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 MGA - Is this for real? 185 BHP B engine.

Is this even possible?

http://www.britishclassiccarspares.com/engine.html

Would it fit in an MGA? Can't afford one these engines, but it'd be nice...
Darian Henderson

Possible, yes. Want to drive it on the street, no.
Derek Nicholson

and overhaul it every 500 hours too
wilbur

What's the price?

It says POA.

That usually seems to mean that the sellers are too embarrassed to say openly that they want too much money ;-)

Neil
Neil McGurk

For a comparision check out Chris Benson's site at MG Octarine Services. http://www.octarine-services.co.uk/alex1950.htm He sells a 1950 crossflow engine that dynoed out at 158 bhp. Engines like this are not cheap, besides the crossflow head you have a lot of high dollar machine work and custom rods and other internal engine components that are necessary to not only make this kind of power but to have the engine live. It's basically a race motor. When Kent Prather (SCCA G Production) blew his 1622 at a race a couple of years ago he commented "there goes another $10K" to give you some idea of what these motors cost.
Bill Young

Correction, the 1950 made 124 bhp, it was the V8 that did the 158.
Bill Young

I'm not going to comment on that engine, but I can tell you that those numbers are possible on race engines. I've dynoed MGB race engines (5-port heads) that made 136-138HP at the wheels. MGBs lose 30-35 HP going from the flywheel to the wheels, so these engines are in the 170 HP range. As mentioned above, these types of numbers aren't for the street. Typically, engines like this will barely run below 4000RPM.

--Carl

p.s. I think Kent Prather engines are much more than 10K these days...
Carl Heideman

The price for that engine is £4,700, or "only" $9,000. That is way, way out of my price range. (That's about the budget for the car I'm trying to get resurrected!)

On a much more realistic note, how expensive would it be to buy an old 3-bearing MGB engine and have it bored out to 1950? What kind of pistons would you use? Would I then be able to take my HRG crossflow head from the 1622 engine it's on and install it on the "new" 1950 engine? Just a thought.
Darian Henderson

Carl, I'm sure you are correct about the price, that was Kent talking about his own engine. I'm sure the price for his labor wasn't included. I just used it as an example of the price range we're getting into when you talk about 170+ bhp engines. It's an old tale that racing can make you moderately wealthy, if you start out extremely wealthy in the beginning. ;-) Speed doesn't come cheap if you limit your engine choice either by regulations or personal preference.
Bill Young

Darian,
if you want to go the 1950 route forget about the 3-bearing engine. Get a 5-bearing 18V-block and do it. It will cost a bit more than a standard engine but will give more power in all rev ranges.
I run a 1930cc engine with HS6 carbs on my MGB with 106hp at the rear wheels. With a 270° cam it is tractable and pulls evenly from 1500 to 6000.
Joern-M.

Carl,

The engine on Chris' site runs perfectly below 4k rpm , and the numbers were recorded on Peter Burgess' dyno.

Darian,

perhaps you can contact Chris about your idea, so did I...

Alex
Alexander M

Thanks for the link to Chris's site; it looks interesting. I have no doubt he knows what he's doing, but I was looking for something more local.

Now I have an idea, though. Thanks
Darian Henderson

Alexander,

I'm sure the one on Chris' site does well run at lower RPM--I was talking about the NA 5 port race engines I dynoed this summer--probably wasnt' clear enough in my brevity.

--Carl

Carl Heideman

I see, my mistake Carl!
I take it these race engines use mad mad cams then?

Jörn,

Is the 3brg crank not strong/stiff enough for higher outputs then?
Alexander M

A three main engine can be built to put out a lot of power comparable to the 5 main engine. There are some issues with crankshaft strength, but these can be overcome with careful engine building. Kent's engines are all 3 main 1622 engines as required by his class and put out amazing power. But the later B racers that can use the 5 main 1800 as a base do. If I was building a hot street engine and could use the 5 main engine I think I would prefer to use it just because of the greater availability in case of breakage. Three main blocks are getting to be scarce.
Bill Young

Carl, how can you lose 35 HP going from flywheel to rear wheels ? There is onle a gearbox (straight theough in top gear) and the CWP gears, plus a few ball bearings, so only 1 gear mesh. Or is most of that lost in the tires? If you were dissipating all that heat in the gears they would be frying.
Art

Art,

I run some engines on an engine dyno (Stusca), some on a chassis dyno (DynoJet 248) at a nearby dyno shop. I've never run the same engine on both, but most stock MGB engines make about 90-94 at the flywheel on the engine dyno and most stock MGB engines make about 60-65 at the wheels--that's where I get my 30-35 HP loss. I've run on other dynos and found similar numbers.

A lot of people want to take the loss as a percentage of power. I figure it would be a constant number for a given car. That is, a 95HP MGB engine should show 65 at the wheels, while a 125HP MGB should show 95. I've got some work coming up for some stories in Classic Motorsports that will probably have us testing the same engine on both dynos and I should know some better numbers after that.

I'd guess the tires eat more power than other things. It's clearly not the gearbox--we get the same numbers in most any gear--in theory 4th (direct) should have less friction but we have never been able to measure a difference.

Don't know if that helps, but after about 1200 pulls, I'm pretty convinced dyno's don't lie!

--Carl

Carl Heideman

I think Carl is right about the tires eating into the hp. What you look for is anything that generates heat when you drive. The heat comes from friction, which is eating into your power. Tires warm up because they are generating internal friction as they flex to conform to the road surface. Another source of heat is the differential. The Hypoid axle gears rotate, but also slide against each other, and generate a bit of heat, so much so that in the NASCAR racers they mount special pumps and oil coolers for the rear axle lubricant.
Bill Young

This thread was discussed between 11/03/2007 and 15/03/2007

MG MGA index

This thread is from the archive. The Live MG MGA BBS is active now.