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I’m looking for smooth power for slick track conditions but just enough to at least not be lapped traffic in the rare instance we have hammer down conditions. So my target HP is in the 650-700 range.
I want cheap and I want reliable which I realize is having my cake and eating it too but I think it can be done if I keep the HP in this range.
Here’s my “recipe†so far and I’m wanting any seasoned engine guys out there to punch holes in it or tell me if I’m headed in the right direction.
Dart SHP or Little M block with 4.155 final bore (I have a local machine shop that will probably do the work for nothing in exchange for some advertising).
Scat fully forged rotating assembly with H-beam rods, top of the line internals for circle track, blah blah blah. 3.75 stroke with 6 inch rods going for 406 final displacement (adjust compression height accordingly depending on deck height of the block).
AFR 227 heads (23 degree) with 65 or 75 cc chambers depending on where we end up wanting to be on compression ratio. I don’t want to spend time or money on head work when it appears they have a really nice out-of-the-box piece that flows well.
I figured from there, I’ll consult Comp Cams on a proper piece to feed it but I’m leaning toward a mechanical roller and whatever needs to be done up top to support the slopes (e.g. shaft rockers, dual springs, etc.) at about 7500 RPMs. If we identify that the lifter bores can’t support the roller cam maybe we’ll go flat tappet.
Super victor intake.
Then I have a good relationship with a carb place that I think can match up my fuel curve requirements if I give them all the specs to this point in the build. But I think this can be fed adequately by an 850 cfm carb since we run mostly shorter tracks.
One other thing is that I want to keep it wet sump to control cost and maintenance.
We’ll light it up with either a high-end HEI or MSD system.
ATI balancer and dual-chain Cloyes for some insurance on the front.
I think this can be done for right at about $10K but…
Pick it apart boys!!!
I want cheap and I want reliable which I realize is having my cake and eating it too but I think it can be done if I keep the HP in this range.
Here’s my “recipe†so far and I’m wanting any seasoned engine guys out there to punch holes in it or tell me if I’m headed in the right direction.
Dart SHP or Little M block with 4.155 final bore (I have a local machine shop that will probably do the work for nothing in exchange for some advertising).
Scat fully forged rotating assembly with H-beam rods, top of the line internals for circle track, blah blah blah. 3.75 stroke with 6 inch rods going for 406 final displacement (adjust compression height accordingly depending on deck height of the block).
AFR 227 heads (23 degree) with 65 or 75 cc chambers depending on where we end up wanting to be on compression ratio. I don’t want to spend time or money on head work when it appears they have a really nice out-of-the-box piece that flows well.
I figured from there, I’ll consult Comp Cams on a proper piece to feed it but I’m leaning toward a mechanical roller and whatever needs to be done up top to support the slopes (e.g. shaft rockers, dual springs, etc.) at about 7500 RPMs. If we identify that the lifter bores can’t support the roller cam maybe we’ll go flat tappet.
Super victor intake.
Then I have a good relationship with a carb place that I think can match up my fuel curve requirements if I give them all the specs to this point in the build. But I think this can be fed adequately by an 850 cfm carb since we run mostly shorter tracks.
One other thing is that I want to keep it wet sump to control cost and maintenance.
We’ll light it up with either a high-end HEI or MSD system.
ATI balancer and dual-chain Cloyes for some insurance on the front.
I think this can be done for right at about $10K but…
Pick it apart boys!!!
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