MG-Cars.net

Welcome to our resource for MG Car Information.

Recommendations

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 - Pre 74.5 Conversion

Is there anyone in the SF Bay Area who has successfully done a pre 74 1/2 conversion? Any shops in the area that's familiar with the conversion? I work overseas most of the time and have very limited space to do any major wrenching myself. Thanks.

Arayan
San Francisco
Arayan Lias

It is a supposedly a TON of work ... weenies like me just used later-model cars ... but it's supposed to be worth the pain ... there's a chrome bumper GT on Ebay and it has a lot of pix ... you can sort of see and read how it was done.
Bill Withum

Hi Arayan,
I am in the middle of doing a 74 chrome bumper roadster conversion at the moment, and it is a lot of "cutting and welding". I live in San Jose, so I am probably reasonably close if you want to come over and look at what needs to be done.
Regards
Tony Bates
Tony Bates

Thanks Bill, I had a feeling it's going to be a lot of work.

Tony, I'll definitely take you up on that. Searching the net, reading and looking at pictures is just not the same as seeing the real thing. Please let me know when you are available.

Arayan
Arayan Lias

The nut of is the time that needs to be expended. Plus you need to know how to weld -- can't be done without it. If you're sure a chrome bumper is the only way to go -- and many people seem to agree -- somehow you can find a nicely converted CB car, even if it's not quite to your specs you might want to just buy it. Much easier to make a few changes to a car that's basically what you want than to do this from scratch! Things like engine mounts and steering cones will kill ya. Bill, holy cow that looks like a serious machine there on Ebay.
Ted

Arayan,
I'll email you off bbs to give you my contact details
Regards
Tony
Tony Bates

I have done v8 rubber bumper car then converted that to chrome bumper, and done a chrome bumper V8, converting the fire wall to rubber bumper spec, including the steering cone.

Both involve welding. The RB to CB is cosmetic requiring the bits to be welded under the tail lights. Front fenders can be swapped to avoid welding in under the parking lights. RB rear bumper mounts can be ignored, as the chrome bumper hides them to all but those who lay on the ground & look up. Front bumper mounts need to be cut off & a cap fitted to close the ends, but this could be pop rivited & caulked. Front cross members need to be exchanged to reduce ride height & lowering blocks fitted in the rear. All in all, this is more work than starting with a CB car, but it requires the least amount of welding, & this can be done at the body shop when the car is painted for just a few dollars more.

All things considered, if you want a CB car, it is less total work to start with a CB car. If you cut the bulkhead pieces from a RB donor car & carefully measure where the motor mounts go, It should not be too expensive to have a body shop do the welding.

You will have to remove the original radiator mounts by drilling out the spot welds. New late model mounts are available new & can be attached withsheet metal screws to avoid welding.

Jim Stuart

Roger Parkers books tell all,

You'll also need to weld (or have welded)a raised bit into the transmission tunnel ( a sort of upside down bakeing tray) & you can buy the bulkheads & engine brackets, front radiator tray, tail light bits etc..
I did a rubber to chrome conversion and got the tail light bits done welded, colour matched spray painted at a shop. I figure welding sheet is something you can do after lots of practice

The rubber bumper conversion was more than hard enough for me, my hats off to the chrome converters.
peter

Arayan,
I have been watching this thread for days. Pretty interesting all the stuff you have to do to place a BOP/R 3.5L V8 in the early cars.You didn't say which driveline you are looking at so if you are considering a different driveline, consider the GM 60 degree V6 such as the 3.4L.

The work to the engine bay is much less and can be done in 45 minutes. Generally most converters are using engines between 150 and 225 bhp. More can be pulled out of these, just like ANY other driveline on the face of the planet, so power output is all in the way you build it. There are kits to install these so no welding special one off headers or mounting kits. Support for these systems can be found on another site: http://www.v6mgb.com/forum/index.php This my primary BBS that is great for reading and discussion, that is a second one for V6 conversions only and is wonderful for that.
Bill Guzman might know of a V6 or V8 converted car in your area, its always nice to be able to drive whatever your going to build before you start. :-)



-BMC.
BMC Brian McCullough

Wow, I'm totally overwhelmed by all the advices and input from everyone and they are all wonderful. Seems to be many conflicting versions here. Some say it's easier with the CBs some say it easier with the RB. One reason I'm stuck on the CB is that I have one and I've owned it forever (10+ years) and the body is straight. Sentimental thing I guess. As far as driveline is concern, I was looking along the Buick 215 and T5 tranny. Pretty much at the reading the cookbook stage and just perusing over the ingredients. V6? 45 minutes? Hmm... Keep them coming please. Thank you.
A Lias

Arayan,
I mean that the engine bay can be ready to accept the V6 in about 45 minutes. Cut off the stock motor mounts (you do this in CB cars for the V8 anyways) and as the gentlemen with V8 conversions would say- "dress" the sheet metal in a couple of spots. This dressing is done with a large hammer in a couple of hits. Very minimal work really. The RB cars require nothing to fit at all. The motors out there are carburetor, TBI, MPFI and SFI, so lots of choices are available.
If you go to the homepage of the website above, you can get to various links on the V6 stuff also I highly reccomend you check out the V8 website.. Usually dont mention it because someone else already has!
Another item that I usually don't get so lucky as to mention is the Ford 302 V8... but thats the utmost in work for someone with minimal tooling and time. Plan you car to be out of commision for quite a while if you plan to build a nice set of headers.
So I think, but then again, I work on cars- British only, and conversions for a living.

Best choice for time and budget: GM 60 degree V6. However, ask anyone here, my opinion is slanted just like everyone elses. :-)

Consider these items:
how much money do you have to spend,
when does the project have to be finished,
what kind of results do you want (power and reliability),
how availible are parts and support and how needed are these items (BOP/R V8 and GM V6 are highly supported by complete kits and aftermarket parts, the 302 V8 does not have a kit and requires alot of welding)
-Brian.
BMC Brian McCullough

Brian,

Checked out the website above. Very informative indeed. Then why go with the V8 instead of the V6 conversion? Seems to put out similiar power and the mod seems to be straight forward with a lot less hassle. What are some of the advantages and disadvantages between the two (6 vs. 8) besides the obvious, i.e. more cutting and welding, more inline with the original GT V8? FWD vs. RWD V6? More cans of worms?
Arayan Lias

Arayan,
V8 because they are cool.
Seriously though, V8 because V8 MG's were a factory production car and has a legitimacy and hence value that other motors swaps don't.
I don't know about the US but here in Australian they are much easier to register than variants. It's essentially an MG motor in an MG car.
You just have to declare that it meets some combination of GTV8 or RV8 spec's.
By the way, I don't mean to criticize those undoubltly very nice V6 conversions (each to their own), it's just that if I were after power and not to interested in retaining the value of the car I'd go for a turbo rotary.
peter

Hi Arayan,
Computer has been out of service since the 28th... Seems like forever.

Its All in personal choice of course. Generally the V6 drivelines are easier to acquire and generally cost less for the same amount of power. Some people still think the V8 is 25% faster due to the additional 25% more cylinders. Some like the difference in sound and Think that the V6 cannot sound good- all in the way the exhuast is built and early V6 90 degree engines were odd fire units (kind of like harley Davidsons V twins sound funny) and would not provide a smooth note. Comparing apples to apples, a small V8 like the 215 CI BOP/R vs the 204 CI GM V6 is quite interesting. IF they had the same technology in heads and all things being perfectly equal, the V8 would have a better chance of providing a little smoother power output and a little more power, however, one of the factors to look at is more friction and more moving parts which take away power as well. IF The heads, camshaft, lifter style, pushrods, maximum engine RPM (BHP & Tq peaks), pistons and everthing else was the same, the V8 would provide a touch more. Of course, that is if they both were made out of the same materials as well.

We are just getting into the hot season, so watch this board light up like a christmas tree with people talking about their V8 engines overheating- even stock units. I think the BOP/R has a good/bad thing going for it... Aluminium.
Aluminium tends to shed heat quicker. This is good if you are planning on running a car hot, or trying to save weight. However, an aluminium engine needs more compression to make up for the loss of heat dissapation (heat=Power. Lost heat from the combustion chamber= loss of power. Power is energy AKA- Torque, AKA- BHP.)

The BOP/R takes up so much room under the bonnet that it has less air flow. This is another problem. There are ways to take care of that too, but its alot more work.

The new generations of V6 are supposed to be coming out as aluminium, and even with the points mentioned above, I would still like to look into them. Yes, sometimes I am good at defeating my own writing and ideas! I personally do not favor the BOP/R conversions as much, but sure I would enjoy driving one. :-)

Disadvantages of the GM 60 degree V6: Current largest displacement is 204 CI. GM announced for 2004, this will be going up again to either 3.6L or 3.9L, I don't remember which. If your into displacement Only and don't understand the concepts behind technology, then the Rover 4.2L is the way to go. If you understand camshaft alterations and settings, compression ratios, heat disapation rates, yada yada yada you can build anything to the power level you need, however, some cost more then others. This is why the V8 conversion board exists, because the MG series B (MGA, B, Magnette and others) have a limit to how much power you can get with a reasonable amount of your pocketbook and all of us know it.

OK, another disadvantage- in some states, you cannot place a new engine in a car without its OEM emmissions equipment. I think CA will let you go with your year of car, but not the newer cars.
Disadvantage: You blow someone away with your 6 cylinder GM and they start cursing you because you just beat there V8 'Stang. (ok, thats an easy one!)
Advantage: Lighter rotating assemblies and better designs allow for higher and quicker revving engines.
Overall, the V8 has more support and more built and is inline with all that the factory had availible at the time. however, the V6 has alot of support and has been installed in many cars for many years.
Most of the issues with the V6 have been worked through and someone has done the same thing before, so the majority of the V6 territory has no real issues or problems just like the V8.

Others have considered numorous other units. Matter fact, there is a company building a Miata powered kit and another kit for Ford Ztec motors. I will wait and see, but dont think those would provide me with what I am looking for in a conversion. The one nice item about those is that they are I4 engines still and some people like the idea of sticking with the same amount of cylinders as what the bean counters put in them.

I am not trying to start the old which is best debate, just giving an opinion...
-BMC.
BMC Brian McCullough

One big point with a V8 is that sound you get with 8 cyl, it does something to the soul.
Steve Nightingale

<<One big point with a V8 is that sound you get with 8 cyl, it does something to the soul.>>

Yes, it does. So does an HD, in Spades!

Brian,

You are the first person I have EVER heard describe the sound of Harley V-Twin as "funny". To me it sounds like a Chevy with a REAL BIG cam, open headers, & a slow idle. AWESOME!

Enjoy your V6. There are some very good ones these days, but it will take some real exhaust magic for them to have THE sound. :)
Carl

How do resale values of V6 conversions hold up? I understand that properly sorted Rover V8 conversions give rise to fairly valuable cars. I could be wrong but I would not guess that even a perfectly done V6 would have much resale value. All biases aside, though, the V6 does sound fairly practical for an MGB.
Floyd Thomas

Arayan,
Don't turn to the dark side!
A big alloy radiator and fan will take care of heating problems forever. 110 degrees F in peak hour traffic and never a hint of trouble. And if you don't want to weld sheetmetal the metalwork/welding can be handed over to an expert and shouldn't cost too much, it's just those two little corner bits/steering cone and a small part of the transmission tunnel.ie get the thing prepared and trailor it to the shop. Just factor it in to your costs.
The small alloy V8 in the MG simply works so well. "A match made in Heaven" (Roger I think).
Peter

Of course, Brian just started (again) the old V8/V6-which is better debate. Nevermind he said he didn't want to.

So.... V8's are better, nya nya nya nya, nya! Betcha'd like to have one!

How's that Brian?

Seriously though, it's just a matter of personal preference. I prefer a V8. So do a lot of folks on this bb. You might, or not. It has a little to do with power, and a lot to do with the reaction when you open the hood, or someone asks what's under the hood. More ego than anything else to be honest, and with public perception. But none of us care about that, right?

For power the 302 is tough to beat. For legitimacy the BOP/R is hard to beat. For compactness the V6 is hard to beat. But they will all give you more than enough power. Here's my personal favorite: http://www.mgbconversions.com/photoalbum/variousv8s/JimBlackwood.htm
It's complicated I know, but it has ALL the bragging rights. Aluminum V8, blown, injected, and intercooled. Plus.

Jim
Jim Blackwood

Hmm...the force is strong in this one...

Thank you all for all the outstanding replies to this thread. As far as my car goes, it is now smog exempt in the state of California hence the thought of the conversion. So it boils down to practicality vs. authenticity and I'm not saying that V8 is not practical. You guys have been very informative and really have opened up my mind in regards to all the choices that I have before me. Keep them coming, please...

Arayan
Arayan Lias

Nah, bragging rights go to Larry. Now that is one fast car, with no affectations.
Ted

I have a 67 with a v-6 and everyone is right, it does go in easily with a small amount of modification and it does have enough power. I had decided to forgo the v-8 conversion but one day a kit car with a 351 passed me and I drove home and told the wife I was doing a v-8 conversion.YOU CAN'T BEAT THE SOUND. I have had a 302 built, I have the car{a 78 that will be converted to chrome bumper}now all I need is time. I am shooting for the west coast meet next summer. I will keep the v-6 until the 8 is complete.
Garret
garret

Arayan,

For me the final choice was based on sound. For those of us that grew up with V8 power (Mopar for me), the sound is a large part of the driving experience. I, like many, have preferences for certain V8 sounds. I profess to liking the sound of Ford and Mopar V8s over GM. Ironic since I put the Rover 3.5L in my B. Don't get me wrong. The sound of a Austin Healey 3000 or a TR6 with a free flow exhaust both stir me. My point is that this will alway be a personal decision and in addition to facts, figures and practicality, emotions are a factor in modifications of this type.

Joe

Joseph Lagasse

Carl,
The word "funny" was probably not a good word to use. The point is a not-normal-everyday-perfect-sound that you will hear from Hondas, F150 pickups and the grannymobiles. I really like the odd sound of a Harley but just used it for an example. I dont remember what the cylinders are offset to but its not a 90 or 180 degree, its something odd I believe causing the odd fire. A 2 cyl odd fire can get away with that sound any day to me. Its like an old hit-miss stationary motor sound- a wonderful thing (to me).

Floyd,
I don't know. I have only seen some bad examples sell on eBay and did not pay attention to price. If your building the car to resell it, your going to loose money no matter which driveline you install. Also, why would you even bother selling the car after going that far through it? To me, its a non-issue.
What do I think one would sell for? A poorly built V6 that someone spends 6 months gathering the cheapest parts and has it up and running is probably only going to sell it off for what they have invested. A V8 in the same shape is going to cost alot more in time and/or money and being as though the parts will cost more or take longer to gather at the same prices, they will loose more.

Ask Jim B or Larry E what they could sell their cars for on the open market.. I'll bet more then most of any of the standard conversions, but they would probably still loose alot... Unless someone is very interested on this board ready and willing to give them what they have in them! Nice cars guys!
Jim,
;-P
LOL!
-BMC.
BMC Brian McCullough

ok, I'm being a board hog now but..

Garret,
Which V6 are you using? What kind of BHP/Tq are you projecting you have and which gearbox/rear end???

Joseph has a point. My favorite sounds from 10 years ago were Mercedes-Benz straight 6, AH 3000 I6, TR6, and maybe a few others. Very different sound from a V6 or V8. Very deep sound and hypnotic sound. My old Bimmer with a straight 6 was wonderful too at road speeds. Now I'm old. Bimmers and MGs do not make good for extra child seats or hauling clients engine blocks for midgets and other projects.
BMC Brian McCullough

Brian
I am running a 2.8 with a T-5 and an S-10 rearend using 3.42's. I am using a Mcleod throw out.
I had the block decked to bring the pistons to the top and the heads have been ported to improve flow. The cam is a special grind from comp.
I centered the gas tank so I was forced to use 15in glass packs with resonator tips to soften the tone.
The car should be around 225hp and 185 tq.
It runs great and is a blast to drive but I drove V-8's in the 60's and will always love the sound and feel they produce.
I am doing a V-8 now and will let you know what I think when it is done. When I sell the v-6 it will probably be to a family member so who knows how much I will loose on it.
Garret
garret

Garret. You centered the gas tank on your car. Does that mean you put a dual exhaust on your V6? What does that sound like?
Dana Wilson

I installed the Camaro 3.4L V-6 with dual exhaust all the way back (side by side). I had a crossover pipe installed early on with straight thru glass packs where the resonator used to be. Too loud for Del. inspection (103db). Addition of some baffles just aft of the crossover pipe helped to pass. But the sound is still a little loud, but not like anything else out there. It sounds very smooth at speed, but does have some rumble at low RPM. Keeps everybody wondering what I have in this car. The performance is very comparable to a stock 215 V-8 and maybe a little better (according to G. Towery), as I've kept the 3.9 rear with 245/60-14 Yokohama rubber on 14 x 7s. I've grown to love the sound, the more I drive it and my wife won't let me quiet it down. Sort of sounds the way the old Fiat Dino (V-6/one half a Ferrari V-12) sounded like in the 60s.
Bob Fish

Garret,
Sounds like the car has some power to it. You could have tried a 3.4L or even brought it out further. Depending on your T5 ratios, you could have had jsut a little more speed out of it though without any more engine upgrades.. A V8 Camaro T5 with a 3.42 rear end gear ratio and your engines BHP/Tq figures would not have been what I would have wanted, but a V6 Camaro ratio T5 would have been as good as you can get with a 3.42. A 3.73 rear end with the 2.8L built up and a T5 Camaro V8 gearbox would be the best bet for your engine build, in my opinion. Are you running headers or just stock exhuast manifolds and a 4bbl carb?
I will be interested in what the overall thought of your V8 will be. Sounds like more fun all over again. :-)
Good Luck,
-BMC.
BMC Brian McCullough

Brian
I purchased the t-5 being told it was a v-8 but when I got it, it is a v-6. It matches up quite well with the 3.42.
I am running headers and a holley 390 DP.
I have lowered the car 1 inch and have Doug Jacksons panhard rod. The car has negative camber bars and a completely new front end. With a 14 in steering wheel the car can feel a little twitchy at times. Being lowered and with new front and rear suspension the ride is great but can feel a little stiff at times.
Garret
garret

Well said gentlemen and a hearty thank you to you all. After pondering all these great advices (thank god for internet), I've finally decided on going with a V8 instead of V6. Thank you Brain, you've also been most informative. Now let's see how far I can take this. So far it looks good on paper. Stay tune guys...
Arayan Lias

Hi Arayan
Now you've decided on a V8, why not come and have a look at my work in progress. You have my contact details already.
Regards
Tony Bates
Tony Bates

Sorry about not contacting you a few weeks ago. Just came back from a business trip to the midwest. I should be able to come by this weekend. Got all the contact numbers. Thanks.

Arayan
Arayan Lias

You won't regret it, most engine swaps are a little nasty in some respect (I've done one or two and there's usually something that doesn't quite work 100%.
Not this one though, there's no bad. It's just nice in every way.
Peter

Someone ask about the resale of a B with a V6. As best of my knowledge a very nice 68 black roaster with a 245 hp 3.4 TBI sold for 16,800k, a 73 GT with a 2.8 190 hp with a very nice interior,2 stage red paint,stereo, etc. sold for $14,500 This car was done to be a everyday driver, in which the owner did, he is now doing a 68 GT with a high output 2.8 .040 bore, ported heads, 1.6 ratio roller rocker arms, higher compression, etc. He owns several cars (43) but he loves the MG for a driver. He owns a MGB V8 original which is pending sale.

I have also seen very nice V8's sell for about the same price.
Bill Guzman

The only possible way my car could bring what is invested in it would be to sell as an art work. Or as a one of a kind to a very specific sort of collector. Neither is likely to happen, because to me it is worth considerably more than the total investment, so I think I'll just keep it. After all, if I sold it what would I replace it with? I'd have to start all over and I'm not willing to wait that long. Besides, it's not finished ;-)

Hey Ted! You old sourpuss, you're just jealous! Actually, anybody who has gone as far as Larry, or me, or a number of other owners sure don't have to be told by anyone about bragging rights, it's a given. As for affectations, name me one single modification on my car that is not FUNCTIONAL! -rant off- Oh, and all the best of course :-P

Jim
Jim Blackwood

Resale's not to bad here in Australia, the cheapest MGV8 coversion I saw was $22000 and it was very rough. I've seen them $40000 plus for a nice looking car. To compare an "nice looking, no obvious problems" 1800 MG goes for about 12 to 16000.
Mind you there are not too many V8's for sale. Generally only someone in the final stage of serious MG addiction would even consider a V8 conversion and they are just not disposed to selling. Add all the effort and time spent and you find the only V8's for sale are either a "me or the car" type wife induced crisis, or deceased estates (or some combination of both)
Peter

The reward for that sort of wifely arrogance should only be her walking papers. Any red blooded male with big enough balls to build the car in the first place has his head seriously screwed up if he'd even think twice about it, and any female who'd even consider such an ultimatum clearly is damaged goods.

Jim
Jim Blackwood

I'm definitely no sourpuss. Good heavens I certainly bear you no ill will. I mean your car is interesting. To me though the killer combo is to create a sleeper rather than something about as noticeable as a nudist colony brass band marching down main street! I mean I'd rather just wear a plain grey suit than a Buck Rogers outfit, even though I certainly defend your right to do the latter if that's what turns ya on.
Ted

Since this thread popped back up:

Brian,

FYI, a Harley is a V45. My understanding is that is not what gives it its distinctive sound, though. It's because the two connecting rods are connected to a single crank pin. That is why it is an odd fire, as you mentioned. BTW, Honda used a single crank pin on their Shadow ACE to achieve the "Harley Sound" & made less HP than the Harley they were imitating. :)

As for mild to wild conversions, although I follow a more stealth approach, I love the outrageous conversions even more!
Carl

Gotta agree with Ted,
Sleepers cool.
I definity get a childish buzz from the slightly disconcerted expressions on other drivers/motor cyclist faces. You can see them thinking "hey whats going on?, that aint right"
A bit like like seeing seeing a little old lady win the 100 meters at the olympics

Peter

Carl,
I have never studied them but it would be interesting to see an exploded view of the engines. Going to look at the harley site right now. :-)

I agree as well. I love the looks of a wild conversion, but my own almost need to be mostly stock in appearance. Every person has a different way about doing things though.

Good Luck,
-BMC.
BMC Brian McCullough

Sleeper is the way to go ,Surprise the hell out of wannabe traffic light dragsters,Honda Mugen sticker powered Civics and mullet(bogan) family sedans.
Unfortunately i too sold my V8'b a few years ago only because with around 250bhp at the flywheel, i had to lose my license at some stage.
But ive got the bug again and will be pushing around a sebring replica v8 or supercharged 4banger GT in a few months

Steve
Steve

This thread was discussed between 24/06/2003 and 23/07/2003

MG MGB GT V8 Factory Originals Technical index

This thread is from the archive. The Live MG MGB GT V8 Factory Originals Technical BBS is active now.