Home ported Sportsman II heads

[steve cowan]

Dan,
Are you going to use the Erson roller and Bowtie intake ?
Be good to run with the heads as is.
If you decide to go a 2.08" valve what are your thoughts on the rest of the induction tract.
Are your other intake manifolds ported.
Hope you don't mind all the questions

[6.50camaro]

Steve,
I don't mind the question at all. It helps me to rethink thru my ideas.
First I do like the results I've had with both the Bowtie intake and the Erson cam . But I was planning on trying the W/P Motown intake which is port matched to the heads and has a small amount of work in the plenum. As far as cam goes I have a Crane with the same durations @ .050 with a 106* LSA instead of 107* LSA and a little less lift. I have a few different ratio rockers to play with to get the lift back.
I would probably leave the heads and 2.055 valves as they are to start. My goal with the engine would be to use it to run 6.50 index. If it runs that I'm good if not I have something to work with.

[steve cowan]

Steve,
I don't mind the question at all. It helps me to rethink thru my ideas.
First I do like the results I've had with both the Bowtie intake and the Erson cam . But I was planning on trying the W/P Motown intake which is port matched to the heads and has a small amount of work in the plenum. As far as cam goes I have a Crane with the same durations @ .050 with a 106* LSA instead of 107* LSA and a little less lift. I have a few different ratio rockers to play with to get the lift back.
I would probably leave the heads and 2.055 valves as they are to start. My goal with the engine would be to use it to run 6.50 index. If it runs that I'm good if not I have something to work with.

I know Randy and Chad had/have great results with the motown.
I was going to buy one about 2 years ago,$700 AUS lol
I have a super victor, 300-25,a couple of Vic jnr, a couple of different Team G and a airgap.
And a edelbrock tunnel ram.
I will make do with what I got.
I think your 380 will run well

[MELWAY]

One week I spent testing intakes on my 358” sportsman 2 engine
And just like Bigjoe Sherman once said the intake just holds the carby off the floor
I tested super victor victor e mow town and Gm bow tie
They were all port matched to 1206 and had some moderate
Plenum mods
They were all within 8ft lb and 8 hp of each other

[6.50camaro]

One week I spent testing intakes on my 358” sportsman 2 engine
And just like Bigjoe Sherman once said the intake just holds the carby off the floor
I tested super victor victor e mow town and Gm bow tie
They were all port matched to 1206 and had some moderate
Plenum mods
They were all within 8ft lb and 8 hp of each other

James, (MELWAY)
That's how I would describe most of my Intakes except it's not a 1206 size it's 1.25"x 2.25" opening. Not that that matters a whole lot.
Do you feel a solid roller cam with 260* int and 268* ex @.050 with lift in the .650 to .700 range, on a 106* or 107* lsa will get the job done. I've been thinking of sending my Crane cam out to be reground. I would go to smaller base circle so I could and a little lift and duration. I would like the 380 to peak about 7200 and run to 7500-7600 rpm for shift and finish line rpm. Your thoughts would be much appreciated. Dan

[MELWAY]

Dan
Are you stuck at 11.1 comp and are you running pump gas?

I found that even when my sportsman 2 heads hit 300cfm with 2.08 valve they still liked big cams.

But you must have to compression to match cam

[6.50camaro]

The 380 would be about 12.0 to 1 with the pistons I have. I could mill the heads about .020 and reduce the chamber about 3cc and raise the comp ratio a little more. They have been cut .020 already and w/p recommends a max of.040 flat cut. In your experience can they be cut more. I have a local airfield close by that I can get 100ll av gas from which I have used before. Dan

[MELWAY]

All my good sportsman heads were angle milled to 52-54cc

I think .040 flat cut is probably limit before cutting into seat

If you have 12.1 or more a crane cam profile with 266/274 on 108 should work well for you

[6.50camaro]

MELWAY'
If you don't mind sharing if you remember or have notes. What was your short side apex height from the deck surface on the Sportsman II heads. Dan

[MELWAY]

I could measure it but all my heads are angle milled hard

I remember trying to take minimal amount of material off the top of ST to try maximise mid range flow

[6.50camaro]

OK thanks I didn't lower mine just layed them back a little bit when I worked them. Dan

[6.50camaro]

A short update. The Sportsman II heads are off the 422. they may be sold to a neighbor that needs iron heads for his truck pull class or going on my 383. A few pics while they are off.
The first pic is of the hard as rock power valve gaskets that did not seal to the billet metering block. This caused the pig rich condition you see in the chambers and exhaust port during idle and moving around at home and trying to figure out why the idle was so rich. What I was happy to see was that after three test and tune sessions that there was no sign of reversion in the intake port. Dan

[steve cowan]

A short update. The Sportsman II heads are off the 422. they may be sold to a neighbor that needs iron heads for his truck pull class or going on my 383. A few pics while they are off.
The first pic is of the hard as rock power valve gaskets that did not seal to the billet metering block. This caused the pig rich condition you see in the chambers and exhaust port during idle and moving around at home and trying to figure out why the idle was so rich. What I was happy to see was that after three test and tune sessions that there was no sign of reversion in the intake port. Dan

Looks good Dan,
What fuel you run

[6.50camaro]

Steve, I have been using 93 octane pump gas with VP Octanium booster mixed to 98.