MG Sports Cars

Hello everyone. I just bought a really nice 69 GT off of Craigslist for a song. It runs and drives great as is, but I've got it bad for a V8 conversion and have some questions. I have given a lot of thought throughout the bleak winter days as to what I would like out of the car. In a nutshell I would like a sleeper i.e.....a "wolf in sheeps clothing." I think that I would like to go with a buick/rover engine, but I know nothing about them. Here are my questions: What is the lightest V8 available? Are the Rover v8's that much lighter than a 302? Is one RV8 heavier that another? Does the sump hang down lower in the RV8's than the stock 4? Will I have to raise the height of the car? (I want the car to stay low) I would like to get somewhere around 300hp with simple engine modifications. Which engine will meet that number? Thanks.

Welcome, Tom. Curtis Jacobson has done an outstanding job developing, maintaining and expanding this board and there is an amazing amount of info just a click of the search icon away. Plow through as many articles as you can and you will come away impressed with the talent and ingenuity you'll discover.

It's tough to get a consensus on this topic! It all comes down to personal opinion in the end.

Weight differences between the Rover and other engines such as the 5 liter Ford and Buick 300 and 340 are dependent upon the engine configuration, alloy heads, intakes, etc, with the Rover engines always coming out lighter but sometimes by a slim margin.

You will not need to raise the car with either the BOPR or 5.0 Ford and there are no sump clearance issues with the BOPR or Buick 300/340. The Ford engines do pose some sump/X-member issues but they are certainly not insurmountable and the solutions have been covered many times in various articles on this site. Pete Mantel

[www.britishv8.org]

and Fast Cars

[www.fastcarsinc.com]

are two who come to mind and who have terrific reputations.

The easiest way to get 300 HP is with a 5.0 Ford. They are common, relatively inexpensive and there are few "how to" questions concerning using this engine that have not been answered. However, finding a 5.0 with alloy heads or adding them might cost a bit more.

A really nice alternative to a V8 is the Buick 3.8/3800 V6. Do a search on this site for information. One of the more knowledgeable guys on this site, Jim Blackwood, is a big proponent of the 3.8.

Regardless of which way you decide to go, you'll find scads of information, support, and really nice folks on this board.

Again, welcome aboard!

Hi Tom and Welcome!

I know plenty of individuals who want a certain BHP number but don't plan to upgrade the suspension, tires, wheels, and so on. If this is a perfectly stock car other than an engine conversion and 5 speed, you will find 300 BHP to be a waste at anything (my guess) below 30 MPH. You'll have axle tramp, one wheel wonder spinning away and even if you go with good tires with a limited slip, your gear ratios and so on will not be the best possible for that type of BHP/Tq numbers. My 3.4L V6 can keep the 195 width tires lit up if I want. It's "only" rated by GM at 160 BHP and 200 Lbs Tq so well below what your going for in its completely stock state.

BHP numbers are fine, but rather than spending all the money on the engine, figure out what you want in the end. Start researching articles on cars built here that actually have 300 BHP and if the owners actually use them for hard driving or just occasionally driven hard but more built as a daily driver or a show car.

A few numbers and ideas based of half the numbers your looking for. I am going off what I know best- my car.

I have had it up to somewhere slightly over 5,000 RPM in 5th gear (stock 3.909 rear end and 0.68 or 0.63 5th gear- we guess its the 0.68) which comes out to 120+ MPH. Does not take long to get there.

2,250 lbs according to the scales at last years meet:
[www.britishv8.org]

Rear axle tramp? Not much because I can't get enough traction with the 195 width tires and the late model MGB (1977-1980) designed rear anti-roll bar is somewhat of a axle hop preventer due to its positioning.

An MGB can have 205 width tires and in some cases 215 series tires installed with little body modifications but 225 with stock bodywork is impossible according to most. Note that if your going to have LOTS of power, flares may be required to get that power to the ground from an absolute stopped position.

Limited slip, which has yet to be installed with my 3.42 axle will help quite a bit and when i do that modification but I will absolutely have to add anti-tramp bars and 205 or larger width wheels and tires.

The stock suspension on the MGB, when properly maintained will hold up really well but updating it will make the car even better.

The stock brakes, when maintained well will hold up pretty well with the replacement motor pending weight is changed little but since you have more potential to go faster and/or you may do more hard braking due to the increased potential for speed in time trail or street situations, upgraded brakes should be considered for competition, possible hilly or mountainous driving or driving habits.

So the idea behind 300 BHP is Great but before you spend all your time on building a 300 BHP engine, make sure you have a plan for the rest of the car... If not, please stop by in Minnesota when your done. I suspect my 60 foot times will be quicker and my 1/8 mile times may be a bit quicker or in line with yours. If you at least put a nice set of wheels and tires on that car, you'll have me in the 1/4 mile..... I'll have you on every track with corners. :-)


Again, Welcome to the board. Make sure to search the How-It-Was-Done articles to see the various builds:
[www.britishv8.org]
The sky is the limit!

-BMC.

Wow, thanks for the great information. I've only been on this site for a couple of days and I am overwhelmed by the different set-ups.

Okay, maybe 300Hp is a little much. I guess what I should have said was "up to 300hp." I want the car to handle well and not be overburdened by too much power and a boat anchor up front.

Here's the latest; I just discovered a 99 Rover 4.0 engine on Craigslist. It's in a Land Rover that has been rolled. The owner e-mailed back and says that it does not have the secondary air injection (whatever that means) and runs great. He wants $1,200-I'm waiting to here back on the miles. I'm thinking thats a little high and will counteroffer even if it does have lower miles. Can I slap an Offy manifold, headers and carb on this engine or do I need older style heads?

BTW, the other criteria is that the car has to sound tough. No mamby pamby wimpy exhaust note! The stock 4cyl engine sounds great as it is. And I'll worry about brakes later. Thanks again.

Yes, you certainly can put an Offy manifold on a Rover 4.0 engine. There's one for sale in our classified section right now. If you find a used Buick 4 barrel manifold, it'll sit a little bit lower. There are lots of header options. The exhaust ports on the 4.0 engine are slightly larger than on early Rover or Buick aluminum engines - like a millimeter or two in both directions - so all the headers will bolt right up, but you'll benefit more from some of the newer, bigger headers.

$1200 might be a good deal if the mileage is low - because machine work and new replacement parts are both expensive. My neighborhood machine shop gets $350 for a valve job on a Rover plus $140 to skim the heads if they're not flat - but you'll probably leave the heads alone, right?

Don't throw away any of the EFI parts - you may decide later you want to upgrade. Worst case, you can sell them pretty easily on eBay. Try to get EVERY part of the EFI system, including the complete wiring harness.

The 4.0 has a different front cover which is going to give you a little extra complexity. It seems that most people retrofit an earlier style of front cover, a cam driven oil pump, and a conventional distributor. You can find info on that several places on this site, or you can start new forum threads on those topics when the time comes...

The heads on all Rovers and 215's accept the same intake and exhaust manifolds.

Brian will disagree but there is no substitute for a V8 exhaust note. The V6's sound nice but give me a V8 rumble every time.

Oh yeah, here's a good deal on an engine and gearbox if it is not sold.

[www.mgexperience.net]

FWIW, I paid about $800 for a 42K mile 3.9 from a '95 Disco including the entire injection setup and ancillaries. Also, you'll probably want to change out the front cover/oil pump on that 4.0 to an earlier version. Go ahead and buy this book, too. It contains a the answers to a lot of questions you will have.

More great information. I'm assuming a couple of things with this engine; 1) that EFI is a pain to set up if you're not into electronics, 2) that i'll get a better sound and perhaps better throttle response with a carb.

Which tranny works best with the 4.0 and stock MGB rearend?

Actually, EFI should be fairly easy to set-up, especially if you buy a 3.9 ("14CUX") Rover engine instead of a 4.0 ("GEMS") engine if only because lots of people have gone down that path before you. Mechanically, the 3.9 and 4.0 EFI systems share a lot of parts. Same intake manifold and fuel injectors, and interchangeable fuel rails. The 4.0 plenum is a little boxier (which could make it slightly trickier to package under a stock hood.) Some of the big differences are in the wiring and ECU. The GEMS ECU needs a crank position sensor. The 4.0's engine management system electronically controls both fuel injection and ignition... and by all accounts its four-coil "direct ignition" system is a performance advantage. In either case, EFI should certainly give you better cold-start performance and better fuel economy. I'd expect throttle response to be a wash (compared with a carburetor.) If your induction system makes a real big difference in sound, that only means your mufflers aren't obnoxious enough. (My mufflers are really obnoxious!)

Want more info? This article should give you an overview. Service and Troubleshoot Rover 14CUX Electronic Fuel Injection
(Note that it contains links to other references at the bottom.)

Which tranny? The Borg Warner T5 (from a V8 Camaro) is most popular stateside, the Rover LT77 is most popular in England/Europe, and the Toyota 5-speed is especially popular in Australia... All three are good options, and probably familiarity and cost are the biggest factors. The T5 is lighter than an LT77 and doesn't have an internal oil pump which may require service in the transmission's lifetime. Shifter feel is different between all three. From my point of view the LT77 has "reverse" in the wrong place, but that's nit picking.

There's nothing fundamentally wrong with MG's "Salisbury" axle, but after awhile you'll probably grow tired of it. Both Rover and Ford V8's deliver a LOT more torque than the MG engine could, so you won't need that 3.909:1 granny gear ratio. It's possible to install MGC gears in your MGB axle, but that may not be economical. With a narrowed American axle you'll get to pick a different gear ratio and probably also get a limited slip differential as part of the bargain.

A couple more irritating questions. Does the Borg Warner tranny fit the Rover bellhousing, or does it need to be modified? Can you use the stock MGB gear shift? Thanks.

Howdy Tom,

I'm hung-up on the v8 exhaust sound just as you are (although I do like the raw raspy v6 exhaust note of my wife's Infiniti G35 coupe - different era). It never fails - when I attend the spring/fall hotrod meet (5000-6000 cars) in Ocean City, MD - someone comes up to me in one of the parking lots where everyone is gathered and says, I HEARD you go by on 28th, 33th, 9th street, etc. - I doubt that would occur with anything less than the v8. As a bonus, it's a great conversational piece (rover/buick) - most folks don't know what the heck it is!

I agree with Curtis, Save the FI if you get that engine. It's not difficult but you will spend more time setting it up and Far less time diagnosing it or spending money on a dyno to tune it if done right. Cold day, hot day, bad fuel, whatever. The FI is going to take to it better and will control ignition too. Fuel injection is PRO-actionary and knows what you need before the engine can really take it. Carb is RE-actionary and the fuel is pulled through with the air and does not have the potential for throttle response, aleit carb has had well over 100 years of production use to figure these things out. An engine tuned properly on the best carb is not going to last as long as a FI engine because chokes wil stay on a little long and there are more parts to fail causing lean or rich burn which has the potentail to shorten the engines life.

David, you are correct. I disagree about the exhaust note. I believe that the note is in the pipes. Twins, singles, size of pipe, where the crossover comes, if at all and so on. I think its like building an organ. Every pipe will cause a different sound and 99.9% of shops are guessing since the majority of their job is to just get the smelly and nosey stuff out behind the car. I had my exhaust system built so it would be hard to be picked up bylaw enforcement. I don't really know too much about how it sounds going down the street as its being driven away since I have hardly ever had the chance to watch it take off hard without me in the drivers seat. Keep in mind that V8s were the "American muscle" for many years and will continue to be and thus, V8s were teh cars that the factories spent time designing good sounding exhaust systems. The idea that any less or more number of cylinders cannot sound as good has me quite skeptical. I know different 4 cylinder engines that have such dramatic sound differences that its hard to believe that anyone could say all V8's are ABC and all other engines are XYZ. Just food for thought. This thread is about Which V8 and my point was not to get in to the hard and heavy of the V6, but to point out that if your going to go for step #1 being XXX BHP and Tq, then you MUST do steps #2, 3, 4, 5 and 6 otherwise, al you will have is bragging rights to power, just dont give the specifics on the rest of the car. Personally, I like the idea of low BHP numbers that rip apart someone else's high numbers. An engine with 500 BHP/ 100lbs Tq engine with no torque in an otherwise stock car against something with 250 BHP and 250Tq and takes the prize? Thats just fun to watch.

Tom, Hope you enjoy the ideas we bounce around here. That 4L sounds of interest... Also, the secondary is probably an air pump and most likely something you would throw away anyways if it is what I think it is.

-BMC.

Where are the "Ford guys"? I would have thought someone would have dropped-in here to discuss the Ford 302's virtues. ALL the engines mentioned in this thread have their advantages.

Quote:

Does the Borg Warner tranny fit the Rover bellhousing, or does it need to be modified? Can you use the stock MGB gear shift?

It's very highly unlikely the rolled Land Rover will come with a bellhousing... because most North American market Range Rovers and Discos come with automatic transmissions. (If you can find one of the rare few with an R380 5-speed transmission, snap it up!) Rover 5-speeds and bellhousings mostly come from earlier model donor cars such as Rover SD1s and Triumph TR8s. And to answer your question: no, a Rover bellhousing won't mate to a GM-spec T5 transmission. To install a T5, you're either going to need to find a used Buick bellhousing (difficult, but not impossible) or else purchase an aftermarket bellhousing for mating the Rover engine to a T5. The transmission won't need to be modified. You'll probably decide to cut the shifter lever shorter than stock; you may or may not want to bend it a bit to the left... Can you use the stock MGB gear shift? The MGB gear shift lever won't bolt onto a T5 transmission, if that's what you're asking. It's technically possible to use the entire MGB 4-speed gearbox (with an adapter plate) - but few people would recommend it because it's not really built to take the torque of a Rover 4.0.

The BOPR(Rover) is a good choice, for decent power, torque, and light weight. It offers a wide range of outputs and is light. The SBB 300 and 340 allow higher power outputs and represent a step up, have an iron block, minimum weight penalty (about 50 lbs heavier than stock) and can be swapped in for the BOPR with a bellhousing change. The SBB 350 can be used but hasn't been done yet, as alloy heads and headers are not yet available for it, and the Buick 3.8/3800 (think Grand National) is an excellent choice and is just beginning to show up in these cars. Eventually headers should become available for it, and alloy blocks and heads are on the market. These have virtually unlimited horsepower potential, twin turbo drag race versions have produced 1700 hp. Then there is the BBB such as we are fitting to the RoadmasterMGB. With alloy heads and intake the weight penalty is about 100 lbs, 400hp and 500 ft/lb of torque, stock. Alloy blocks for these engines are available with displacement potential well over 700 cu.in. This should make a car that weighs about what it did before the swap, maybe less. How much can you spend?

All of these engines can be used in the MGB with a reasonable level of body mods, some with none at all. That pretty well defines the Buick and Buick derived lines with one last possibility I'd like to mention. Elsewhere on this site we've seen that a 340/350 Buick crank will fit in a Aussie Rover P76 block, and that the BOPR can be sleeved to a 3.8" bore. This combination yields 350 cu.in. (5.7L) in a lightweight package. Sleeving and finding the right rod/piston/head/intake package are the challenges, but TA Performance will have a new Rover head available in about a year for around $2500/pair complete, and that might include the roller rocker assemblies. (have to check on that last part) These heads, based on their GN V6 heads promise tremendous performance potential at a reasonable cost. 350 alloy heads should come shortly thereafter.

The 60*V6 is a fine choice, especially in terms of space in the engine bay and offers performance comparable to the 3.5L Rover. It is possibly the least expensive option there is, depending on how the swap is done. The 302 SBF is an excellent choice and has been well developed. It is the same weight as the 300/340 SBB and offers a wealth of performance options, but does require crossmember modification or replacement with Ted's most excellent front suspension. (at a cost approaching 4 grand iirc)

There have been some other engines used. The SBC, which is heavy, not a good fit, and requires custom headers, the LS series, at the same weight as the SBB/SBF, and a completely custom install of largely unknown proportions, and various lesser known swaps. HTH

Jim

Jim,

If I may hijack this thread momentarily - any guesses on what the weight of the Buick 350 might ultimately be with aluminum heads?

About the same as the 340/300 with aluminum heads, which is give or take within a few pounds of the SBF and the LS. Roughly 50lbs heavier than the stock engine.

Jim

Jim,
I just came across this thread. I found a 340 SBB in the paper running for $150. I'm not familiar with buick engines at all. This may have alreadye been cover but how does it compare in size to a 4.o rover and the 215 buick. Matt

Matt, don't let that one get away from you. At that price you can easily recover your costs if you decide not to use it. If it's a 4 bbl, even better. (where are you located?) Try to get some history on the engine, and if it's in a car ask to hear it run. Otherwise spin it over by hand and maybe do a compression check.

The deck is roughly 1-3/16" taller than the BOPR engines, and I don't have a measurement for the carb height. Based on deck height it should be about 5/8 to 3/4" taller. Everything else is the same except for the exhaust ports being larger. Currently there is no aluminum intake manifold available for the 340, but spacers can be used to adapt the 300 intake. Alloy 300 heads will fit, and the new Rover heads from TA Performance will be available in about a year. Obviously an IR setup for a 215 would also work.

Jim

Jim,
Thanks alot for the info I will call about it tomorrow and see if it still available. I am in the process of putting a SBC in my 1980 MGB but a guy was giving away a 74 MGB-GT on another forum I'm picking it up next week so I'm looking for a different set up. I won't repeat the SBC. Should have went Ford or Rover I would be driving it by now. Matt

Forgot to to mention I'm in northern Alabama

"The deck is roughly 1-3/16" taller than the BOPR engines"

Humm....I happen to like the look of a C hood - without the SU bump!