A VX cylinder head on a standard 2000cc engine block , pistons etc

[monte]

Hi, Evening all , I am new on here , this is indeed a great resourse for beta fans .  I would be very interested to hear an comments in relation to clearance issues when fiting a VX cylinder head to a standard 2000cc engine . the engine is a carb version , not fuel injection ( as fitted to the later betas) . My concern is prompted by the fact that the compression ratio on the Vx is lower , how is this done , by a greater volume in the cylinder head ? or I would think more likely a "shorter" piston ? which will also allow extra clearance for the valves. My question is ;  will the larger valves in the VX head make contact with the standard beta pistons , or is the difference so small that ther is no clearance issue 

[rossocorsa]

wasn't a similar head used on the fiat ritmo/strada 130tc and that's high compression?
you'd need to use standard cams of course not the vx ones. It might be worth posting this on guy crofts   forum for a definitive answer

[hutch6610]

The compression ratio was lowered on the VX by using a different piston with a larger dish cast/machined into the crown bringing it down to 7.5:1.
Guys claimed (past tense) the head also has a larger volume but when i checked my VX head with a standard IE example they were pretty much the same - what with skimming etc etc.

Valve clearance will be fine - although Guy will tell you to make double sure.
Funny - Guys book claims the VX has standard diameter 41 mm valves as opposed to 43.5mm the VX/105/130 TC should have but i suppose it could be a mistake, like the 45 DCOE float levels!

I have fitted large valve heads from 105/130 TC as rossocorsa just mentioned and used standard gaskets (carb) which are thinner than the later gasket and had no clearance issues with quite a few early Betas.

One head was fitted to my own personal car a 1982 2000cc Trevi retrofitted with fuel injection and it sure made a difference.

And again as rossocorsa has quite rightly pointed out you will have to use your cams + your cam boxes.
The manifold stud pattern is different on the inlet side but don't worry if you look closely you will see an extra threaded hole cam end of the head so your manifold will fit.

 

[monte]

Hi, thanks for your quick response, I should have said the head is already built using standard cams and cam boxes, its going on a montecarlo which still has its existing head in place , this clearance issue came to mind, lets say as an after thought  . Your responses are reassuring , but maybe I should do a test build using plastacine , just to be sure . Thanks again for your comments. I will let you know how it goes.

[markwast]

hi monte, so how did this conversion go?
having read the thread, thought id ask how the valve clearances get on with the pistons?

[betaveloce]

I'm curious as well, as I have a revised VX cylinder head I was thinking of using on my HPE i.e. (off course with the i.e. cams as mentioned above)