Sportsman 2's porting

[Carnut1]

Nearly finished with an old set of World Sportsman 2's. would like some feedback by those who know of areas that need improvement.
408, 2.05/1.6 valves ported to 215cc intake, 68cc high swirl chambers, 80cc exhaust ports, 2.37" pinch, 93% intake throat, 90% exhaust throat,( limited by kids small headers).
3500 lb 70's Camaro,m21,3.42 10 bolt.
Engine combo not fully decided upon, for now either 750cfm or 850cfm carb, Holley strip dominator, solid flat tappet due to cost, stock 400 crank, 5.7" Lunati street race rods, Probe flattops, total seal rings. Being built as a stout street car. Having problems posting pics so I will post them separately. Thanks in advance for your thoughts

[Carnut1]

bowl

[Carnut1]

exhaust bowl

[Carnut1]

exhaust port

[Carnut1]

Intake port

[Donmcgowen]

bump. Currently doing my first set of heads. Lightly ported exhaust and CC to mirror finish. Opened up intake runners to 210cc. Expecting 525hp from 377 with below specs.

[Carnut1]

These two combos are more similar than different. I wish the kid I am doing these heads for had steeper gears or would buck up for the solid roller. Post some picks of those heads! Thanks.
Yankee Cutter

[WeingartnerRacing]

Nearly finished with an old set of World Sportsman 2's. would like some feedback by those who know of areas that need improvement.
408, 2.05/1.6 valves ported to 215cc intake, 68cc high swirl chambers, 80cc exhaust ports, 2.37" pinch, 93% intake throat, 90% exhaust throat,( limited by kids small headers).
3500 lb 70's Camaro,m21,3.42 10 bolt.
Engine combo not fully decided upon, for now either 750cfm or 850cfm carb, Holley strip dominator, solid flat tappet due to cost, stock 400 crank, 5.7" Lunati street race rods, Probe flattops, total seal rings. Being built as a stout street car. Having problems posting pics so I will post them separately. Thanks in advance for your thoughts

Please take this as critism that you can use to improve. You know need to cut the head to a 2.08 intake valve because your throat is too big. It should be around 90-91%. You should make the bowl (the area perpendicular to the guide) 94-95%. It doesn't look like you touched the short side in one view. That is one area you should definitely mess with because a lot of your flow comes from there. Your pinch is tiny for the size of motor but I understand not messing with it because of fear of breaking through on cast iron. Try to take material from common wall. I don't like the kick on the chamber it looks like you created an air Dam. I don't think it helps swirl and looses compression with larger chamber. Also swirl is not always good. Looks like you spent some time with them though.

[Carnut1]

Eric, I appreciate your input! I have been watching your career for a long time and I know you know your stuff! Thank you.

[Carnut1]

The core shift was quite bad on these and the pinch was pushed to breakout on one port. I am interested in what work on the shortside needs to be done and on which port.Thanks

[lada ok]

For my first couple of ported heads, I left the valve guide in as you have done ... forget it

before you start work on the ports,go find some phos/bronze replacement guides that would suit your intended head... so that's length, id and od isn't too important.
now you can blast into the ports properly, and remove the guide lump completely so you will get a much better port and bowl
once your done ...take the head to the engine shop and get them to m/c and fit the new guides ... and cut new seats while their at it oh and taper the port ends of the new guides to

[Carnut1]

Needed to .060 out of the center wall just to bring the pinch to 1.10" wide on the bad core shift ports.

[Carnut1]

For my first couple of ported heads, I left the valve guide in as you have done ... forget it

before you start work on the ports,go find some phos/bronze replacement guides that would suit your intended head... so that's length, id and od isn't too important.
now you can blast into the ports properly, and remove the guide lump completely so you will get a much better port and bowl
once your done ...take the head to the engine shop and get them to m/c and fit the new guides ... and cut new seats while their at it oh and taper the port ends of the new guides to

I have done that with a set of e7te heads that worked really well after the guide was cut out. I have the equipment to cut my own valve seats. Thanks. Charlie

[groberts101]

I'm glad Eric spoke up about the throat sizing and I also think his points are right on.

The bigger valve will work to help pick the port back up but I'd also maybe even consider running a 2.05" tuliped intake after the short side work is all done. Especially if you'll need to install new seats to get to the 2.08 valve size. You'll likely want to lay that short side back a bit but don't do it too abruptly right off the bottom cut(stay about .040 - .050 thou away if possible and blend it all in nicely on the final tootsie roll passes).. obviously easier to take more out rather than put it back in place. Now, most will tell you that this style of valve is not typically used for these ports/valve angles but in this case could potentially help displace some extra area through that largish throat(for a 2.05 valve anyways) and pick the port speed up without really squashing the cfm all to hell. Also good to remember that more consistent wet flow around the valve(improved wet flow curtain) can sometimes be worth more than increasing peak flow on a flowbench. I've also seen some relatively smart dudes pick up power on max valve size deals that were already overly bore-shrouded and the bowls and SSR were way overblown for the application(not that this is entirely the case here). Bandaid of course, plus you lose some compression with a concave valve head and also gain some valvetrain weight.. but still works to pick up a bigger port and/or throat speeds.

PS. As a quick side note. If this was a solid roller setup?.. this throat sizing wouldn't be as big a concern. And specifically because of the FT cams time/area and spring limitations, I wouldn't knock those "small headers" too hard since they might just end up being a small saving grace for an extra bit of tug on that intake port to get things livened up a tad quicker. That'll help you hit the booster a bit faster/harder and make power feel crisper since you'll come up on the cam even faster too. Tune the collector extensions and/or run cutouts to maximize it. Maybe consider running 1.6 or 1.7 rockers on the intake side only(more area under the lift curve but you'll need more spring and possibly lobe oiler faced lifters to find it all). Just a bit more gear would also help matters with slightly larger throats on heavier vehicles(probably around 4,000 lbs with a few passengers, right?). Pull all the little details together and get the cam timing even close to right and you're golden. Course, there's always something else to improve on from there.

[Carnut1]

I'm glad Eric spoke up about the throat sizing and I also think his points are right on.

The bigger valve will work to help pick the port back up but I'd also maybe even consider running a 2.05" tuliped intake after the short side work is all done. Especially if you'll need to install new seats to get to the 2.08 valve size. You'll likely want to lay that short side back a bit but don't do it too abruptly right off the bottom cut(stay about .040 - .050 thou away if possible and blend it all in nicely on the final tootsie roll passes).. obviously easier to take more out rather than put it back in place. Now, most will tell you that this style of valve is not typically used for these ports/valve angles but in this case could potentially help displace some extra area through that largish throat(for a 2.05 valve anyways) and pick the port speed up without really squashing the cfm all to hell. Also good to remember that more consistent wet flow around the valve(improved wet flow curtain) can sometimes be worth more than increasing peak flow on a flowbench. I've also seen some relatively smart dudes pick up power on max valve size deals that were already overly bore-shrouded and the bowls and SSR were way overblown for the application(not that this is entirely the case here). Bandaid of course, plus you lose some compression with a concave valve head and also gain some valvetrain weight.. but still works to pick up a bigger port and/or throat speeds.

PS. As a quick side note. If this was a solid roller setup?.. this throat sizing wouldn't be as big a concern. And specifically because of the FT cams time/area and spring limitations, I wouldn't knock those "small headers" too hard since they might just end up being a small saving grace for an extra bit of tug on that intake port to get things livened up a tad quicker. That'll help you hit the booster a bit faster/harder and make power feel crisper since you'll come up on the cam even faster too. Tune the collector extensions and/or run cutouts to maximize it. Maybe consider running 1.6 or 1.7 rockers on the intake side only(more area under the lift curve but you'll need more spring and possibly lobe oiler faced lifters to find it all). Just a bit more gear would also help matters with slightly larger throats on heavier vehicles(probably around 4,000 lbs with a few passengers, right?). Pull all the little details together and get the cam timing even close to right and you're golden. Course, there's always something else to improve on from there.

Thanks for your input!I was hoping you would add your opinion. I am hoping to convince the kid to go roller and to up the gear ratio. The exhaust may stick with the small headers, extended collectors opening to anti reversion tubes, x pipe and low restriction mufflers.