MG Sports Cars

So as I understand it... on account of having a longer deck height and stroke the Buick 340 is taller, wider, and significantly heavier than a Buick 300. (The Buick 300 is in turn taller, wider, and heavier than a Buick/Rover aluminum motor.) Since it was only produced for two years, there are very few performance parts made specifically for a 340.

The stock heads have big exhaust ports... so you get to make custom headers to suit an MGB, right?

As Jim pointed out, you could save some weight by using aluminum heads from a smaller Buick or Rover engine - and presumably that would fix the header sourcing problem too. Sounds good... but I'm skeptical for three reasons:
(1) Buick/Rover aluminum heads aren't exactly famous for being free-breathing, and you're talking about pumping extra air through them.
(2) compression ratio. Has anyone done the math to verify what compression ratio you'd have with Buick 300 heads? (They have big combustion chambers: 54cc.)
(3) any suitable set of aluminum heads are likely going to cost a bunch more than $150.

Jim mentioned that you could, possibly, use a Buick 300 aluminum intake manifold IF you install it on custom spacers. Four custom machined spacers, right? As I understand it, you'll need spacers to seal the intake manifold to both the block (both ends) and the heads too.

"Doable" - but a lot more uncharted territory than a small block Ford "stroker" would be

Wow

Reading all of the above would have one thinking twice about a conversion, just kidding (sort of)

If you find a mid 80s to mid 90s 5.0 Mustang with a five speed you will have almost everything you need, maybe even the rear end. If you want 225 hp you can install the engine rite out of the donor car, if 300 hp is what you are looking for just put a good set of heads on it. Parts for the 5.0 Ford are as common and almost as cheap as Small Block Chevy parts are.

I believe that you can even buy headers now for the 5.0 swap. If you want to run Fuel injection you can find tons of info on how to wire the Mustang set up or you can purchase one several aftermarket harnesses from the likes of Ford or Painless. To run a carburetor just change the intake and Dizzy. The early 90s 5.0 have forged pistons and roller cams as well.

Putting the 5.0 in a Chrome bumper car will require some tunnel mods and the crossmember will need to notched but there is a lot of info around and I think Pete Mantell (see advertisement on this site) is putting a kit and directions for this swap.

One last thing a stroked 5.0 to a 331 or 347 will give you more power than you could ever harness in the B or Gt, but think of all of the fun you could have trying:)

Joe

Not, "significantly heavier than a 300" Curtis, there's a 2 lb difference in the block weight, the rods are slightly longer and the crank is a little larger but not necessarily heavier. I'd say about 3-5 lbs would cover it easily. The exhaust ports are larger but use the same flange so I don't know where that business about custom headers comes from. By this time next year I'd expect the TA heads to be available and in the meantime 300 heads will work and certainly will make more power than any stock Rover heads available. Dan Jones has demonstrated that they can be ported to flow as well as SBF heads. The 340 may not be quite as much of an orphan as you think. About the only thing really missing is the aluminum intake manifold, and I know a guy who will make you one if you like.

Yes, the 300 heads have a 54cc chamber. This is not a problem for a 300 or 340 and it can be worked around with the smaller engines. IIRC a high compression Buick 215 fitted with the '64 heads is still over 8:1, and incidentally nothing has been disclosed about the chamber size on the new TA head design but the V6 head from which it is derived has a 46cc chamber, 55cc if CNC ported. Port flow is 247 intake, 195 exhaust at .550" lift, or fully ported, 275/200 at .650" lift. That compares pretty favorably with big block heads.The Rover heads can be expected to flow exactly the same.

And some people still like the Buick engine line because it has a legitimate connection with the MGB-V8's origins. Whether it sits well with the Ford and Chevy crowd or not, it's still there. Finally, an aluminum 350 can be built with a sleeved P76 block and 340 crank, so we're back into the lightweight category again. Even if Matthew only uses the crank out of his 340 and throws the rest of the engine away he breaks even, since that's about what 340 cranks are going for on ebay, IF you can find one.

Jim

This has got me very intersted. While I respect all of your opinions its nice to know I can still do something different. Matt

Jim I sent you a PM with some info on the 340 I found. Matt

"And some people still like the Buick engine line because it has a legitimate connection with the MGB-V8's origins."

I guess that's one reason why I'm still leaning toward the Rover V8 with a carb, after market manifold, headers backed with T-5 sp. It's funny, because a lot of guy's are trying to talk me out of it! The guys at a wrecking yard here in Spokane (I was getting parts for my daughter's Honda Accord that she smashed up last week!) said that they get a lot of calls for Land Rover V8's because of head gasket problems. They were really pushing me to get a modern GM V6.

But I think that many of us middle agers want to experience the "retro effect." My first car was a '68 GTO-nothing but engine under the hood, very fast, sounded fantastic, horrible handling, 5-8 mpg, brakes that might stop you if you prayed during the 5 minutes it took to get from 100 mph to 0, no A/C, no fuel injection. I also had a V8 Vega in H.S. that would roast tires for a city block......(that is until I blew the rear end out the back of the car, but it was great fun while it lasted). I don't really like muscle cars anymore, but I still haven't got rid of the sensations and the simplicity of the cars that I grew up with.

Thanks for all of the great advice. I'll post some pictures of my GT soon.

Tom



Edited 1 time(s). Last edit at 01/22/2009 11:52PM by BMWTom.

I am currently starting to tear down the 3.5 Rover I bought from a friend, going to go through it and replace the necessaries. Plan to install it into my B with a t5 transmission, I was lucky enough to get the bellhousing that mates the two along with the headers and many other parts from a board member here. Personally so far I like the 3.5 because I don't need an engine crane to move it, I thought it was great that me and my husband can pick it up without any problem. I am sure you will find something that will work for you as it appears these guys are chock full of knowlege. (Just wait til I start posting questions, I will drive them crazy!)

Welcome to BritishV8, Michelle!

Thanks Rick. Spent most of today carrying the rover block to my basement to work on cleaning up, along with all the parts that were taken off. Also carried in the other block I picked up from Kurt S. Now to spend the evening recovering from the climb up and down the steps. :)