Hi guys,


I am driving a Mini Cooper S manufactured in 2004 and am considering to buy a ported and polished-big valve Minispeed 's Cylinder head and install it together with the 264/272 degree Schrick race cam.

I would like to get advice from you guys on the following:

1) When fitting the CAM and up rated head, is it recommended to upgrade the following at the same time:

i) Titanium lightweight valve spring retainer
ii) Spring Shims
iii) 0.5mm Oversized and strengthened intake and 1mm Oversized and strengthened exhaust valves
iv) High Performance, and High Temperature Valve Seals
v) Dual Valve Springs
vi) Valve Spring Seat

Was thinking if I do the following all at once I could properly save quite a fair bit on labour charge. However another main issue is when using the P&P head and race cam, is it a need to have all those up rated items listed in the above to avoid major problems to the engine or head in due time?

Thank you in advance..

cheers

 

and how will you drive it? with that info, talk to your head builder. If you plan on revving way above current red-line, a lot of those parts will help. If not, they become optional...

Matt

 

Hi Dr Obnxs,


I will usually do hard street driving and probably 1-2 track time in a year.
I should be using Unichip to max performance the mods done. So its an optional rather than an essential upgrade unless I do over reving?

Cheers

 

I'm running 8150 rpms with stock versions of all of the above. I've run at redline for up to 2-3 seconds at a time on some occasions [before braking zones!], and I've run above 7500 rpm or so for a couple of minutes, on one occasion. I've been running this redline since right before the new year and seen redline probably 100 times, with no ill effects. Just a bit more engine oil abuse !

 

Spank it hard!

One the valve train debate, I've talked to people who have had float at these levels, and those that haven't. It might be you're lucky, and it's the edge of the envelope for the stock parts.

Matt

 

You only need the valves, those from MiniMania are great.
If you mount a big valve head with high boost you need to use 2 0,65mm headgaskets to lighty reduce compressionratio.
If not the engine starts pingin in 4th and up gear, the knocksensor retards timing and the engine loose power.
With 2 gaskets the timing should be able be at about 28,5° at high rpm without pinging.
We experienced this while highspeed driving with a datalogger on the german autobahn.

 

Hi Madmick,

Thanks for the advise, you mentioned if I run with high boost, i will need 2 head gaskets, I will be running with a schrick 264/272,15% or MAX 17% reduction pulley and Unichip. Does that apply being high boost for 2 gasket?


Cheers

 

Definately, you need 2 gasket!
I recommend to use the M7 180°F Thermostat in addition, it will helps too for a small buck.
Do you have a racing header with highflow cat?
The strongest Mini in germany with this mods has 265hp at the cranck.

 

I've researched the same thing a couple months ago. You could also put a coating on the valve stems to help extract heat, but you don't really need all of this crap, especially for a street/weekend track car. Unless you really want to spend money. The stock valve springs are fine; you’re really not going to gain a lot of hp by raising RPM. Plus with the dual springs you are creating more drag. Call around and talk to different manufactures or local machine shop. Hope this helps -- Johan

 

Hi Madmick,

I will get 2 gasket just incase then.
I already have the M7 180 deg F thermostat on my car.
I also have full system of supersprint (Header,race hi-flow cat and cat back)
I am hoping to achive at least 250HP.

Cheers

 

I take it there is no thicker head gaskets available?

Doubling gaskets is a good way to get a leak.

 

The standard head gasket is .65mm and the other OEM gasket is .95mm. Cometic makes custom gaskets to any spec (for a price) if you so desire.

 

Thanks. That sounds like a better idea to me.

 

hi guys,

so what thickness would be the optimum thickness for the headgasket while safeness of head and engine is not compromised...

by the wat,anyone knows what is the website for the custom gasket manufactrer?


cheers

 

Website http://www.cometic.com/ ; for a recommendation you should consult the one doing the headwork.

There are many factors regarding the head that have an effect on combustion chamber volume, the amount milling the deck requires, the amount of material removed within the combustion chamber, some remove the manufacturer’s indexing boss, others don’t, valve face shape and size (although only to a minor degree); there are other considerations for “safeness” that have to do with environmental factors, fuel quality etc. In other words no one-size-fits-all beyond basic stock thickness.

 

We had the best experience with one 0,95mm and one 0,65mm gasket.
You have to consider that most heads get planned 0,2mm.
I know about 10 Minis with double headgaskets, no one was leaking.
Important is, ever use new gaskets!
I have a ported head on the workbench, the combustion chamber are milled on this gead, I will litering out the chambers against a normal non milles head.

 

Hi K.H,

Anyidea what would one expect to pay a custom gasket for our head from Cometic? Was initially thinking to order 2 new OEM gasket but was afraid of potential leak.... If the custom gasket is affortable, for a piece of mind, I might as well...

Cheers