coozer
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| posted on 21/2/08 at 06:38 PM |
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Zetec Turbo comp ratio
Following my decision to build a zetec turbo over the coming years the subject of compression ratio has raised a little thought with me.
To upgrade a 1.8 with 2.0 cams its recommended to swap the cams and not the heads because a 2.0 head on a 1.8 block results in a low compression ratio
due to combustion chamber shape.
Would that not be ideal for a turbo set up? or as usual am I way off the mark?
Steve
1972 V8 Jago
1980 Z750
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Volvorsport
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| posted on 21/2/08 at 07:07 PM |
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forged rods , 8.2:1 CR with custom pistons to get the squish right , with enough boost you should be looking on the good side of 450 bhp .
so yes , a lower CR is ideal .
www.dbsmotorsport.co.uk
getting dirty under a bus
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coozer
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| posted on 21/2/08 at 08:04 PM |
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quote:
Originally posted by Volvorsport
forged rods , 8.2:1 CR with custom pistons to get the squish right , with enough boost you should be looking on the good side of 450 bhp .
so yes , a lower CR is ideal .
I know the lower cr is ideal but I'm skint! I want to build a engine on a budget.
I was thinking along the line of Vauxhaull turbo pistons that will bring it down to 8.5:1 I don't mind spending a few hundered on that but
forged rods! Don't want to spend thousands!! I'm tighter than a 18" corset!!
Was wondering how low the cr will be with a 2L head on a 1.8 block....
Thanks,
Steve
1972 V8 Jago
1980 Z750
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paulf
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| posted on 21/2/08 at 08:56 PM |
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I have been thinking of the same thing recently , i would like a turbo engine but dont like the idea of spacer plate and 2 gaskets etc. I think the
comp ratio would be about right but the 2.0 has a bigger bore which would leave a step at the top of the bore in the combustion chamber, which i
think would cause a problem, the gasket may also not line up but not sure about that.
I have been tempted to skim the pistons on the 1800 by a couple of mm but this would weaken them and upset the squish band.
Only other option is a change of pistons or shorter rods.
The other idea i had was to keep the comp standard and run a lower max boost or use water injection.
Paul.
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Volvorsport
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| posted on 21/2/08 at 11:37 PM |
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£200 for a set of rods .
from usa admittedly , but you get the idea .
www.dbsmotorsport.co.uk
getting dirty under a bus
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chunkytfg
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| posted on 21/2/08 at 11:59 PM |
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quote:
Originally posted by Volvorsport
£200 for a set of rods .
from usa admittedly , but you get the idea .
Jeez Forged rods for cars must be well cheap!!!
I not long ago paid £320 for a pair of carillo's for my race bike
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Volvorsport
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| posted on 22/2/08 at 12:23 AM |
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they are , if you have the contacts .
www.dbsmotorsport.co.uk
getting dirty under a bus
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