Topic: 16hp Vanny Head Shave

[1989marathon]

Can a 16hp Vanny V-twin(horizontal shaft) head be shaved to increase the compression without the piston hitting the spark plug? I am using thin copper gaskets.

[lawncheif]

Yes

[leadslead]

Copper head gasket adds about .015 I think stick is .015 copper is .030???

[1989marathon]

My copper gaskets are much thinner than the stock graphoil gaskets. I think they might be copper coated steel gaskets. If I install a plug in the head(on the bench) and place a straight edge across the head mounting surface, the tip of the plug(autolite 3926) is about .015" from the straight edge. Maybe someone has already cut these heads?

[PJG56]

There are a lot of factors involved here,deck(+-) height,head gasket thickness,etc.buy some indexing washers,index electrode towards ex.valve,I like mine .060 -.080 from top of piston(plus)P.S. never built a vanny,but rules apply to all.

[1989marathon]

I believe my piston comes to the top of the deck, or very close. Since the piston is dished, there is a little clearance for the plug tip.
Here is a pic of what I am talking about with the plug.

[pullingman]

I have taken off .060 from the head on the 16's and had no clearance problem.  That is using the thin metal head casket too.  That is also if you are using stock length rods and stock pistons that have not been machined.

[EUBANK RACING]

how much can you take off a 28 ohv non avs head with stock rod length and piston

[Ron Atchison/A.C.E. Race Engines]

how much can you take off a 28 ohv non avs head with stock rod length and piston

this is a toally different subject but, it doesn't matter what length rod or piston,  cut them to around 38cc's. that's usually somewhere between  .120-.180. 

[rotten ron]

If the spark plug is too close mark the piston and grind a bit of a relief in it,some car pistons have notches for spark plugs