how do you tell the difference between a f7p and f7r lump?

[ashdadrummer]

Just bought a new mk1 valver and I want to put a new set of pistons in as it has low comp ones at the moment.
Im not sure if its had a f7r engine fitted though.
the engine codes been removed from the inlet so no luck there.
theres no oil cooler or holes where it would have been but could the plate have been changed?
is there anyway of checking what I have before ripping it to pieces?

 

[stan*]

Check the back of the block, where the starter is, are there gussets cast into the block?

Less definative indicators:
f7r dipstick has a white dot on the top
f7r has a smaller starter
f7p has a higher rev limit
f7p has an 82.00mm bore

these are all assuming the engine is standard and untouched.

The best way would be to measure the stroke, 83.50mm for f7p, 93.00mm for f7r.

 

[ashdadrummer]

ok thanks, ill have a look in a bit.
its chipped so the rev limits up to 7500, so thats no good.
would amagine the gussets would still be there and the smaller and dipstick should tell me.
thanks

 

[Oliver_K4M]

Best indicator, the F7R-lump has casted bulges for the con-rods due to bigger stroke. So if you want to make a valver-lump a F7R you have to machine it in order tu get enough clearance.

 

[ashdadrummer]

that should help!
Cant see the starter because of the heatshield and I wasnt putting my hand anywhere near the manifold at that point.
the dipstick has a black splodge on it.
Ill check the block In a bit. that should tell me for definate what it is.
theres nothing in the service history about it being bored out just low compression pistons, forged rods etc etc

 

[Oliver_K4M]

If you follow this link you will find two photos that show very good the differences:


http://faq.clio-forum.com/index.php?action=artikel&cat=1&id=41&artlang=de

 

[frediiii]

best way is to measure the stroke. as oliver said, if you machine the f7p internals, it's also possible to fit a F7R crank. so from the block alone you will never know for sure.

just take out a sparkplug, put a long rod in, crank to highest position, mark it on the rod, crank to lowest position and mark again. measure between the marks. 93mm = F7R, 83.5 = F7P

 

[ashdadrummer]

thanks alot guys, those pics are a good help (I couldnt find anything that really showed it) I will have a look tomorow and measure the stroke aswell just for good measure.
thanks alot guys