Performance cylinder heads

[MtyMous]

I'm stuck. I've been looking at cylinder heads for months and I just can't pull the dang trigger on one. I've been looking at a couple different ones and I just need some opinions from friends. Hopefully some experience with the manufacturers or even the specific heads as well.

My engine is yet to be built, but the specs are as follows:

1380cc A+, 7cc dish cylinders, Kent 286 cam, new crank (not a regrind), Kent Vernier duplex chain, MED SC/CR gearbox (standard helical drop gears), MED ST2 ultralight flywheel and clutch. I'll have a Specialist Components 5 port injection and electronic ignition setup. Ask if you think of anything else that is needed to make an informed decision.

Option 1: Minispares MSE9


- 35.7mm intake & 29.5mm valves in plasma-nitrided EN214N s/steel
- manganese bronze valve guides
- Nominal 24-25cc with by pass and heater take off holes open
- Perfect for use with 7cc dish on mega pistons 1380cc.
- With by pass and heater holes which can be blanked off.

Quoted £742.76 ($1160.68) shipped to my house


Option 2: Calver ST, Stage 3 Sport, Unleaded (From 7ent)



- 35.7mm intake & 29.5mm exhaust valves plasma-nitrided EN214N stainless steel
- 4 angle inlet seat, 3 angle exhaust seat
- Valve Guides: Magnesium bronze
- Valve Springs: Nominal 240 lb. at 0.500" valve lift.
- Stem Seals: Latest 'top-hat' design with tensioner springs.
- Chamber Volume: Nominal 21cc.


Quoted $1,910.34 shipped to my house

Option 3: Have someone modify my 12g938 that's sitting on one of my workbenches. It's in good condition, but bare. I have Kent VS2 double valve springs to match my 286 cam, but I would need everything else. Not sure what it would cost (or who to go to) to get a similar quality as the other two heads listed and I doubt it would cost much less to go this route.



So what do you guys think? Do you have a better option for a performance motor that will see road driving and the occasional weekend track day?

[94touring]

I talked with Mike at minisport and will likely buy one of their heads.  They said a stage 4 would actually work great for street use on my 998.  I thought about using a 1275 head but all the work involved just buying one done up that bolts on makes more sense.  For my 1275 engine I'm still undecided.  Maybe just send what I have out for some modifications.

[MtyMous]

I just don't like the lack of info on the cylinder heads on the website. I asked mike to get with his engineers over there and get me some specifics and they basically told him "it will work". I'd like to know if they use nitrided valves, what kind of valves, what kind of guides, what kind of springs, what kind of seats, what angles are the valves ground at, what's the chamber volume... Until then, I'm not sure they are in the running.

The price is certainly right, though.

[Willie_B]

You could email Calver for his input. I notice his shop is closed on his website at the moment.
keith@calverst.com

[94touring]

This is off their website as far as what they're using.  They did give me chamber volumes for compression ratios when I had my email exchange.  I didn't ask what springs but I assume their own. 

This Grand Tourer Mini Sport modified Cylinder Head is ideal for rally and race use on your Mini 1275cc. High flow competition cylinder head with superior Rimflo inlet valves. Fitted with bronze alloy valve guides and extra strong double valve springs. Fully gas flowed, polished and ported with balanced combustion chambers.



The Mini Sport Grand Tourer 1275 Modified Cylinder Head boasts:



* 35mm inlet valves

* 30mm exhaust valves

* Extra strong double valve springs

* Bronze valve guides

* Unleaded valve seats

[tmsmini]

I believe that Keith does the MS heads or used to.
I got a Calver ST head for the MPi. The other heads in use are Minisport.
I looked into having someone remake a stock head I have and it was close to the other options.
Granted these are MPi heads, so a little different beast in use.
Terry

[John Gervais]

I'll second E-mailing Keith directly. or give him a phone call (I think he takes calls on Monday or Wednesday mornings, before 1200 hrs.).  I spoke with him last week, and his webshop is undergoing some updates.  But, he's still 'open for business' and keeping busy.  He generally answers any questions you've got, and explains 'why' he does things the way he does. 

I've had my small-bore stage 3 head for close to 15 years now.

[Trigger]

1st post here. Check out http://turbo-mini.com/66091/66153.html Phil is highly regarded over in the UK. He is quite a bit cheaper and is extremely helpful. Do a search on theminiforum under turbo phil. Beautiful heads. He is a turbo guy but does normally aspirated heads also.