ? While I cant guarantee it is perfect as I assembled this data by measurement of known original components and no one has access to the original drawings, I believe its close and all the dimensions cross check


Re: Thinner Valve Tappets

PostPosted: Fri Jun 11, 2021 10:23 am
by paw140

I decided to leave the head in place and inspect the valve collets and retainer first. I took them off last night and the collets are slightly damaged. It most definitely would have self destructed at some point if I had run it longer. The retainer is fine. I’m going to order the parts today and hopefully I’ll have it back together soon.

BTW, a coworker introduced me to a really unique type of valve retainer removal tool: Lisle 36050 Valve Keeper Remover and Installer Kit ... BWBAZ15GFM

It is a device that you place on top of the retainer and then push down or hit with a hammer, and it compresses the spring and grabs the collets with a magnet. It worked really well. Hopefully it goes back together as smoothly.



Re: Thinner Valve Tappets

PostPosted: Fri Jul 30, 2021 12:05 pm
by paw140
Just wanted to finish off this thread for completeness. I was successful in installing the thinner tappets from Dave Bean, which gave me a little more total clearance so I could install thicker shims and also avoid tappet contact with the spring retainers. Gaps are all within spec and the noise is now gone! I also wanted to mention that the Lisle tool I mentioned previously is magic! I highly recommend this. I used the 'rope trick' to keep the valves in place, then just used the Lisle tool by literally compressing the spring by hand. When compressed, there are magnets inside the tool that grab the collets and then everything comes apart. To reassemble, you just put the spring and retainer on the valve, slide the collets in, then use the tool to compress the spring and it will pop the collets back in place.

Now I can at least run the engine without danger of dropping a valve, but I have other issues I still need to sort out. First, the engine smokes like crazy and it seems to be oil. Hopefully the new rings have just not seated yet and it will sort itself out. Also, the engine hesitates and has little power at partial throttle. I have to rev the engine a lot to take off. At greater than 1/4 throttle, it seems to be ok. I think it might have something to do with the silly crossover tube / secondary butterfly setup. I'm going to eliminate the crossover tubes and remove the secondary butterflies and see if that helps.