Home ported Sportsman II heads

[6.50camaro]

What heads where you running before this and what where you shifting at then and now?

I need to make a correction . Just checked the car and the shift lite was set at 6500 not 6600 that I posted earlier . Dan

[1980RS]

It would be interesting to now bolt on a out of the box as cast Sportsman II head (or similar as cast 200cc head)
and run it down the track. ET/MPH comparo.

Would be an interesting test for sure. I ran out of the box Sportsman's against my mild ported 292 Turbo heads back in the early 90's, they ran about the same at that time. Maybe the newer ones are better. The set on my 358 pump gas engine work pretty good this year @ 7.15 in the 1/8 mile, was happy with that. My Dart 215's I ported ran the best of a 6.59 in the 1/8 mile. Next year the plan is to put the set of Dart 200's I just got on the 358, that will be a good test.

[steve cowan]

I am estimating approx 600hp
9.90 et at 3200 LBS,anyone make that with stock SP 2 heads ??
I am more interested in what valve job and intake manifold Dan used

[steve cowan]

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20210823_174436.jpg

As cast the SP 2 are not very pretty

[6.50camaro]

It would be interesting to now bolt on a out of the box as cast Sportsman II head (or similar as cast 200cc head)
and run it down the track. ET/MPH comparo.

Probably won't happen unless someone sends me a set of heads free. Because that's the only reason I have these heads and was playing with them to see what I could do . I could test at some point in time if I feel like it , against as cast RHS 220cc aluminum angle plug or Promaxx 225cc "as cast" I say as cast because that is what I ordered and what I got was a set of heads with an as cast exhaust port and a cnc intake port that measures close to the SP II's in most critical dimensions. But at the time being I need to concentrate on getting the car dialed to run 6.50 run after run . Dan

[6.50camaro]

I am estimating approx 600hp
9.90 et at 3200 LBS,anyone make that with stock SP 2 heads ??
I am more interested in what valve job and intake manifold Dan used

Steve, Wallace racing calculators says 600 hp for e.t . and 580 hp for mph . I'll take either . I don't think the mph takes into account converter slippage over locked up manual clutch ,which with my finish line rpm vs. gearing and tire size calcs out to 9% slippage . I did get a set of 5.38's I might try to get that slippage down . I was running 5.13's before put chipped some teeth before moving. I have 4.88's in the car now as that what I had on hand .
The intake is a GM bowtie single plane . A real GM manifold not the Hurricane knock off . The valve job is 37-45-60-75 . Tried to copy the vj in DV's small block book that's all, pretty simple .I do have a Holley strip dominator and a W/P Motown that I want to try on this motor at some point in time. Dan

[6.50camaro]

20210823_173516.jpg20210823_174350.jpg20210823_174436.jpg
As cast the SP 2 are not very pretty

To say the least . If I didn't know better I'd say you snuck in my garage 1 night and took pics of my heads . About the only thing that looks different is I left the double cut burr finish .No sand roll finish it looks more like a modern hi quality as cast finish.

[Hrdlx62]

I have A set of Sportsman II heads in the shop to do a patch up recon job on.These heads are destined for a modified tractor puller. The heads look to have a homegrown porting job on them. My question is, do these heads work and favor a 50 exhaust seat? The reason I ask is that when touching up the ex valves they appear to be at 50. Checking with a protractor supports that. I'm inclined to go to a 45 unless that would be detrimental. I dont think the budget will support sending these heads out to a dedicated porting shop to be worked over. Thanks.

[steve cowan]

I have A set of Sportsman II heads in the shop to do a patch up recon job on.These heads are destined for a modified tractor puller. The heads look to have a homegrown porting job on them. My question is, do these heads work and favor a 50 exhaust seat? The reason I ask is that when touching up the ex valves they appear to be at 50. Checking with a protractor supports that. I'm inclined to go to a 45 unless that would be detrimental. I dont think the budget will support sending these heads out to a dedicated porting shop to be worked over. Thanks.

I have a set of sportsman 2
I done a 50 deg seat with a 40deg top cut,the chamber transition is reasonable.
Keep the 50 on the exhaust because you have it and if you keep 45 on the intake I would do a 40 top cut .

[6.50camaro]

No expert here but check the exhaust throat. Chances are if the 50* was done correct the throat will be to big to put a 45* back in without increasing valve size . Dan

[6.50camaro]

Should these heads have the same HP and performance potential on a 380 (4.125 bore x 3.562 stroke) sbc with a 12.0 to 1 comp ratio and a few more RPM's. I ask because I have a complete rotating assembly just waiting for a block as my next engine project. Dan

[steve cowan]

Should these heads have the same HP and performance potential on a 380 (4.125 bore x 3.562 stroke) sbc with a 12.0 to 1 comp ratio and a few more RPM's. I ask because I have a complete rotating assembly just waiting for a block as my next engine project. Dan

What valve size Dan?

[6.50camaro]

Steve, it currently has a 2.055 intake valve. I could recut the intake seats for 2.08 as I have those on hand. Dan

[steve cowan]

James (melway) made over 600 with those heads on a 355-358sbc.back in the day.
With the CSA you have should work for sure.
Melway on this forum you could PM him

[6.50camaro]

Thanks, Steve I have done the math for velocity at the pinch and avg for the runner with the csa and rpm's and by that I should be ok . The few runs I've made out to the 1000' mark and 7000 rpm's found that it stops pulling and starts to go flat at about 6800 - 6900. Reverse working the math says the 380 with those heads should be good to 7500-7600 to achieve the same velocity. Dan