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2.0 l zetec with 10.9 CR?
02GF74 - 14/1/09 at 10:06 AM

I did the sums last night and fitting a cylinder head from a 1.6 l zetec onto a 2.0 l zetec raised the CR from 10.0 to 10.9.

Is this too high?

i.e. too high for engine running with say twin 40s or bike carbs and spraking via EDIS with a megajolt like controller and regular pumnp 95 octane 4 start petrol.

Can the ignition map for a standard 2.0 l be used?

Presumably an ignition map can be set so that pre-ignition (pinking) does not occur but will it be so retarded that it is detrimental to bhp?

AndyGT - 14/1/09 at 10:09 AM

MAY be OK with 98 octane rated fuel. But not 95 octane rated fuel.

tomgregory2000 - 14/1/09 at 10:24 AM

why do you want to put the head from a 1.6 on a 2L?
Tommy

cd.thomson - 14/1/09 at 10:26 AM

probably so he can raise the CR?

tomgregory2000 - 14/1/09 at 10:30 AM

quote:
Originally posted by cd.thomson
probably so he can raise the CR?


But also reduce the amount of air the head will flow therefore reducing power.
Thats how i see it but i could be wrong, but surely the 1.6L head has smaller valves to fit with the smaller pistons.
But please correct me if im wrong

[Edited on 14/1/09 by tomgregory2000]

AndyGT - 14/1/09 at 10:34 AM

tomgregory, you are probably right but can the head be flowed and bigger valves be fitted to make it breathe (better flow) better and still have the higher CR?

tomgregory2000 - 14/1/09 at 10:41 AM

but a decompression plate and a supercharger would be better use of time me thinks

Dusty - 14/1/09 at 11:01 AM

1.6 ports are tiny compared to the 2.0L. I also suspect your sums are wonky. CR would be much higher. Simpler just to mod a spare 2L head.

cd.thomson - 14/1/09 at 11:10 AM

quote:
Originally posted by tomgregory2000
but a decompression plate and a supercharger would be better use of time me thinks


Could not agree more

02GF74 - 14/1/09 at 11:33 AM

quote:
Originally posted by tomgregory2000
why do you want to put the head from a 1.6 on a 2L?
Tommy


oops - brain is not working - I meant 1.8 l head.

1.8 and 2.0 have same size valves.

zetec - 14/1/09 at 11:33 AM

Agree just skim the head...only slight issue with this is if you fit too high a lift cam you will have piston contact. Normal first stage is cam change with gas flowed head on standard CR with TBS, then moving onto pocketed pistons and even more lift on cam.

coozer - 14/1/09 at 12:18 PM

Combustion chamber sizes and shapes are different across the 1.6, 1.8, 2.0 range.
Be carefull there is no clash of pistons on head or valves on pistons.

martyn_16v - 14/1/09 at 08:41 PM

A CR of 10.9 isn't in itself a problem, VAG 16v engines tend to be around there as standard (9A engine is 10.8 for example).

paulf - 14/1/09 at 09:38 PM

The gasket sealing rings may be in the wrong area and there would be a step with a sharp edge between the head and block faces.I had considered doing the opposite with a 2.0 head on an 1800 to reduce compression for a turbo but decided against it for those reasons.
Paul.

scutter - 15/1/09 at 08:33 AM

As i've the same situation waiting to happen, I've ask on Turbosport to see what the response is.

ATB Dan.