53 replies to this topic

[who_loves_the_mini?]

This is becoming a great thread, thanks

Is the 7 Port head a bolt on head? I know its not "bolt on" but do you need speacial things to be able to run it, such as the cams etc with the 8 port or S rods when stroking a crank. Or can you just use the head on a normally built engine

[Jammy]

I believe (but don't hold me to this) the 7 port head is essentially bolt on, which was the beauty of it when it was cheap! However, with both your going to need to think about uprating parts like the clutch and differential to cope with the power the engine will be chucking out.

With the Arden 8 port, apart from the cam, you also need special pushrods, and there are several ways around this. Some people get custom carbon ones made up, otherwise grind some down, or I think it *maybe* possible to use pushrods from another Austin engine, but again, not too sure on that.

Another thing to consider with 7 and 8 ports and 16Vers is that you need special bonnets to clear either the carbs or the cam cover.

[Sprocket]

Another thing to consider with 7 and 8 ports and 16Vers is that you need special bonnets to clear either the carbs or the cam cover.

Not if I can Help it

[The Matt]

I would personally love to do an Arden 8-port, they are seriously lush and are a way of pushing AN A SERIES ENGINE alot further than in standard guise.

I do see the logic of using a 7 port head, they utilise the same camshafts, exhausts etc, but with the added benefit of increasing your fuelling options. So you can get the best of both worlds, you can modernise the fuelling of an A-SERIES ENGINE without loosing the benefit of hundreds of other well-established bolt on mods (cams, exhausts etc).

As for 5-port heads, they are ultimately what limits and restricts THE A-SERIES ENGINE IMHO.

Sorry to accentuate the A-Series bit so much, I just didn't want to go off topic at all!!!

[CharlieBrown]

I have removed the irrelevant posts in this topic.

Charlie

[who_loves_the_mini?]

I seriously want a 7 port head now so might start saving for one. I am rebuilding a 1275 to replace my 998 so might have a think about doing a 7 port build.

One other thing I was thinking of when reading oldschool's thread, what would a supercharged 7 port be like?

[who_loves_the_mini?]

Ive decided to go 7 port. After having a think today I reckon i should be able to order one at the end of April if everything goes well, maybe a bit sooner

Oldschool - how long did you have to wait for yours?

Now just need to sort out an overal engine spec and i can start getting bits and pieces

[The Matt]

Oldschool - how long did you have to wait for yours?

bit of a sore point for Brett that one! shhhhh

[Dan]

Refering to what Jammy said above, if you are careful Mini Sprocket then you are quite right that you don't need to change the bonnet. The Jack Knight twin cam fits under the standard bonnet and if used with a plenum chamber injection system instead of throttle bodies then you don't need to cut the front open either.

[who_loves_the_mini?]

i was thinking about the bonnets, could you add an inch or so onto the wings and bonnet to cover the heads and carbs? or is it the height that is the issue?

[miniboo]

its the height that tends to be the problem.

you can get bonnets with an added bulge tho that dont look tooo bad

[Pavel]

Incidentally, anyone know the legalities of driving without a bonnet? Did it a couple times around here after my bonnet flew off on the highway, and got really dodgy looks from pedestrians and cops alike!

[Oldskoolbaby]

who_loves_the_mini? Posted Today, 06:03 PM
Ive decided to go 7 port. After having a think today I reckon i should be able to order one at the end of April if everything goes well, maybe a bit sooner

Oldschool - how long did you have to wait for yours?

It took just over 2 months and that was with no chamber and port work carried out. Minisport initially said 5 weeks but I knew it would be longer a they were sorting out the casting problems when I first ordered.

As for the fitment, the only things that will be needed is a set of carbs or throttle bodies. I got mine off Ebay and was first considering fitting GSXR1000 throttle bodies, but when looking at it, Id have to have manifolds made up and Id rather do that when I add the Garret T2 turbo at a later date.

[who_loves_the_mini?]

What head did you go for in the end? Im thinking og going for the race one so the head wont be the limiting factor in the engine, like it is in most 5 port builds

Im going to go for a set of twin weber 40's if I can find a pair in decent nick.

Before i can order the head though im getting the bodywork sorted and the 1275 completely rebuilt but with the standard head. Once the mini is solid and sprayed ill order the head so should be fitting it around the summer hopefully

[Oldskoolbaby]

I ordered just the casting with 31/37 valve seats and Silicone bronze valve guides. I thought it would be best to modify the head to suit my engine instead of the other way round. And it'll probably work out alot cheaer to get somebody else to do it.

As for carbs, I was going to fit twin 45 Webers until I read that it is actually better to use Dellortos on the 7 Port. Bassically you can finely tune them more than the weber and this is what is needed for this head in particular.