Hey I was wondering I have a 12g940 head and was thinking is it worth sticking on a 1100 like will it give me much more power or am I wasting my time I no I have to machine the top of the water pump and pocket the motor

Hi

Four or five things affect the power
1. How much fuel you can get into the cylinder.
2. How quickly you can get it in
3. How effectively you compress it and then ignite it.
4. the bigger the bang the more power
5. How effectively and quickly you get the burnt gases out.

So, yes a 940 head will help you do most of that. It will give a fair bit more power but it must be matched to the rest of the engine modifications.

That is the carby that allows enough fuel to flow, he camshaft that has the right valve opening durations and timings, the exhaust that can cope with the volume of burnt gases.

Finally the bottom end that can cope with the extra revs and stresses.

Then at the end of the day when you have spent $5000, a good 1275 is just steadily going to leave you behind.

And the average commodore or falcon will leave the 1275 behind as well.

Mike

My brother said it is a non worked one if that helps at all

Even a none worked one has bigger valves, bigger ports and a better combustion chamber sahpe that a mini 202 head.

But you really are better looking for a 1275 motor and bolting that in. The're around - But remember it has to stop when you tread on the brakes.

Mike

oh ok so it is worth bolting it on

IMO - no !!!

Spent the $5000 and then maybe but still slower than the $1,000 1275.

Mike

dont have that sort of money lol

1. do you have a die grinder?
2. do you have Vizards books?

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1975 Leyland Mini: 1060cc - resto/ ex-hsc project.

I've been there and done it years ago. Yes it's worth it. But only if matched to other mods in the engine, as Mike said.
Mine was faster (when 1220cc) than with the same carbs, cam and 940 head on a new 1275 short motor after I blew the 1220's bottom end....

Start with a 1275 for reliability.

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DrMini- 1970 wasaMatic 1360, Mk1S crank, 86.6HP (ATW) =~125 @ crank, 45 Dellorto (38 chokes), RE282 sprint cam, 1.5 rockers, 11.0:1 C/R.

put the 940 aside until you have a decent motor that can handle it - are you still running a 2nd hand clunker motor, or the one that your uncle built that isn't quite right

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did I tell you that I won a trophy?

nah i am guuna buy a recon motor off warick aguston he is gunna build it for me cause he knows what he is doing cant ask him cause he is away on holidays atm so i thought i would ask all your pro people

well if that's the case, and he's willing to do the work, then it's a good thing - just make sure you can afford it before you ask him to do it, because he's not going to do it for free

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did I tell you that I won a trophy?

The motor is only a pump - it may burn the fuel inside it but it only sucks in what its being given and then it pumps out what its burnt.

This is provided that it is structurely sound and can withstand the stresses being put on it.

Yout are still going to need the right carby with the correct jets or needles, the right exhaust and enough fuel pressure to feed the carby. Also a good sports camshaft.

If you dont do that then you are only going to have an 1100 motor that goes just a littl bit harder but uses a heap more petrol. Then you need to be able to stop the car.

If I was building you a motor then I would be doing all the necessary performance engine things that would ensure that it didn't fly apart just in case you did put a Weber on it with a good exhaust and a good road camshaft and did a sustained wheelie.

A standard mini motor will rev all day at 4500 rpm without modifications but it wont do that at 7,000 rpm without modifications and there is is the $5000.

Also knowing the need for burning rubber smells of the youth - you also start to consider other things like gearboxes, strengthened diffs etc etc -

It all adds up to be bit money for the same thing a 1275 with for a $1,000.

Mike

i am going to put a re13 cam shaft in it and hopefully webber if not a webber a 1.5 carbie i have LCB extractors on it and will have a rc40 exhaust