B Roadster : Engine upgrade for fast road use
Discussion
V8's can be had fairly cheaply. The potential is there for an easy 200hp if you want it (upgrade the brakes and suspension though 
)
An MGB 1800 bored to 1950, with all performance mods will be costly compared to the V8 and will be screaming when near 200hp. It's all about preference. The V8 will need a bit of work to put it in, but I don't know how much.
)An MGB 1800 bored to 1950, with all performance mods will be costly compared to the V8 and will be screaming when near 200hp. It's all about preference. The V8 will need a bit of work to put it in, but I don't know how much.
Depends!
Keep a good B block in. Allegedly they get fragile if you go up to 1950, but I've got mates who've not had any problems. I ran mine with a slight overbore and got a comfortable 105 at the wheels. The cost comes from making the B breath better. Changing the head for a x flow one will cost over a grand, but in conjunction with all the other breathing mods (filters, exhaust, manifold, needles etc) you could be looking at 130-140 at the wheels. I had my head gas flowed and ported and ran a stage 2 cam. The cam makes it pretty lumpy, so I couldn't run a weber on it at the same time. If you were going to run a weber, I'd go with just a mild fast road cam. Mine didn't pull at all below 2000 rpm, but delivered all of the torque beautifully for overtaking.
Cost = 3 grand including all suspension and brake updates (you might just be able to get away with uprated pads - I did).
V8 cost will depend on whether you've got a chrome or a rubber bumper car. The rubber bumper cars already have V8 ready mounts in them and the modified front cross bar gives sufficient clearance to take the V8 straight in. This could be costly. After that it depends on what you want. Standard V8 will give you about 140 at the wheels, but the torque will give you all the acceleration you want. A mildly breathed 3.5 V8 will go to 200 bhp without much work and still give you 25mpg. Once you go to 3.9 or above, then you're in the teens for fuel consumption. You're not going to convert to a V8 for much less than 5 grand. You have to alter inner wings, rear diff, propshaft, change gearbox, alter floorpans etc to take the larger wider gearbox. You normally need a new bonnet to give it clearance. Fuel feed will affect cost greatly - EFi will be costly to install properly, Holley carbs are just expensive to buy. Standard carbs are just dull!
By the way, my stage 2 B engine gave me 31 mpg over the ten years I had it, and I drove it in a spirited fashion!
Another alternative is to just buy a converted V8 and just keep the bodywork in good shape! Much cheaper, but you'll have to wave goodbye to your pride and joy. This was the way I was thinking!
Keep a good B block in. Allegedly they get fragile if you go up to 1950, but I've got mates who've not had any problems. I ran mine with a slight overbore and got a comfortable 105 at the wheels. The cost comes from making the B breath better. Changing the head for a x flow one will cost over a grand, but in conjunction with all the other breathing mods (filters, exhaust, manifold, needles etc) you could be looking at 130-140 at the wheels. I had my head gas flowed and ported and ran a stage 2 cam. The cam makes it pretty lumpy, so I couldn't run a weber on it at the same time. If you were going to run a weber, I'd go with just a mild fast road cam. Mine didn't pull at all below 2000 rpm, but delivered all of the torque beautifully for overtaking.
Cost = 3 grand including all suspension and brake updates (you might just be able to get away with uprated pads - I did).
V8 cost will depend on whether you've got a chrome or a rubber bumper car. The rubber bumper cars already have V8 ready mounts in them and the modified front cross bar gives sufficient clearance to take the V8 straight in. This could be costly. After that it depends on what you want. Standard V8 will give you about 140 at the wheels, but the torque will give you all the acceleration you want. A mildly breathed 3.5 V8 will go to 200 bhp without much work and still give you 25mpg. Once you go to 3.9 or above, then you're in the teens for fuel consumption. You're not going to convert to a V8 for much less than 5 grand. You have to alter inner wings, rear diff, propshaft, change gearbox, alter floorpans etc to take the larger wider gearbox. You normally need a new bonnet to give it clearance. Fuel feed will affect cost greatly - EFi will be costly to install properly, Holley carbs are just expensive to buy. Standard carbs are just dull!
By the way, my stage 2 B engine gave me 31 mpg over the ten years I had it, and I drove it in a spirited fashion!
Another alternative is to just buy a converted V8 and just keep the bodywork in good shape! Much cheaper, but you'll have to wave goodbye to your pride and joy. This was the way I was thinking!
I have been told, but I'm not sure how reliable the information is, that the 2-litre T-series engine (as found in the Rover 220GSi/420GSi/820GSi) will bolt up to the MGB box.
These puppies are 140bhp in stock form and have gobs of torque (ex-220GSi owner
). Would be fiddly with the electrics and the EFI (but if you had a complete car to take the stuff from then possibly not too bad) but a whole lot of fun. Then there's always the turbo version too! 
These puppies are 140bhp in stock form and have gobs of torque (ex-220GSi owner
). Would be fiddly with the electrics and the EFI (but if you had a complete car to take the stuff from then possibly not too bad) but a whole lot of fun. Then there's always the turbo version too! I have both:
- a red roadster, with a 1950cc engine with a breathed crossflow head, dell'orto carbs, piper 285 cam, ... It makes 124 bhp at the wheels (around 150 at the flywheel), is very tractable from 1500 rpm, quite good on fuel (this really surprised me!) and leaves most other 4cyl MGBs as if they were not moving.
- a black GT V8. This one is standard (for now), but is more of a tourer then the 4cyl. The sound it makes is just to die for, but it's not that good on fuel.
Sadly, I'm thinking about selling one of both (they're both rhd), but I have no clue as to which...
- a red roadster, with a 1950cc engine with a breathed crossflow head, dell'orto carbs, piper 285 cam, ... It makes 124 bhp at the wheels (around 150 at the flywheel), is very tractable from 1500 rpm, quite good on fuel (this really surprised me!) and leaves most other 4cyl MGBs as if they were not moving.
- a black GT V8. This one is standard (for now), but is more of a tourer then the 4cyl. The sound it makes is just to die for, but it's not that good on fuel.
Sadly, I'm thinking about selling one of both (they're both rhd), but I have no clue as to which...
Church of Noise said:
I have both:
- a red roadster, with a 1950cc engine with a breathed crossflow head, dell'orto carbs, piper 285 cam, ... It makes 124 bhp at the wheels (around 150 at the flywheel), is very tractable from 1500 rpm, quite good on fuel (this really surprised me!) and leaves most other 4cyl MGBs as if they were not moving.
- a black GT V8. This one is standard (for now), but is more of a tourer then the 4cyl. The sound it makes is just to die for, but it's not that good on fuel.
Sadly, I'm thinking about selling one of both (they're both rhd), but I have no clue as to which...
What suspension/brake mods have you made on the roadster please?- a red roadster, with a 1950cc engine with a breathed crossflow head, dell'orto carbs, piper 285 cam, ... It makes 124 bhp at the wheels (around 150 at the flywheel), is very tractable from 1500 rpm, quite good on fuel (this really surprised me!) and leaves most other 4cyl MGBs as if they were not moving.
- a black GT V8. This one is standard (for now), but is more of a tourer then the 4cyl. The sound it makes is just to die for, but it's not that good on fuel.
Sadly, I'm thinking about selling one of both (they're both rhd), but I have no clue as to which...
Steve
Brake mods: just installed Mintex 1144 brake pads and shoes. These make an incredible difference. They make quite a bit of dust too though.
Suspension:
Suspension:
- 3/4" anti-roll bar on the front,
- uprated lever arm dampers front, Koni dampers rear (will probably be replaced for standard lever arm dampers, the Konis are even too hard on their softest setting)
- panhard bar at the rear
- poly bushes all round (the fast road type)
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