Porting Kappa inlet?

[berjohansen]

Hi

I see there is a few posts about the kappa inlet, i have got hold of a brand new one wich is going on my Fiat Coupe.
Does anyone have pictures or tips on the porting prosses of this? It seems hard to enlarge the runners all the way to the plenum, is it just a case of portmatching and smooth transition to std diameter? Any help welcome :)

[Guy Croft]

Just match to ports and enlarge the few inches you can reach at the head end, dead easy. Makes a big difference, about 10% higher flow. I am not sure I archived the data but I think I got it up to about 146cfm. This is what member Dave Harper has on his Integrale.

In point of fact the 16v Coupe manifold flows more than the Kappa - if modified...! See Alexis Grant's flow data att. You only need to mod the inboard section which is very accessible at both ends.

If you still have the 2 piece Coupe inlet I suggest maybe you mod that and just ell the Kappa one to a 16v Integrale owner.


G

[tricky]

There are advantages and dis-advantages with both the coupe and kappa inlets, the kappa has a straight shot to the port and nice injector placement. I'd be tempted to cut the plenum off it, port the runners as nesacery and make a new plenum to fit them. This also gives you options with throttle size and you can then cut the runners to any length you want.

Just another way of doing it you might want to consider.

[berjohansen]

Thank you guy!
Regarding cutting the runners, I have considered it using this plenum http://www.jenvey.co.uk/home/turbo-plen ... et-apsc-70

[Guy Croft]

ask Richard very nicely and he might do one for you!!

I am not going to tell you what I said his was worth - a lot - and very difficult to make (esp to his high standard) but it would be worth every penny...

And the bonus of having a really high flow inlet (that equals or outflows the head) is that less boost is needed for same power compared with a lower flowing model..


G

[berjohansen]

I read his thread (fantastic build by the way!) and actually contacted him regarding making one more but no luck :o) thats one of the reasons i settled with the kappa inlet as a upgradable solution. Just to understand the theory behind it, is it correct that due to the restriction the inlet pressure drops after restriction and is actually lower at the valves than gauge pressure and that this is the reason for same hp at lower boost (need higher plenum pressure to reach same pressure at valves) ?

[Guy Croft]

kindof, the more restrictive a component the greater pressure difference one end compared to the other is required to move the air thru it


G

[tricky]

Well, who's ugly mug is that then :-)

No, sorry I don't get get much time to myself as is because I run a business full time and playing with engines is just a hobby, maybe if things were different I could have made a few up for people. I don't like the look of the jenvey plenum at all, it's the one size fits all nature that I don't like and the diffuser system is strange too, admitidly I've not had the pleasure in the flesh but from the outside it doesn't look very special.

The plenum size is important, the kappa one will be getting drained at higher rpm's imo. It would be worth the effort to fabricate a new one to fit.

[1NRO]

I honestly believe the Jenvey plenum to be wrong in design, the concept I belive in but the interpretation by Jenvey is flawed.

With regard to the Kappa manifold it is my belief that the inside dimensions of the runners are wrong for a ported cylinder head, Lancia got it right for the standard head but had no care for the after market tuners. I say this as I used a Kappa maniold to make a manifold but only a section of the runners, the plenum and a length of runner was cut off and thrown away! With the reduced length of runner I had a difficult time getting the internal size correct, I believe in having a tapering cross section all the way to the tightest point in the port from the plenum. I did manage a size I was happy with (carefully measured with port molds that were sectioned and measured on graph paper, very carefully) but it was getting nervewracking near the end of grinding, much more grinding and I'd of had breakthrough. I was just happy I managed it without having to resort to building up the outside with weld. to do the same sizing to the manifold with full length runners is impossible unless you build up a lot of material with filler rods. Some pictures below that show what I mean.

When you measure square to the runner the cross sectional area is consistent along the length,I know it doesn't look it in the picture but that is the reality.

I ground the runners up a little and made a start on forming a taper towards the valve, still a bit of meat that can be removed but I didn't want to make welding too hard so they were welded to the plenum at about this size, just a start on taper at this stage.


You can see the welds in the first picture,I opened out the entrance after this until it was about the size of the second picture. The second picture is prior to rolling the entrance into a bigger radius. It was getting pretty thin at this stage but I managed a half way decent taper with at least half the runners cut off.


The maniold ended up looking like this.

[berjohansen]

Wow! Great work! I just love to see how different people solve the same problem!
Ok i would think the Jenvey plenum was quite good? cannot find any documentation on flow but the cosworth camp seems to see it as a major upgrade? Why do you think they have got it wrong? I see you have your version with the "vent"? Pointed straight on the runners, is this what you meen?
My idea with the Jenvey plenum was that its an easy "lego" solution for a non welder like myself.
I can cut of the runners and port them, deliver them and the backplate to a pro welder port and smooth the transition to the runners, bolt together and Voila! Almost home made :)

[1NRO]

The nature of a diffuser or slot to feed the plunum is linked directly to the size of the valves, ports and manifold runners (and also the throttle), they are all linked together in dimensions. The sizing (of the system that feeds air to the plunum that then in turn feeds the engine) is crucial if the concept is going to work correctly and to say a product fits all applications is nothing more than sales talk, sorry to sound harsh but that's how I see it.
The inside of the manifold I made is a bit more involved than a slot, not to everyones taste but it flows a lot more than anything else I've seen.

[Guy Croft]

Some nice craftsmanship on show here gotta be good for the tuning 'cause' well done both!!

Nice to see your work on show Nik,


G

[1NRO]

Thank you Guy.

I had a closer look at the drawing for the Jenvey plenum and whilst they don't quote dimensions for the diffuser slot it's easy to see that it is much bigger then it should be, it would suit a massive throttle (a fair bit more than 100mm!) and certainly not the 60 mm or?! 70 mm that they quote. Very odd.

[Guy Croft]

oooh crikey don't mention diffusers Nik


we'll never hear the end of it......!

Seriously - anyone who wants to talk about diffusers in plenums get your own website.


90% of the people I work for couldn't even fit a piston to a conrod....


G

[1NRO]

! :-) !