A few head questions.

Pacman

Registered User
1: Does anyone have pictures of ported heads so i can get an idea where to start?

2: How much can be safely milled off of SC heads before affecting CR?
 
i recently ported my heads with a die grinder ( you better be good with one... )

the middle intake port can be opened way way up... but only if you tig weld the two spots where you will break through... and be very sure not to nick or scratch the valve seats

when i machined the head surface i only took a max of 0.003" all around
i used a milling machine with a 6.5" single point fly cutter (hss tip was all that was needed) and good set up
 
Be very careful with the short radious especially on the exhaust port. You go just a tad too much and it'll flow worse than stock.

Fraser
 
Pictures anyone?? these heads are gasket matched already but since they are off i thought what the heck. I was thinking the same thing about a fly cutter to mill them but havent quite figured out how to set it up. I thought about clamping them directly to the table and indicating the head of the mill to the cyl head surface.
 
I never had to have a head milled yet, just lucky I guess..
I ported the exhaust side only on mine.
Didn't really enlarge it much or change the shape,
just opened the outlets to match the inlets of the exh. mani,
leveled the guides, and smoothed everything.
The intake ports don't seem to need help for the mods I have done.
The restrictions don't show much til over 300whp (If I am reading things correctly).
I don't expect more than 250.
1015091417-00.jpg

1015091419-02.jpg

paul
 
Cool the cutaway pictures are very helpful! how much can one gain from a good port job? im running the stage II cam that SCP sells if that helps.
 
I ported the exhaust side only on mine.
Didn't really enlarge it much or change the shape,
just opened the outlets to match the inlets of the exh. mani,
leveled the guides, and smoothed everything.

1015091419-02.jpg


paul

I would avoid port matching or even enlarging the exhaust port gasket area. Also, I would not cut down the valve guides, they provide valve stem stability.
 
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Cool the cutaway pictures are very helpful! how much can one gain from a good port job? im running the stage II cam that SCP sells if that helps.

Have yet to see anyone make 300 rwhp without significant head porting. With that cam, good heads, MP intake, and 42's or more, exhaust ... 300 should be easy with just 10% OD. Maybe 30 horses, depending.
 
mannysc

he's not on here anymore but used to do alot of port work for members here.

he ended up with some bad luck and family problems and had to go take care of that stuff
 
Have yet to see anyone make 300 rwhp without significant head porting. With that cam, good heads, MP intake, and 42's or more, exhaust ... 300 should be easy with just 10% OD. Maybe 30 horses, depending.

I've also got a 76mm MAF full exhaust catless downtubes magnaflow resonator and mufflers. Ported late model blower with 10% js pulley IC fan. So with a good head port job and 42's i could see 300?
 
with everything i have in my member page i estimate im making 260-270 rwhp.

of course i havent been on a dyno, thats why its an estimate based on my 1/4 mile time. i need to get on a dyno and verify my AFR.

but anyways, i'd put a cam in (even a mild one) if i was gonna pull heads off to port them

just a thought
 
with everything i have in my member page i estimate im making 260-270 rwhp.

of course i havent been on a dyno, thats why its an estimate based on my 1/4 mile time. i need to get on a dyno and verify my AFR.

but anyways, i'd put a cam in (even a mild one) if i was gonna pull heads off to port them

just a thought


Just a thought, I make 274 and trap 104. If your are making 260-270 I think you'd be trapping 100+. But Id dyno it anyway and see where you're at.

Corey
 
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