Building a 1275

[andrew.searston]

I’ve just stripped down what I believe is a 1275 marina or ital engine (oil filter high up on block and no tappet chest cover just ribbed) having identified it as a good engine and that I will be building it myself, what are worthwhile modifications at a budget while it’s apart? It will need to be bored and on standard pistons at the moment, what size should I go, cam ect. It will be bolted to a 1098 gearbox so building it for a nice road car with a bit extra power
Thanks

[philthehill]

Just re-bore the block the minimum required to give good/new bores with pistons to suit.

Replace the oil pump.

The Marina cam is quite good as it is and is the same cam as fitted to the MG Midget. Fit new cam followers.

Just clean up the 940 head and fit new valve guides and springs - double springs not required.

Use the Marina inlet/exhaust manifold/HS4 carb with ESM adapter front exhaust pipe.

Use a Minor front engine plate for the engine mounts. Make sure that the Marina engine mount bolt holes in the block are blind - if not fit a bolt to block the through bolt hole.

Fit a duplex timing chain set up with Marina chain tensioner.

In standard form and on a budget the 1275cc engine in reconditioned form will give more than sufficient power.

Use the ESM rear engine plate and modified flywheel to allow fitment to the 1098cc gearbox.

[andrew.searston]

Brilliant thanks
Forgot to add my 1098 in the car currently has the maniflow full big bore exhaust system, is that a straight bolt on job as I’ve heard the engine is taller but not sure, And has a hif38 carb. Where’s best to buy the engine parts online?
Engine Plate starts with 12v e-h361...

[andrew.searston]

Brilliant thanks
Forgot to add my 1098 in the car currently has the maniflow full big bore exhaust system, is that a straight bolt on job as I’ve heard the engine is taller but not sure, And has a hif38 carb. Where’s best to buy the engine parts online?
Engine Plate starts with 12v e-h361...

[philthehill]

The Maniflow exhaust manifold and big bore system will bolt straight onto the 1275cc engine with no problems.

I would suggest that the re-bore/engineering co should be able to supply pistons to suit.

You really do need the pistons before the re-bore as then the bores can be bored to suit the pistons.

Make sure that the pistons/rings are good quality. Ask what make are the re-bore/engineering co supplied pistons and come back on here for opinion.

Mini Spares/Mini Sport are two good companies for supplying spares to the 1275cc 'A' Series engine. I use both.

[IslipMinor]

The 'big bore' 1098 exhaust should be fine for a standard(ish) spec 1295 Marina engine, but I would think that the HIF44 would be a more suitable carburettor, especially if you envisage making some tweaks in the future?

[Monty-4]

For a road car it might be worth looking into AC Dodds "Road Torque" cams or something similarly mild? Basically higher lift than period cams but tame timing.

Very inexpensive extra torque and mpg.