I am in the works of building a head. I know I could just buy one that’s already been R&D but what’s the fun in that? I am looking for help for guys that are experienced in this line. I know that on a supercharged engine that the exhaust is going to be the key so that’s where we’re starting. Just had a few questions, I think we're going to drop compression a little bit (look at the mods I have) to try to help timing from being retarded…I know some guys put on 2 head gaskets, to me that’s a temporary fix. I need some help on where to find a good set of valves. I plan on using a shrick cam with stock springs. What’s the deal with roller rockers on a mini? Experienced guys please chime in!

Also can anyone hook me up with tube dimensions of an OBX header? Thanks! -- Johan

 

how can you drop compression without running two gaskets or getting into the bottom of the motor? are you planning on changing the combustion chamber?
FWIW, there was mention in previous threads of thicker than stock gaskets, but the memory is fuzzy.
For valves, call the head builders... They may even sell you some!

Sorry, my header is on my car, so no dimensions on that one! Someone is selling one in the marketplace, maybe they'll do the measurements for you.

Matt

 

Thanks! My header is on the car too. I just got off the phone with my machinest and we talked about cnc'ing the chambers to drop compression a little. Not sure if it's possible at this point, just some idea's we kicked around. He did mention that he had a contact to make bigger gaskets. So that's a option down the road. I remember too somwhere a thread talking about this...I would rather pay money for a thick gasket than putting 2 together...from the experience that I have that just doesn't sound like a good idea -- Johan

 

You can get MINI head gaskets of varying thickness from:

http://www.vacmotorsports.com/cgi-bi...pl?item_id=424

.024" to .140"

 

For another gasket option http://www.cometic.com/ , for the valves http://www.theoldone.com/components/...ead_modifi.htm & http://www.ferrea.com/productlines.php , for some DYI tips http://engr.smu.edu/rcam/cpm3v/minih...nihead_21.html , can’t help with the OBX measurements.

 

I'm gonna use all Ferrea stuff when i do my head. I'm going private...same as you. I find a lot of the vendors heads to be a little pricey and have a buddy in a machine shop that'll work for "beer labour" and i can get good discounts on Ferrea through work. Also as posted above I'm gonna grab a Cometic gasket and some ARP studs...

 

I have an OBX header sitting here - whatcha want measured?

 

in college, my mechanic rebuilt my VW Rabbit motor for $25 and a quarter oz of the kind! And since VW sent him the wrong pistons, he did it twice for that price....

Matt

 

Thanks k-huevo and gmcdonnell for the sites on getting thicker gaskets!

Saifa, do you know how much lager the the Ferrea valves are from stock??

I need the tube diameter so we can build a mock-up for the flow bench. Thanks! -- Johan

 

What's everyone's thoughts on trying to drop compression? Especially with the mods that I have? Also Ideas on a cam? I'll probably end up with a shrick just because it is a proven cam, and there's not too many other options out there. I know that m7 and WMS were woking on a cam, but never heard anything new. I think that the m7 cam is designed to high revs anyway.

 

Ferrea offers valves a stock size or +1mm oversize. The Mini already has a compression of I think 8.3:1 (correct me if I'm wrong) which is sick for boost. i wouldn't even bother changing it.


Seann

 

Call these numbers approximate - I have a good micrometer/caliper but the tube diameters aren't consistent - it is an OBX after all.

The 4 average ~1.78" OD
The 2 average ~1.85" OD
The downpipe is 2.5" ID

 

Thanks man That's really going to help! -- Johan

 

Just wondering but what are you setting the car up for? I don't see why you would want to lower compression. Back before I strapped on a turbo I was considering going higer compression.

At the same ignition advance you would be losing horsepower with a lower compression. However the factory computer, given all variables stay the same, would add more ignition advance with lower compression.

So if you worked on the other variables that make the computer pull timing (IAT's and knock sensor) you can make even more power. For example get more air flow to the intercooler or use a different intercooler. And give the car a little bit more fuel with larger injectors and tune it with an AFC.

Also Ferrera makes 1.5mm oversize valves for both intake and exhaust. I would suggest going with there double valve springs and titanium retainers. Then rev the car to 8,000+. With this setup cars have been taken to 8500+.

Of course at that point a stand alone ecu would be required. Because at 8150 the factory computer closes the throttle body. Which I am currently working on.

 

1.5mm..?? My bad.

 

Yeah I'm currently having my head done. So the information is fresh.

 

You might want to define where you want the performance to be. Low to Mid RPM. Mid to High RPM. You really can't have both and do it well so you need to pick one. Then maybe you can get more directed answers.

Big valves and 8200RPM is great if you want a top end monster. If you want stop light brute(for a tiny 4 banger) acceleration you need to go another direction.

Sorry but you can't have it all
So far most MINI tuner products are high RPM oriented because that's what the little engine that could does best.
I know a good tuner could change that. At least as far as physics will allow.

Stuffing that M62 in there is a good first step. The next best bet is better pistons. A better dome and quench area will get you HP with no other changes.

After that I think a good water injection system would work wonders for the MINI. That's high on my dream but can't afford list.

When there's only one cam to choose from you're ******'d. That's one of the most serious dead zones going for the MINI.

Random thoughts as usual

 

How 'bout this one? (Ultrik, from Mini Mania - specs here).

 

there's more than just Schrick. Dinan make one, GT Tuning makes one, FBT/El Dablito is working on one. And then there is custom. Don't know what that costs, but Mini parts are so expensive, custom may be cheaper!

Matt

 

True, and I know TOO has/had one as well.

Anybody have specs on the others? Roland doesn't have then published on the GTT site.
Here's what I have so far:

ULTRIK HIGH PERFORMANCE CAMSHAFT - MINI COOPER 'S'
*
Ground to Mini Mania's exacting specifications by a selected major OEM camshaft supplier, this high performance camshaft increases horsepower and torque throughout the RPM range. Similar performance to the Schrick camshaft at a lower cost. The camshaft can be used with the stock or ported cylinder head and stock valve springs. A great way to improve performance without disassembling the motor – a difference you can feel!

Intake: Duration 264, Lift 9.5mm, overlap 0.5, peak timing 114, open at 18, close at 66.

Exhaust: Duration 272, Lift 9.0mm, overlap 0.65, peak timing 114, open at 70, close at 22.

Professional installation is recommended.

NEW MINI COOPER 'S' PERFORMANCE CAMSHAFT - SCHRICK
Schrick is one of the premier automotive performance companies in Germany. This street performance cam has been designed to increase horsepower while working with the stock cylinder head and valve springs. A great way to improve performance without dissassembling the motor!

For those interested in numbers...

Intake: Duration 264º, Lift 9.5mm, overlap 0.5, peak timing 114º, open at 18º, close at 66.

Hmmmm. So far the only difference is price

Can't find spsecs on the others. Must be superspecial secret stuff


So OK maybe it's a Zombie zone

 

I'd rather have low to midrange power myself. I'd like to have Larry (www.theoldone.com) put in the new cam while he's doing my head...guess I'm stuck with one choice spec-wise. It's an imperfect world.

 

I thought Larry was working on a cam at the time he was working with John on the neverending engine story?

 

MINI cam information has not shown up on the ENDYN website, but that does not mean he is not still working on one.

And Johan, check out what ENDYN offers in the way of heads and pistons, at http://www.theoldone.com/components/...ead_modifi.htm

 

I believe Larry is indeed working on a cam but does not yet have it available for sale yet. Very likely when he does bring one out I will buy it, but it seems a waste to have a head ported, polished and revalved without also putting in a higher performance cam at the same time, so I'll probably get an Ultrik unless I can another part of equal quality for less $$.

 

What I would like is to increase torque thoughout the powerband. I don't a motor to only make hp at high rpm...running a 19% I don't think that would be very efficient. I thought that I read somewhere that lowering compression a little will help reduce knocking and from loosing timing. I looked for the thread but couldn't find it. Maybe I'm wrong if so I will tell Seth (my machinist) not to worry about it. Like Matt said it's a never ending quest to keep timing from backing off.

I called Endyne a while ago and asked about cams. The responce that I got was that they were so busy with other things that they put that project on the back burner for now. Also when I called, the person I talked to wasn't that helpfull so I ruled them out. Maybe a good place to get some parts from.

I did look at the Ultrik cam, it's the same as schrick and I think they even say that somewhere. It's a little cheaper I think.

Anyone know what size over valve Randy uses on his head??

Also what is the compression ratio on a MCs?? I did a search and got anywhere from 8.3-10.5:1 Anyone know for sure?

What do you mean Obe, I want it ALL. I still need to finish my other project that you seen. LOL

Thanks again for everyones input -- Johan