23 replies to this topic

[mill 750]

I sprint a 1380 mini in a upto 1400cc class , over winter will be rebuilding, looking for a good power increase so was thinking of going 7 port. anyone using one might have any info .I am running about 123bhp at present , would like to get to 140+! sound possible? thanks

[Cooperman]

To get to 140 you might need an 8-port head with twin Webers and the appropriate cam. The 7-port will give more though and you could well get to 130+ a bit.

[mini13]

Phil short was running a 7 port in the 1400cc hilclimb class, i belive it was compeitive.

he sold the car when he moved on to racing somthing else.

[m1tch]

Mill 750, I have a spare Weber DCOE 40 if you need it

[mill 750]

Mill 750, I have a spare Weber DCOE 40 if you need it

Thanks for your offer! I want to use 45's of which i already have,

[mill 750]

I sprint a 1380 mini in a upto 1400cc class , over winter will be rebuilding, looking for a good power increase so was thinking of going 7 port. anyone using one might have any info .I am running about 123bhp at present , would like to get to 140+! sound possible? thanks

Thought i might be pushing it about , Looked gentle into 8 port with Med soon added up cost wise not written it off cheers!

[bmcecosse]

As i'm sure you know only too well - problem with all that power is holding the transmission together!

[minivanman]

Minisport reckon they can get 140ish from the 7port.

[Cooperman]

Quite right. When you think that dimensionally the gearbox was designed to take 34 bhp and now we are putting 4 times that figure through it, albeit with some unreliability, it is quite remarkable, Yes, we have stronger gears and needle roller bearings where once we had plain bearings, but the overall dimensions have not really changed. It's a credit to its designers really, although we complain - well, I do as the transmission is the weak link on my rally 'S' which has about 117 bhp at the flywheel at 6400 rpm.

[mill 750]

Quite right. When you think that dimensionally the gearbox was designed to take 34 bhp and now we are putting 4 times that figure through it, albeit with some unreliability, it is quite remarkable, Yes, we have stronger gears and needle roller bearings where once we had plain bearings, but the overall dimensions have not really changed. It's a credit to its designers really, although we complain - well, I do as the transmission is the weak link on my rally 'S' which has about 117 bhp at the flywheel at 6400 rpm.

Tha age old problem! more power less reliability, i have got the bottom end pretty sorted but i know thats no complete guarantee, just looking for that little bit more , another age old problem!!!!

[Sprocket]

As i'm sure you know only too well - problem with all that power is holding the transmission together!

140hp normaly aspirated is naff all and the transmission will survive surprisingly well, as i am sure he is running a straight cut gearset

Infact, I have been running 140 hp on a standard well built transmission. That doesnt mean it wont go pop, but a rebuild at 5k is about due.

[Paul Wiginton]

I have never come across a 7 port, 8 port or 16v that can stay within a second of my 5 port up the 1/4 mile (normally aspirated). Personally I see it as expensively unnecessary.
Mine shows 140+ at Southern carburettors and 150+at Pete Baldwins, pulls strong from 3,400 in 4th gear right upto 9,500.
Its more about how the head is modified and how well the engine is built than how many ports it has.

Paul

[CobraV8]

I have never come across a 7 port, 8 port or 16v that can stay within a second of my 5 port up the 1/4 mile (normally aspirated). Personally I see it as expensively unnecessary.
Mine shows 140+ at Southern carburettors and 150+at Pete Baldwins, pulls strong from 3,400 in 4th gear right upto 9,500.
Its more about how the head is modified and how well the engine is built than how many ports it has.

Paul

Hi Paul,

I have a 970 Cooper S motor that I want to get humming along better - and it is the upper rev range that needs improving.

What are the specs of your motor to get it producing that kind of power?

I would prefer to be able to use the 5 port rather than going to a different head.

Cheers
Bevan

Edited by CobraV8, 06 September 2009 - 10:38 PM.

[Paul Wiginton]

Bevan,

I run a turbo crank and A+ rods with as much weight taken off as I could to let it rev quickly - quite run of the mill really, but Im meticulus in my assembly.

Its the head thats the power producer. Basically its the best Swiftune could produce for me. it was expensive but no as much as buying a 7 or 8 port then having that modified.

Oh and a 310sp cam

Paul

[Sprocket]

I have never come across a 7 port, 8 port or 16v that can stay within a second of my 5 port up the 1/4 mile (normally aspirated)

Supra light weight car. I say Supra as in a whole other level of super