Valve Tappet Variations?

Hi folks, for the 2 1/2 and 3 1/2 litre Mark V engines there were two valve tappet numbers specified, depending on early/later engine numbers. The part numbers are C.435 earlier and C.2963/1 valve tappet.

The service manual indicates on page B.41 that these tappets have 2.25" total length. The 1946-1948 Service Manual (Autobooks, Section A, page 12) says 2.25" total length.

There are 23 spare used tappets sitting on my counter, all of them are about 2.35" long, at least some of which came out of a T-series engine.

There also are two pushrod parts numbers (C.562, C.2965) which don’t quite overlap on early/late change numbers for the tappets. Did the pushrods come in two lengths?

What are the variations in tappets, pushrods, and depth of engagement hole in the tappets? Any advice on mixing and matching?

The front rank of 10 little Indians from an unknown engine are 2-1/4" tall. Probably a 3.5 Mark V as they came with a lot of other Mark V parts from a guy in Iowa cleaning out his stash after selling his restored Mark V and scrapping what was left of the parts donor car, and all the Mark Vs sold in the USA had 3.5 engines. It had C2844 aluminum con rods so was probably in the range of T6791 to Z2198.

The rear guard of 10 soldiers, all 2-11/32" tall, plus one headless horseman and one without a foot to stand on, are from engine Z3353, which exploded a piston and sent pieces through the block and sump.

The bundle of pushrods from the same guy in Iowa labeled Mark V 3.5L are 11-9/16" long.
The pushrods from Z3353 are 11-5/8" long.

Should I look at any other characteristics?

I could, but should not, write a book on SS pushrods. BUUt as you asked about variations. I have some here withe a ball at each end and others with a socket each end, These obviously to go with the cam followers that have a ball on them and the rockers which aren’t adjustable. But these rare all early [ 1936]
There seem to be variations in pushrods, 2 1/2 were a different length to 3 1/2 and to do with the extra spring, later abandoned.
The depth of the recess in the socket seems to vary.
Surprisingly people seem to ask for pushrods, although I’ve never seen one worn. Brysons used to have bundles of new ones in their spare parts dept.
But in recent years I’ve just had new ones made, quite cheap and they have sockets and balls to fit.
But that’s mainly to go with the MGB rockers I use.

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The extra springs Ed mentions, on my '38 SS.

A couple of dead soldiers; one lost his head and the other his foot.

These car parts might make a fun set of chessmen.

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Layshafts make good candle holders too. We used the two that I replaced in my Rebel when they both lost one and a half teeth off third gear. A Nice matched pair.


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Hey, if @Kirbert can write one, so should you!


Wow!! Did that happen when power-shifting its massive engine?


That reminds me…of a painful choice I once made…

We used to rebuild TONS of VWs, such that dad would buy–when they were cheap–lots of new parts for them, which was cheaper than rebuilding units, like heads, jugs and pistons.

36 hp Bug engines had the lifter integrated into the pushrod, and was a soft point of the engine: after the mid-to late-60s, we didn’t see many of them, so trashed the pile of new 36 hp stuff.

Including a 5-gallon bucket, full of new, still-in-cosmoline pushrods, which I junked around 1977.

Guess what those are worth today?


It’s amazing the power you can get out of 700 cc if you rev it hard enough.


I’ll hafta take a picture of one of my DKW engines, coupled to the one gearbox I have left: I think they got the gearboxes out of a Panzer tank!!

In all the years I was around/worked on/owned Deeks, I never saw a broken/worn-out 'box.