Board logo

Using BMC A-series 1275cc
Jermyn - 9/2/05 at 10:09 PM

I am kicking around using a spare A-series BMC 1275 I have sitting on my garage floor. The engine is complete and ran well when removed. Easily rebuidable and the right price. (free)

I also have access to triumph uprights for front suspension and a ton of other MG/Triumph parts. This would help me limit my build costs to steel/aluminum, paint and welding supplies as I have most of the other stuff.

Question is.....What kind of performance am I looking to get out of the BMC 1275? I'd like to stay in the spirit of Low-cost but If I'm going to take the time to build it, shouldn't I go for a bigger engine?


locogeoff - 9/2/05 at 11:16 PM

to misquote (probably)
"Speed is just a matter of money, how fast to you want to go"

with 75 bhp
0.60 about 8.5 seconds? top speed above the national speed limit by enough to get you a court appearance

The A and A+ is quite tunable so you could get more out of the engne, or probably retro fit a different engine all together at a later date with minor modifications

[Edited on 9/2/05 by locogeoff]


Peteff - 10/2/05 at 12:18 AM

White130d, he's using a Midget engine for his car. He's in the U.S. as well.


DarrenW - 10/2/05 at 10:24 AM

75BHP in a car of 500KG is 150 BHP/tonne. I calculated that my M3EVO (321bhp, 1450KG) had 220BHP/tonne and that was a seriously fast car. Take an Astra GTE (guessing here) @ 150 BHP and approx 1100KG = 136bhp/t.

Im using 2.o Pinto cos chassis is designed for it. Im only fitting an FR32 cam cos head needed rebuild and i got the cam cheap. After SVA and learning to drive the thing ill probably take engine out and rebuild it as another winter project. I may play about with diff ratios the year after to improve acceleration times - the project lives on. Im concentrating now on spending money making the car safe then save up later for the upgrades.

If the 1275 is OK why not go with it and enjoy further projects to improve it. You may find a race engine for sale or even go for something else. 1.4 16V? VX XE? Honda power? Bike?


britishtrident - 10/2/05 at 01:41 PM

Not sure what the BHP of a standard US spec Midget engine 50 something bhp ? -- 65Bhp was claimed for the UK market version but I suspect this was a bit inflated so lets say 57 allowing transmission losses 57 - 20 = 37 hp.

Roughly 65 hp per ton -- might not be enough for sub ten second 0-60 times and top speed (with windscreen) won't be much over 80 mph.

[Edited on 10/2/05 by britishtrident]


white130d - 10/2/05 at 02:19 PM

With the cam, headwork and carburation, I am hoping for about 90 crank HP, probably around 60 by the time it gets to the wheels. The 998 Lotus 7a I think ran the 0-60 in 13 seconds, not exactly a speeding bullet and topped out at 103, I may be wrong, that is from memory. As I am not building this one for performance I think the 1275 will be just fine. My next build will be more spirited with a 2 ltr ALFA that I have that is pushing out about 175 at the wheels....

David


MikeRJ - 10/2/05 at 08:52 PM

quote:
Originally posted by britishtrident
Not sure what the BHP of a standard US spec Midget engine 50 something bhp ? -- 65Bhp was claimed for the UK market version but I suspect this was a bit inflated so lets say 57 allowing transmission losses 57 - 20 = 37 hp.

Roughly 65 hp per ton -- might not be enough for sub ten second 0-60 times and top speed (with windscreen) won't be much over 80 mph.

[Edited on 10/2/05 by britishtrident]


Since when has power to weight been calculated using the estimated power at the wheels?


smudgersmb - 10/2/05 at 11:30 PM

Have always been into Minis, now own a Mosquito. I normaly run MG Metro Engines which are 1275 10.5:1 with a "Sport" cam. Got 76hp at the fly so in a Mini Pickup was fun. Now buying a 1380 from Morspeed which should have 110hp at the fly, in a car that weighs sod all. Engine/Box is costing £2,300 GULP, but should give me 250hp per ton


johnjulie - 5/6/05 at 11:28 PM

If you decide on a tuned A series engine, you'll probably need a type 9 gearbox conversion, as the standard Midget four speed box wont withstand much power, plus it has no synchro on 1st.
Cheers John


DEAN C. - 6/6/05 at 12:01 AM

You wuss!
No synchro on first! what the hell do you need that for?
I dont think most of us can remember how to drive RWD non synchro box cars.


johnjulie - 6/6/05 at 12:08 AM

Russ, do we really want to remember?
Get to sleep mate, it's late.
Cheers John