MGB-GT: Engine choices, what to do?

David S. Wallens wrote: You saw that we're fully detailing a Miata/MGB swap in GRM, right? Just crib from our notes.

yep! thanks! I am reading them with earnest.

(And I ordered all the backorder ones from 2007 or so too).

In reply to Keith Tanner:

Thanks! I agree about the ECU. When I did my e36 + 5.0, I used the stock ECU stuff, and it worked great.

I'm really starting to think the 1.6 might be the way to go, especially since they seem to be the lowest common denominator of the Miata world (i.e. really cheap).

I've been going back and looking at some of carl's pictures and it does seem that going for the smaller 1.6 may be beneficial (there MIGHT be enough room to not move the steering rack because of the front crank pulley, for example).

Robbie wrote:

NOHOME wrote: I had to throw out the 1.6 engine and gearbox after nearly a year of trying to sell them for any amount of $$$.

Dang. Maybe 1.6 is the way to go.

NOHOME wrote: If you read the Carl Heideman article, note that at the end he does not come out as the biggest advocate for this swap.

I do remember that. But isn't that in part because (no offense to Carl) he works with mainly MG owners who feel that "since the two engines basically make the same power between 1000 and 3500 RPM, and no MGB owner in their right mind would ever run the tach higher than 3500 RPM, that therefore the swap is a lot of work for little return?" I guess that's part of the MG exp board (all the parts but the engine swap subforum) that turn me off a little bit. Lots of people are kinda on the bandwagon of "unless it is a full out racecar, you should focus on torque because that is what you need on the street", blah blah blah. Doesn't anyone want to really wind it out now and then? No, probably not, because every trip over 5500 RPM means one headlight stops working and you need to re-adjust the valves. Isn't Norman Garrett quoted by saying something like "the rev limiter in the miata is set at 7200 RPM, and it is meant to be used"? Now THAT is a sports car engine. Don't mean to crap all over MG owners and MGBs themselves, nor am I trying to disagree with you. More just checking to make sure I remember right, and to explain further to myself why I do not want the stocker.

I seem to recall reading that when Fiat came out with the 124 spider with it's rather high strung 1.4 DOHC.. for most people it was simply an "Italian MG" and nobody saw the need for such a high revving engine in such.

I just picked up 3 more Buick 215 complete engines sitting on a 2 axle car trailer. Whole thing.... wait for it.... $150. Told you these engines were cheap. Anybody in Mass need a home built car trailer??? Anybody have any suggestions on how I load and open deck car trailer with flat tires on an open deck car trailer???? Thinking I will need some cribbing between the deck of my trailer and the frame of the other trailer to get it up high enough so it doesn't rub on my tires/fenders. A buddy of mine is selling a running 92 Miata with front end damage as a parts car for around $800, so there's a complete driveline.

heck.. how bad is the front end damage? bumper and hood or more extensive?

Robbie wrote: Doesn't anyone want to really wind it out now and then? No, probably not, because every trip over 5500 RPM means one headlight stops working and you need to re-adjust the valves.

Ha! Okay, that one got me to laugh out loud.

Different crowd than I hang with. I show them an engine with 400+ ft-lbs of torque from 2800-6600 rpm in a 2400 lb car, and they complain about the low redline...

Here's a link. Sorry, he only wants $700. He buys about one about every other week from salvage auctions. Always has half a dozen or so at his house. They come and they go, so I don't pay too much attention to them. He did just finish fixing a nice white one with a 6 speed and a bunch of bolt on performance parts. I drove it. For a Miata, its pretty sweet. https://southcoast.craigslist.org/pts/5506770074.html

nah.. too beaten up to make the 6+ hour ride home.

Use a Datsun/Nissan A15 and 5 speed (out of a 210); a moderate tune will yield 110hp motor that revs to 7600 RPM's and the motor tranny combo is 240lbs lighter than an MGB motor/tranny. Plus Datsun motor is amazing compact you could mount it well back in the chassis. Nissan used the motor until 2007 so lots of parts available.

OK OK a Miata motor is the smart way to go.

There is one other thought; have you considered fixing the most annoying issue on the MGB motor. Electronic Distributor and a set of Mikuni or Keihin carbs etc?

Tom

Robbie,

Sorry I'm so late to this party...here are some thoughts I'll add.

First, I did the 1.8 swap in my 1973 B/GT in 1999 (the car has now had a Miata engine longer than orginal!) and wanted the 1.8 for the reasons everyone states. But if I were going to do another one for myself, I would do a 1.6. The drivetrains are much easier/cheaper to find and the slightly smaller size is important as Keith said. The 1.8 is about 1/2" too big in more than one dimension and 1.6 solves that. You have to remember that most of my work is for customers. They just won't take a 1.6 because they know the 1.8 is "better." But either is so much more than the stock engine.

It's less work to cut down the wiring harness and use the EFI than it is to fab the stuff for a carb setup and make the ignition work. And then you've got a great EFI that never gives you trouble. I tell people that you do the Miata swap for the driveability of the EFI and the best-5-speed-ever-made and you get the extra power as a bonus. Don't forget if you use carbs, you've got to get the jetting right--that's trial and error or dyno time.

Regarding Zetecs, we had an unfinished swap in the shop about 10 years ago. As stated, changing a longitudinal engine to a conventional is a lot of little changes and it adds up price and time-wise. After we talked price with the owner, we didn't finish it either.

Keep in mind a swap is a lot of work--I figure about 80-100 hours. I am fussy and that slows things a bit, but I also have a lot of equipment and experience that speeds it up. I talk to so many people who have started a Miata swap and gave up after about 10 hours. They also think the hard part is mounting the engine/gearbox. That's about 5 hours. The details take all the time.

While MGB engines are dogs compared to modern cars, they are more fun if you:

--Port the head. I get calls and calls and calls from people who put big carbs and cams and valves and other things on but they never address the ports. Nothing else works until the ports are good, and honestly the other stuff doesn't help that much until you rev to 8K (not a good idea unless you're Kent Prather). A stock MGB makes 60-65HP at the wheels. With ported head and a good tune they make 80. With a bit more cam and compression they make 90. My 1.8 Miata-powered makes 116--quite a bit more, but 80-90 is pretty fun too.

--Put on a supercharger. Yea, its $5K or so. But it takes the car to 85-110HP at the wheels depending on what else is done and gives a lot more torque than a Miata engine. And you can install it in about 5 hours. I've been daily driving my superchaged 1978 MGB lately. It's got more grunt than the Miata-powered car while the Miata-powered car is more fun when I want to buzz an engine past 7K RPM.

Finally, regarding the car that's in the current set of GRM stories, it's overkill. We have a fun customer that wants a supercharged 1.8 Miata engine with AC, cruise, etc., and trick suspension and there is a ton of fabrication to make it all work. I'm writing the stories more to offer fabrication/swap tips for any job than to show how to swap a Miata engie. Of course, it does show how to do an overkill Miata swap. There are tons of pictures of this linked on the homepage of the website: http://www.eclecticmotorworks.com/

If you go way to the bottom of this page, there are a few pictures of the swap in 1999: http://www.eclecticmotorworks.com/previous.html

Good luck with your swap and give us a shout at the shop if you have more questions.

--Carl

By the way, I've got an MGB/GT that I'm currently running Mikuni's on. I've dyno'd every carb setup there is and like I said above, the ports in the head are the key to power. Properly setup, SUs, Webers, Delorto's, Mikuni's, etc. make within 1-3HP of each other. Putting a big carb on bad ports is like making the big end of a funnel bigger without making the small end bigger.

Cool, thanks for the been-there response, Carl.

Tom1200 wrote: Use a Datsun/Nissan A15 and 5 speed (out of a 210); a moderate tune will yield 110hp motor that revs to 7600 RPM's and the motor tranny combo is 240lbs lighter than an MGB motor/tranny.

Is that the engine that's a descendant of the old BMC A-series? Basically a Mini/Spridget engine?

In reply to Robbie: While several of the choices you mention would be interesting, they devalue the car.. Sorry but few people will buy non- original cars. Those that do will only buy them if they are really cheap.

Rebuild the MG engine properly.. It's the simplest way.. and don't laugh at simple.. Engine swaps have dozens of hidden problems that from what you've written so far I doubt you have the ability to overcome.. A properly rebuilt stock engine will give you plenty of smiles and fun. If you want more power a simple bolt on supercharger will give you that without de-valuing Your car..

13b.

I couldn't disagree with you more about engine swaps devaluing his car. Its a MGBGT and has very little value as it is. What is a really really nice one going for? I'd be surprised if you could sell one for 10K. Go over to British V8 and see what modified and ones with engine swaps are selling for. A buddy of mine just sold his roller GT set up for a Rover V8 for $9K, and that was with no engine. Modified TR8s are now routinely selling for 15 to 20 and the stock ones can't fetch 10. Its not just British cars. When was the last time you saw a stock Miata sell for $40K? Did you see the 8K lexus with a LS engine sell on here a month ago for 20? How about that sweet 944 with an LS? The list goes on and on. Even muscle cars. Plain jane 65 Mustangs done up with modern drivelines are fetching what the stock rare Mustangs are seeing. At least for now, modified cars are worth more. Anybody that thinks a stock MGB is worth more than one with a V8 probably also thinks they look good wearing tweed jackets with leather elbow patches.

frenchyd wrote: In reply to Robbie: While several of the choices you mention would be interesting, they devalue the car.. Sorry but few people will buy non- original cars. Those that do will only buy them if they are really cheap. Rebuild the MG engine properly.. It's the simplest way.. and don't laugh at simple.. Engine swaps have dozens of hidden problems that from what you've written so far I doubt you have the ability to overcome.. A properly rebuilt stock engine will give you plenty of smiles and fun. If you want more power a simple bolt on supercharger will give you that without de-valuing Your car..

All true, but lets be honest here: MGBs really have very little value to start with! The best MGBs on the market will only sell for around $15,000 as evidenced by this example.

https://grassrootsmotorsports.com/forum/classic-cars/classic-motorsports-car-catche/116964/page1/

Truth is that if the job is done properly, it will still sell; maybe not to am MG purist, but it will sell just fine. A botched swap will sell about as well as a botched restoration.Not everyone interprets the agonized mechanical screeches of the B series as anything other than rotating metal begging to be recycled.

sadly it is true.. the cars that made people want sports cars.. are quite undervalued and unloved. you can pick up nice MGs, Triumphs, and Fiats for what a used Hyundai Accent would cost you.

frenchyd wrote: Engine swaps have dozens of hidden problems that from what you've written so far I doubt you have the ability to overcome..

Ouch.

re value:

Yeah, not too worried. Remember I owned and drove this thing in high school? I'm sure I did more damage to any 'value' back then, just being a kid.

I also don't own cars as investments, because I think they are incredibly bad investments when you look at the odds and returns.

cough .... 13B..... Cough

In reply to Carl Heideman:

Thanks for responding with your experience!

I appreciate it very much. As you might be able to tell from my most recent few posts, I am strongly leaning toward the 1.6 at this point.

wvumtnbkr wrote: cough .... 13B..... Cough

hahaha.

Yep, thought about this many times too. I have heard it requires quite a bit of frame rail modification because it is wider lower in the chassis. Have you done it? Is that the case?

Forgetting about any kind of a budget but one of those Eco Boost 4 cylinder things look like it would be a hoot in an MG

Robbie wrote:

wvumtnbkr wrote: cough .... 13B..... Cough

hahaha. Yep, thought about this many times too. I have heard it requires quite a bit of frame rail modification because it is wider lower in the chassis. Have you done it? Is that the case?

Have not built one, but have seen a few conversions and the area where the frame and the steering rack and the steering shaft come together becomes an issue.