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MG MGB Technical - MGB Engine options

Hi everyone, I am new to this section having spent most of the time on the T series section as I have a 51 TD. Until recently I was looking at buying an RV8 to replace my E Type but given the heavy steering of the RV8 and the expense of powering it (£2500), I have started to look at an MGB project possibly using a heritage shell but with a larger engine ( not necessarily a V8 )

Do you guys with the MGB experience have any suggestions as to the options available. I do not want blistering performance but something a bit different from the norm. Someone mentioned a Cosworth unit but our conversion was interrupted and I never did get the full story!

All suggestions gratefully received.

Thanks,

David Tinker

David Tinker

might want to bounce down to MGB Engine Conversions.

While tailored mostly for V8's (and in the US, V6) conversions, they welcome all commers
greg fast

It will be much easier, and way less $$$$ to 'hop up' the stock engine.
Much!
What I did was install a '71-73 engine, with the larger intake valves, add a header and 2" exhaust, port & polish the head, bored out .040" with 8.8 c.r. pistons, deck the block to the top of pistons, balance all assemblies, lighten the flywheel to 15 #'s Re-grind the cam a bit more aggressive, and time it to 7 degress BTC.
With very satisfing results.
The next year, I pulled the head, and added the larger stainless steel rim flow valves, and 1.5 ratio roller rockers.
It has K&N air filters with the short velocity stacks inside them.
Twin HS4 carburetors. Pertonix ignitor, with the Flame thrower coil, and the Pertonix 'Second Strike'
It will hit 90 mph, where a more stock engine hits 80 mph in the same distance.
Rendezvous 2005, Grand Rapids Minnesota.

Keep the stock block............

Safety Fast
Dwight
Dwight

There is a cosworth powered car around, and I have even heard tell of a B with complete 4-wheel-drive clockwork and suspension from a Sierra Cosworth - it is aparrently a complete hybrid of the two cars, with a lot of the underside of the B removed. No doubt performance is impressive!

I shoved a Rover T16 turbo in my BGT, with results rather more electrifying than even the wildest B-series. Makes the axle hop a bit though...

--
Olly
Oliver Stephenson

Don't know about the handling of the RV8, but the Rover V8 engine is lighter than the B serises lump, so steering shouldn't be heavier. Your choices for power plants is different in the UK than here in the US where the Rover/Buick or Ford V8 are the most common followed by the GM V6. The midget crowd likes the K series, which in the 2 litre version would make a good choice for a B. Perhaps the Nissan V6 from a 300Z would make a nice swap, plenty of power and light weight. It also has great under bonnet appeal as well with some detailing.
Bill Young

I've put a 300zx (SOHC version)in a B and it is not an easy job. It is a wide engine. The DOHC is wider yet. Setting it up for fuel injection with a round trip gasoline supply is a pain but doable.

In looking at the current options, it appears to me that swapping the late model (post 1999) 3.4 gm v6 is the way to go. The engine is lighter and smaller than the BOP alloy v8. It has a very free flowing head design and there is a supplier of complete kits.

Typically these are converted from efi to carb intake systems. The stock efi systems have a tuned intake that adds significant power. The late versions in GM suv s have factory 200 hp ratings and rev very nicely up to 6000 rpm. Installing the computer and injection system is some challenge, but doable. The van/suv intake systems are higher but should fit under the hood. The sedan version is rated at 175 hp and has a very low profile intake system.

Retarding the camshaft a few degrees and an aftermarket progamable computer would probably make substantially more high end power.

There is a 2nd supplier of kits for the earlier engines. The head design is not as efficient and carburation is the only option. It is an easier less expensive conversion, albeit with reduced performance potential.

For about the same $ and a lot less work, a supercharger kit can be added, that will produce similiar performance levels.

The supercharged engine typically has dramatic increases in mid range torque and a more modest increase in top end horsepower output.

A more modern lighter trans such as the Nissan 280z or Sierra also makes a difference with the more evenly spaced ratios and overdrive 5th gear.

Barry

Barry Parkinson

David,

I am one for the Supercharger. This is only a option for what you are asking.

Take a look at what I mean click on this link:

http://treasure-island-jewelers.com/1977mgbSupercharged.htm

Regeards,

Ray



Ray 1977mgb

David, Welcome to the place or at least this part of it anyway.
The magazines MG Enthusiast and Total MG frequently have features with B's of various types having transplanted engines from elsewhere so that would be a good starting point.
For back issues try your local MG Club.
Also there is an MG B "modifieds" section on this board as well soa browse through the relevant archives would be time well spent also.
Finally , treading the "well trod" path ( as opposed to the one less travelled) is usually easier , cheaper amd less frustrating at least as far as engine conversions are concerned.
The wealth of information on the Rover / MGB conversion is huge and even kits are available.
That said I wish you well on your project.

Cheers , Pete.
Peter Thomas

The Cosworth conversion was done by Falla Classics http://www.fallaclassics.co.uk/ (there's a link to the Cosworth car on the main page).

My engine has been modified rather extensively by Chris Betson, who regularly posts on these boards. The build process and a comparison with some other modified MGBs (including Chris' Rover V8 powered car!) can be seen at http://www.octarine-services.co.uk/alex1950.htm
Alexander M

Many thanks for all your replies putting me in the right direction. I now have a great deal of reading to do.
Cheers,

David Tinker
David Tinker

How about a Merkur/Ford 2.3L supercharged/turbocharged motor?
Mike MaGee

This thread was discussed between 12/09/2005 and 18/09/2005

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