Engine re-build...the joy!

That's OK then Now you can see ,could you please measure your crank and main bearing diameter .

Will do, but I can guaruntee there wont be anything 19mm.....the big ends are bigger and the mains are massive by comparison. As I recall the atmo big ends that Meca sent were substantially smaller.....but I cant see you have an atmo crank fitted

Don't know what the 19 mil bit is Can't think of anything else that could get in there The big ends are 16 mm width they cant be any bigger there's no room, I've got two sets off 6&3 sitting on my desk

Oh no...I see what you mean....I will measure the mains for you tommorrow! If its mains thats very bad...your block and crank could be f!*ked!

I don't think it's mains ,but I can't be sure .
The mains I have are for a Pug 505 2.8i V6 ,engine code ZN3J .Are we certain all prv cranks are the same as far as mains go

Mains are definitely 23mm...measured one tonight. Will measure big ends for you soon.....but 19mm sounds too big. Get it pulled to bits and see what it is!

ALL mains on ALL PRVs are the same. And I've built odd-fire engines using even-fire blocks, so I's be knowing this for a fact.

In fact my #2 DeLorean, now with its new owner, has a late Volvo B280E block with larger oil pump and cross bolted journals. It's still a K-Jet boggo odd-fire in that car though.

The big ends on the even fire engines are larger than on the odd fire which makes sense when you think about the strength compromise in the split crankpin.

Cams are on their way back. They have ground them to F421 spec....which is 240 degrees duration and 0.85mm extra lift. Sounds great.....but Ive no idea how much of a difference it will make

Thats 1.2mm lift at the valve extra...all helps..

No, thats already done.....its 0.85mm at the valve, which isnt a great deal really, but it should help!

You sure?, cam regrinders normally quote lift at the lobe..

If its 0.85 at the valve then its about 0.62mm at the cam..

He told me he had increased the lift by some amount or other at the cam which equated to 0.85 at the valve. Dont ask me!!!!

What is the standard lift? Surely a rough order of magnitude calculation will give an estimate of increased air flow by a similair percentage.

What is the standard lift? Surely a rough order of magnitude calculation will give an estimate of increased air flow by a similair percentage.

Did you just swallow a tech spec

What is the standard lift? Surely a rough order of magnitude calculation will give an estimate of increased air flow by a similair percentage.

6.8mm at the valve

You can work it out on a calulator I wrote.

www.alpinerenaulttuning.co.uk/valves.xls