1941 346 Valve stem end to cam lobe clearance?

[kkarrer]

Can someone out there tell me if the 3" measurement from the end of the valve to the heel of the lobe on the cam is valid for a '41 346cid flathead?  I would think so, but I'd like to be sure.
Thanks,
Ken Karrer 1941 6227D coupe

[pauldridge]

Ken,

Everything I've read indicates that, and the guys at Terrill Machine do confirm also.

Phil

PS... curious if you were able to extract those lifter bodies as easily as I described?

[harry s]

Ken, That measurement is 3" exactly and very critical to quite lifter operation. It is best to measure with a mic. Good Luck,    Harry

[Brad Ipsen CLC #737]

If the cam has been reground and/or the lifters faced that measurement would not be valid. 

[kkarrer]

Phil,
    Please call me and let me know if you have an extra torus gasket for the hydramatic (512-626-7268). I got the lifters out easily as you described.  Of course pulling the manifolds was no fun...dropping one of the brass fittings caused me to have to pull the pan and getting those lifters back in was a real bear.  If I have to do that again I'm going to make a 4 fingered feeler gauge looking tool.  The inner oil passages were pretty plugged up (otherwise the engine internals are spotless) and I found that two of the lifter bodies were late 1948's.  I replaced them and all 16 of the upper portions of the lifters with parts from Terrill, but things are still not as quiet as they should be.  I suspect it's the clearance between the end of the valve stems and the tops of the lifters is too great although it was tough getting them in place.  The transmission now works, so that's great, but it's leaking between the flywheel and the crank so I'm going to have to back the trans back out and pull the flywheel and use some sealant this time and no gasket.  You hear different things about that area...don't use a gasket, use a gasket, don't use sealant, use sealant (not the usual blue or black silicon pookie).  I'm going to apply some special GM sealant this time, but that's why I need another torus gasket.  I have one on order, but it won't get here by Saturday and I'd like to get the trans buttoned up so that I can concentrate on the lifter issue.
Ken Karrer 1941 6227D coupe

[Dave T]

Kkarrer, I had the exact problem with my 1946 Cadi, After replacing the rear main seal and the tarus cover gasket I still had a trans oil leak,By putting a piece of cardboard under the flywheel area and running the motor there was an oil pattern coming from the back side of the flywheel.  I pulled the trans and flywheel off and  I noticed that there never was a gasket used . so I just used permatex, after about an hour the centrifugal force just threw the sealer out. After some research into the Cadi parts manual they do list a gasket being used , I was able to locate a gasket at Olsons Gasket. Good luck.
                                                                Dave T CLC 22554

[Terry Wenger]

In a correction to what was said earlier, if the cam has been reground, the 3 inch measurement is still valid. Brad Ipsen and I discussed this and agreed. If the lifter has been refaced,however, the 3 inch clearance is no longer valid.

Terry Wenger

[kkarrer]

Got it.  Thanks.  I know that two 1948 lifters were used (w/out springs in the upper mechanism) and there may be a clearance issue there with the new lifter.
Ken Karrer 1941 6227 D coupe

[Glen]

In a correction to what was said earlier, if the cam has been reground, the 3 inch measurement is still valid. Brad Ipsen and I discussed this and agreed. If the lifter has been refaced,however, the 3 inch clearance is no longer valid.

Terry Wenger

Can you please elaborate on this?  I thought the purpose of the hydraulic lifter was to take care of small differences in the cam to valve stem dimension. 

What kind of tolerances are we talking about plus or minus .002”?