I now have the m20b25 out of the car and on the engine stand etc.
+
Non stretch head bolts
Tubular manifold
I plan to use a holset H1c and megasquirt.
Just a few questions for the peeps in the know.
1 The motor has done 160k and probably requires a rebuild, where is the best place to source parts, what should be replaced/refurbed (in your opinion) and do any of the internals need upgrading.(aim of 1 BAR boost)?
2 I also want to limit head gasket failures, which HG should i go for (company etc)?
3 Im aware every one uses volvo intercoolers, are they recommended and do you think they can stand up to track abuse.?
4 Rad upgrade ?
5 Also with engine box now split, should i have the fly wheel lightened (as it seems v v heavy) and if so how much?
When finished the car will be used primarily for trackdays and the odd trip to the ring,
Thank you for your time
Turbo engine spec
Moderator: martauto
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oldroydsr4
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Last edited by oldroydsr4 on Thu Jan 04, 2007 1:32 pm, edited 1 time in total.
i'll try to answer a few questions, though i'm a novice
going backwards...
Rad should be fine as far as i'm aware, i haven't read of anyone changing them.
The Volvo intercoolers should work fine, i guess they have their limits but a 2.5 running a bar should be within them.
Cometic make very good quality gaskets but are certainly not cheap.. I'd be tempted to simply renew yours with an original BMW one and see how it goes, although i'm not 100% if this will be enough running a bar.. someone will know though!
As for your engine.. to be honest unless your not too fussed about spending some good money i'd look around for a lower mileage engine and buy that rather than a rebuild. Personally i'm sticking with my 132k lump, aware that it may go pop but am happy to replace it if it does, providing you don't mind hauling engines about you could just go for it with your current engine. Mine is only a 2.0 however, i'd of expected a 325 to of had a slightly tougher life.
Rad should be fine as far as i'm aware, i haven't read of anyone changing them.
The Volvo intercoolers should work fine, i guess they have their limits but a 2.5 running a bar should be within them.
Cometic make very good quality gaskets but are certainly not cheap.. I'd be tempted to simply renew yours with an original BMW one and see how it goes, although i'm not 100% if this will be enough running a bar.. someone will know though!
As for your engine.. to be honest unless your not too fussed about spending some good money i'd look around for a lower mileage engine and buy that rather than a rebuild. Personally i'm sticking with my 132k lump, aware that it may go pop but am happy to replace it if it does, providing you don't mind hauling engines about you could just go for it with your current engine. Mine is only a 2.0 however, i'd of expected a 325 to of had a slightly tougher life.
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oldroydsr4
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My main aim when complete is as good reliability as possible, trackdays and the ring are no fun if your car is breaking down/ blowing up etc, So i would prefer to rebuid the engine.
Also i would know what the engine has done.
Thanks for your help
Also i would know what the engine has done.
Thanks for your help
uprated head bolts, stock gasket and welded water channels should see no issues at 1 bar, some are running much more. Bottom end could use some better bolts too but then again a 2nd hand bottom end every six months won't cost much anyway.
Rad - stock, no issues there
Clutch - poss upgrade but no-ones bothered so far
Diff - a good condition stock LSD should last, the M3 diffs are being used with silly power and no issues.
Gearbox - typical BMW over engineering should mean it'll hang in there till you get upto silly power.
HTH, Mark.
Rad - stock, no issues there
Clutch - poss upgrade but no-ones bothered so far
Diff - a good condition stock LSD should last, the M3 diffs are being used with silly power and no issues.
Gearbox - typical BMW over engineering should mean it'll hang in there till you get upto silly power.
HTH, Mark.
Im selling my engine and ledburys not far PM me, built by QEP, forged low CR pistons, orings etc all the stuff with full rebuild, PM me for full spec its still in shop waiting for payment, whole projects up for sale as I need money for property fast or im stuck renting 
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oldroydsr4
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Hi Will
Interested in your engine, however will have to get ful spec and price
Many thanks
Interested in your engine, however will have to get ful spec and price
Many thanks
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Turbo-Brown
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Ooh, Matt at QEP sort you out with the forgies Will?
Got any details on them?
Got any details on them?

