Cam Thrust Washer and spacers spec?


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By Brent - 5 Years Ago
Is there a standard specification for the thickness of the Thrust Washer, spacer, gear, counterweight combo? Engine builder is questioning.

[Once I had a moment to search the site, I learned it's the thrust washer and plate in question. See Ted's post that I copied to the last post in this thread.]

Thanks!!!
By Florida_Phil - 5 Years Ago
One of the professionals on this forum can answer this question much better than I can.  For what it's worth, I ran into this issue last summer.  The thrust washer and the spacer must match or you will not be able to get the correct amount of cam end play.   I messed around with engine parts for a week.  It looks like there are at least two different thicknesses of plates. I happened to have a virgin 1957 272 in my shop.  To get enough cam end play, I took both the plate and spacer from that engine to use in my motor.  I checked the cam end play with a dial indicator and the timing chain uninstalled.   I couldn't get a good reading with it installed.  This was probably due to the roller chain and gears I used.  My motor now has about 3,000 miles on it since the rebuild with no problems. 
By Genuinerod - 5 Years Ago
The parts books only list one size retainer plate (.190" thick) and one spacer (no size given).  But Y-Block how to build book recomends .006" is max end play with .001"-.003" is optimum.
By Brent - 5 Years Ago
Rick machined the spacer and ended up with .005 end play. He is happy with the timing gears alignment which he says is important. 
Thanks for the replies!
By Brent - 5 Years Ago
I found this very informative past post by TED.

http://forums.y-blocksforever.com/uploads/images/55c0dab9-b349-4566-84a4-e661.jpg 
 

The cam thrust plate bolts directly to the block only after the camshaft has been inserted into the block.  The cam thrust washer is placed on the camshaft snout with the chamfered side facing the camshaft and before installing the woodruff key in the camshaft snout.  The cam thrust washer (#6265) is slightly thicker than the cam thrust plate (#6269) and the difference in those two measurements will dictate how much camshaft end play is present.  Here are some past threads on the subject.
 
http://forums.y-blocksforever.com/FindPost132964.aspx
http://forums.y-blocksforever.com/FindPost140366.aspx
http://forums.y-blocksforever.com/FindPost99441.aspx
By Ted - 5 Years Ago
The typical cam thrust plate thicknesses are 0.187” - 0.191”.  The cam thrust washer thicknesses are 0.192" - 0.196”.  Depending upon how you pick up the pieces, you could have anywhere between 0.001” to 0.009” cam shaft end play.  I like to target for 0.005” with the acceptable range being 0.004” - 0.006”.  Measuring these two pieces prior to installing on the engine will give an accurate measurement of the camshaft end play once installed.