M30B34 block and B35 head?
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winx
- E30 Zone Camper
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Will there be any issues if I use a B34 block and B35 head?
Last edited by winx on Thu Apr 02, 2009 10:31 pm, edited 1 time in total.
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Speedtouch
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Issues are problems, aren't they? 
///M aurice
ECU Upgrade EPROM Chips, £40 posted within the UK. Note these are not Zone chips.
viewtopic.php?f=6&t=279421
ECU Upgrade EPROM Chips, £40 posted within the UK. Note these are not Zone chips.
viewtopic.php?f=6&t=279421
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winx
- E30 Zone Camper
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er, well, er typed that a little quickly and didnt read it back 
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Theo
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I think the exhaust side engine mount is different, or rather the holes in the block for the engine mount to bolt to are not in the same position.
Other than that not sure what problems there would be. They both use the same headgasket so it should work..?
Other than that not sure what problems there would be. They both use the same headgasket so it should work..?
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winx
- E30 Zone Camper
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From what I can glean from mye28.com a b35 head will fit onto a b34 bottom end fine.
I could swap the b35 pistons into the b34 bottom end and keep the correct compression ratio. Or if I kept the b34 pistons the cr would be better for Forced Induction (which I plan to do within a year)
Not sure about the engine mount issue, will try and have a look tomorrow...
I could swap the b35 pistons into the b34 bottom end and keep the correct compression ratio. Or if I kept the b34 pistons the cr would be better for Forced Induction (which I plan to do within a year)
Not sure about the engine mount issue, will try and have a look tomorrow...
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Jonah
- E30 Zone Newbie
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m30b34s and b35s have different pistons and combustion chamber shapes - b34s have 58cc combustion chambers and b35s 65cc, so fitting a b35 head on a b34 block will indeed drop the compression.
Whilst this may be ideal for forced induction in the US where the cat equipped m30b34 has 8:1 compression ratio, the UK spec 'dirty' m30b34 has 10:1 compression, so fitting a b35 head onto a UK b34 block will probably give a compression ratio similar to a standard m30b35 (9:1) so you won't gain anything, and you will have mismatched piston and combustion chamber shapes into the bargain.
Whilst this may be ideal for forced induction in the US where the cat equipped m30b34 has 8:1 compression ratio, the UK spec 'dirty' m30b34 has 10:1 compression, so fitting a b35 head onto a UK b34 block will probably give a compression ratio similar to a standard m30b35 (9:1) so you won't gain anything, and you will have mismatched piston and combustion chamber shapes into the bargain.