Re: Ported Dart 215 pro1 platinum with port energy discussion 2.0

Carnut1 · Post by **Carnut1** » Sun Mar 11, 2018 7:28 pm

Continuation of Ported Dart 215 pro1 platinum with port energy discussion. I have a message in to Stan, problem with new port energy program. Just would like to post some pics and I will get some graphs up this week.

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Intake bowl pic.

Carnut1 · Post by **Carnut1** » Sun Mar 11, 2018 7:31 pm

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Exhaust bowl, fine surface treatment. Radius under 45 degree seat.

Carnut1 · Post by **Carnut1** » Sun Mar 11, 2018 7:36 pm

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I decided on a floor fin for the Dart ssr. Interesting developement. Not as easy as it looks! Seems to work well on this port. Ssr is still fairly tall which helps at the lower lift numbers. These are destined for a nasty street engine.Thanks, Charlie

mag2555 · Post by **mag2555** » Mon Mar 12, 2018 6:28 am

Sorry to take this off track some, but what's cooking with the reports of the dyno sessions on the iron Ford heads?

Nice port work here by the way, but why did you kick the roof up so high on push rod side so as to blow thru the roof Charlie?

Carnut1 · Post by **Carnut1** » Mon Mar 12, 2018 6:52 am

mag2555 wrote: ↑Mon Mar 12, 2018 6:28 am Sorry to take this off track some, but what's cooking with the reports of the dyno sessions on the iron Ford heads?

Nice port work here by the way, but why did you kick the roof up so high on push rod side so as to blow thru the roof Charlie?

Dv did some high end chamber work and pushed the 289 heads even further along. Dyno tests in the future. The hole in the roof is the rocker stud, these are still very thick. Not even cut through straight wall bolt hole. Thanks, Charlie

Carnut1 · Post by **Carnut1** » Tue Mar 13, 2018 9:06 pm

dart cfm-1.jpg

Just for fun I decided to post my Dart 215's ported out to 232cc intake and 79.5cc exhaust up against Chad's cnc 205cc intake and 83cc exhaust ports. Chad's made nearly 700hp on a 380ci mill. Not apples to apples but interesting. Thanks, Charlie

Carnut1 · Post by **Carnut1** » Tue Mar 13, 2018 9:09 pm

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My bigger cc intake port is noticably slower but my smaller exhaust port is faster. Input welcome. Thanks, Charlie

Carnut1 · Post by **Carnut1** » Tue Mar 13, 2018 9:15 pm

port energy dart 215.jpg

Port energy curve, Chad's intake port kicks on port energy. At this point I cannot get a intake port that size to flow that much that fast. No doubt that helps his 380 ci motor make excellent power. Input welcome. Thanks, Charlie

Carnut1 · Post by **Carnut1** » Thu Mar 15, 2018 7:55 pm

Conversation with a fellow head porter and told him I was 400ft/sec and pulsing a bit over 295 cfm. He said try it at a higher depression. Ok.

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bench set for 35" 359cfm 440ft/sec over ssr. Sounded smooth no pulsing. Is this any good? Thanks, Charlie

Carnut1 · Post by **Carnut1** » Thu Mar 15, 2018 8:00 pm

I should add that was at .8" lift they flowed 357@ .7" lift and a surprising 286 cfm backwards at 28".

statsystems · Post by **statsystems** » Thu Mar 15, 2018 8:16 pm

Carnut1 wrote: ↑Thu Mar 15, 2018 8:00 pm I should add that was at .8" lift they flowed 357@ .7" lift and a surprising 286 cfm backwards at 28".

That's a bunch of reverse flow. You have to reduce it, even if you reduce forward flow.

Edit: if the valves are back cut, that would be the first thing I would get rid of.

Carnut1 · Post by **Carnut1** » Thu Mar 15, 2018 8:52 pm

With 322 cfm forward an 286 cfm reverse I thought that was pretty good. This port loses with no back cut to .6" lift. Thanks, Charlie

Post by **GARY C** » Thu Mar 15, 2018 9:01 pm

I have always heard that you want to do what you can to minimize reverse flow but I have never seen anyone post a # or percentage of what is considered acceptable.

286 doesn't seem bad considering a 1.6 ex valve and port can flow 230.

Maybe someone will post up what they look for in reverse flow vs forward flow.

statsystems · Post by **statsystems** » Thu Mar 15, 2018 9:12 pm

GARY C wrote: ↑Thu Mar 15, 2018 9:01 pm I have always heard that you want to do what you can to minimize reverse flow but I have never seen anyone post a # or percentage of what is considered acceptable.

286 doesn't seem bad considering a 1.6 ex valve and port can flow 230.

Maybe someone will post up what they look for in reverse flow vs forward flow.

That's about 80%. That's a higher percentage than intake to exhaust ratio.

If you are married to flow numbers then you are stuck.

I'd ditch the back cut and I wouldn't care if it lost flow across the lift range.

Post by **GARY C** » Thu Mar 15, 2018 9:25 pm

statsystems wrote: ↑Thu Mar 15, 2018 9:12 pm
GARY C wrote: ↑Thu Mar 15, 2018 9:01 pm I have always heard that you want to do what you can to minimize reverse flow but I have never seen anyone post a # or percentage of what is considered acceptable.

286 doesn't seem bad considering a 1.6 ex valve and port can flow 230.

Maybe someone will post up what they look for in reverse flow vs forward flow.

That's about 80%. That's a higher percentage than intake to exhaust ratio.

If you are married to flow numbers then you are stuck.

I'd ditch the back cut and I wouldn't care if it lost flow across the lift range.

I think many have abandoned trying to you I vs E percentage #'s for anything set in stone but I agree if you want to reduce reverse flow then no back cut and bevel the face/chamber side of the intake valve.

Then again these are only flow bench #'s so do they really mater either way?