Re: SU'S help

[Nicholas Abraham]

Adam, SU's are a British automotive institution, like MG, Triumph, Austin-Healy etc.. They are sized imperially (in inches), so you may be talking about 1 3/4 inch SU's.   As you know air is drawn into the engine through the carburettor, where it is mixed with fuel. There are 5 or 6 main parts along this intake path. 1. Air filter housing 2. Carburettor 3. Carburettor gasket/insulator 4. Manifold 5. Manifold gasket 6. Head   When you 'match' port your carbies you make sure that all the above pieces have the same diameters and that there are no steps or impediments to airflow. For instance, your head port will be about 1 inch in diameter (?), but the SSS manifold has 1.5 inch runners. You will have to grind out the head port to 1.5 inches so that there is no step.   It is fairly easy to do this yourself.   If you are really keen you dowel the head and manifold so that they are guaranteed to bolt together without any step or mismatch.   The only problem with 1 3/4 SU's is that the SSS manifold is made for 1 1/2 inch SU's, so you will need an adapter or something.   Regards, Nick 1978 Datsun Stanza L20B with twin 1-3/4 SU's         I was thinking of getting a set of 45mm SU'S on an L18SSS matched ported manifold for my L20 and someone told me that I should do the porting and matching the manifold before fitting the carbs. What exactly does this mean as I am only a beginner and dont know much about working/modifing engines. Any help would be great. Thanks --membersozdat------------------------------------------------------- OZDAT Mailing List Please Note:- Send (un)subscribe requests to [EMAIL PROTECTED] Send submissions to [EMAIL PROTECTED] No unauthorised redistribution of this email http://www.ozdat.com/ozdatonline/index.htm http://www.ozdat.com/ozdatonline/listindex.html http://www.mail-archive.com/membersozdat@datascribe.com.au/ ---------------------------------------------------------------------