that bit won't be shrouding anything, and I want to keep some squish, in fact I probably won't take as much off the sides either, aiming for more of a butterfly shape. But then I want to keep the CR up, you'll be wanting it lower I guess? The other thing is that I'll probably have to take quite a bit off the head face to keep a sensible CR, such that the valves would probably stick below the face of the head.Originally Posted by Ashy
Adey - all gain is good
ok so ive got a ported/matched lower rs mani on its way, i wouldnt mind doing something while the upper part is off, how do i go about ****ing it up for some more flow, match the upper to its gasket going back about 20 mm?
also do you know how much cc u added by working combustion chamber? im not planning to take the head off yet and im to cheap to buy forged pistons to lower the comp ratio a little, want to go for about 10.1? was looking at ferriday plates as a cheaper option?
or some machined ones??
That would be good tho then I have to take the engine out, I can see me doing more than I want too lol
[quote=Adey aka Ewok;190663]ok so ive got a ported/matched lower rs mani on its way, i wouldnt mind doing something while the upper part is off, how do i go about ****ing it up for some more flow, match the upper to its gasket going back about 20 mm?quote]
I'm thinking about doing this job myself too, buying an inlet manifold and RS item then attempt to DIY match the ports. Can anyone point me in the right direction in what i'd need to use to grind out the ports please
If you get into trouble Ric, I've heard Code Red Motorsports is pretty good at this stuff, quick turnaround too....
Matt@codered.
If you get into trouble Ric, I've heard Code Red Motorsports is pretty good at this stuff, quick turnaround too....
Matt@codered.
We need to talk then, when's a good time?
Is there a photo around of the inlet gasket sitting on the F4R head around...?
whats the picture of ?
I might be wrong but assumed the blue imprint was what was left of the gasket on the head showing the ports on the head to be smaller than the gasket... Matching the ports to the gasket... Like i said i might be wrong
It's not an F4R head though ?
But I think the 172/182 inlet gasket matches the ports on the head pretty well. I had my new manifolds flange made using a gasket as a template.
the ports on the lower section of manifold are a lot smaller though.
I found the pic on a thread about someone taking out the Williams lump to replace with an F4R. Maybe its a head of the F7R
looks like F7R to me
it's deffo looks like a F7R head
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hi andrew,is the flow curve of the gtt port representing a good ported head with valve installed??or is it just a std port?? by the way,great comparisons on the 16valver anyone owning these engines will be greatful for the work you`ve done!!i now i would be.
This is an interesting comparison, it compares the flow through the single 34mm inlet valve on a GTT head with a single 33.5mm valve in a 172 head
It's clear that the 172 valve doesn't flow anywhere near as well as the GTT one, why might that be? My guess is it's the proximity of the cylinder wall and edge of the combustion chamber in the 172 engine.
Andy, Was up in th loft today and spotted that I still have the old DD raider head (Heavily Ported) just wondering if it would be interesting to flow test against a std one?
That's a 'standard' GTT head, well it's the one out of the cup car, so should be a good one...
I'd give it a go Ashy, the kit is spread around the house though, so may take a while. House repairs are taking too much of my time at the moment...
Andy,
I will have a 225 head also for your pleasure?? I really need to see if my '25% less flow' than the 172 head stacks up!
I'll bet the difference is less than that, esp at the lower lift of the 225 cams. Maybe we can arrange a handover at a meet?Andy,
I will have a 225 head also for your pleasure?? I really need to see if my '25% less flow' than the 172 head stacks up!
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this is really interesting.... Have you tested any F7R heads to see how they compare to the F4R? Would be interested to know
Love it, well done with your flow bench
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