Skimming head

[DaviesDJ]

Hi guys

4.7 rebuild now going great guns - have extensively de-shrouded the enlarged intakes - which has taken the CR down a little bit.

I am keen for compression on this build as it has a custom cam with more overlap.

So - standard 40thou skim was the plan - but out of curiosity how much can be skimmed in you guys experience before you get bolt fitting issues?? Timing cover and injector issues??

Best wishes

Dave

[ukkid35]

First head skim I had was less than 40, but I still felt it was pretty brutal.

Both timing cover bolts and injector fitting was badly affected.

I now have to loosen the intake manifolds to fit the injector rail, and it's still difficult.

[DaviesDJ]

Useful info!

[DaviesDJ]

You all may be horrified - but I think a smaller o-ring may be useful on the manifold to injector. As a pressure seal isn’t really required here - just enough to prevent a significant vacuum leak

[ukkid35]

Agreed, and on a 4.5 the injectors are above the butterflies so vacuum leaks are irrelevant

However I use the same top and bottom, never had a fuel leak

Nitrile 70 Rubber O-Rings 3.5mm Diameter C/S Sizes 7mm ID

What sizes are you proposing?

[DaviesDJ]

Not entirely sure - but would simply size up a thinner o ring or even a Teflon seal to sit the injectors in