Which engine building for a 1275cc BMC A series?
Discussion
Snake the Sniper said:
wildoliver said:
If you can afford Swiftune then go with them they will look after you.
Or Oselli.
But really most of the fun of the A-Series is building it yourself. But only trying to give advice....
I tried that, but he wouldn't listen to me either. Or Oselli.
But really most of the fun of the A-Series is building it yourself. But only trying to give advice....
Also, I can take one apart, but putting it back together with the result working at least as good as before I took it apart is ... iffy
Si - Still on for Sunday @ Stoneleigh?
Compression ratio is pretty important in an A-series. I used 10.5:1, which gave nice performance, good economy and no danger of pinking.
FYI, I built one myself for my MG Midget that put out 90bhp at the wheels. The machining work was done by MED in Leicestershire, who were great.
Spec was:
1380cc (73.5mm Powermax Pistons) All balanced.
Kent 276 Cam
Ported cylinder head, with MG Metro valve sizes.
1.75" SU (HIF44) from an MG Metro, ported internals.
Titan alloy inlet manifold
Janspeed LCB Exhaust manifold, modified RC40 exhaust system from a Mini.
10.5 : 1 compression ratio
Distributor modified with new advance curve by Aldon Engineering
It was a pokey little beast, but note that with small displacement, higher output engines, you will sacrifice low down torque for power, as they require higher duration cams to get the power out of them. Mine didn't do too much below 2000rpm.
FYI, I built one myself for my MG Midget that put out 90bhp at the wheels. The machining work was done by MED in Leicestershire, who were great.
Spec was:
1380cc (73.5mm Powermax Pistons) All balanced.
Kent 276 Cam
Ported cylinder head, with MG Metro valve sizes.
1.75" SU (HIF44) from an MG Metro, ported internals.
Titan alloy inlet manifold
Janspeed LCB Exhaust manifold, modified RC40 exhaust system from a Mini.
10.5 : 1 compression ratio
Distributor modified with new advance curve by Aldon Engineering
It was a pokey little beast, but note that with small displacement, higher output engines, you will sacrifice low down torque for power, as they require higher duration cams to get the power out of them. Mine didn't do too much below 2000rpm.
Morris Marina A+ block is the one you want ideally! Also in the Morris Ital I believe?? Not seen one in a scrapyard for quite a while though....
The A+ block is a little stronger than the original inline A block. Normal Inline A blocks are found in Midgets and Sprites. Should be a few cars rusting away by now!
BTW, mine was a daily driver and my only car. The spec I mentioned above was great to drive in most situations, and was actually a VERY reliable car. It only ever broke down once, due to a wiring connection coming loose. Fixed in 2 mins at the side of the road! I would strongly advise a 1.75" single SU over either a Weber or twin SU's. Twin SU's are a PITA to set up and tune, and Weber sidedraughts just DRINK fuel (although they do sound good!). The SU was a fantastic all-round carb.
The A+ block is a little stronger than the original inline A block. Normal Inline A blocks are found in Midgets and Sprites. Should be a few cars rusting away by now!
BTW, mine was a daily driver and my only car. The spec I mentioned above was great to drive in most situations, and was actually a VERY reliable car. It only ever broke down once, due to a wiring connection coming loose. Fixed in 2 mins at the side of the road! I would strongly advise a 1.75" single SU over either a Weber or twin SU's. Twin SU's are a PITA to set up and tune, and Weber sidedraughts just DRINK fuel (although they do sound good!). The SU was a fantastic all-round carb.
A+ inline was used in marina ital as above.
This is the other big problem with this choice of engines, A-series engines sell for an easy £300+, and A+ while cheaper are like hens teeth as all us midget lads have scrapped the marina's they resided in for engines, gearboxes and gearbox conversion kits.
FYI the transverse engine is different at flywheel end as above, but you can't just put an inline flywheel in as the rear main cap is different, and the oil pick up is different, you could convert either to the other configuration for sure, but too much hassle to be worth it.
And all A-series will look iffy. All you want is an engine that is complete and turns over, the engine builder will bin half of it anyway, you could get away with buying a straight block, bare head and crankshaft.
This is the other big problem with this choice of engines, A-series engines sell for an easy £300+, and A+ while cheaper are like hens teeth as all us midget lads have scrapped the marina's they resided in for engines, gearboxes and gearbox conversion kits.
FYI the transverse engine is different at flywheel end as above, but you can't just put an inline flywheel in as the rear main cap is different, and the oil pick up is different, you could convert either to the other configuration for sure, but too much hassle to be worth it.
And all A-series will look iffy. All you want is an engine that is complete and turns over, the engine builder will bin half of it anyway, you could get away with buying a straight block, bare head and crankshaft.
That's one of the only A series I haven't ever worked with, it would be interesting to see if it is the inline a+ as fitted to itals, logic suggests it is, back in my mini days i always wanted to fit it to a mini as it would give that lovely fifth gear, but I think the package is a smidge too wide. VW polo box from memory?
But yes good thinking provided it is an inline engine which it should be, there will be more chance of finding one of those than an ital.
But yes good thinking provided it is an inline engine which it should be, there will be more chance of finding one of those than an ital.
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