thoughts on makeing a 7port from a 5port?
Turbo Mini Forums

well ive been thinking... random thoughts..

what if a 5 port mini head could be "built up" in the intake ports

you know right there where the brake is between the valves in the port what if that brake came all the way out to the gasket face?

then it would be 4 intake ports all be it tall narrow ones but hell that dose away with the whole charge stealing crap right? also makes efi easyer as you can stick fuel in when ever you like not just when the valve is open like we currently have to not to mention the arf can then be fixed

think the only way to add material into our cast iron head is to braze it in then shape it all nice
a case of laying bead on bead till its a wall separating the valves into there own ports
then you would probably have to take the existing port out in the corners to make it carry the required volume of air

of cause this then means we need a new intake manifold


random pic i fond of my intake port on the std 202 head the yellow line most easily seen on the right represent the port shape witch is quite square you can see where at the gasket face there is a round 45 degree cut in to make a round intake fit the square port crude but its better than 90 degree edges...

i suggested this about a million years ago and.someone told me it haf been done a million years before that. I believe a slot was cut and sheet brased into that to form the devide. wish I could remember the name of the heads... theres defo pics on here somewhere

turbo 16v k-series 11.9@118.9 :)

Denis O'Brien.

http://www.turbominis.co.uk/forums/index.php?p=vt&tid=340608

Easiest way is to make an inlet manifold with the divider.

Think that was done decades ago too.

It's probably kill a n/a engine due t making port a lot smaller....boosted could well respond very differently though.

9.85 @ 145mph
202mph standing mile
speed didn't kill me, but taxation probably will

perhaps a mix of the two mill the slot down te guts of the port then weld up the alu intake flange with the sheet sitting in the head to locate it this way there is just a neat fit with the devider rater than haveig to braze the head just make it near inpossible to remove when on the car lol

If you look at Paul S work, there is likely more to gain with a proper 5-port EFI setup. There are significant gains to be had with well designed intake and exhaust manifolds and sequential EFI can take care of the charge stealing issues.

http://www.jbperf.com/

i remember seeing pictures of a head that had new ports cut down at an angle from above
inlet ports went down through where the rocker cover would have been
anyone know what im talking about?

Yes i moved to the darkside

Instagram @jdm_brett

Probably the Weslake 8 port head Brett, IIRC.

I know exactly what you mean Brett, it was a really odd cylinder head!

nope not the westlake this baby -

edit- i actually thought the top port was bigger and split in to individual cylinders and the original inlets blocked but apparently not

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Edited by Brett on 6th Jul, 2014.

Yes i moved to the darkside

Instagram @jdm_brett

That looks crazy how dose the intake mani work?

It would burn a shitload of oil

I saw one of these in the force workshop what, 12, maybe 14 years ago... Perhaps he'll grace us with his knowledge

Dividing the port is a nonsense. You will severly restrict flow.

The siamese port effectively supplies one cylinder and then the next, so each cylinders gets the full port capacity.

With moderate cams such as used with a turbo, the affect of charge robbing is negligible. It does occur but what the inner cylinder loses in VE, the outer cylinder gains. If you use a race cam, then the impact will be greater but not as much as the "experts" would have you believe.

To get the best out of 5 port, spend your time and money on manifolds. Tune the design to use the pulses that are generated and effectively ram the cylinder whilst the inlet vale is open and suck it out whilst the exhaust valve is open. Then a moderate cam will allow the engine to rev and get you the airflow you need with minimal interaction between cylinders on a siamese port.

Saul Bellow - "A great deal of intelligence can be invested in ignorance when the need for illusion is deep."
Stephen Hawking - "The greatest enemy of knowledge is not ignorance, it is the illusion of knowledge."

+1 .

Super long cams are mostly senseless for anything else than a long circuit racer with flying starts where you can pin it right in it's super narrow powerband .

My EngMod 4T simulations suggest that ( using a VP3c up to about 5K inner cylinder make more power, but suggest that after that the more efficient exhausts of the outer come into play and cause the outers to produce more power. I suspect that a backwards seven port with four proper exhausts coupled to modern fuel injected siamese ports would not be half bad if not entirely sane

Edited by Sir Yun on 7th Jul, 2014.

That sir, is not rust, it is the progressive mass reduction system

http://aseriesmodifications.wordpress.com/

i have to agree paul the work your doing is outstanding and like you say the cash (milling,tooling) could be used better on the manifolds with most probably better results
seen how the valves are aways behind the demand on the cylender like you say its the mass of air moveing at speed that dose the filling of the cylender not the piston moveing down

what i was really getting at with the divided ports was getting better fueling easier as in the injector could fire when ever and all the fuel will go to the intended cylinder but there are ways around that as said already above

I did not mention the injection as that is the easy bit.

You could always use a carb, just get the manifold design right.

Saul Bellow - "A great deal of intelligence can be invested in ignorance when the need for illusion is deep."
Stephen Hawking - "The greatest enemy of knowledge is not ignorance, it is the illusion of knowledge."

carb on a "proper" intake mani? whould you recoment this if still if ive got MS3X?

plan is to run the carb till ive got my selft sorted with the programing and gotten the spark down then once i feel comfortable ill build the intake at the proper lengths and sizes to get the resolts of couse at that stage it will move to efi

was mainly looking to see if there was a good amount of gains to be had by divideing the port but it seams there is not when tou use a short turbo cam and such so sort of point less really

just a thing i was thingking about that was kinder buggin g me to find out about lol

Buy this.

http://mk1-forum.net/viewtopic.php?f=7&t=10044

Man that would be a tight fit...

I run a supercharger and I don't care the TB is on the wrong side.
VEMS + 12 PSI + Liquid Intercooler = Small Bore FUN!

http://www.jbperf.com/

I have seen that workmanship before..

turbo 16v k-series 11.9@118.9 :)

Denis O'Brien.

Whaaaaaaat the fuuuuuuuuuuuuuuuuuuuucccckkkkkkkk ???????

On 14th Jul, 2014 evolotion said:
I have seen that workmanship before..

lol each time i see that there is more and more wrong with it

half kinda thinking of a 16v head and boost the van with the other 5 port stuff ive already got/made