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88mm pistons - should that be with 88mm or 90mm stroke crank?

4K views 52 replies 10 participants last post by  PhilM 
#1 ·
Obviously the 90mm with give max capacity but will making the engine have a longer stroke than bore cause problems at higher revs?

Does anyone have any recommendations in this area?

Cheers, Jon
 
#30 ·
With one off pistons though? The gudgeon pin would have to be 8.6mm closer to the piston crown...

Steel rods too, it's an expensive old project still!! lol..

Personally I wouldn't bother stroking the XE either, not really worth it, I'd rather have something that revved a bit easier..
 
#35 ·
ever driven one? they bloody do!! you dont spend 2k on the crank, rods and pistons and run a 7kg fly and 5kg clutch!!!
driven a 90mm stroker on 86s and that setup revved like a bike, hits 10k too
also my mates stroked flat 4 in his spyder is a hotrod special, again revs better than mine lmao
drive a couple then get back to me mate ;) its one big myth.

if you are that fussed kiddie also does the touring car spec cranks and thats restricted to 86mm
 
#41 ·
16vastra said:
you have your opinion thats cool, i will have the facts ;) :p
largest available pistons for the xe are 88mm i believe, wouldnt like to go much larger or theres little point in having a 4 pots lol
pmsl :p lmao whatever, *clicks fingers several times in random places*

QED's ally block get's taken out to 94mm bore, never actually seen how they achieved that with the same bore spacing, but they don't use a re-cast head as far as I'm aware, so it must be the same spacing.
 
#44 ·
why do people say strokers dont rev? they bloody do!
They can me made to rev. However, reciprocating loads go up with stroke and piston speeds also. So wear rates and stress levels all rise. For the effort involved you only get a 10% increase in capacity with no more valve area. My opinion is that it's not worth the effort. It's better to stick to tried and tested XE tuning. It's cost effective and reliable.
 
#45 ·
yawn
tried and tested?? thats exactly what i am saying they are!!
10k limits, fine. 2 days nonstop racemeets, fine. more stress than you ever get on the road.
i guess you are looking at an all round package, which unless you show the readies this aint i imagine, hence the 'strokers dont rev' bollox
use a proper fly, clutch, box etc and you are laughing past the opposition ;)
 
#46 ·
As I say, each to their own, but in my opinion, stroking doesn't make a difference that is worth doing, or that I would enjoy on an XE.

At the end of the day if someone wants to do it, QED, 94mm crank, and rods, and you have yourself a stroked motor, or do as Steveboyslim has suggested.

PERSONALLY I don't like stroked engines that are undersquare. I beleive undersquare engines do not rev as nicely. I'd much rather have a larger bore and shorter stroke.
 
#48 ·
This QED alloy block seems to be a bit of an urban myth. I rang up about 4 years ago to enquire about it, they reckoned 3 years before it was available and they told me the same thing about 1 year ago.

Generally, there seem to be so many ways to do things and overall people have stuck to the tried and tested. Does anyone here actually have an XE with a 94mm stroke that they can comment on - if not, why not? Is it just down to cost?
 
#49 ·
The engines with the 94.6 stroke do rev, you can use short compression height pistons and standard rod length but it is very tight.
The short rod version had a bad vibration.
The tall block(standard) version was better, with 2.2 length steel rods.
You can get the dry sump system to fit.
The QED alloy block does exist Millington Engines is now assisting with the project they cost about £4000.
I am told it has siamesed bores to enable bigger bores.
DK do make different stroke XE cranks, if you order one do not forget to tell them what crank sensor you will use ie standard type or external as their 'off the shelf' crank is designed to run with an external sensor.

Steve
 
#50 ·
Cheers for the info Steve.

DK did ask about the sensor when I enquired.

Siamese bores - sounds very interesting! The price seems to have gone up 1K :)

Who would make or supply short compression height pistons?

I'm not keen on using a tall block setup because of the height awkwardness and apparent lack of availability (and cheapness) compared to the 20XE block.

It probably hangs on how much it is to obtain the short compression height pistons.
 
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