2pc engines. Pushrods?

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ignacio vivancos
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2pc engines. Pushrods?

#1 Post by ignacio vivancos » Wed Mar 07, 2018 12:27 am

Are those a 25/36 hp vw part? Porsche pushrods with vw lifters?
Can 3 pc lifters be modified to be used with Porsche puschrods?
Thanks
Ignacio Vivancos
Austin TX

53 PreA
56 A
65 912
77 carrera 3.0
78 SC
88 911 coupe

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James Davies
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Re: 2pc engines. Pushrods?

#2 Post by James Davies » Wed Mar 07, 2018 12:01 pm

Hi Ignacio,

The pushrods and lifters are unique to Porsche, but very similar to VW parts.

You can use any Porsche pushrod. The original pre-A ones through 1953 were steel with wooden inserts. The 1954-55 ones were aluminum, so that the the thermal expansion rate of the cylinders was a closer match to those of the pushrod, which is why the valve clearance changed and the 1954 cars have that neat brass plaque on top of the distributor.

There was a very small difference in pushrod length and valve stem length during the pre-A period. If you're using 1953 and later valves and pushrods, you shouldn't have a problem. I don't know why there was a difference in length and why "hats" on the ends of the valves were used. Backwards compatibility issue? I don't think you'll need to worry about it. And of course you can always shim your rocker assembly if needed.

The lifter looks just like a 25hp/36hp VW lifter, but there is an insert in the bottom with a circlip that allows the standard Porsche pushrod to clip in and swivel, just like the later 3-piece case pushrods. Recall the VW ones do not swivel.

You could use the 3-piece case lifters on your 2-piece case, but it would require some custom machining. Probably not worth it.

Photo below of the Porsche 2-piece case follower assembly.

These lifters are now being reproduced in Europe and the USA. Ray at Speedwell makes them in the USA. They are carried at Parts Wise in Europe.
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