27 replies to this topic

[cristiano1968]

Hello .
I've got a 998cc mini
minispares stage one kit
New clutch with lightened flywheel.
Thinking going for a stage 3 head from calver uk
Straight bolt on so I can do it myself
What power increase could I get from this stage 3 head .?
Is it worth it?

[Minigman]

I think you’d gain 20% ish.

[cal844]

It's worth it, you'll need the car set up on a rolling road to maximise the performance and reliability

[sonikk4]

You need a decent camshaft as well to go with the head otherwise you will not be gaining a lot of power. The combination of the two will give you far more than just the head alone.

[luismx123]

Hello .
I've got a 998cc mini
minispares stage one kit
New clutch with lightened flywheel.
Thinking going for a stage 3 head from calver uk
Straight bolt on so I can do it myself
What power increase could I get from this stage 3 head .?
Is it worth it?

 

I spoke to an expert regarding exactly this as my mini is the same.
He said you'd need to make sure your carb is set up correctly. I.e there are hs4s that were made for "economic driving" so youd have tocheck if yours falls into this. Also, cam/rockers are not necessarily needed. Youd probably get around 60 out of it if everything is set up properly. 

I know some will say you need XYZ or there is no way to get those figures out of just a head, but I trust my guy.... he owns 50+ minis...

[cristiano1968]

Think I'll go for calver stage 3 head.
I refurbished my carb su.
Got also aldon electronic ignition plus stage one kit
Everything working good
Alas I've never changed a cylinder head myself

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[Anthony30]

I would also fit Megajolt ignition.

[unburntfuelinthemorning]

I have an otherwise standard 998 but with the Calver head you're looking at. 

 

I needed a cylinder head overhaul and unleaded valve seats so thought I may as well spend a bit more and get a really good head. 

 

It's got some go in it after going to the rolling road - a noticeable boost in mid range power and a small amount at the top end. 

 

This is restricted at the moment of course by the standard cam and induction/exhaust system. 

 

On the rolling road I went to it showed max power 50 bhp @ 4800 rev/min, max torque 63 lbf ft @ 3500 rev/min and over 60lbf ft between  2400 and 4150 rev/min. 

 

Now with standard figures being 39 bhp and 51 lbf ft that represents a 28% increase in power and a 23.5% increase in torque. 

 

The compression ratio is fairly low as well so I think the rolling road figures are slightly optimistic but it hopefully gives you a bit of an idea of what the head will do. 

 

With your stage 1 kit on top of that you'd be doing nicely with a good chunk more mid and top end and possibly a little more low end too.

 

Make sure you get a decent compression ratio - discuss that with Mr Calver.

[Twincam]

As agreed, a suitable cam will aid in the power delivery. Don't be fooled into getting the cam that'll produce the highest BHP, look at the cam(s) that'll give you the best driveability (also look at what rev range you will mostly be driving in, no point getting one that only gives you top end if you're only doing town and motorway driving)

As mentioned above, getting the carb set up is paramount after any mods. AC Dodd did mine and I shall be returning time and time again. Others can equally do a good job but make sure they know what they're doing.

If you're thinking about servicing your HS, throw the kit away. You'll want to get a rebuild kit with bushes and get the bushes done. No matter how good the tuner is, if the carb is worn you can't tune it. Failing that, a replacement carb with custom needle could be a good shout.

Ignition curves could be adjusted to help optimise power delivery too.

Diffs could also be changed to suit so it's worth finding out what diff is in your engine (can use guessworks decoder to find out what it was originally with unless someone has changed it)

[Earwax]

I know that i am tilting at windmills, but i cannot help myself. 

 

Why do we conform to Stage 1, 2, 3 etc naming when they provide no definable elements. I can see why manufacturers could use it, ... naming rights but no responsibility to back it up with effective data. -stage 3 is better than stage 2- cool  i 'll pay the difference.  Now , i am not actually knocking the manufacturers or suppliers, as the vast majority of them are decent people who offer a valued service, i just think we the buying public have to demand more information which is backed by data. Unburntfuel's description above is an excellent example of what that head spec can provide, and i do think it is a good service by a clever cylinder head guy. I am not after extensive and costly testing under all conditions - but giving an example of a head spec with a CR, a useable cam and whatever rocker combo is being used is a good comparison. Another example is a 1380 build that provides near 100/100 (HP /torque). Again , all the good builders and suppliers have some of these stories that they share freely when asked.  Maybe i am just sour grapes for buying those superbling substacks that lost 3 or 4 bananas on the dyno or buying the head with those big lovely ports all shiny and polished that didn't get up and dance until 6500 rpm. I think i will go back to polishing my SU chrome cover and eating chockie easter eggs.   Windmill tilt over, and apologies to the OP, i am not having a go at you at all, because you are asking the right sorts of questions to correlate what exactly a Stage 3 head could be.

[Trissy B]

I know that i am tilting at windmills, but i cannot help myself.

Why do we conform to Stage 1, 2, 3 etc naming when they provide no definable elements. I can see why manufacturers could use it, ... naming rights but no responsibility to back it up with effective data. -stage 3 is better than stage 2- cool i 'll pay the difference. Now , i am not actually knocking the manufacturers or suppliers, as the vast majority of them are decent people who offer a valued service, i just think we the buying public have to demand more information which is backed by data. Unburntfuel's description above is an excellent example of what that head spec can provide, and i do think it is a good service by a clever cylinder head guy. I am not after extensive and costly testing under all conditions - but giving an example of a head spec with a CR, a useable cam and whatever rocker combo is being used is a good comparison. Another example is a 1380 build that provides near 100/100 (HP /torque). Again , all the good builders and suppliers have some of these stories that they share freely when asked. Maybe i am just sour grapes for buying those superbling substacks that lost 3 or 4 bananas on the dyno or buying the head with those big lovely ports all shiny and polished that didn't get up and dance until 6500 rpm. I think i will go back to polishing my SU chrome cover and eating chockie easter eggs. Windmill tilt over, and apologies to the OP, i am not having a go at you at all, because you are asking the right sorts of questions to correlate what exactly a Stage 3 head could be.

Apart from Mini Sport and Cooper, does anyone actually sell stage 2 and 3 packages?

Stage 1 is obviously quite well defined as pure bolt on parts. The problem with heads is how do you define what is better? Valve size obviously. But that doesnt give an indication to how well its been done... Gas flow rating on every head?

Let's say I bolted on lots of "stage 3" goodies, cam, head, rockers etc onto my old 1275. That is not equivalent to a brand new engine prepared by a professional engine builder.

[Steve220]

Stage tuning is a dead commodity that, for some reason, has become a sliding scale of BS. No one truly knows what it all means, and is different to every tuner.

[unburntfuelinthemorning]

Here's the power curve for mine:

 

 

Power runs out early around 5000 with the standard cam and manifolds etc but engine pulls well in top from 2000 and 30 mph.

 

It will rev to 6000 in first, second and third but there's no power there so it's pointless. 

Edited by unburntfuelinthemorning, 22 April 2019 - 07:18 AM.

[Earwax]

Nice power curve  unburnt fuel. thanks for sharing.Cristiano1968 take some good notes.

 

 

To Trissyb and steve 220 -  a quick search , has minispeed, minisport, Specialist Components, Calver special tuning, 7ent -(uses Calver) and  Moss Europe still advertising using the term  -   I am with you that it is undefinable term that should have been  superceded. (I also know each supplier does add more information in terms of spec)    So just a pet peeve of mine---    I am going to start my own little revolution by never uttering the term Again!!!!  

[InnoCooperExport]

Nice power curve  unburnt fuel. thanks for sharing.Cristiano1968 take some good notes.

 

 

To Trissyb and steve 220 -  a quick search , has minispeed, minisport, Specialist Components, Calver special tuning, 7ent -(uses Calver) and  Moss Europe still advertising using the term  -   I am with you that it is undefinable term that should have been  superceded. (I also know each supplier does add more information in terms of spec)    So just a pet peeve of mine---    I am going to start my own little revolution by never uttering the term Again!!!!  

 

you can add Maniflow to that list with their stage 2 LCB manifold. 

 

I completely agree that the terms are entirely redundant. I remember I was the Maastricht Interclassics show this year looking at a souped up Mini on a trader's stand (which was stood next to a rather pretty Fulvia Zagato). Seeing I took an interest in both cars the owner of the stand came over to have a chat and he immediately started throwing these terms like "it's got a stage 3 head and carbs you know" at me. When I pressed him on what that actually meant in terms of work done he couldn't really tell me, only that it meant it was quick! 

Edited by InnoCooperExport, 22 April 2019 - 09:15 AM.