Cylinder Head Flow Benches (recent tuning threads)

Cylinder Head Flow Benches (recent tuning threads)

Author
Discussion

Pumaracing

2,089 posts

206 months

Wednesday 31st December 2014
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PeterBurgess said:
And above the valley soars the Eagle and it can be heard saying, "Aquila non capit muscas"
Indeed but the eagle occasionally snacks on little rabbits from either boredom or the lack of better game. I think we went there in the 90s but more worthy opponents later reared their heads.

Kokkolanpoika

161 posts

150 months

Wednesday 31st December 2014
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Big valves will not make any power if port is limiting flow. And usually if use big valves, your short side radius will get worse. Like i said you can use smaller valve if use bigger valve/throat ratio. If you look at "optimal" gas speed with small port´s. If it is fast, it will try to flow straight as possible and it will hit roof/long side radius before it will turn in to the valve/cylinder. Less speed/bigger port it has got mutch more time to turn in the valve/cylinder. Bigger port is usually better than smaller one if we want top end power. I do not like any theoritical numbers, they are only therotical. Usually nothing to do with real life horsepower.

Just like why wild cat engineering use big valves and engines dosen´t make any power?

http://www.automotivecomp.com/v8engines.htm
5.0 WILD CAT ENGINE 398 BHP @ 5950 RPM, 340FTLB @ 5600 RPM
This engine use M248 camshaft at least 47mm inlet valve, big CNC ports etc. Real race engine? Oh yeah..
Those are very pathetic dyno results on that money. My own RV8 will make 4hp less and 400rpm less, it will use Home ported heads and M238 camshaft witch is milder. My head´s flow 350hp and use 43mm valves. I will make quarantee that i can see +20-30hp more if use more radical cam and make slightly more porting work.

Pinto engine is not Toyota. But our Ford OHC is similar like pinto. And our best OHC will make 256hp@9000rpm and it will use 44mm or 46mm big valve heads. Head measured on the flow bench and it will flow 170hp. Port diameter is mutch bigger than theoritically needed.
And this toyota 5k head flow over 200hp also exhaust flow ~200hp and use 32mm exhaust valve.

Pumaracing

2,089 posts

206 months

Wednesday 31st December 2014
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Kokkolanpoika said:
And this toyota 5k head flow over 200hp also exhaust flow ~200hp and use 32mm exhaust valve.
I assume by "flow over 200 bhp" you're referring to the Superflow equation or something similar. So let's have some actual flow figures and the pressure drop used.

Stan Weiss

260 posts

147 months

Sunday 18th January 2015
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While I have a few calculators on my web site which do HP to cfm and cfm to HP. Those are only a very loose estimate.

IF you raise your CR (just one of many items) in most cases the HP will increases. Unless you are using a full engine simulation package, these simple equations will not show any changes.

Stan

Pumaracing

2,089 posts

206 months

Sunday 18th January 2015
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Struth. Where did you just pop up from? I thought you were dead. Or at least your doublewide had blown away in a tornado with you in it.

Stan Weiss

260 posts

147 months

Sunday 18th January 2015
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Dave,
Every now and then I have to check in and see that those that drive on the wrong side on the road are not about to drive off a cliff.

Stan

anonymous-user

53 months

Sunday 18th January 2015
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Stan Weiss said:
Dave,
Every now and then I have to check in and see that those that drive on the wrong side on the road are not about to drive off a cliff.

Stan
No chance of that happening, we are all stuck in traffic jams on this side of the pond! ;-)

Pumaracing

2,089 posts

206 months

Monday 19th January 2015
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Stan Weiss said:
Dave,
Every now and then I have to check in and see that those that drive on the wrong side on the road are not about to drive off a cliff.

Stan
Well at least it's nice to know that in the months since we've seen you you haven't been shot, beaten up or choked to death by the cops over there. smile

Stan Weiss

260 posts

147 months

Thursday 22nd January 2015
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Pumaracing said:
Well at least it's nice to know that in the months since we've seen you you haven't been shot, beaten up or choked to death by the cops over there. smile
Dave,
Isn't it a wonderful world we live in. Just try and stay safe.

Stan

Pumaracing

2,089 posts

206 months

Friday 23rd January 2015
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Stan Weiss said:
Dave,
Isn't it a wonderful world we live in. Just try and stay safe.

Stan
Ah, you'll be ok. You're white. Well, a sort of crusty brown anyway. The cops over there mainly seem to specialise in killing blacks for no apparent reason.