Welcome to our Site for MG, Triumph and Austin-Healey Car Information.
MG MGB GT V8 Factory Originals Technical - Former Vitesse 3.5, 9.75 CR
I recently bought a 3.5, 9.75CR Rover SD1 Vitesse engine. It has only 6000 miles under its belt since rebuild. It ran beautifully with the twin plenum injection, but the seller kept the EFI. Can you guess why? So I have to get everything new on the induction side and I am contemplating the Weber/Edelbrock 500 on a twinport Offenhauser manifold. Does anyone have a clue what to expect power and torque wise with a properly set up Edelbrock/Weber. How much do I loose compared to the 194 bhp specified with the twin plenum Vitesse EFI? Roughly ofcourse.
Thanks in advance.
|Erik - there is no simple answer - depends on so many things notably the exhaust system you choose but you could be looking at a similar power output - the carbs tend to be a lot more thirsty around town 'though.|
Have a look at the RPI site:
You could always go single plenium, or hotwire.
I have used both on my Vitesse engine over the years, in my opinion hotwire is the route to go.....slightly more mid range torque and flexibility than flap-valve, and much better fuel consumption, carbs are notoriously thirsty when compared with Fi.
I was fortunate in finding an inlet system with 45mm shortened trumpets and a 65mm throttle, it's perhaps a bit excessive for a 3.5, but loads of pulling power.
The Rover products does´nt grow on trees up here in the north and breakers are reluctant to sell an EFi less engine. The Swedish MOT-inspections facility does not want to hear of any 3.9 Range Rover conversions with EFI, so I have to aim as closely as possible to the original setup of the MGB GT V8. That´s why I talk carburation. There is also a tendancy, that future conversions is to be stopped by proposed regulations of the European Union. Sofar the Swedish government has listened to a strong movement of motorheads in this country. We have a long tradition of working on Yank iron. It is more or less a peoples movement, in the non socialist meaning. I have to get the conversion of V8 power approved first and maybe EFI in a future.
|It's a pity really isn't it? My EFi has Lambda sensors so presumably also produces less harmful emissions from the exhaust, as well as using less fuel per Kilometre, and not going off tune............sometimes I worry that legislators are missing the point !|
E Bay (UK) often has twin SU'S and Holley setups so you should hopefully have no difficulty in obtaining carbs and manifolds..
Good luck with the conversion it will be worth all the effort I promise you.
Apart from the usual Edelbrock/Carter setups, there is a very nice twin double-choke Dellorto setup for sale on E bay at the moment, and it looks low enough to clear a standard MGB bonnet.
Can you give me a clue where to look for the Dellortos and under what title to look for MG v8 carbies?
Over here, the norm for a conversion is a Buick or Oldsmobile factory intake with a 500 cfm Edelbrock, electric choke, & a 14" low rider air cleaner. This clears the hood when used with a 2 1/4" K & N filter element & provides enough air flow for 4.6 L motors. Hp should be equal to the twin plenam setup. The Edelbrock will run right out of the box, although for best performance & economy, some re-jetting is required. The FI system has the advantage of a bit better fuel economy & great cold starts. I just switched to a hot wire from a carb on my 3.5 & really see no difference in performance as a daily driver.
I am not aware of the customs/duties involved in importing from the U.S. but the dollar/Euro is very much in your favor at this time.
I would suggest you e-mail D & D Fabrications & get a quote from Dan for a complete setup including a properly jetted carb. You should also get a Buick 300 style thermostat housing. As the intake is a used part, that should reduce import duties, if any.
e-mail is email@example.com
The same setup is also available from Glen Towery who can be reached at firstname.lastname@example.org
Sorry, Glenn, did not mean to leave you out.
Jim has ofered some good advice - just to give a balance with the cost of petrol at £0.86 litre in some places in the UK; a plenum might cost £50, the 14CUX loom £100, the Computer £100, the HP pump £85 - the plenum would need some machining to reduce height £60 which altogether would mean you would need to drive the FI setup up a long way if you were recoup the extra cost.
Agreed, but you also get a lot of extra performance, no tuning needed, nothing to wear out,And parts (hopefully) available for years to come throughout Europe (I'm off to Le Mans & Bergerac next week knowing if I run into trouble I'll just have to find a Bosch agent to put it right ).
Try 'Rover V8' or 'fuel injection' as your search , there are always interesting items on the UK pages, cost of carrige to Europe is not enormous ( I shipped a fuel injection sytem to a V8'er in Australia earlier this year.....surprisingly cheap carriage I thought)
Thank´s for the searching tips and have a nice time at Mulsanne.
Jim, Can you give me some information on electric vs manual choke. Is the electric actuated by water temperature and soforth an electric stepper motor or does it have anything in common with the horrid Stromberg auto choke? I don´t want any sticking chokes no more. As I understand the engine is kind of a gas gobbler without a faulty mixture enriching system.
I have a GT V8 fitted with a P6 engine all stock.
I fitted an Edelbrock carb and feels that the car is rather thursty. Can anybody help me with the jets to use?
|A general call.|
There seem to be a trend that converters are leaning more against the RV8 exhaust manifold and that the "blockhugger is dead". For various reasons I plan to go the blockhugger route. #1 Our summers aint that hot up here in the far north #2 The kind of driving that I generally do, will fill my engine compartment with road dirt. #3 I do not want to cut my inner fenders.
Since there must be V8:ers that has changed route and crosses over from blockhugger to RV8 manifolds. I presume there would be a chance of being able to pick up a set of secondhand blockhugger in good nick. I there a place, internet site or an individual on this site that are willing to sell me a set or point in any direction where to look? I would greatly appreciate any help in that matter. Tips on exhaust, induction or any other bits are welcome.
Please mail me off site and kindly substitute the "dot" for a . in my e-mail.
The supply of OE cast iron blockhuggers has almost dried up - most use a tubular version and the debate is whether to go stainless throughout - it's worth the extra money - the mild steel tubulars are short lived in our winters.
You will find your e-bay gets hot - you have a choice of lagging, fitting louvres or worrying about fried electrics.
|Sorry, I meant tubular blockhuggers.|
I went from block-hugger tubulars to RV8 type.......I have no regrets, there is VERY little space around the steering column/manifold bolt area (my manifold actually had a depression on the underside of it to,clear the column!), downpipe/chassis rails, and starter motor cover and wiring. Alot of hot metal in a very confined space !!
|I have built my own exhaust system, tubular manifold 2 in 2 in 1,two red bullet "silencer" and two latéral (lhd) tailpipes. slightly noisy but beautiful sound. I use exhaust wrap for insulating the manifolds.|
|erik tried to mail you, did not work. I know of a abandoned V8 project here in Norway. There is 2 original cast iron manifolds for sale. And there is also a brand new RV8 front suspension, a 3,9 litre from a Morgan ready convertet to fit under the hood, new rear drive with 3,07:1, new leather and wood interior and a 1978 rustfree roadster shell and +++++|
|Michel en Aix,|
I have seen your work, beautiful. Sorry to say that I am not as an accomplished mechanic as you are. I have to buy pre-fabricated stuff or rely on good friends. Does your exhaust wrapping do good work in keeping the under bonnet temperatures within reason?
|Seems like something went wrong with my e-mail, so here it is above.|
|Well, well, well, it is´nt my day today.|
Here is the E-mail that WORKS:
This is what happens when computors are designed for use in anglo-saxon languages. You get letters substituted or just taken away.
Sorry about this.
This thread was discussed between 04/06/2004 and 10/06/2004
This thread is from the archives. Join the live MG MGB GT V8 Factory Originals Technical BBS now