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Need Camshaft Advice


Best Answer Cooperman , 22 March 2019 - 06:49 PM

I think the EVO 001 will be ideal for what you want.

 

I told you there would be so many replies that you would be confused!

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#1 BaronVonchesto

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Posted 20 March 2019 - 05:24 PM

Hi all, rebuilding my A+ 998 and some of the lobes on my stock camshaft are visibly worn. This engine has never been rebuilt as far as I can tell.

 

Could I get some advice on what cam to use? I plan to fit +20 flat top standard pistons from minispares as the current piston ring clearance is beyond the maximum specified in the haynes manual.

 

I'm not sure what counts as "fast road" but I would like to make my car more zippy and give it more power at lower revs. For the time being im keeping the head unmodified due to budget constraints, not changing the final drive or anything like that, but i would like to fit a stage 1 kit in the near future, and perhaps port the head and fit 3 angle valves and seats later down the line.

 

Also this is a road car, but not a daily driver. i like to take it on country roads and also do town driving, so good acceleration is important to me where i can pull out from traffic lights quick.



#2 Cooperman

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Posted 20 March 2019 - 05:58 PM

The EVO 001 from Mini Spares seems a good cam for a 998. The price is right as well.

 

You are going to get lots of suggestions which will only confuse you even more. Basically you can only make a 'not quite so slow' Mini if it is to be driven on the roads. You need good torque to optimise the acceleration and the EVO 001 seems fine for that.



#3 BaronVonchesto

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Posted 20 March 2019 - 06:15 PM

Thanks cooperman. I was looking at that too, but this statement on minispares worried me a little: "Ok in 998cc upwards but depending on tune might have slightly lumpy, erratic tickover. "

 

Seems like this cam was designed mainly with the 1275 in mind.

 

would a milder cam like a 255 be better suited for road use in a 998?  a "not quite so slow" mini that does better than my current unmodded one, especially at lower revs would still be better than leaving it stock for sure!



#4 Gilles1000

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Posted 20 March 2019 - 07:56 PM

I would definitely build a Stage 1 kit as it makes the engine much more free and you get more torque in lower revs.

I made only this modification on my previous Mini, and the difference was easy noticeable.



#5 Moke Spider

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Posted 20 March 2019 - 08:29 PM

I'm not going to suggest any particular Camshaft, however, I'll just say that Generally, going to a Cam that 'makes more Power' does so at higher revs comes at the expense of a loss of low RPM Power (often referred to as Torque).

 

There are some things that can be done to improve on this, but essentially, with 'Cams' what happens is the Power Band is moved up high in to the rev range.



#6 Mini Manannán

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Posted 20 March 2019 - 10:54 PM

If it's all you're changing go for a mild cam, yes, 255 etc.



#7 BaronVonchesto

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Posted 21 March 2019 - 03:07 AM

I'm not going to suggest any particular Camshaft, however, I'll just say that Generally, going to a Cam that 'makes more Power' does so at higher revs comes at the expense of a loss of low RPM Power (often referred to as Torque).

 

There are some things that can be done to improve on this, but essentially, with 'Cams' what happens is the Power Band is moved up high in to the rev range.

 

yea so i'd like to move the power band a little lower down from what the stock offers. Do you have a recommendation Moke?

 

The evo1 suggested by cooperman is certainly reasonable in cost (a big plus point) but I'm nervous about minispares saying it has a lumpy turnover on 998s.



#8 BaronVonchesto

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Posted 21 March 2019 - 03:08 AM

If it's all you're changing go for a mild cam, yes, 255 etc.

 

im also changing the pistons to +20 oversize flat tops.



#9 DeadSquare

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Posted 21 March 2019 - 07:16 AM

 

I'm not going to suggest any particular Camshaft, however, I'll just say that Generally, going to a Cam that 'makes more Power' does so at higher revs comes at the expense of a loss of low RPM Power (often referred to as Torque).

 

There are some things that can be done to improve on this, but essentially, with 'Cams' what happens is the Power Band is moved up high in to the rev range.

 

yea so i'd like to move the power band a little lower down from what the stock offers. Do you have a recommendation Moke?

 

The evo1 suggested by cooperman is certainly reasonable in cost (a big plus point) but I'm nervous about minispares saying it has a lumpy turnover on 998s.

 

 

Don't worry about the cam being a bit lumpy, it will be OK as you are not lightening the flywheel, just adjust the tick-over to about 1000/1200RPM.



#10 DeadSquare

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Posted 21 March 2019 - 07:27 AM

Hi all, rebuilding my A+ 998 and some of the lobes on my stock camshaft are visibly worn. This engine has never been rebuilt as far as I can tell.

 

Could I get some advice on what cam to use? I plan to fit +20 flat top standard pistons from minispares as the current piston ring clearance is beyond the maximum specified in the haynes manual.

 

I'm not sure what counts as "fast road" but I would like to make my car more zippy and give it more power at lower revs. For the time being im keeping the head unmodified due to budget constraints, not changing the final drive or anything like that, but i would like to fit a stage 1 kit in the near future, and perhaps port the head and fit 3 angle valves and seats later down the line.

 

Also this is a road car, but not a daily driver. i like to take it on country roads and also do town driving, so good acceleration is important to me where i can pull out from traffic lights quick.

 

Hi all, rebuilding my A+ 998 and some of the lobes on my stock camshaft are visibly worn. This engine has never been rebuilt as far as I can tell.

 

Could I get some advice on what cam to use? I plan to Have the engine rebored as the current piston ring clearance is beyond the maximum specified in the haynes manual.

 

I'm not sure what counts as "fast road" but I would like to make my car more zippy and give it more power at lower revs. For the time being im keeping the head unmodified due to budget constraints, not changing the final drive or anything like that, but i would like to fit a stage 1 kit in the near future, and perhaps port the head and fit 3 angle valves and seats later down the line.

 

Also this is a road car, but not a daily driver. i like to take it on country roads and also do town driving, so good acceleration is important to me where i can pull out from traffic lights quick.

 

 

The engine that you are describing can be given the desired characteristics by supercharging it.



#11 unburntfuelinthemorning

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Posted 21 March 2019 - 08:16 AM


I'm not sure what counts as "fast road" but I would like to make my car more zippy and give it more power at lower revs. For the time being im keeping the head unmodified due to budget constraints, not changing the final drive or anything like that, but i would like to fit a stage 1 kit in the near future, and perhaps port the head and fit 3 angle valves and seats later down the line.

 

Also this is a road car, but not a daily driver. i like to take it on country roads and also do town driving, so good acceleration is important to me where i can pull out from traffic lights quick.

If this is the criteria then I recommend the Kent 256.  I have experience of this cam and have used it in the way you are planning to.  It will work in an otherwise standard engine and will compliment the later improvements you are planning.  Make sure you check the camshaft timing though using a protractor and dial test indicator for maximum benefit.  The carburettor needle will need changing to suit too and the ignition timing will likely need tweaking.  Afterwards prioritise the cylinder head improvements as soon as possible as your budget allows.

 

Additionally, you said you don't wish to change the final drive; but it can be transformative on a 998.  A simple change to a lower ratio will definately make the car more zippy and enjoyable to drive on country roads, in town and pulling away from traffic lights.  Of course there is a trade off in that high speed cruising engine speed is going to be raised but if you don't do much of that it won't matter, especially if it isn't a daily driver.  It might be better value for your money than the engine modifications.



#12 BaronVonchesto

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Posted 21 March 2019 - 02:24 PM

 


I'm not sure what counts as "fast road" but I would like to make my car more zippy and give it more power at lower revs. For the time being im keeping the head unmodified due to budget constraints, not changing the final drive or anything like that, but i would like to fit a stage 1 kit in the near future, and perhaps port the head and fit 3 angle valves and seats later down the line.

 

Also this is a road car, but not a daily driver. i like to take it on country roads and also do town driving, so good acceleration is important to me where i can pull out from traffic lights quick.

If this is the criteria then I recommend the Kent 256.  I have experience of this cam and have used it in the way you are planning to.  It will work in an otherwise standard engine and will compliment the later improvements you are planning.  Make sure you check the camshaft timing though using a protractor and dial test indicator for maximum benefit.  The carburettor needle will need changing to suit too and the ignition timing will likely need tweaking.  Afterwards prioritise the cylinder head improvements as soon as possible as your budget allows.

 

Additionally, you said you don't wish to change the final drive; but it can be transformative on a 998.  A simple change to a lower ratio will definately make the car more zippy and enjoyable to drive on country roads, in town and pulling away from traffic lights.  Of course there is a trade off in that high speed cruising engine speed is going to be raised but if you don't do much of that it won't matter, especially if it isn't a daily driver.  It might be better value for your money than the engine modifications.

 

 

hmm the kent 256 on minispares is listed as "new blank" meaning i can't get this cam without giving a blank cam (whatever that is). i don't think its going to be a feasible option for me. minisport sell them without mentioning the blank, but at a much higher price.



#13 gav

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Posted 21 March 2019 - 02:36 PM

I've just replied to your email ;) a blank cam means it's manufactured on a new cam blank not a regrind so no old cam needed.



#14 Moke Spider

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Posted 21 March 2019 - 05:29 PM

Another 'trick' to improve low end Engine Power is to Advance the Cam Timing. Most Grinds call for them to be set to 106 to 112 degrees Full Lift on the Inlet Valve. Try winding that forward by around 4 to 6 Degrees and you'll get quite an improvement in low end power, but it won't rev as high before running out of breath.

 

Just one other aspect to consider here.

 

Power is a function of Torque multiplied by Revs. Given that many Mild Cams give a flat-ish Torque Curve, any Power it will make comes from Revs. I know many refer to Low RPM Power as 'Torque' however Torque on it's own does not require any RPMs and without any RPMs, the Car doesn't Move. A perfect example of this is a Torque Wrench to Tighten Fasteners. Once it 'goes off'. there is Torque produced, but the Speed is zero.

 

Engines over their entire Rev Range are making Power, because they are spinning. It is the Power that Moves the Vehicle in a particular time frame.

 

Where I am going with this and given that the engine is a 998, while you'll get some improvement and noticeably so, at lower RPMs, it won't be huge amounts. The bigger improvements will be higher in the Rev Range, which, is not really compatible with trying to get low end power. To get that broader power range, you need a bigger engine or go to a boosted set up. I mention this not to discourage you at all, but just so you have a better picture of the likely outcome.



#15 BaronVonchesto

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Posted 22 March 2019 - 03:01 PM

 

Another 'trick' to improve low end Engine Power is to Advance the Cam Timing. Most Grinds call for them to be set to 106 to 112 degrees Full Lift on the Inlet Valve. Try winding that forward by around 4 to 6 Degrees and you'll get quite an improvement in low end power, but it won't rev as high before running out of breath.
 
Just one other aspect to consider here.
 
Power is a function of Torque multiplied by Revs. Given that many Mild Cams give a flat-ish Torque Curve, any Power it will make comes from Revs. I know many refer to Low RPM Power as 'Torque' however Torque on it's own does not require any RPMs and without any RPMs, the Car doesn't Move. A perfect example of this is a Torque Wrench to Tighten Fasteners. Once it 'goes off'. there is Torque produced, but the Speed is zero.
 
Engines over their entire Rev Range are making Power, because they are spinning. It is the Power that Moves the Vehicle in a particular time frame.
 
Where I am going with this and given that the engine is a 998, while you'll get some improvement and noticeably so, at lower RPMs, it won't be huge amounts. The bigger improvements will be higher in the Rev Range, which, is not really compatible with trying to get low end power. To get that broader power range, you need a bigger engine or go to a boosted set up. I mention this not to discourage you at all, but just so you have a better picture of the likely outcome.

 

I understand. Considering that the Kent 256 is double the cost of the EVO1, what sort of driving experience can Iexpect with the EVO cam were i to go with that? Since its not settled if I need to change my pistons or not, let's assume that I'm sticking with my standard dished pistons for now.




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