1973 MGB resto-new user

[joyhale]

We recently bought a "barn find" 1973 B. It has an 1800cc in it, not known if it was original to the car, and we were given another 1800 engine with tranny. Engine would not start when purchased it. Naturally all my husband's friends feel that we should put a V8 in it. Is this detrimental to the value of the car? What engine would be the easiest and least costly to swap it out for? Looking for ideas. Thanks

[Moderator]

Congratulations on your lucky find, and welcome to the BritishV8 message board!


The easiest and least costly things to do would probably be to fix up the MGB/engine you have, or to sell the MGB you have and buy a car that's already been converted.

Sincerely, for those of us who have a passion for these little beasts it's truly sad to see the "which engine" question boiled down to just ease and cost. You haven't even mentioned what you want from the car - in terms of performance, for example. 1973 MGBs aren't rare or precious, yet. ANY decent conversion will probably enhance the value of your car since it's currently not running. There are many swapped MGB's on this website with values well into five figures and several times the value of an immaculately restored all "original" 1973 MGB - but that value comes from a combination of craftsmanship and passion. On the other hand, it's unusual to make money on an engine swap project, and a botched or abandoned project will be a big waste of your time and money.

Looking for ideas? Take some time and look through our Photo Gallery (found under the pull-down menu at the top of this page) and you'll find all sorts of excellent ideas. They might help you decide just what you really want from your car, and then we'll be here to help you realize your goals or even estimate what they might cost.

If you decide to sell your barn find, don't forget that we have a great classified ad section. We love barn finds!

[joyhale]

I do apologize. I, in no way, meant to insult you and your members, by making it seem that all I was interested in was a "bottom line"
I LOVE this car and I intend to tool around in it for many years. My husband is an awesome body man and is the process of finishing the paintwork.  We were thrilled at your suggestion to replace the original motor, which was what our intention was. But, as we were getting so much unsolicited "advice" and while we had the motor out, we were considering other options.
My intent of the post was to help avoid making a mess of things by putting a "wrong" engine in and end up in the scenario that one thing leads to another, and other, and another, spending money and wasting time when I could be out enjoying the ride! .  I do understand that there is no "wrong" motor, it's a preference as to what you want the car to "grow up to be". We've decided to go with "plan A" and use the original motor. Maybe we'll just convert it to a single two barrel carburator, instead of the SUs. Any suggestions on that?
I want to drive this car, and I want to do it asap! We're bringing it back to the original color and I just want to go to some car shows with it and cruise around the countryside following the cobras, vettes, and trans ams, that we run with.
I'll check out the photos and get ideas and maybe when I'm in my eighty's I'll post it for sale.
thank you

[mgb260]

Joy and Ralph, I don't think anyone feels insulted. There is a Weber progressive 2 barrel and intake. It is a little spendy and I doubt if performance is any better than well tuned SU's. There are fans of both. I think if you look at the "how it was done" section on this site you will be tempted to do a V6 or V8 swap. There are kits for 2.8-3.4 GM V6's,Ford 302(5.0) V8. Also the 215 Buick,Olds,Rover V8 is what the factory put in the V8 cars. There are a few GM LS aluminum V8's too.There is increased interest in modern OHC fuel injected fours and modern aluminum Toyota,Lexus V8's also. Also check out MGBExperience site also,lots of good info.

[BlownMGB-V8]

What engine to use is largely a matter of not only how much power you want, but future plans as well. You can divide the cars into stages if you like, beginning with the stock engine, hovering about the 75hp mark, plus or minus about 15. Here the car is fun to drive, but passing is very difficult and it won't keep up all that well in traffic, at least not with the new cars. So that's your baseline, and for someone who knows what they are about, restoring the engine to that spec is about the same expense and difficulty as the next stage.

Here we are in the roughly 150 hp range. You can get here with the four but it is expensive and difficult. Better options exist. You can easily keep up with traffic, the car is a joy to drive, and a great number of conversions fall into this category. There are few if any drivetrain or cooling issues to address. Typically these conversions use either the 60* V6 or the BOPR aluminum V8. In either case the swap is simple and the engine a bone stock junkyard mill. All parts needed are readily available so this is without a doubt the cheapest and easiest way to go, and can even be done for less than the stock rebuild.

At around 200 hp the MG begins to become a performance vehicle. The power level now allows very spirited driving as your weight:power ratio approaches 12:1 and there is enough power to break the tires loose if you want to. Many owners are very happy at this level.

At around 250 hp you have exceeded the 10:1 level and are now truly into the performance or muscle car range. You can now execute power slides, break the rear end loose at will, and do donuts in the parking lot if you like. For some this is the only place to be but their numbers begin to taper off. Now you need to be concerned with cooling and the driveline and the conversion costs can escalate rapidly. Here, you are pushing the limits of a V6 conversion and really are into V8 territory. A SBF or SBB engine becomes a likely choice along with the BOPR.

300 and above. Probably not what you are looking for, these are the fire breathing dragons of the lot. They are capable of breaking loose the tires on demand, extreme acceleration, but at the same time present serious demands in design to control that power. Cooling gets great attention. The BOPR is straining a bit to get here but is still viable. You get into diminishing returns. Once at 300, the car is capable of doing anything you could ask of it, and bigger numbers don't gain you all that much. The horsepower junkies among us would appreciate it but our ranks are getting pretty thin by now.

If I may, allow me to point out something about the above. Do you notice one engine that falls into every category except the first? The BOPR. This is a clue to it's continued popularity as an engine choice. It is one engine that allows you to do the swap, then modify it to achieve the power level that you are most comfortable with, regardless of what level that happens to be. And if eventually you do want the fire breathing dragon you can easily change over to the SBB 300 to extend that range and even recover some of the cost in the bellhousing swap. On the other hand, you can easily reduce the power level should you desire to concentrate on driveability and economy.

I have to confess to being a fan of this conversion. It is the most versatile one out there, it has been around for near 50 years, and it continues to please. It also has the legitimacy of the factory sanction if that means anything, and to a surprising number of folks it does. Plus it lightens the nose of the car by 30 lbs where the others do not. For a late model car it is a bolt-in swap and not much more difficult for the earlier cars, has been done a hundred different ways and the process refined. A V6 swap makes a dandy car but the V8 just sounds so much better. A 302 makes for a great car but isn't any better than a SBB 300 and requires crossmember mods. Considering that you'd like to run around with the Cobras, Vettes and Trans-Ams, wouldn't it be a great thing if you could bump up the power easily should you find them running off and leaving you? I'm afraid you will be mightily disappointed in the stock engine. You might be fine with the V6, but you also might find it lacking. On the other hand, a low mileage Rover junkyard pull is a great choice, with EFI and electronic ignition, meaning easy starting and no gasoline smell. Since your husband is a body man, the firewall mods and openings for RV8 style headers (highly recommended) will pose no problems at all. The rest of the swap is largely a straightforward bolt-in proposition. And just so you know, one of our vendors has a reputation for doing one weekend BOPR conversions at the customer's site, so the time to get running need not be greater than a stock rebuild.

Whatever you decide to do, you have come to the right place. We are Conversion Central. Browse the magazine articles on file here, you will find answers to most of your questions and we will help you with the rest.

JB

[joyhale]

Thank you Jim!
That was exactly the type of information I was looking for, even though I didn't know how to ask.
 I, too, had a vision of running behind all those guys,pointing up the road and yelling to the crowd "I'm with them, which way did they go?" lol
I appreciate all your advice.
Joy

[J Man]

I plan to do a swap in mine as well, mine os a GT. I have picked up a couple books on e bay and Amazon for modifying MGBs. This might be a good source for ideas of stuff you can do. If you are considering the stock engine there is a guy in CO doing 5 spd swaps. There is a book for building a performance 1.8 motor. There is also one for swapping the aluminum BOPR engine. The third book I know of is in regards to upgrading the vehicle as a whole.

Depending on where you are located there are always some popping up for sale. As mentioned earlier the V^ swap is an option and these can easily be found in salvage yards. I know in other cars Ecotec 4 cylinders are very popular, find one from a Solstice or Sky and the will be set up in a rwd configuration.

[motek]

Jim,

Good job on spending so much time helping a newcomer. I agree with everything you wrote except one thing:

"A 302 makes for a great car but isn't any better than a SBB 300..."

Not any better in performance, but the Ford allows you to say the three magic words -  "3"  "0"  "2".  :-)


George

[kstevusa]

Wow!  Maybe 5.0L sounds better than 302???  
Both engines are 5.0L  but very different.     Maybe I am   Blue Oval guy ?

[MGBV8]

3 0 2 is only magic when used to refer to the engine in a 67-69 Z28 Camaro!