12 replies to this topic

[jim4eva]

hi,

I have a pretty much bog standard 998, except for a straight through exhaust and a k&n filter,
what cam would give me the biggest power increase?
I am looking for faster acceleration ( think it's called low-end torque).
I apologize if this is a painfully stupid question, but I am still learning.

thanks guys!

[Nu2mini]

Mis-post

Edited by Nu2mini, 29 June 2011 - 03:49 PM.

[Retro_10s]

Hi there, Sounds like you have half of a stage 1 kit,... I suggest you go onto the minispares website, search for 'stage 1 kit' and look at the bits you need to complete the kit, usually consists of:

Airfilter
Alloy inlet Manifold
New exhaust system (straight through systems do not equal power by the way, infact you're probably losing power)
New needle in the carb

It's not a painfully stupid question, but the 'I want to go faster and don't know much about minis yet' is asked a lot ,... I suspect your mini actually just needs a Good service (when did you last change the oil, point and condensor?) and a tune up on a rolling road when the stage 1 kit is complete.....

A question I shall ask you in return is are you prepared to take the engine out to change the cam or to pay someone to do it for you? (it can be done with the engine in situ, but you will have to chop up the inner wing)

what type of mini is this engine in? is it the correct engine for the car? the you have fitted at the moment has a large effect on the kind of driving you'll be able to do, and it is a trade off of top speed and acceleration, On a daily driver i wouldn't be tempted to fit a Diff with a ratio that will give you amazing acceleration, as you will suddenly realise you have to drive around everywhere at 4500rpm.

by the way if you really are tempted to fit a new cam, the MG metro cam is a good, useable choice. Or the 997 cooper cam.

Edited by Retro_10s, 29 June 2011 - 03:55 PM.

[Cooperman]

On a standard 998 just fitting a different cam will give virtually no improvement unless a better gas-flowed head and improved induction system are fitted, as the head is the main limiting factor on the 998.
You need a properly gas-flowed head with larger inlet valves and the compression ratio increased to around 10:1.
Only when you have this can a better cam be considered worthwhile. With the better head should be added a 3-into-2 tubular exhaust manifold, a 1.625" bore exhaust system if you don't already have that and an alloy inlet manifold with a 1.5" SU carb.
Now, when you have that it is worth fitting a better cam and either a Kent 266 or MG Metro cam would be ideal.
Remember, all a cam does is allow more mixture to flow in and more exhaust to flow out so long as the induction and exhaust systems will allow it. It's a bit like trying to get more water from a hose pipe, but just fitting a larger hose won't help if the tap before the hose is still a small one which won't allow any more water to actually flow.
I hope this makes sense.

[jim4eva]

Hi there, Sounds like you have half of a stage 1 kit,... I suggest you go onto the minispares website, search for 'stage 1 kit' and look at the bits you need to complete the kit, usually consists of:

Airfilter
Alloy inlet Manifold
New exhaust system (straight through systems do not equal power by the way, infact you're probably losing power)
New needle in the carb

It's not a painfully stupid question, but the 'I want to go faster and don't know much about minis yet' is asked a lot ,... I suspect your mini actually just needs a Good service (when did you last change the oil, point and condensor?) and a tune up on a rolling road when the stage 1 kit is complete.....

A question I shall ask you in return is are you prepared to take the engine out to change the cam or to pay someone to do it for you? (it can be done with the engine in situ, but you will have to chop up the inner wing)

what type of mini is this engine in? is it the correct engine for the car? the you have fitted at the moment has a large effect on the kind of driving you'll be able to do, and it is a trade off of top speed and acceleration, On a daily driver i wouldn't be tempted to fit a Diff with a ratio that will give you amazing acceleration, as you will suddenly realise you have to drive around everywhere at 4500rpm.

by the way if you really are tempted to fit a new cam, the MG metro cam is a good, useable choice. Or the 997 cooper cam.

Hi,

thanks for your response,

1) I would be prepared to remove the engine myself, however wood and picket is pretty much just up the road from me if I run into problems
2) the engine is in a 1990 checkmate, completely standard, except for the filter.

thanks for all your input, some very useful information there.

thanks!

[twrminisport]

As above. You need to do the head first.
12G295 cooper casting is a good stage to go to for head modifications before even THINKING about a camshaft change.

I love your analogy cooperman

[jim4eva]

On a standard 998 just fitting a different cam will give virtually no improvement unless a better gas-flowed head and improved induction system are fitted, as the head is the main limiting factor on the 998.
You need a properly gas-flowed head with larger inlet valves and the compression ratio increased to around 10:1.
Only when you have this can a better cam be considered worthwhile. With the better head should be added a 3-into-2 tubular exhaust manifold, a 1.625" bore exhaust system if you don't already have that and an alloy inlet manifold with a 1.5" SU carb.
Now, when you have that it is worth fitting a better cam and either a Kent 266 or MG Metro cam would be ideal.
Remember, all a cam does is allow more mixture to flow in and more exhaust to flow out so long as the induction and exhaust systems will allow it. It's a bit like trying to get more water from a hose pipe, but just fitting a larger hose won't help if the tap before the hose is still a small one which won't allow any more water to actually flow.
I hope this makes sense.

Hi,

I had read somewhere (I think in 'tuning the A-series engine') that the cylinder head is what holds the engine back,
I then read in Mini magazine, that changing the cam in the 998 would give you the 'biggest bang for your buck'.
I will definitely take the head into consideration, however, I am by no means an expert and will have to do a bit more digging around previous posts to find out more about heads and what not.

thanks!

[twrminisport]

Yes what you heard is correct.

The cylinder head is what holds the engine back AND a cam gives you a bigger bang for you buck.

However the Head is necessary to let the cam do its job properly.

Also what do you want the car to do?
Where do you want the power from the cam?

Edited by twrminisport, 29 June 2011 - 06:11 PM.

[jim4eva]

Yes what you heard is correct.

The cylinder head is what holds the engine back AND a cam gives you a bigger bang for you buck.

However the Head is necessary to let the cam do its job properly.

Also what do you want the car to do?
Where do you want the power from the cam?

ultimately, I want to extract more power from my 998...
and the second question I do not quite understand,
if you mean do I want low range or high range torque, the answer would probably be either low range or somewhere in the middle...
hope that helps!

thanks for your help!

[bmcecosse]

And - consider if fuel economy is important to you....... ie Do you commute 100 miles a day in the car ??

[jim4eva]

And - consider if fuel economy is important to you....... ie Do you commute 100 miles a day in the car ??

no its more like 20...
but well worth taking into consideration

[twrminisport]

Put simply,

Either way you NEED to do the head first.

Then you either want something you can drive in traffic. Swiftune sw5-07

Or a more of a racey design. Kent 266/276

I know it's mine but can i recommend this...
http://www.theminifo...howtopic=195601
Ill even throw in my camshaft specification sheet for you

Cheers

[minimender]

This is what I would do....

Fit new timing chain and tensioner (if not already done)

Make sure plugs , points and condenser are as new

Get timing set spot on, more advance the better just so it dont pink

It will then go like stink

Oh and make sure the mixture isnt weak

Edited by minimender, 29 June 2011 - 11:59 PM.