Hi all,

Im using a 1.8 zetec head which is not skimmed, 2ltr block with standard pistons and a standard 2ltr motorcraft head gasket and weber alpha 45mm throttle bodies. the engine is built and running in the car! Problem is, its over fueling on a standard 2.0ltr map which im told is going to happen due to higher the C Ratio.

Does any one have the volumes of these to hand or know where i could get them from.

Thanks in advance.

John T

 

I think someone has lead you up the garden path.

What you need is it to be properly mapped for YOUR spec. Also, it'll be a pain to map as those throttle bodies are faaaaaaar too large for the spec you mention above. You'll only have to map about the first 25% of throttle opening and that'll be it!

 

CR has very little effect on the fuelling really.

Someone has been talking horseshit to you IMHO

 

Ive got cams and ported head on it also but didn't think that would matter.

I need to get it running in a drivable manner as I live in Jersey Channel islands and need to drive it to the rollers on the mainland. I want to get a chip made up for me and sent over so I was thinking If i new the CR it would help them with creating the basic map.

 

Ported head, TBs and Cams, all effect the fuelling FAR more than the CR does IMHO

All 4 of those will effect timign though, and in this case the CR is the key factor

 

PS what management are you on?

 

Im using weber alpha.

Just thought im using a map created for this set up but with 1.8 bottom end so really all ive done is increase the cc and cr

 

When you say for that setup, you mean designed for the headwork you have etc?

 

Anyway, bottom line is, take it to someone to get it mapped, dont bother guessing at more basemaps

 

thats correct.

oh and it will cost Ł700 extra sheets to get a trailor onto the boat to get it to the rollers. so a couple of base maps sent over to me seems a better option.

 

Aside from the other excellent advice you've been given, as the 1.8 and 2.0 have the same CR when standard, at 10:1, its easy to just back calculate the combustion volume. Although there will be a slight error due to the piston dishing, to all intents and purposes, a 1.8 on a 2.0 gives a CR of 11:1.

As has been said, that won't really effect the fuelling MAP, but check for the spark being a bit too far advanced under load.