4 replies to this topic

[Bruiser]

Hi, lads - would anyone happen to know if 1.7's will hit the edge of the bore without the ground reliefs if I pull a spring? Open chamber head, 52cc, I want to a bit bigger in lift and can't tell how much has been taken off the head. Can this be figured out with head on motor? Going to pull a spring and measure up, check how much lift i could get away with, figure out what the springs are and the coilbind bizzo all at the same time. Just need to know if that click will be the block or the piston.

Cheers, bruce

[I'm a Red Motor fiend]

This is mine when checked. 1.68 valve checked before the bores were relieved.
Open chamber head with over 100thou taken off (around 45cc)
600 thou lift. They won't hit the slugs and you will just sneak them in I think.
100% still pull a spring and check.

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[Bruiser]

Hey, that looks pretty close! Would all low comp open chamber head chambers be the same? I'm not chasing THAT much lift. Was only considering around 0.530"ish, and mine may not be as skimmed as yours. How easy do you find it to get away with - reliability wise? Have read the stories here about your motor. Pretty serious sort of thing it looks like. Is it the one with that 9/12 port tony knight head? Street car, or racing? How long between valvetrain rebuilds with cam (and springs to match) of that size? Thanks for the pic
Cheers
B

[I'm a Red Motor fiend]

The same yes but all would no doubt vary slightly.
Your head wouldn't be skimmed as much if your still at 52cc. I can't skim mine anymore, it's getting too thin.
Mine is a serious 9 port that Tony did but not on the level as some of the 9 ports he has done.
Reliability? Don't know, I've still only done probably 1000ks at best and only on the street thus far.
I use it so little it will be years before I think about new cam and lifters.
I'm still f*ck assing around with the SU needles and am about to switch to a locked dizzy.

[Bruiser]

All good fun, innit? Best of luck with your needles mate. Cheers