19 replies to this topic

[RSA Mini]

Gents, I've done a lot of research and I think the best conversion for me at this stage is a 7 port head, bolt on power Vs the bmw k conversion ( requires some serious cash ). I've noticed that piece manifolds are about the cheapest for a std 7 port head +\- $1200 Vs most of the stores in the UK. Any recommendations regarding the conversion ( place to buy, things to take into consideration before buying it ). Thanks in advance

[Northernpower]

Buying the head is just the start of the process. If you're going to go down the 7 port route you need to consider what else you need to enable you to extract the true potential from it. You also need to consider the quality of the 7 port casting as well. Personally I wouldn't fit a 7 port without a programmable ecu and fuel injection. If you go down the injection route do you want a complete package from one supplier or look at a cheaper option by mixing and matching ECU, throttle bodies, injectors, trigger wheels etc. The alternative is a distributor with either bike carbs or webers but these are not going to delivery the true potential and driveability.

 

You also want to consider what you're going to do with the cam and the bottom end. It's pointless putting a 7 port on a standard bottom end when it's designed to deliver at the higher end of the rev range.

[Spider]

Graham, have you done a build thread on yours anywhere?

[Northernpower]

Graham, have you done a build thread on yours anywhere?

No, unfortunately not.

[RSA Mini]

Thanks for the info graham, do you have a 7 port though?
I was planning the Weber route as I already have a pair of almost new carbs that's in storage for a couple of years now. If I'm to go the injection route, besides the std injection kit package most suppliers sell, is there any their injection setup that will bolt in straight to the head? If not, I'm assume I would have to make a custom manifold for the setup?!

Regarding the bottom end, I'll be going the 1380 route with a mild cam, the intention of the car is not to race on the track or anything, just a weekend car with power on tap when needed.

Cheers

[Northernpower]

Yes I run a 7 port on injection. Once fully set up on the rollers it's a very smooth power delivery. With the correct cam, the torque i.e drivability is fantastic. There have recently been a couple of threads on 7 port heads, http://www.theminifo...eber-questions/ and http://www.theminifo...um-7-port-head/ have a read of them.

[RSA Mini]

What head and injection system you have on your car?

[mk1leg]

My 7port set up from Vintage mini

[Spider]

 

Graham, have you done a build thread on yours anywhere?

No, unfortunately not.

 

 

Bummer. Opportunity missed.

[RSA Mini]

Wow, that looks awesome, by the looks seems you running bike carbs? Was it a complete bolt on kit?

[Northernpower]

What head and injection system you have on your car?

I've run different 7 port heads including one with twin Webers. The problem with Webers is you need to find someone with plenty of experience setting them up on the rolling road and more importantly plenty of chokes, jets and emulsion tubes etc. This wasn't such a problem a few years ago but with the increase in mappable ECU's these specialist (as they now are) are becoming increasing difficult to find. Even when the Webers were set up correctly in my opinion they were still not as good as a well set up ECU running injection, but the bark from a Weber is hard to beat.

 

My current set up is the Specialist Components head with their throttle bodies and ECU.

 

 

It currently run a Keith Calver cam with his 72.5mm pistons giving 1342cc. This leaves room for a rebore, or maybe two. You mentioned fitting a mild cam, I can't see the point if you're going to the cost of 1380cc and a full 7 port head, then not using it. With the correct cam you can exploit a lot more torque and hence better drivability. My current set up gives torque from 2,500 revs all the way through to 7,500. I've included one of the early graphs showing how flat it is.

 

[GraemeC]

That looks the business!  I find it quite amusing how 'empty' it looks behind the engine with a 7 or 8 port.

I fancy doing this one day, but in a pick up so injection will be a must as getting to the dizzy would be a nightmare!

[paulrockliffe]

Has anyone ever reversed the head to get the exhaust to the front so the bonnet still fits, not sure if there's a sensible way to run the exhaust past the gearbox?

[mini13]

nope, no they havent

[Northernpower]

Has anyone ever reversed the head to get the exhaust to the front so the bonnet still fits, not sure if there's a sensible way to run the exhaust past the gearbox?

With the advent of extremely short throttle bodies I don't think space is the problem it was with Webers. The space at the back of the block keeps the manifold cool and having the intake at the front gives more opportunities to feed it with a cool intake charge.