Tappet clearance

[esper]

Originally Posted by zefarelly

CAT Cams profiles

os its not only their beer you like!!!!!! interesting posts on kent engines/ I am trying to figure out what I can learn for an FF engine ???????????

[phoenix]

Originally Posted by esper

interesting posts on kent engines/ I am trying to figure out what I can learn for an FF engine ???????????

I doubt anything new as the regs are well established and there is little you can do to change the valve timing or lift as that's not permitted!

[esper]

Originally Posted by phoenix

I doubt anything new as the regs are well established and there is little you can do to change the valve timing or lift as that's not permitted!

but 8000 revs is impressive!!!! would bang an ff engine.
but there are different standard camshafts. one is better than the other!
changing tappet clearing doesn't do a lot as mentioned before

[Dennis.Doyle]

FWIW:

Built mine on recipe to find a cheap way to get one that revved a bit for a 1600 class. Hence quite a few compromises in it. Took so long over it they changed the limit to up to 2 litres! Doh!

It's a twincam crank, or so the seller said, had an identifier on the casting, something like 3020 - can't quite remember. Looks a bit spindly to me.

Std xflow rods but topped & tailed, balanced & polished. Longer would have been nice, but rarely see them cheap. Again the FF engine builder I was talking to reckoned he'd not seen one break, at least not at silly revs.

83.5 twincam pistons - again, 'cos they used to be as cheap as Powermax, to lessen the load on the crank & 'cos I assumed the crank was designed with counterweights to suit those pistons.

Zero squish. Not good so I'm told, but there's only so much you can take off the bock & it's showing no signs of detonation.

[zefarelly]

I've built quite a few crossflow bottom ended precrossflows, you can't skim enough off the block to get good squish with pre crossflow flat top pistons, but MGB pistons fit and have a higher crown height . . . the exoensive alternative is posh long rods, but spending a frtune defeats the object of cheap power !

back on topic, a skimmed xflow block with skimed precrossflow head uses std precrossflow push rods and maintains rocker geometry so you can get . . .. . . .

wait for it . . . . . . . .


tappet clearance !

[trikesrule]

Dennis and Zef. To get squish we don't mill the block on our Holden engines, though we do run 20 thou above zero. We angle mill the head to obtain the squish we want. Then fit studs cause we were breaking bolts..........trikes

[Dennis.Doyle]

Originally Posted by zefarelly

I've built quite a few crossflow bottom ended precrossflows, you can't skim enough off the block to get good squish with pre crossflow flat top pistons, but MGB pistons fit and have a higher crown height . . . the exoensive alternative is posh long rods, but spending a frtune defeats the object of cheap power !

back on topic, a skimmed xflow block with skimed precrossflow head uses std precrossflow push rods and maintains rocker geometry so you can get . . .. . . .

wait for it . . . . . . . .


tappet clearance !

Ten out of ten for artistic interpretation of the rule that says we should stay on topic . My excuse for ot doing so is that the essence of the thread is trying to get something for almost nothing out of an xflow. So, how about an alternative recipe, this time for a cheapo steel bottom end? It involves:

Datsun L18 crank
Ford Mondeo 1800 Turbo Diesel rods
Alfa 145 . 155 . GTV . or Spider . 2.0i 16v twin spark pistons

This was used by a Classic Clubman’s racer. Quite obviously it departs from originality just a tad, but I think they accept it because it is in the spirit of the original 750MC regs, i.e. DIY with cheap off-the-shelf components for I.E.s.

BTW Boys & girls, I wouldn’t attempt that one at home & it’s not that cheap if you had to pay someone else to do it, but anyone who wants details PM me & I’ll pass on the link.

Re. Trikes suggestion: Sorry, I don’t understand angle milling the head since the xflow head is completely flat, barring the fact that the valves stand proud of it.

BTW I’d quite like to follow up the discussion on squish – I know I don’t understand it, but I feel what I’ve read so far isn’t very persuasive. How about on a different thread?

[zefarelly]

the Aussie guys use Datsun cranks . . .try finding one here, most Datsuns dissolved 20 years ago !

rods, good idea, but I bet Alfa pistons are more expensive than JE forged at the moment

re squish . . . very simply miniminse the gap betwixt piston and head so it all happens in the combustion chamber . . .I think