MG-Cars.info

Welcome to our Site for MG, Triumph and Austin-Healey Car Information.

Parts

MG parts spares and accessories are available for MG T Series (TA, MG TB, MG TC, MG TD, MG TF), Magnette, MGA, Twin cam, MGB, MGBGT, MGC, MGC GT, MG Midget, Sprite and other MG models from British car spares company LBCarCo.

MG MGB GT V8 Factory Originals Technical - easyist and most reliable engine conversion

in a top 10 ranking in both most reliable and cheapest with horse power gain what are the best engines to swap into a 1968 B roadster
Scot

Scot ,
I think that's what's called an inflamatory remark.

A whole bunch of us are going to say rover V8 3.9 (obviously the best, 'cause that's what I've got)
A whole bunch more will like the orrigonal GM version which isn't as strong (the british are seriously into cross bolting) . However, there are apparently at least ten million GM's spread unevenly across the US(cheaper)GM215cu (buick, Oldsmobile, Pontiac.
The V6 brigade will then chime in with remarks along the lines of "less is more", (these people are very cylinder disadvantaged and they're terribly defensive about it, poor things).
I will now lay low for a while until the crossfire dies down.
Peter

Peter & the rest of you that want to bash the OLD G.M. motor, The Rover gang think that the rover is a LOT better than the buick BUT the buick was a real good START. Everybody thinks the cross bolt mains is the way, BUT with the cross bolt you have a bigger mains & rods & this is the wrong way to go for the heaver the crank the slower it hits revs & I love the revs! The small crank journal crank was NEVER a problem, nor the small main caps till after 400 hp. & lots of luck trying to get that out of a street motor. I look for a 93-95 3.9 rover motor for it has the small journal crank with the BIG HEAVY main caps, just not the cross bolts. The crank rear rope seal was a mess with the buick & early rover, but now you can get a real seal to go there. Rover put more alu. in the block & heads, than the G.M. motor, but there was enough alu. there for a small mid size car. I have several 215 G.M. motors with 300.K + on them & still running strong & 451k on a early rover 3.5. One thing the G.M. motor has over the rover you will NEVER see a sleave move, were the rover has a real problem hear. The G.M. moter was a real good start & it took rover a good bit of time to better it! & yes the rover did better it, But as I say the G.M. motor was a real good start, even for today.
Glenn Towery

HEY NOW!!! :Pulls flamethrower off WW2 Tank: Don't forget the Ford V8, Ford Rules, everyone else drool!! :-P

Sorry, had to rise to that one heh. Must be winter time, because the which conversion is best questions are popping up all the time again.

There IS no best, period. Anyone that thinks otherwise is probably delusional (which we all are I guess) Every swap has it's Pro's and cons.

I am not sure I could come up with 10 motors that I know have been used, but will give it a shot. I always considered the rover and GM 215 the same motor, no offense to those out there. I will try to rank these in relation to how many conversions I know of for an order, not best just most popular...

1 - Rover/GM215
2 - SBF V8 (based on actual and inprocess)
3 - Chevy V6
3 - Ford V6
4 - Rotary
5 - Ford 2.3L 4cyl
6 - Chevy 350
7 - Chevy 454
Larry Embrey

Pick your swap by the size of your wallet, time,how soon you want to be on the road, avoid all of the litle problems, what practical hp & torque gain, and type of use intended.

I have look into several engines before I decided to use the V6. I had several engines in my garage Toyota 22R, Mazda Miata, Nissan Maxima V6, second generation RX7, 2.3 Ford, 2.9 V6 Ford, Buick 3.8 (have one on my MK II Jag) I even had a Mercedes alum V8. None of this offer the simplicity to install in a CB B. Their power range is in the 3200 rpm (except the 2.9 Ford)or they were to wide and very complex due to the ECU wiring and must 4 cylinders are tall, this creates a problem with drive line alingment and hood. The 22R leans to one side which it does help a bit, the RX7 the output shaft is to high and creates other problems.

My first swap on a B wans in 1971. I install a 215 3 speed on a 64 B that had an electrical fire and was cheap. My second swap on a B was in 1978 a 2.8 V6 Ford into a 74 GT (I still own the car)I also did a 75 B for my friend with a 292 ci Chevy (283 .030 over) Great car fast drove it for a year sold it, build another B a 73 the first B with a 2.8 V6 with some extras dorve that car 3 years until he lost control on a turn.
The point is that at the end is a matter of economics and taste.
I drive my GT daily rain or shine.

If you want to spend time and money and brute hp go and buy a crate 302 put a carb and hope that you can put all of that power to the ground. If you want high tech FI go and buy a high tech sport car, such as a S2000
If you want inexpensive, quick to put on the road and with plenty of useable power then install a V6.

The botton line, any swap that you choose will be the correct choice.






Bill Guzman

im looking for the cheapest and fastest way to get it on the road....but jus for kicks everyone take a look at this 427 conversion

the car is basterdised but damn

http://adcache.collectorcartraderonline.com/10/0/7/81094607.htm

Scot

I've seen the 427 conversion in person at the DesPlaines, IL all British show a couple of times.

It will definitely go in a straight line. Turns, I believe, may challenge even the most experienced driver.

A conversion, in my opinion, should provide the owner with the performance and streetability that he/she is looking for....the 427 conversion referenced here has a very narrow audience to play to...

rick
rick ingram

Cheapest most reliable "conversion" is a Peter Burgess head on your Totally re-built engine with a good cam and new carbs. Since it did not come that way from the factory, the purist will hate you and your progeny, and you can be welcomed to the dark side of "Bastardized MGs".Of course to harness all this power, you will need to restore/upgrade the brakes and suspension to "as new condition". If you already have an old MGB the above will transform the car almost as much as bolting in a killer warhead. If you absolutely must have more power after this, at least you have the chassis to step up to the plate. JMHO

I get the feeling that you do not plan on doing a swap, just making conversation no?

Pete
Pete

actually im wanting to do the swap durring next spring....every year i drive my 68 b roadster during the winter and it sits durring the hotter months because it over heats bad lol i never even put the top up it is bad ass driving in the rain with the top down...but i have been thinking of a few different engines i just dont know whats best, i wanted to go with a twin turbo 13b rotary engine from a 3rd gen rx7 which would push 440 hp that or find a way to fit a 20b 3 rotor in it then i decide to see what everyone else thought see what would be easiest and most cost effective...also see what will give more performance then the rotary all around.
scot

Surfing the internet I found this interesting conversion.


http://34v6miata.tripod.com/




CW Strong

scot,
Don't forget the whole power to weight ratio aspect of things. The relationship's geometric, not arithmetric and MG's only weigh about one ton. Also you'll be hard put to transmit 400 plus horsepower onto the road from something as light in the rear end as an MG. Even my 180 odd BHP 3.9 can be a bit frightening in wet weather and the axle certainly tramps about the place in dry conditions if I let it.
In other words, if you're going over 200HP then you'll need antitramp bars (and maybe a panhard rod). If you're getting up over 250 then you'll need a stronger back axle and probably LSD. That should get you up to 350 (I saw a supercharged V8 using this set up). If you're really thinking 400 BHP then you'd better be looking at, at least frontlines 5 link rear suspension kit for 1400 pounds or even the IRS rear end that NG-Hawk cars will sell you for about 1700 pounds.
Peter

Miata? If I had one it would be this one:

http://www.cardomain.com/ride/291686

IMO 200-250 HP is plenty for an MGB. Go higher and it loses the sports car feel. It will morph into a hotrod muscle car. I already have one of those.

Everyone thinks they want more power, but how often can they really use it (and can they really handle it)?

I enjoy driving my MG really hard. I push it hard in the corners and wind the snot out of that little 215. I have a blast. I would certainly have to change my driving with 300-400 HP.
Carl Floyd

Scott, for your criteria I would think that it would be close to a dead heat between the Rover/Buick V8 and the GM V6. Both have kits available at reasonable prices and engines are available from wrecking yards at a reasonable cost. I like using an engine/trans combo that requires no special parts if possible. Less to engineer. This would favor the V6 unless you could find a Rover SD1 as a donor. Both will give excellent performance and reliability in a B.
Bill Young

Day dreaming from a USA prespective

1. Buick/Olds/Rover V8 (old standard)
2. GM 60 degree V6
3. SB Ford V8 (If I had to do it over, I'd be here)
4. SB Chevy (saw a beauty at Terre Haute)
5. GM 90 degree V6 Buick or Chevy (see Bock's beauty in HotRod)
6. V6 Ford(early 2.8, there was a kit for these at one time)
7. GM quad I4 (make it look like Ofty)
8. GM Iron Duke I4 (how about the 1/2 V8 used in USAC migets)
9. Ford 2.3 I4 (seems tall but has been done)
10. ????? (How about new GTO engine)
Boyce

The original question was easiest. A Mazda rotary can be done with a minimum of changes. I put one in a MGA with its smaller engine bay than a MGB without changing anything under the hood. It even sits on stock motor mounts. The only cut and weld mods were the rear trans mount and widening the tunnel to clear the starter. The rotary is so compact that it could fit in almost any car easily. It also places the weight lower and more rearward in the chassis. This conversion was done 15 years ago. If I were to do it now that 3rd gen turbo RX7 sounds like the best way to go.
R J Brown

And some poor folks have no cylinders at all!

But seriously, if you don't give the remotest... about resale or economy, and want to do you own thing, then the roteries are way up there in the power to weight game.

However if you want to get it done yesterday then you need 'off the shelf, bolt right on" parts. Got to be late 3.9 Rover. The block with the provision for cross bolting but no bolts. Been done 1000's of times . Glenn Towery was even offering a 'do it in a week-end' service at one stage.
Peter

Rover V8 and then bolt two turbos to it . . . but then I'm biased!
OT Hayter

The cheapest and easiest has to be the V6, hands down.
BUT, I'll never give up my 302 :))))))
Steve Carrick

steve, hope all is going better these days?? still in the biz?? i have the body and still want to crunch the numbers on the 302, let me know, jim
james madson

Scot,,I'm not a car guru,, couldnt do a conversion from scratch if i tried... but have always liked mg's and awhile back decieded to buy 1 with a v/8,, the car has a lot of riggins that are slowly disappearing..I've done most of the riggin fixen myself had local engine guy do some mods & improvements it's a 215 buick with 4 barrel /rv8 headers/ crowler cam/slightly higher comp.& 30 over pistons/balanced crank/elec.ignition/hot coil/alum.radiator/5speed[tr8]& rear from post office jeep,,was told by dpo that he dyno'ed it & got 238.7hp at rear wheels,,[I dont for one minute believe this he told me all kinds of crap,,& i cant see that engine putting that much hp to the rear wheels,,maybe the tranny but not the wheels,, local race shop has dyno & i've thought about it,,but hate to spend $75.00 bucks to blow it up...][ it'd be my luck!!]anyhow 300 or 400 hp.in a b I cant imagine??this little car of mine gets it,,was on the interstate took it up,,10mph. at a time to 130/135 mph.?? lost my nerve!!!had a good bit of peddle left,,front was getting very lite,,dont know why you'd need more than that??the car runs great,,handles great,,theres a ton of these engines out ther & performance parts to [have to look in the right places][wont get the stuff from summit/napa/ jeggs]& D&D fab. has everything on the shelf for this conversion & hop up parts too..thats my two bits!! good luck..
denny

I'm thinking the 300 Buick would be a real good choice.

Jim
Jim Blackwood

I am very impressed at the open-mindedness displayed in this thread. My thought was pick your performance benchmark and then work backwards from there. Straight line missile or long-legged GT. It will probably also entail full restoration and/or upgrades of the suspension & brakes.

But of the popular conversions out there, The carbed iron head 60 degree V6 sounds easiest and perhaps cheapest.

Then again, cheap is relative to your ability and fabrication skills: buying a conversion or fabbing up your own brackets, same for headers, Wiring, driveshaft, fuel injection or carb, cooling, clutch hydraulics, instruments, body mods and re-inforcement etc...

I've got a 3.4 V6 collecting dust on an engine stand, waiting for me to finish the body restoration - painfully slow. The upside to being really slow (assuming there could be one) is you have the luxury of time to collect all of the right parts at the right price. You get to spend too much money over a longer period of time.

For me the 60 degree v6 family is the right choice. Nice power, cheap, available, easy install and not too heavy. But maybe aluminum heads...

Regards,

Brian C.
Brian Corrigan

Brian,

Someplace I read you cant use the aluminum heads on a 3.4 v6. They cant handle the loading from what I understand. Are you using a carb or FI?

CW
CW Strong

No, CW, there is no problem with the alloy heads and in fact they offer superior flow and power. The only problem with them is that there are no manifolds available for anything but the stock injection - not a problem, really, as the injection is very good.

It is just that a lot of people wanting to do swaps seem unable or unwilling to wrap their minds around fuel injection when the good old boy route of just bolting a bigger carb on will suffice. Unfortunately this isn't an option with the alloy heads.

We have other options on the cast iron heads because they used these engines in carb form in trucks for years, and it was worth producing after market manifolds. Not so for the alloy headed versions.
Bill Spohn

The aluminum heads for the 3.4 also have MUCH smaller chambers compared to the iron heads, so if you just swap the heads and not the pistons, you will have an insanely high compression ratio. So, you also have to swap out the pistons or use third party ones to maintain a workable compression ratio. Bore stroke and rod length are all the same, so a simple piston swap and you ae good to go.

This has been done in the Fiero and F-body world to good effect.


Regards,

Brian C.
Brian Corrigan

CW, Brian,

I'm in that corner. I just purchased a gm 2.8 aluminum head on Ebay for $75. I had already picked up a carb and manifold, but I couldn't turn this one down. Time to start learning about FI. I checked on autozone and their is only 10 sensors. I guess I can handle that. I'll use a chip from the camero, it should be a better match. I have the bell housing. Now I need a flywheel, clutch tranny etc. Time will tell with the water pump. But as for chaep, I'm off to the races. Mike
Mike

has anyone ever tried putting in a little jap engine other then the rotary? like the r22 nissan engine
john

Yes, John, both the Miata and the Toyota twincam are fairly common, giving 140 - 180 BHP.
Bill Spohn

the toyota twin cam comes out of the older corrolas doesnt it? and how much work is involved in installing one of these
john

Mick has a nice picture of one of these conversions on his site. I don't believe there is much bother in installing them - similar to the Miata conversion.
Bill Spohn

thanks bill whats micks website?
john

sorry guys if this is getting repetitive about different engines but has anyone ever tried the inline 6 out of a 1989 jaguar xj6?
scot

Scot,
Check the weight of that Jag motor, its very heavy.
Its also LOOOOOOONG.
Mike
Mike

Scot, I seem to remember that this thread started on the most reliable and cheapest engine to swap and somehow drifted off into the realms of fantasy. There are B's out there with Jag V12's, so almost anything is possible. Just remember cost and complexity go up with uncommon swaps and conversions to electronic engine management systems. There are good reasons why the Rover/Buick V8, small block Ford, and the GM 60 degree V6 are popular. Weight versus horsepower is one. None of these engines has an undue negative effect on the B's handling where some other heavier engines start to enter into territory where suspension work is almost mandatory for a safe car. If you're not an expereinced mechanic or loaded with extra money I'd advise sticking with one of these three choices.
Bill Young

i appreciate it yeah i was jus curious cuz my brother just totaled his xj6 and the engines still in perfectly good condition thanks for everything everyone
scot

This thread was discussed between 16/10/2005 and 03/11/2005

MG MGB GT V8 Factory Originals Technical index

This thread is from the archives. Join the live MG MGB GT V8 Factory Originals Technical BBS now