Home ported Sportsman II heads
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Home ported Sportsman II heads
Just got back from first outing to the track since June 2020. { bat flu , move from La./Tx. border, remodel new place , help daughter with her new place} its been a long 16 months with no track time . In another post stated that I had a set of W/P sportsman II given to me . I said that I might get them flowed but that don't happen .Instead I bolted them on my 421 flat top 6.50 index motor to see how they perform .
Off the trailer with a base tune of 35* adv. and what I hoped was a safe jetting on my 1000 cfm race demon carb . It went 1.41-60' 6.46-1/8 @ 104.87.
The second run after a hour cool down and pulling a plug to check the ground strap for timing . I retarded the timing a touch {didn't put a lite on it just gave it a little nudge.} 1.371-60' 6.409- 1/8 @105.28 ran it out to 1000' and went 8.474 I have to much gear in it to run out to the 1/4 . it did coast to a 10.507 1/4 .
3rd run was off a little ,I might have over heated the tires or it was just starting to sprinkle and the 60' drop to 1.452 6.499 1/8 @105.06 performance .
So all and all I'm pleased with the performance I just wanted to see If they would run 6.50 in the 1/8 .
Off the trailer with a base tune of 35* adv. and what I hoped was a safe jetting on my 1000 cfm race demon carb . It went 1.41-60' 6.46-1/8 @ 104.87.
The second run after a hour cool down and pulling a plug to check the ground strap for timing . I retarded the timing a touch {didn't put a lite on it just gave it a little nudge.} 1.371-60' 6.409- 1/8 @105.28 ran it out to 1000' and went 8.474 I have to much gear in it to run out to the 1/4 . it did coast to a 10.507 1/4 .
3rd run was off a little ,I might have over heated the tires or it was just starting to sprinkle and the 60' drop to 1.452 6.499 1/8 @105.06 performance .
So all and all I'm pleased with the performance I just wanted to see If they would run 6.50 in the 1/8 .
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Re: Home ported Sportsman II heads
What heads where you running before this and what where you shifting at then and now?
You can cut a man's tongue from his mouth, but that does not mean he’s a liar, it just shows that you fear the truth he might speak about you!
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Re: Home ported Sportsman II heads
have they been rubbed on??6.50camaro wrote: ↑Sat Oct 23, 2021 6:07 pm Just got back from first outing to the track since June 2020. { bat flu , move from La./Tx. border, remodel new place , help daughter with her new place} its been a long 16 months with no track time . In another post stated that I had a set of W/P sportsman II given to me . I said that I might get them flowed but that don't happen .Instead I bolted them on my 421 flat top 6.50 index motor to see how they perform .
Off the trailer with a base tune of 35* adv. and what I hoped was a safe jetting on my 1000 cfm race demon carb . It went 1.41-60' 6.46-1/8 @ 104.87.
The second run after a hour cool down and pulling a plug to check the ground strap for timing . I retarded the timing a touch {didn't put a lite on it just gave it a little nudge.} 1.371-60' 6.409- 1/8 @105.28 ran it out to 1000' and went 8.474 I have to much gear in it to run out to the 1/4 . it did coast to a 10.507 1/4 .
3rd run was off a little ,I might have over heated the tires or it was just starting to sprinkle and the 60' drop to 1.452 6.499 1/8 @105.06 performance .
So all and all I'm pleased with the performance I just wanted to see If they would run 6.50 in the 1/8 .
steve c
"Pretty don't make power"
"Pretty don't make power"
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Re: Home ported Sportsman II heads
I was running a old set of Dart 220 race series heads 64cc chamber 2.125in 1.625 ex that had Darts super mod 230cc or so porting . the cam is a Erson solid roller 260/268 @ .050 .675 in .645 ex lift . 850 holley HP carb . shifting @ 6600-67000 best that went was 6.31 but I never really pushed it to see if it would go quicker because I'm really only set to go 6.41 safety wise . {don't have full cage just 8 point rollbar} .
New combo shifted at 6600 still. Same short block and cam different heads , intake and carb. new heads are 70 cc chambers Dan
New combo shifted at 6600 still. Same short block and cam different heads , intake and carb. new heads are 70 cc chambers Dan
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Re: Home ported Sportsman II heads
Yes , Steve they've been rubbed on . stock 1.70 intake throat is now 1.83 with 2.055 valves the stock 1.299 ex throat is now 1.42 for a 1.60 valve. The guides have been trimmed down bowls have been opened up and reworked for good cylinder wall side port bias , pinch opened to 1.10 x 2.20 ,manifold opening 1.25 x 2.25 . chamber opened up valves unshrouded . A big thing I feel was the .460 reach plug was 2or 3 threads back in the spark plug hole. I relieved the chamber wall back till the end of the plug was flush with the chamber . also using an NGK projected tip plug . Flat milled back to 70 cc giving me 11.0 to 1 down from the 11.6 with the dart heads the ports pored around 226 cc . Did my own 4 angle valve job with a Toledo EZ eccentric stone grinder
Re: Home ported Sportsman II heads
What kid of car are we talking here? your work and performance is most impressive.6.50camaro wrote: ↑Sat Oct 23, 2021 6:07 pm Just got back from first outing to the track since June 2020. { bat flu , move from La./Tx. border, remodel new place , help daughter with her new place} its been a long 16 months with no track time . In another post stated that I had a set of W/P sportsman II given to me . I said that I might get them flowed but that don't happen .Instead I bolted them on my 421 flat top 6.50 index motor to see how they perform .
Off the trailer with a base tune of 35* adv. and what I hoped was a safe jetting on my 1000 cfm race demon carb . It went 1.41-60' 6.46-1/8 @ 104.87.
The second run after a hour cool down and pulling a plug to check the ground strap for timing . I retarded the timing a touch {didn't put a lite on it just gave it a little nudge.} 1.371-60' 6.409- 1/8 @105.28 ran it out to 1000' and went 8.474 I have to much gear in it to run out to the 1/4 . it did coast to a 10.507 1/4 .
3rd run was off a little ,I might have over heated the tires or it was just starting to sprinkle and the 60' drop to 1.452 6.499 1/8 @105.06 performance .
So all and all I'm pleased with the performance I just wanted to see If they would run 6.50 in the 1/8 .
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Re: Home ported Sportsman II heads
sounds like you have done well with those heads6.50camaro wrote: ↑Sat Oct 23, 2021 8:26 pm Yes , Steve they've been rubbed on . stock 1.70 intake throat is now 1.83 with 2.055 valves the stock 1.299 ex throat is now 1.42 for a 1.60 valve. The guides have been trimmed down bowls have been opened up and reworked for good cylinder wall side port bias , pinch opened to 1.10 x 2.20 ,manifold opening 1.25 x 2.25 . chamber opened up valves unshrouded . A big thing I feel was the .460 reach plug was 2or 3 threads back in the spark plug hole. I relieved the chamber wall back till the end of the plug was flush with the chamber . also using an NGK projected tip plug . Flat milled back to 70 cc giving me 11.0 to 1 down from the 11.6 with the dart heads the ports pored around 226 cc . Did my own 4 angle valve job with a Toledo EZ eccentric stone grinder
nice job
steve c
"Pretty don't make power"
"Pretty don't make power"
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Re: Home ported Sportsman II heads
sounds like you have done well with those heads6.50camaro wrote: ↑Sat Oct 23, 2021 8:26 pm Yes , Steve they've been rubbed on . stock 1.70 intake throat is now 1.83 with 2.055 valves the stock 1.299 ex throat is now 1.42 for a 1.60 valve. The guides have been trimmed down bowls have been opened up and reworked for good cylinder wall side port bias , pinch opened to 1.10 x 2.20 ,manifold opening 1.25 x 2.25 . chamber opened up valves unshrouded . A big thing I feel was the .460 reach plug was 2or 3 threads back in the spark plug hole. I relieved the chamber wall back till the end of the plug was flush with the chamber . also using an NGK projected tip plug . Flat milled back to 70 cc giving me 11.0 to 1 down from the 11.6 with the dart heads the ports pored around 226 cc . Did my own 4 angle valve job with a Toledo EZ eccentric stone grinder
nice job
steve c
"Pretty don't make power"
"Pretty don't make power"
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Re: Home ported Sportsman II heads
Thanks Steve . You do some nice work also. Dansteve cowan wrote: ↑Sat Oct 23, 2021 9:07 pmsounds like you have done well with those heads6.50camaro wrote: ↑Sat Oct 23, 2021 8:26 pm Yes , Steve they've been rubbed on . stock 1.70 intake throat is now 1.83 with 2.055 valves the stock 1.299 ex throat is now 1.42 for a 1.60 valve. The guides have been trimmed down bowls have been opened up and reworked for good cylinder wall side port bias , pinch opened to 1.10 x 2.20 ,manifold opening 1.25 x 2.25 . chamber opened up valves unshrouded . A big thing I feel was the .460 reach plug was 2or 3 threads back in the spark plug hole. I relieved the chamber wall back till the end of the plug was flush with the chamber . also using an NGK projected tip plug . Flat milled back to 70 cc giving me 11.0 to 1 down from the 11.6 with the dart heads the ports pored around 226 cc . Did my own 4 angle valve job with a Toledo EZ eccentric stone grinder
nice job
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Re: Home ported Sportsman II heads
The exhaust port can take so work to get up to scratch but the intake respond well, not having a small unworkable pinch definitely helps in my opinion.6.50camaro wrote: ↑Sat Oct 23, 2021 9:11 pmThanks Steve . You do some nice work also. Dansteve cowan wrote: ↑Sat Oct 23, 2021 9:07 pmsounds like you have done well with those heads6.50camaro wrote: ↑Sat Oct 23, 2021 8:26 pm Yes , Steve they've been rubbed on . stock 1.70 intake throat is now 1.83 with 2.055 valves the stock 1.299 ex throat is now 1.42 for a 1.60 valve. The guides have been trimmed down bowls have been opened up and reworked for good cylinder wall side port bias , pinch opened to 1.10 x 2.20 ,manifold opening 1.25 x 2.25 . chamber opened up valves unshrouded . A big thing I feel was the .460 reach plug was 2or 3 threads back in the spark plug hole. I relieved the chamber wall back till the end of the plug was flush with the chamber . also using an NGK projected tip plug . Flat milled back to 70 cc giving me 11.0 to 1 down from the 11.6 with the dart heads the ports pored around 226 cc . Did my own 4 angle valve job with a Toledo EZ eccentric stone grinder
nice job
Dan,
How do you find doing seats with stones,those powder metal seat rings can be tough
steve c
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"Pretty don't make power"
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Re: Home ported Sportsman II heads
Steve ,this was the first set of heads I did not counting a couple seats on a junk practice head I had . So I really don't have any experience on anything else. I just did thing very slowly ,not trying to make money just trying to learn thing for my self. Dan
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Re: Home ported Sportsman II heads
Steve, I did raise the exhaust port roof some till it match the top flange on my headers and work the short side some not wanting to hit water or ruin things .Mostly worked the bowls and guides ,focusing on a good bias to the cyl. wall side and getting a good throat percentage. Dan
Re: Home ported Sportsman II heads
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.
and run it down the track. ET/MPH comparo.