38 replies to this topic

[Fordy]

Been reading through various posts on camshaft selection and still non the wiser on which to go for....

 

I purchased the engine fully stripped down for a project.

 

I have a A+ series 1275 MG Metro engine block (looks to be standard bore), single HS4 carb and 12G940 cylinder head (inlet 35.7mm, exhaust 29.3mm).

 

Looking at keeping the block at standard bore, currently debating changing to a twin SU HS4 carb and work/modification to the cylinder head such as: cleaned up, porting, convert to unleaded, new valves, springs, collets, caps... and skimmed (undecided on compression ratio). 

 

A few of the camshafts I have looked at are the Kent 266, 276, 286, and then have been pointed in the direction of the AC Dodd cam by others and from reading other posts.

 

I'm looking for more acceleration and 'put you back in your seat', than top end power. Also looking for something which will create a good noise.

 

Open to any ideas or suggestion on what to go for, and any advice in what other work to be done.

[ACDodd]

What rev range do you drive in?

What is the engine going to be used for?

What idle qualities do you want?

How long do you want the engine to last?

Emission limits?


Don't do anything with your engine or buy any parts till you have decided on the spec. The spec starts with cam choice. From here you can set your budget as the cam denotes the required parts and machined clearances that are needed for a successfull combination.

Ac

Edited by ACDodd, 11 March 2016 - 06:15 PM.

[MRA]

Then you need an RB211, these are known for putting your back in to the back seat....  and the noise is amazing, fitting it to your average mini might be a little tricky though. 

 

What ever your budget after you have gone through AC list above and picked the parts you require, do not forget to consider, brakes, suspension, wheels tyres and a good rolling road session to make it A) safe, B) good fun to drive and C) reliable.

[Fordy]

What rev range do you drive in?
What is the engine going to be used for?
What idle qualities do you want?
How long do you want the engine to last?
Emission limits?
Don't do anything with your engine or buy any parts till you have decided on the spec. The spec starts with cam choice. From here you can set your budget as the cam denotes the required parts and machined clearances that are needed for a successfull combination.
Ac

We'll this is my first mini, currently only got the engine (due to space) and then with buy the body when I have the space and completed the engine.

So in terms of Rev range that I drive in I haven't really got one...

Would just be using the car for a bit of fun at a weekend, and idle qualities not too fussy if it was lumpy. I would want the engine to last as long as possible but wouldn't be doing massive mileage in it anyway.and would want to be ablessed to pass emissions tests etc.

[Cooperman]

You are building a classic car, not a modern quick vehicle. It won't push you back in your seat. All you can hope for is to make it a bit less slow than a standard Mini.

Work out what you want, then write a specification for consideration and post it on here. If you want it to be pleasant to drive and last well, do not 'over-cam' it. Aim for best torque and look for peak power at something below 6000 rpm.

[MRA]

I think lots of Mini owners will disagree with you Peter, myself included, you can build a Mini engine that WILL push you back in your seat, the question is how much do you want to spend ?

 

at 200bhp totally reliable in a Mini weighing 650kg you have 308bhp/tonne that is more than enough to push you back in your seat and still be totally drivable and reliable if all the right parts are used.

 

Most powerful Classic Mini engine is 318bhp .... 460bhp/tonne !  your world is your oyster

[Cooperman]

The OP was looking to build a 1275 engine with SU carbs for road use.

He was not suggesting boring to 1380 plus the huge expense of getting high power. Sure, for £20000+ you can get an 'S' engine with SU's giving 125 bhp but that is for racing and a re-built at least once a season.

You will never make a classic Mini, or really any other almost 60-year old design go like a modern car, no matter how much you spend. It will always be a classic car, so why not just enjoy it as the 1960's icon it has always been and still is.

My current road car has about 250 bhp and huge torque. It is superb as a driving car for normal road use. My Minis are just great classics for fun. There is really no comparison.

For the cost of a blown 1380 with all the bits I could buy a Mk.1 Escort twin-Cam. I know which I would rather have. But I would not swap my 1964 Cooper 'S' for any other classic.

[MRA]

Wow show me this Mk1 Escort twin cam for £6k ?

T3 turbo = £300

1380 = £3000 which will get you a much better spec than most 1380 turbo Mini engines

a decent gearbox £1800

leaves £900 for a few suspension and brake mods metro 4 pots etc... 

 

I guess you don't like Minis as much as some of us then.   there is no way I would swap my Mini for an old Ford !

 

"S" engines whilst they where good in their dy are far too dated a spec for any good today, a modern 1330 or 1380 build to modern specs will give you much more.

Edited by MRA, 12 March 2016 - 12:39 AM.

[ACDodd]

If its your first car and mileage is one of you concerns then cams on the sw5, Kent 246, Kent 256, Kent 266, piper 255 ACD-RT, ACD-RS ranges are what you should be looking at for a successful road engine. More information about how you drive would help me narrow it down.

Ac

Edited by ACDodd, 12 March 2016 - 09:49 AM.

[Fordy]

If its your first car and mileage is one of you concerns then cams on the sw5, Kent 246, Kent 256, Kent 266, piper 255 ACD-RT, ACD-RS ranges are what you should be looking at for a successful road engine. More information about how you drive would help me narrow it down.
Ac

I have another car I use as a daily driver, and only do 2000-3000 miles a year in that, so I would probably only be doino below 500 miles max a year. Would be taking it much over 5000/6000 rpm and would be used for a bit of fun at weekends so a fast road car.

What other information would help you narrow it down?

Edited by Fordy, 12 March 2016 - 03:56 PM.

[ACDodd]

Is that would be taking it over 6k rpm, or would not be?

Ac

[Fordy]

Is that would be taking it over 6k rpm, or would not be?
Ac

Sorry damn auto correct!

Wouldn't be taking over 6000.

Somewhere between 2000 and 6000 I think would be good for a fast road from what I've read if that's correct...

[MRA]

1500 and 6000 would be acceptable power band, or 1500 and 7000

 

But it really depends on your driving style not anyone elses...

[Fordy]

1500 and 6000 would be acceptable power band, or 1500 and 7000

 

But it really depends on your driving style not anyone elses...

 

So where does this leave me in terms of cam selection?

 

And how do I determine driving style to suit a cam when the specifications are purely number based, not based on driving style? 

[mk1leg]

well a good mid range cam is the Swiftune SW5....but if you can find the old 731 profile then this is a good road cam