So as the project continues on more questions have arose, at the mo i'm stripping down a head to replace valves (or at least check) valve springs and possiably the cam. Does any one have any recomendations???
What springs should i replace them with, is a new cam nessisary also is there anything else i should think of when i have it in bits?? The head has been cleaned checked and skimmed and i'm planning on using a holset turbo with uprated injectors and de comp gasket plus uprated head bolts???!
Any advise will be greatly appriciated.
Thanks
Peter
Upgrading the old M40 to take a turbo
Moderator: martauto
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e30_Turbo
- Boost Junkie
- Posts: 3158
- Joined: Mon Jan 10, 2005 11:00 pm
- Location: East Anglia
Malcom and Chris P are the peeps to ask, Malcs was less engine work IIRC and Chris P ended with a rebuilt head in the end. Can't say I can remember exactley who had what but I don't think either had much work done, more getting the stock equipment back into top shape.
Stock cam will surfice, stay off wild cams with turbo's, maybe a set of pistons to lower the CR a bit, the head bolts I may be able to get for you through a engineering company I work but will need to do some checking on that for you.
Not sure what size injectors to get, I use 440cc/min and that's good for 80bhp per cylinder @ 3bar, so they'll do 320bhp on a 4 pot.
What Holset are you using? Please don't say you're gonna use Sean's old one? It's FAR too big, you need a HX27..... I know a man with one of them for sale too
What manifold are you using?
HTH, Mark.
Stock cam will surfice, stay off wild cams with turbo's, maybe a set of pistons to lower the CR a bit, the head bolts I may be able to get for you through a engineering company I work but will need to do some checking on that for you.
Not sure what size injectors to get, I use 440cc/min and that's good for 80bhp per cylinder @ 3bar, so they'll do 320bhp on a 4 pot.
What Holset are you using? Please don't say you're gonna use Sean's old one? It's FAR too big, you need a HX27..... I know a man with one of them for sale too
What manifold are you using?
HTH, Mark.
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FIREBREATHER60
- E30 Zone Newbie

- Posts: 147
- Joined: Tue Apr 03, 2007 11:00 pm
Ha well its a holset wh1c got it off rossle just finished a compleat rebuild on it so its in tip top condition, hopefully i will speak to ant about manifold, the head that i have is in great shape and the cam looks good too, at the moment i'm stripping it all compleatly down and checking all parts for wear.
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CHRISP
- Boost Junkie
- Posts: 714
- Joined: Thu Aug 18, 2005 11:00 pm
- Location: Wellington somerset

