5 replies to this topic

[The Matt]

Much of a muddle. I have this engine, which I bought dirt cheap as a supposed 1340. The more I look at it, the more I think it may aswell be rebuilt if I am gonna use it, as it is a real unknown (damn impulse buying). Thing is, I can get my hands on a 1275 A+ block in good nick. My question is:

If I use my stage 3 cylinder head, 296 cam, my 1.5:1 roller rockers, the 1 3/4" SU that I have bought and my Maniflow LCB and scorpion system........... will I get reasonable gains.

Or do I really need to gain some CC's by going to the engine shop? Will the 296 cam be too much for a 1275 with standard compression pistons etc? Or is the crux of it the cylinder head? OR, shall I just bite the bullet and go to Morspeed for a 1380 and solve all of my problems in one hit?

[Guess-Works.com]

First of all your 1340 is likey to be a 1330 ( +.060" overbore ).

Depending how deep your pocket is, you could go for a MSPD engine, but if the pistons, rings and bores are ok, and there is no need to perform any machining on the block, then I see no reason why you could not get a good performing unit from the engine as is...

As you have illuded towards, the key is breathing.

Flowed Head, with big valves ( something with 1.4" inlets at least ) also increase the CR.
The 296 may be a little overkill, 286 / SW5/10 are a little tamer
1.3/4" carb works well on my 1330

Try it without the 1.5 rockers to start with as you may find it pulls well without them, then you can justify the extra cost vs the power gain.

[Oldskoolbaby]

Why dont u just rebore the block to 1380 or 1400 as ive done. The gains are pretty substatial i think cause itll be squarer hence smoother and with the type of cam and rockers youve got the driverbility may be a lot better. It should only then need a set of pistons. I certanly wouldnt by a block from somewhere else. It must work out more expensive that way wouldnt it?

[TimS]

If you go for 1380, you will need the bore to be offset bored(not as cheeps as normal boring) as well as new pistons and rings! it really coems down to money!

[The Matt]

Thanks guys! Right, so I can finally clear it in my own mind I am going to measure the cylinder bores on my supposed 1330/1340 (whichever it is). What should I expect them to be? I'll get my verniers on it tonight. Guessworks, you said it was +0.060" overbore, so what is standard bore? I can compare the standard bore with what I have and see what engine it really is once and for all. I have had a look at the bores on it and they do look ok but I might pull the pistons out of it and inspect the rings and shells whilst I am doing it. I guess I might aswell strip it down to a bare block to inspect it.

I am still considering Morspeed as my best option to be honest. I think if I am going to all the trouble and expense of doing a full rebuild of the car (which is taking ALOT longer than expected) I want the engine to be right.

Furthermore the last thing I want is to be sitting in my car in 6 months time thinking: 'If only I'd gone for a 1380'.

[Madmax]

u want to speak to flappyplasticbits, he's building a morspeed 1330 at the moment