not so famous bob
Well-Known Member
about like a decent sbc head .................not much for a 440/ or bigger.....jmo
440 Source CNC head review on YT
- Thread starter LowDeck451
- Start date
RBCharger
Well-Known Member
Why no mention of the TF 270?
I do understand the additional costs to use the TF heads (going through that now), but for the $ they look great on flow numbers. I also realize this is TFs flow bench.
.600 343/253
On the video it looks like a lot of "pepper" in the casting. Where are those made?
I do understand the additional costs to use the TF heads (going through that now), but for the $ they look great on flow numbers. I also realize this is TFs flow bench.
.600 343/253
On the video it looks like a lot of "pepper" in the casting. Where are those made?
diesel_lv
Well-Known Member
I didn't request it. This was in 2019 or 2020. I'm not sure if the flow every set. I would think w a CNC that every set would be exactly the same, no need to flow each. If the customer wanted some extra "blending" or something special besides the standard, proven CNC then they might flow those. But the deal behind CNC is it is computer machined and replicated every time.
PRHeads
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From what I understand, the current cnc stealth heads have the same valve job as the non-cnc heads.
The seats are cut rather small……. Not utilizing anywhere near the full diameter of the valves.
These are from the last set I prepped…… about a month ago.
First pic is of the lap line on the seat(the grey line).
Above that is the top angle, and the thin line below it is still part of the 45(seat).
The second pic shows the reason the lap line doesn’t take up the full width of the 45. It runs off the inner edge of the 45 on the valve.
Also, if you did any kind of back cut to the valve, you’d be reducing(or eliminating, depending the width of the back cut) the 45* interface between the valve and the seat.
And, I’ve seen examples where the lap line was about 1/2 as wide as what’s in the pic.
Recutting the seat to move the contact area towards the outer edge of the valve increases the effective curtain area, as well as making the angle below the 45 on the head longer, which allows you add another angle, which helps provide a smoother transitional region to get the air out around the valve and into the chamber.
I suspect the CNC ported version would respond well to a reworking and blending of the seats and the addition of a back cut to the valve.
I don’t think that would quite get you to what the MCH reworked heads flowed, since those also had some work done in the chambers, which combined with the reworked seats, is part of where the really nice flow in the mid-lifts came from.
But I can see where it could easily split the difference between what Eric saw on his bench(280’s), and the 315-320 that others got out of the MCH version.
The seats are cut rather small……. Not utilizing anywhere near the full diameter of the valves.
These are from the last set I prepped…… about a month ago.
First pic is of the lap line on the seat(the grey line).
Above that is the top angle, and the thin line below it is still part of the 45(seat).
The second pic shows the reason the lap line doesn’t take up the full width of the 45. It runs off the inner edge of the 45 on the valve.
Also, if you did any kind of back cut to the valve, you’d be reducing(or eliminating, depending the width of the back cut) the 45* interface between the valve and the seat.
And, I’ve seen examples where the lap line was about 1/2 as wide as what’s in the pic.
Recutting the seat to move the contact area towards the outer edge of the valve increases the effective curtain area, as well as making the angle below the 45 on the head longer, which allows you add another angle, which helps provide a smoother transitional region to get the air out around the valve and into the chamber.
I suspect the CNC ported version would respond well to a reworking and blending of the seats and the addition of a back cut to the valve.
I don’t think that would quite get you to what the MCH reworked heads flowed, since those also had some work done in the chambers, which combined with the reworked seats, is part of where the really nice flow in the mid-lifts came from.
But I can see where it could easily split the difference between what Eric saw on his bench(280’s), and the 315-320 that others got out of the MCH version.
Last edited:
diesel_lv
Well-Known Member
@440plymouthgtx you might need to expound on what you disagree w on my head flow chart. Hope that's not too big a word.
not so famous bob
Well-Known Member
My victor knock offs were cast in china, but fully cnc`d and assembled here , (we changed the retainers and keepers anyway) , the standard port cnc, ''cleaned a little by me'' , flow 354 @.600 lift , a little more than the 270 trickflows advertise !
68-500
Well-Known Member
Its not that I don’t believe there isnt any quality in them.
I just feel that being a lineman they can’t outsource my job to China, so in return I try to not support products where labor was outsourced.
not so famous bob
Well-Known Member
dont see the relationship in being a pole rat and alum. heads ...
68-500
Well-Known Member
My labor can’t be done in China for pennies on the dollar. But by making products overseas by labor that isn’t paid a decent wage. And it leaves American’s sitting on the unemployment line or working for less than a living wage, just to to able to compete and have a job. I do my best to support American companies that employ American workers. Just like the utilities that I work for support American labor.
Go pokes!
Go pokes!
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