crossflow porting results

[Crazy2287 1,886]

I'll take 2

[PRO250 1,506]

ill take the other 3 so the head with work with 6 cylinders

[Thom 6,651]

Have you cosidered filling the recess to clear the injector, or would that show negligable gains?

[Clevo120Y 815]

LOL funny lot aren't ya's

Thom I have thought of it and will do that as well one day, one of the reasons I am using an XD alloy head for the speedway engine is because the injector cutout isn't there. What I might do is retest this port tommorow with that injector notch filled in with playdo. When I test the port as is when I put the cotton near it there is turbulance there, giving a measurable difference maybe not when just testing the head but I think it may make a small difference with a manifold on, all the 1%er's add up in the end and it won't hurt flow by filling it in.

[ando76 4,354]

That port with an individual runner manifold like the webber one Rob is running would go off.  Straight entry into the chamber and optimum fuel air mix on each port.  Hold on Rob .. Yahoooo. 

 

The figures look good, especially with the intended lift.  I can't help but thinking that a bigger inlet valve would be better tho - provided we could lift exhaust flow to match - which I reckon would be a piece of piss. 

 

Why not undercut the inlet valve stem while you are going to see if there is a high lift gain there - I'm confident there will be.  Easy for me to say - I don't have to do the lathe work.  LOL. 

[Clevo120Y 815]

Cheers Tony, I would like to try a bigger valve but I would have to get a bigger seat insert put in and recut seats etc etc. I hand cut this seat and there was only enough room to get a 45 and 70, not 30 topcut on this one. I only have the 30, 45 and 70 angles here.

The port would suit the webbers nicely you are spot on there, Rob has a good head already maybe someone else one day would like some ports like these

[slydog 7,873]

I wonder how dear the Del West skinny stem valves would be? Fuck all that shit off and put some super light weight skinny stem items in there and run a much lighter spring and yet still rev the thing till 7500 with less stress on it....Hmmmmmmm TBH I don't like my chances this year but a big bore de-stroked big RPM xflow has always interested me.

 

230-232 cubes fat bores light weight EF crank,grouted block,roller cammed straight runner head and custom pipes and extractors for a 7500 plus xflow.That sounds like some real fuck off fun.  

[wazzy250 167]

Yep sounds great. You will be changing them every 3-5 meetings but. That's when it becomes very expensive.

[slydog 7,873]

LOL

[wazzy250 167]

. 230-232 cubes fat bores light weight EF crank,grouted block,roller cammed straight runner head and custom pipes and extractors for a 7500 plus xflow.That sounds like some real fuck off fun.

 

Can I have 2 off these for the kids go carts pls.

[TF_250 398]

Rob has a good head already maybe someone else one day would like some ports like these

 

Just do  1 port and there are about 3 or 4 people in Australia that i know of that would be about to cnc port a head for you, problem solved you could line them up and do half a dozen of them!! LOL

 

ps how do i convert 10" to 28"???

[ando76 4,354]

multiply by 1.67 - yes I finally remembered.......

[matt_lamb_160 252]

Yep, sqrt(28/10)

[TF_250 398]

cool i just found that out as well.

 

So mine flows converted to 28"

 

100               60.30

200             125.23

300             186.07

400             217.08

450             220.65

500             230.12

550             238.00

600             241.14

 

that was done in 2006 in SF120 @10" with 1.860" valve exhaust flows average 73%  half decent numbers but i does have a slight water leak problem at the moment...LOL

 

off topic for a sec Found this on Atomics website this is stock head flow!!

 

BA-BF 6 Cyl DOHC Head at 25”H20

       

Valve lift Inlet - CFM Exhaust - CFM % - EX to IN .

100”               72.0                      75.9                       105% .

150”             107.0                   111.7                       104.5% .

200”             144.3                   141.1                        97.7% .

250”             177.8                   162.4                          91.3% .

300”             206.9                   174.9                         84.5% .

350”             228.3                   184.1                           80.6% .

400”             242.7                   190.2                         78.3% .

450”             249.9                   194.3                          77.7% .

500”             252.9                   198.3                          78.4% .

550”             254.1                   200.8                         79.0%

[matt_lamb_160 252]

Wow.

[Clevo120Y 815]

I sent this head to be cut up just to check the port wall thicknesses before I can call it a complete success, I used my sonic tester on it and the results were all good but I want to see the inside, I will post upsome pics when I get it back.

[ando76 4,354]

That's some impressive figures there Jason - especially considering the year.  No wonder the corty runs the numbers on relatively low comp.  Great stuff but gee look at those figures from the BA crowd.  No wonder they go so good with just a cam upgrade and a set of extractors...

[PRO250 1,506]

well i cant find my head chart of my cam card for my new engine

 

but heres my very first head i did in 1999

 

100 69.4

200 123.7

300 180.6

400 226.2

500 224.6

600 224.1

[P100_Ute 460]

 

off topic for a sec Found this on Atomics website this is stock head flow!!

 

BA-BF 6 Cyl DOHC Head at 25”H20

       

Valve lift Inlet - CFM Exhaust - CFM % - EX to IN .

100”               72.0                      75.9                       105% .

150”             107.0                   111.7                       104.5% .

200”             144.3                   141.1                        97.7% .

250”             177.8                   162.4                          91.3% .

300”             206.9                   174.9                         84.5% .

350”             228.3                   184.1                           80.6% .

400”             242.7                   190.2                         78.3% .

450”             249.9                   194.3                          77.7% .

500”             252.9                   198.3                          78.4% .

550”             254.1                   200.8                         79.0%

i think this calls for a dohc porting thread and see what tricks you can do and ill happily roadtest this at track to see improvements.

[Clevo120Y 815]

Yeah Tim gave me a BA engine when he came down so I have a head to test at a later date, I won't be able to do it for a while as I have to make double valve opening fixtures and I just opened up a facebook page and now have some work got a 4L head and manifold to do for a skid car and another manifold for a speedway car YAY.

Look me up if you guys want "Stumpers cylinder heads N manifolds"

 

Dave those results are great mate they top out quickly but over 220 at 400 is fat.

[Mixalis 266]

Awesome work mate good to hear! maybe its just on my end but i cant find your page anywhere on facebook or even google for that matter?

[Clevo120Y 815]

Sorry mate it's my fault, "stumpers heads n manifolds" my wife setup my facebook, me and computers don't get along very well hahahaha can't even get my own page name right LOL

[Clevo120Y 815]

Got the head back today cut up, she's all good, plenty of material left so this port shape is good to go YAY

 

[slydog 7,873]

Fuck yeah bro...looks sweet as.Your gunna kill it with this sort of application to it.

 

Props to ya bro

[ando76 4,354]

nice work - shows the need to go easy around the short turn.  good stuff.