Any given sunday....

[vlad01]

Hi all, scored some 'cake making silicone moulding compound' and the boys are having a play with it. We are talking about building a flow bench, looking like some fun to come

P.s can't remember who said it on here but we used the paint stripper trick to clean the inside of the manifold, works a real treat - better than our hotwash!

yeah that was my idea of the paint stripper

How good is it!

[immortality]

That looks like good cheap fun.

[Jayme]

im risking looking like an idiot here.... but can someone please explain the point of taking a mould of the intake runner?

[Holden202T]

so you can see what the port looks like, use calipers to measure certain points and can work out where the restrictions are etc.

[Gareth]

As Holden202t said, it gives you the chance to visually see and issues/restrictions in the intake

see how it necks down in the injector area, no sure why they would do this?? to speed up air going past the injector tip??

I was shocked at how bad the steps are in the port matching of the inlet manifold (from factory) we fiddled with the fitment a bit before we took the mould...

I wish we had have taken more time with the port mould, we has excess left over from the inlet so the guys raced out the back and found the first head they could find and were pouring the silicone in as it was going off - hence the bubbles...

[Jayme]

sharper bend down at the valve than I expected....

[vlad01]

Thats real interesting.

[Holden202T]

sharper bend down at the valve than I expected....

so now you see the point of it

[Charlescrown]

I have always been intrigued with port design. I don't think that narrowing around the injector causes a restriction rather a velocity increase to improve mixing the fuel and air. I would have much more concern with mismatched port/manifold and any area that causes unwanted turbulence but yes it is interesting with that elbow near the valve area. Looks like they got that wrong but not much you can do to fix it other than cast your own heads.

[vlad01]

I dont think they necessarily got that wrong, I remember reading a engineering paper on the DOHC EJ25 suby engine design and how they changed the straightness and valve to head angle of the ports to gain more top end performance at the loss of low end torque compared to the less valve angled more bent port design of early EJ25 SOHC 4 valve engines.

Being torquey engines, I would say that this is more deliberate.