Tappets?

midgetracer said:
After reading this thread, I panicked and checked the adjustable tappets that I had purchased a few years ago to build a spare engine for my Model As. I checked them and sure as hell, they are about 1/8 inch smaller in base diameter than stock ones. I am not even sure where I purchased them, so return is not an option. They are exactly the width of the cam lobes. Will these cause problems for my cam? Should I just junk them and buy good ones? Being car poor, I have waited to assemble this engine and another $100 seems like a lot right now, but early failure of this engine would be even more expensive. What do you think.... A. give up beer?:rolleyes:...B. put the junk tappets on Ebay and pass along the problem? :D..C. Wait for my ship to come in?;) D. use the tappets and go to church a bit more often? :)
No option seems right. Seriously would I have much of a chance of getting by with these tappets ?
Click to expand...


What is the actual base diameter of the tappets that you bought ?
When you mention the "stock ones" are they the non adjustable type ?
What type of cam are you using; original;reground,new Stype performance cam ?
 
It depends on the opening and closing ramps for the cam lobes. You could put a thin coat of blueing on the tappet base, then roll the cam around and check to see if the blueing got scraped off the edge of the tappets.


I bought a set of adjjustable tappets several years ago, and they are still in the blister pack, but I have a feeling they are also the small diameter ones.
 
Mikeinnj said:
What is the actual base diameter of the tappets that you bought ?
When you mention the "stock ones" are they the non adjustable type ?
What type of cam are you using; original;reground,new Stype performance cam ?
Click to expand...

Actual base diameter of the purchased tappets is just shy of 1 inch. Cam is stock Model A not reground 5 bearing style. The stock ones are the non adjustable type originally used in the Model A.

Tom, I will try the bluing test tomorrow and post results.
 
The stock lifter is 1.110--1.125. That is a lot of tolerance. As I recall, the so called double lock lifters are .998, and the single lock friction fit are 1.118.
 
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