Minispares vernier cam timing

[Minigman]

I bought a minispares vernier cam timing kit and found the back of the adjustment sprocket hits the bolts which hold the cam thrust triangle when pushed right down.

I changed the spring washers for shake proof ones and got about 4 thou clearance between bolt head and the back of the sprocket.

When I pull the cam outwards I get 7 thou.

Is this enough clearance?

Could I run without washers on the cam triangle bolts and just use locktite?

Advice would be appreciated.

Graham

[Spider]

If the Cam has been ground correctly, it will only thrust towards the front of the block (water pump end) when running, so you really only need concern yourself with it in that position, however, if it hasn't been ground correctly then you'll probably need to add a shim between the sprocket and the cam.

To check if the cam has been ground correctly in regards to the above, measure for taper in the lobes, the oil pump end of the lobes should be about 0.002" bigger than the Sprocket end.

[Herbert]

I use rounded-off-head alan bolts with a star washer. 8-10 thou is all you need.
The heads being round will grind down if the cam gear moves. R

[Minigman]

Assuming it’s been ground ok (brand new Piper255).

I guess 7 thou will be enough when running?

It’s still tight and I assume heat won’t allow that much expansion to foul the bolt heads.

What’s your thoughts on running no washers and using locktite instead, as that would solve it completely?

[Minigman]

I use rounded-off-head alan bolts with a star washer. 8-10 thou is all you need.
The heads being round will grind down if the cam gear moves. R

That’s a great shout. Just ordered some.

Thank you.