[Adrian II]

Er, no it isn't!

The tappets/cam followers themselves can snap at the foot, and I have seen an instance of the top of the AVL exhaust tappet becoming badly chipped. You can modify the tappet guides from a cast iron Bullet to fit the AVL crankcases so that you can use the tougher C.I. Bullet tappets, and also the tougher old-style 1/4" adjusters in a set of C.I. Bullet push rods, but these then have to be modified to take the AVL push rod tops! It's worth doing if you're going to start using the Fireball AVL's extra performance.

Here's a 500 AVL crankcase modified for me by Bullet Whisperer to take the C.I. style tappets. Note the solid cam spindles replacing the adjustable spindles.



and here's the AVL tappet guide on the right of the picture compared to its C.I equivalent (actually a bronze Redditch version rather than Indian) with a reduced external diameter to fit the AVL crankcase. The alloy sleeve is to set the height correctly.



Photos by Bullet Whisperer

I am convinced that getting the best out of a 500 AVL Bullet engine involves retro-fitting some of the C.I. Bullet's better features (which the AVL Bullet really should never have lost) while keeping the best bits of the AVL re-design.

A.

[mattjohnson207]

Easily pulledoff the broken peice.    Appears to have been broken before ...looks like it has a few miles of grinding the broken peices together.  Pic shows the broken side turned upside down
   I will start researching your suggestion. ...i would like to do this now rather then when I' m ten years older....65 now

[ace.cafe]

Yes, that's a shame.
But, the tappets really need the support, and it needs to be replaced.

Adrian makes a good suggestion with the way he did his tappet guides. If that is too much to undertake, just a replacement will at least bring it back to stock condition.

[Bullet Whisperer]

The alloy sleeve I made to fit over the Redditch tappet guide in the picture above has two important roles. Firstly, as Adrian points out, it sets the tappet guide at the required height in the crankcase, but just as importantly, I made it a firm fit on the guide and a firm fit into the crankcase, to increase the lateral support of the guide, which I felt would have been inadequate otherwise and may have led to problems.
 B.W.

[Adrian II]

Sorry, just to clear up an error in my last post, the crankcases are stock 500 AVL apart from the oil level tube and some breather modifications, it was the guides that B.W. modified to fit.

B.W.'s alloy collar actually provides more lateral support for the guides than the factory AVL set-up. If they were to loosen and start fretting it would be back to the machine shop, so I'm hoping with B.W.'s revision they won't need to be disturbed again in my lifetime. I'm not 65 yet, but it's not that far off.

If a set of AVL tappet guides were to become loose and start fretting it might still be possible to reclaim the crankcases by boring out to take the C.I. Bullet tappet guides on their standard outside diameter.

Looking at some of the Indian C.I. tappet and guide sets available I notice there are two different designs, the "classic" and a second option which is actually has the same shape of tappet guide as the AVL.



Copyright of the photo seems to rest with ClassicSpareParts and VintageAutoSpares!

http://www.ebay.co.uk/itm/171247980895?_trksid=p2055119.m1438.l2649&ssPageName=STRK%3AMEBIDX%3AIT

The outside diameter of these guides could be turned down to match the AVL's, but of course this would preclude fitting B.W.'s extra support collar.

Using anything other than the stock AVL exhaust tappet also means losing the AVL valve lifter.

A.

[mattjohnson207]

Sending for extractor tool....

[Adrian II]

I must admit the broken guide is a new one on me, it's usually the tappet the fails.

A.

[mattjohnson207]

Adrian..i like the coller BW fabricated for you...

[Bullet Whisperer]

Adrian..i like the coller BW fabricated for you...

The photos seem to have vanished 
 B.W.

[Adrian II]

So they have, I will see if there are problems with the photo hosting site I have been using. 

[Adrian II]

Imagesia seems to be down, I can't see photos hosted with them on other forums either, and I can access their web site. Hacked? We'll see if they come back up.

I might have to look for an alternative, the obvious ones don't appeal.

A.

[Adrian II]

Signed up for a different (UK based) host, let's see if we can get one of B.W.'s pictures back up.



Hopefully Imagesia will get its knickers out of their current cyber-twist before too long.

www.imageupload.co.uk

A.

[mattjohnson207]

Did the clay test...snugged down the head...but not tight.   The head gasket is old...base is new
     Spent two hours getting those pita rods in!
      Thanks Ace. Adrian & BW for all yoyr help.
         Looks like the guide was broken at the factory..   Looks like the clay is not getting touched....but this is the first time I've. Done piston valve clearance check....Matt

[mattjohnson207]

Push rods measured.
      Ex.   9. 15/64.   Or. 9.234"
       In.    8.  48/64.    Or.   8.75"

[ace.cafe]

Did you manually rotate the engine all the way thru two full revolutions with thehead and valve train fully assembled when you did the clay test?

It would be very unusual to not have any imprints from the valves anywhere on the clay.
How thick were those clay pads?

What we are checking is that the valves don't touch the piston at any point of rotation. It requires that you carefully rotate the engine manually, trying to feel if any contact or binding/stoppage occurs.  If you begin to feel like it is making any contact, you must stop immediately and move the crank back a bit, and then disassemble and look at the clay. It is VERY easy to bend a valve by piston contact, so you have to rotate the engine carefully and slowly during these tests.