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billjam billjam is offline
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Join Date: Aug 2007
Location: Perth, Western Australia
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Quote:
Originally Posted by JFairman View Post
I don't think building them up with Devcon or JB weld epoxy and hogging them out would last long.
I tend to agree, that's why I'm nervous about this approach.
The other issue is if I go for the max port size, there's no turning back once I've ported the manifold and heads.

Quote:
Originally Posted by JFairman View Post
They used small ports on the 930 to speed up intake velocity at lower speeds.
That improves low speed driving, makes a smoother idle and keeps CIS fuel spray from the injectors atomized better.
Hydrocarbon and CO Emisions are probably lower because of this.
I figured there had so be some sound engineering reason behind the small port size - damn it - don't you just hate those Germans!!

It would be interesting to hear from anyone who has gone with larger ports to see if they have noticed any adverse affect on driveability. Considering that this is what I'm trying to improve, Mr Fairman may just have tipped the proverbial bucket of cold water on this subject if he is correct.

As far as HC and CO emissions are concerned, in Western Australia they are an environmental issue only. We don't have to worry about smog tests.
Old 07-03-2008, 03:23 PM
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