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MG MGB GT V8 Factory Originals Technical - cb steering rack & rv8 exausts

I am in the process of collecting parts for a 1974 cb b roadster conversion to 4.6 litre rover v8. My questions concern the use of rv8 style headers and the steering rack.

Are the "normal" (other than smaller universal joint) modifications to the cb steering rack neccessary if the rv8 headers are used?

Are there any stainless steel 2pc rv8 style header suppliers in the U.S.

Any help would greatly be appreciated.

mick mckelvey

1.Dont go to 4.6 the 3.9 is a better engine and revs far better.
2. The RV8 headers are well clear of the steering column on my ex FL Roadster.
robert pulleyblank


I am in the same situation as Mick but using a 3.5 with Weber/Edlebrock in a 73GT cb with Towerey AC engine mounts.
If I stay with the cb crossmember & steering column and use RV8 headers:
1. Will I have air filter clearance problems?
2. Is the only modification to the engine bay and steering to cut holes in the inner fenders for the exhaust exit?

My alternative is to use "block hugger" headers change to rb crossmember/steering column/rack/lowered springs/dish the inner fenders.
This should at least give me bonnet clearance.

The first method seems a lot less work.

Regarding Mick's comment on Stainless steel headers, I would suggest Jet Hot coating on mild steel. The finish looks good an helps in preventing radiated heat from the system into the engine compartement. Any comments?

Andrew Worman

Andrew, by Weber I guess you must mean the carb that Edelbrock supplies. I can only comment on my cars fitted with Edelbrocks and Holleys.
1. If you use the K&N lowrider - or equivalent 14 inch x 2 inch filter assy, all you need to do is cut out the centre bracing strap that runs across the underside of the bonnet (hood).
2. If you use a lowrider with deeper filter - which I have done on my roadster you will need a bulge in the bonnet.
Another tip worth considering is to modify the engine mount brackets so that the sump(oil pan sits as low as possible giving you max clearance above the carb.
3. If your carb has a choke assy - delete it. Have the horn of the carb milled off to provide better airflow into the throat.
4. Fit a higher pressure fuel pump and a regulator if necessary - to give 7 lbs/sqinch - unless you use SUs when you should just convert to an electronic SU or other pump.
5. Dont use Block hugger headers, they are too small in dia on the primaries and leave the port at too sharp an angle. Spend the money and get about 12 hp with the RV8s. I suspect Moss has them or Glen Towery.
6 You dont need any mods to the engine bay with the RV8 headers except for the holes. I had some special stainless baffles made which can bolt around the down pipes and prevent the ingress of crap in winter. See for a picture. Ive never used them as Im only home in the UK in Summer. You may well want them in Canada!!
7. The car will run cool when on the move but if stuck at traffic lights will warm up. I have vents in the bonnet to help that a little. Some people also suggest retaining a mechanical fan on the engine. Another tip is, if you fit an oil cooler below th front flat part of the nose - space it down with rubber mounts so that it doesnt impede airflow to the rad.
8. Use a late model MGB Radiator as it is the same capaity as the V8 one..

That ought to give you something to think about eh!
robert pulleyblank

I am converting a 70B roadster and have just bought an Edelbrock 500CFM with low rider and also have the RV8 stainless exhausts. Are you saying that if you take out the bonnet crossmember that you can keep the chrome bumper cross member and steering rack??? I assume that I'll need the smaller uni joint anyway. Regards,


This thread was discussed between 10/10/2000 and 15/10/2000

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