25 replies to this topic

[minisilverbullet]

I wonder if anyone who has a 7 port head would mind describing their engine spec.

I am looking at the SC kit, its basically bolt on, but i wonder what the spec of the block should be for best results?

Cheers
Craig

[Sam Walters]

I think your regular performance bottom end would suffice for most configurations. You don`t need to go mad if its not a race engine.

http://www.med-engin...mp;vlang_id=562

276 cam perhaps for something thats entirely tractable, but with a cross flow head you could probably get away with a 296 and it be easier to drive then a 276 in a 5 port. 

decent 1.5:1 ratio roller rockers

omega or powermax cast pistons unless its a race engine. 

the rest being mostly decent quality standard components ect....

A decent rebuilt box with a cross pin diff on helical drops should suffice for the gearbox.

I wouldn't say its just a bolt on job! You will have to adapt the car a little bit to run the injection.

Edited by Sam Walters, 19 November 2010 - 01:20 PM.

[johnK]

Cam spec wise you don't want to go too conservative, the Calver RE13PP, circa 280° deg cam is an absolute road monster of a cam with my design of 7 port head - real torque from 2000rpm all the way to 7k (hence not requiring fancy bottom end components) in a side by side pull from 2000rpm with a race 5 port car would have this cammed 7 port would kill the 5 port stone dead all the way to the top end. If you want to go alittle more extreme we do a special grind for the 7 port cica 292° deg duration. This cam loses torque to the RE13PP at low rpm, still very very gutsy, but makes a run for the redline at 4000rpm (peak power circa 7400rpm - usable torque still at 8000rpm)- completely street tractacble, 4th gear at 1200rpm on a 3.44 diff and pull comfortably is no issue, 900rpm idle etc. Watch out for the rolling road figures for this one soon in Mini World mag shootout.

JK

[minisilverbullet]

Thanks for the comments guys - Sounds tasty!

I had originally thought about a project mini with some sort of conversion perhaps pro-motive, but the Swedish fun killers have killed that idea as the Bhp to weight ratio is too high!

So have been looking at the 7 port head for my current mini!

Its an 96 SPi; is there any reason why this block cant be used?

I do wonder about the emissions levels of a 7port head though as its very strict here, especially given the car is a 1996. Any comments of that?

I guess it would be possible to run different ecu maps to over come this?

The 7 port is sounding perfect. I mostly use the car in the city, with a 15 km trip to work a couple of times a week, so its low down power and torque i am after!

@john I will look out for the magazine since youve mentioned it - although its a pain the #¤& getting it, involves a train trip to Denmark!

Oh and Johnk whos "we"?

Cheers

[mini13]

"we" is specialist components.

John is SC's engine Guru.

just for the record hot cams are more important on other 7 ports due to their larger ports, but that beside the point, the SC one is the one to go for.

[JakeJakeJake]

Not sure how emissions rules work in Sweden but here some people with newer minis fit and older engine (usually just the number) so it tested with the requirements for that year of engine. So no cat etc is required or even just a visual check is needed.

[wolfie]

if you go for the seven port then go for Johns billet one or HRE's pierce one, dont get one from webcon there quite expensive, need a fair bit of fettling and dont return your calls to sort out issues.

[richieg]

Just looking at the HRE, SC and MED heads and I notice the HRE version is running much smaller valves (33.5/29.5) compared with the others (36/31 & 37\30 respectively). Do you think you would notice much difference?
How would the smaller valves compare with a 5 port 36/31 or 37/31?
Do you know if you can fit twin 40s with this head under a std round nose bonnet and use filters?

[samsfern]

i built my engine with a 7 port in mind, mines a 1330, piper 649+ race camshaft, lightened balanced bottom end, steel centre strap, straight cut drop gears, 3.65 fd. this block is an spi block, the only thing id advise doing is changing the oil transfer pipe to the braided hose upgrade or even an oil cooler.

[Southy]

Just looking at the HRE, SC and MED heads and I notice the HRE version is running much smaller valves (33.5/29.5) compared with the others (36/31 & 37\30 respectively). Do you think you would notice much difference?
How would the smaller valves compare with a 5 port 36/31 or 37/31?
Do you know if you can fit twin 40s with this head under a std round nose bonnet and use filters?

The thing with a 7 Port head is that bigger is not always better in respect to the valve size. The 7 Port head already flow's a lot better than you would get from a 5 port so having such large valves fitted is not always the right route to take, infact it could even make you loose some bottom end power.

A friend of mine running a 7port with 37/31's with a similar spec 1380 as myself only managed 1 lbs ft more than myself on the rollers over a 35/31 5 Port head, albeit it made 23bhp more than my setup though.

I seem to recall you can't fit the 40's under the bonnet with the above head's mentioned although I'm not fully sure but I imagine someone will be along who does know soon.

[minisilverbullet]

Southy - What made you go down the 7 port route instead of something else!

What is the car like; lots of low down power /torque?

[Southy]

Southy - What made you go down the 7 port route instead of something else!

What is the car like; lots of low down power /torque?

I haven't myself, I'm still running a 5 port head though would like to add a 7 port head on it at some stage, if I decide to keep the Mini. My friend is running the 7 port and it is really nice to drive and pull's fairly well from the bottom end, but I suppose with it being run on injection helps out.

[wolfie]

Just looking at the HRE, SC and MED heads and I notice the HRE version is running much smaller valves (33.5/29.5) compared with the others (36/31 & 37\30 respectively). Do you think you would notice much difference?
How would the smaller valves compare with a 5 port 36/31 or 37/31?
Do you know if you can fit twin 40s with this head under a std round nose bonnet and use filters?

if you buy from webcon they come with girls valves and you have to change them to mans valves.

I am in the middle of a 7 port turbo, currently doing the Plenum, 7 ports can still cost alot unless your sticking to carbs or have deep enough pockets to pay others to do it.

[minisilverbullet]

Does anyone know if I am going to be able to use an SPI block for the SC head? Are there any considerations?

Also any one who has the head with the new ECU - does the ecu contol the lambda sensor. Im thinking about strict emissions in the swedish mot since teh car is a 1996!

[wolfie]

spi block is fine its the same as any other A+

The Lambda is not controlled if anything its the other way round, Lambda's send signals to the ecu.