valve guides

What is the correct amount of press fit for BTSV valve guides? I have looked in Palmer's, the factory service manual and searched this forum and have not found the answer.

Woody, Don't know the exact spec. However, when I redid mine awhile back, I took them to my friend who's been doing these motors for years. He actually Hammers them in. The rationale is the abrupt shock is less stress overall in the fitting process. I tried .002 over guides and they wouldn't go. We turned them to about +.0005 and heated the jug with a Bernz o matic torch 'till it was warm, pulled the guides out of the snowbank and bam, bam, bam they were in! I've always chided him on his crude method, but in the right hands, a hammer can be a tool of finesse.
Long and short, the holes in the block don't change much, and std or slightly oversize should do the job.
This may not help you, but I thought I'd pass it on anyway.
DD

If it goes in easy, it's not stable.

Thanks, Panic.

The reason for the question is that I am making my own guides. Every guide that I have bought has the ID at .005" to .006" over the valve diameter. This puts the starting clearance at the top of the specifications (.003' to .0055"). Unless someone has more information, I will go with a press fit of .001". I will be heating the cylinders to 250 deg. F and using Sunnen 200L press fit lube. If you have not used it, it makes a big difference.

I would recommend 0.002-0.003" as a press fit,especially with this installation,in a heat environment. Check your local library for a machining reference for further details. BREWSKI

Hi Woody. I use Rowe cast guides with excellant results. Rowe advertizes them as being .374 id and normaly they will need to be finished to size after instalation. Fit them at .001 to .0015 with cylinder at approx. 250 degrees and guides at room temp or chilled if you prefer.As these guides are quite long, .002 or more is a little stiff and not really necessary,but will sure close up the id. Hope this helps.

Thanks to all who replied. I went with .001" press, heated to 250F, and used Sunnen press fit lube. Flawless installation. Everything went perfectly. .001" is exactly right.

woody did you make your own guides in the end? what material did you use if you did , regards jib

Yes, I did. I used Durabar cast iron.

cool ,cheers jib