M42 BBTB - the boring details!
Moderator: martauto
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cheesebox
- E30 Zone Regular
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- Joined: Sat Jun 11, 2005 11:00 pm
- Location: Buxton, Derbyshire
Can anyone advise how far the M42 throttle body bores can safely be enlarged, and whether there's any stock butterfly valves which can be fitted after machining?
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cheesebox
- E30 Zone Regular
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- Joined: Sat Jun 11, 2005 11:00 pm
- Location: Buxton, Derbyshire
What I'm really asking here is if someone could tell me the internal diameter of the bores of a 318 big bore throttle body.
(I wasn't planning to start a production line or steal business from the guys who do this as a sideline - I just wanted to have a go at doing this upgrade on my own 318is - I have access to a lathe and a handy dad!).
(I wasn't planning to start a production line or steal business from the guys who do this as a sideline - I just wanted to have a go at doing this upgrade on my own 318is - I have access to a lathe and a handy dad!).
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Omi
- Witty custom rank.
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- Location: Darlington, North East
4mm is the overbore... - Easy enough to make the butterfly with a circle of copper providing you machine the edges correctly for a snug fit on closed throttle.
...or is it?
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cheesebox
- E30 Zone Regular
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- Joined: Sat Jun 11, 2005 11:00 pm
- Location: Buxton, Derbyshire
Thanks for sharing the knowledge Omi!