Yes, that's what I think too.

Interesting, in the engine I worked on for my Brothers special the tappets were very similar to the Austin item, they were D section as opposed to the Austin item with two flats on the flanks, and the foot had an identical radius to an Austin tappet. I know this because when we got the engine it was in boxes, and one tappet was missing, I adapted an Austin guide and follower to replace it. I did not photograph any of it so can not post here. I hasten to add this is the only Reliant SV that I have any experience with, it makes me wonder if they changed the engines to a flat follower later in production??

Location: Auckland NZ

Tim Reynolds, your tappets look something like those my father used to supply for use with standard camshafts. I got a very stern lecture about why they were wrong for use with a high-lift shaft.

Location: Richmond, Texas

Tim your tappets look to me to be assymetrical so they will have to be installed the right way round. Can someone on the Forum suggest whether the sharp radius of the tappet makes contact first with the cam lobe or whether it is the shallower radius?
Presumably if the sharp radius makes contact first it will result in the valve opening very rapidly.
Second question, when assymetric tappets such as Tim's are used, are they only used on the inlet valves?
This is the sort of thing that keeps me awake at night!

The shallow radius allows the valve to open without too violent an acceleration. The sharp radius allows it to stay open late and then close very quickly. Think of valve opening periods in the same manner as pub opening hours and you won't go far wrong.
You could use them on the exhaust too I suppose but there wouldn't be as much point.

A question for Alan and Dave, are you sure you are not talking about an OHV Reliant engine? With a round flat tappet in a Side Valve Reliant how are the valve clearances set?

Location: Auckland NZ

Ian, I'm absolutely sure. I've never taken an OHV Reliant apart. I can only think that Reliant altered the design as time went on.

I can't check either,the engine is in storage 300 miles away.
I seem to remember they were bolts with a locknut similar to 7's.Definitely SV.

Thanks, yes the one I worked on had tappet adjusters identical to the Austin ones, with a round tappet fitted these might not work because the tappet could spin when you try to adjust. I am thinking they would have to use some kind of thimble and shim arrangement. All purely academic I know, I am just curious!

Location: Auckland NZ

Hi Ian, normally round followers had two flats to enable a thin tappet spanner to fit,
Also congratulations on the rebuilding Classes you & josh a running

Location: TINOPAI NZ

Could have had 2 spanner flats on them to stop rotation,but it was about 5 or more years ago when I last looked at it.

Yes, I believe you're all right! The early Reliant engines were virtually A7, and then developed across time. The tappets I've seen were about 1/4" longer than A7 ones though I've never seen any with just one flat side. The last engines had a flat headed mushroom tappet in a circular guide, the 'stalk' had two flats to retain it when being adjusted.

Photo thanks to Terry Griffin

One obvious question to ask regarding Tim's flat followers...

What valve spring set up was used? Do you just need a nice fresh set of standard valve springs or do they need doubling?

Location: Essex