30 replies to this topic

[1994alex]

Cheers that really helps, is boring a 1275 out to a 1398 putting too much pressure on the engine?
Alex

[_mini1000_]

1293 with a good free flowing head and cam etc will give you good figures while still maintaining reliability.
is this engine for your daily driver or more of a weekend/trackday car?

[Cosford Cowboy]

Small block max is 1251cc
Large block max is 1632cc

.

Edited by Cosford Cowboy, 13 November 2011 - 10:29 PM.

[Shifty]

I've never really understood why people like to bore out to the max size?

All that means is that when it starts to wear the block is generally scrap.

The bhp difference due to CC increase is fairly marginal. If you're chasing ultimate BHP then fair enough but for the sake of pub bragging rights, its just not worth it.

Spend the money on a better head or cam instead.

[1994alex]

1293 with a good free flowing head and cam etc will give you good figures while still maintaining reliability.
is this engine for your daily driver or more of a weekend/trackday car?

It would be my daily drive

Small block max is 1251cc
Large block max is 1632cc

.

1632 how would you get it to that?

Alex

[Cooperman]

I've never really understood why people like to bore out to the max size?

All that means is that when it starts to wear the block is generally scrap.

The bhp difference due to CC increase is fairly marginal. If you're chasing ultimate BHP then fair enough but for the sake of pub bragging rights, its just not worth it.

Spend the money on a better head or cam instead.

That is one of the truest things ever posted on this forum.

[1994alex]

I've never really understood why people like to bore out to the max size?

All that means is that when it starts to wear the block is generally scrap.

The bhp difference due to CC increase is fairly marginal. If you're chasing ultimate BHP then fair enough but for the sake of pub bragging rights, its just not worth it.

Spend the money on a better head or cam instead.

You are right but I am getting a racing cam of some sort of some one i'm not too sure what it is yet, and the better head i would be going for is a turbo.
I can see where you are coming from and why a lot of people would agree with you and in some ways i agree also, the reason i am doing this is to prove to other 17 year old lads you don't need a new car to be quick and win races and so on, to say the least i wont be doing this as i don't want to lose my license, but I will also have another engine one that is slightly tuned not to the limits to replace it with after i have had a bit of fun with it.

Alex

[_mini1000_]

if its for your daily you dont want anything too extreme as reliability will be a key factor so as shifty said youd be better with a 1275/1293 which gives you the option of boring further if the bores wear in the future
if you stick a "racing" cam in it you will never be within the power band and it will be a sow to drive around town
have you priced insurance for a bigger engine with the modifications your planning as most 17 year olds would be lucky to get away with a 998 or 1275 if their lucky

[Cosford Cowboy]

Its not about the BHP though guys ... the torque increase is a lot more than the BHP increase and well worth it if you have blocks lying around.
The point is if you want to keep your engine then don't go to the max, but really it only matters if you are going 50,000 miles plus because a well built engine will last that long if built carefully and with the right parts.
More torque often means more wear, to counteract for this extra wear, you need to get "special" parts that will resist the wear for longer.
So extra cost, if money if not an issue then just go for what you want, otherwise keep it fairly standard.
y tto uhave to spend money on parts that t

[Cosford Cowboy]

What makes you think a turbo head is better ?

It is designed for a turbo engine, not an N/A performance engine, it has sodium filled exhaust valves that have a larger stem diameter and hence less flow.

The CR would be ok, because the turbo CR was 9.4:1 with dished pistons, 9.4:1 is reasonable but an MG head will do you more good than a turbo head will.

[1994alex]

I thought that a turbo head would have been better as it would be letting the air into and escape quicker because the valves are bigger. Or am i wrong?

Alex

[Cooperman]

I thought that a turbo head would have been better as it would be letting the air into and escape quicker because the valves are bigger. Or am i wrong?

Alex

I think you have been given a lot of mis-information.
Are you going to race the car under MSA regulations? You mention not needing a new car to win races. If so you'll be governed by the regulations applying to the classes you want to enter and you'll need a lot of cash to fund this.
For a non-turbo engine the turbo head is not ideal. The valves are no bigger.
You also mention a 'racing cam of some sort'. What sort. There are so many cams that it's important to ensure the cam you will be fitting is correct for your use and application.
If you are 17 and intend driving gthe car on the road, the insurance for a Mini with a full-race engine will, literally, be thousands of pounds and that's assuming you can get a company to cover you at all. All modifications have to be declared for a policy to be valid.
Now, to build a Mini you must first define what you want to do in it and what the driving profile will be. From that you can evolve a specification which will meet the requirements. For example, it's no good fitting a cam which will only give smooth power above 4000 rpm, if you want to drive to work or to the shops - it would be useless.
Let us know two things:
How you want to use the car and how much nyou can afford to spend on insurance.
As a new driver you might be best off having a completely standard car until you paas the driving test and then, subsequently, learn how to drive safely and whatever you do, don't try to drive faster than you know how to or you will crash.

[1994alex]

I admit i may have been given some mis-information, or it is something that i did not completely understand.
I don't know MSA regulations and i don't plan on racing at this period of time. The races would be one off ones between friends as there is an old track near me, well abandoned circuit to be precise.
As i have said it's all i have been told by someone, i am presuming that if the head is modified that it would be letting more air in and out the engine.
The racing cam I am unsure about at the moment but as soon as I find out I will post it in this section to see what you think of it.
I know that having a modified engine boosts the insurance up and have looked into it with different insurance companies finding out which is the cheapest. I know that you have to declare modifications to make the insurance valid.
The car would be used as my daily drive, I can afford to spend about £4000/£5000 on insurance.
I have a full Uk driving licence with a modified car that is insured at the moment. I have done a few driving courses as well. I don't plan on driving faster then what i can cope with.
Alex

[_mini1000_]

you could have some engine for £4/5000 if you held off until insurance dropped a bit and put the money towards that. 1293 16v k headed a series from specialist components
keep us posted with your decision

[Ethel]

An 1100 uses the same block as 850's & 998's. In fact it's the same bore as a 998 too, it gets the extra cc's from having more stroke.

The easiest route would be to drop a 1275 into it - more oomph to start with, and more potential with more readily available parts.