Hi

I am about to start making a manifold for k4 gsxr 600 boddies for a zetec.

I have an inlet manifold for the basic shape and spacing, but does anybody know the port size on the head, I would like to have a good match and dont want to strip my motor at present ( still enjoying the driving).

I know its oval and should be somwhere arounf 26 x 50 mm, can anyone confirm this.

The gsxr 600 are 38 mm ID, and I have 38mm id ali pipe to match this, will heat and compress in vice to make oval.

Then I would like to hear from people with regard to runner length. I am figuring on manifold to throttle at 150 mm, then throttle boddie +- 80, and then an 80 trumpet in the air box , any thoughts?

Thanks Andre

Hi Andre

No idea about inlet lengths I'm afraid, but could you get a Zetec Inlet Gasket and use that as a template? Shouldn't cost more than a few quid? And you'll need one anyway?

Cheers

Mike

Yep, get a gasket. The inlets are heart shaped, oval with a dimple at the top where the injecter sits.

The oval is 45 X 30mm.
Rescued attachment Inlet Port.JPG

cheers

I have a ruberised type gasket thing , but not sure of exact port dimensions, ( I thought the gasket hole may be slightly bigger that the port so as not to intrude into the air flow.

It is my intension to move the injectors from the manifold into the bodies and not use the cut out, i.e just cut an oval into my adapter plate.

wanted to be spot on with matching the port hole size

I used a gasket to mark the manifold plate and then squashed the tube to fit.I used 40mm id tube with a 5mm wall and then after welding matched the manifold and ports, I ground both to get an exact match, you may find 38mm tube is a little to small to fit perfectly and will really need to match the parts after welding.
Paul.

I would suggest using the original placement of the injectors if you can. The one on my gsxr bodies ended up quite a distance from the valves and my acceleration enrichments took some tuning and needed some more work before my engine blew up. So while everything is apart I'm going to move the injectors closer to the valves.

Interesting thread about injector distance.............

I'm also doing a TB conversion using the K1-K3 GSXR600 bodies (but on a 2 ltr cvh engine)....

Been reading Dave walkers book on engine managment, and there is a ver interesting section on distances from injector - valve.

Interestingly enough, the theory is that set up correctly, it can actually help havinf injectors further away for the simple reason of the fuel cooling effect on the air!...The longer the distance, the more heat is taken from the air by the cool fuel!!.....Well, thats what he said!...Also brings on problems of fuel droping out of the air flow due to is weight, and pooling in the bottom of the manifold....But thats another story!.

The other option is to adapt a DCOE manifold (which is what I'm doing)....

PJ...

How do you guys plat to do with the injector dimple? I use Gsxr 1000 TB on my Zetec. And my manifold is build as Paulf describes.

This means that there is a "hole" in the port celing, just behind the mainifold plate.

Can this upset the flow in the inlet?

Micael

I've got the Dave Walker book and as far as i remember it says that having the injectors far from the valve can help with power but throttle response can suffer. For basically the reasons Jenko has said. That's why two sets of injectors is a good thing.

I am actually using a DCOE/DHLA manifold with adaptor stubs which puts the injectors back a long way. But my manifold also has bosses which I can machine for injectors so that's the way I am going to do it. I'll grind out the manifold to match the ports on the head - including the injector cutouts of course.

Must admit, thats the main reason I am sticking with the DCOE manifold....When I had the head ported, I also got the manifold matched....For this reason I'm going to give it a go and see what happens...I've ordered the manifold adaptors from Throttle-boddies........

Two injector sets wpuld be nice, but takes some setting up.....

PJ.

I actually blended in the edges of the cut out at the top of the port , but didnt fully match it, I didnt want to have a sudden increase in the port size in that area.I reasoned that as it was a step increasing in the direction of flow it would not have to much of an effect on the flow into the port.
Paul

quote:

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Originally posted by Micael
How do you guys plat to do with the injector dimple? I use Gsxr 1000 TB on my Zetec. And my manifold is build as Paulf describes.

This means that there is a "hole" in the port celing, just behind the mainifold plate.

Can this upset the flow in the inlet?

Micael

---

I was thinking of using some sort of heat resistant chemical metal to fill up the cut-out.
An other way could be to fill it with a large weld blob(tig-weld).

however, i'm in the process of building a flowbench so it will be fairly easy to test how much the cut-out will inteference with the flow.

I was thinking of welding a cover/flap on the aluminium manifold plate to protrude into the port , and sort of shield most of the hole.

my thinking was that this would smooth out the flow.

I am battling to find a lathe to neaten up my runner tubes before welding to the manifold plate, (its a winter project)

quote:

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Originally posted by Micael
I was thinking of using some sort of heat resistant chemical metal to fill up the cut-out.

---

I know it will destroy the engine if it lets go.

But i'm willing to take that risk. I use my car mostly on track days. I'm not the only one with this idea. It's fairly common in racing.

http://www.mototuneusa.com/homework.htm

http://speedtalk.com/forum/viewtopic.php?t=327&postdays=0&postorder=asc&start=0&sid=fe123da4e277b823ad4bd27b7e3597a2