Hi all.

in a cosworth engine (4x4) that has montune cams (mt30 exhaust and mtpl9 inlet) and isky valve springs, is it necessary to machine the head for the spring seat and if so by how much?

It is impossible to check the clearance with the cam and tappet installed.

any help greatly apreciated.

Thanks

 

Hi,
You can check clearance spring.
If your head is of (complete, with camshaft fitted), install a 1.5 mm jauge between lifter and one inlet cam (in ex), and turn carefully inlet cameshaft with 24 mm. tool. If camshaft "block" , your spring clearance is to short. If camshaft pass, clearance is 1.5 mm. minimum and is OK.

If your head is on, same process, without timing belt, and with all pistons on middle of stroke.

Claude.

 

Thank you very much for the advice.

So to clarify: you put a 1.5mm feeler guage between the cam and tappet and turn over, and if it clears its fine.

Cheers: Bart