Well, my home ported D0OE's have failed me with a crack in one of the exhaust runners. I ported these 2 years ago and have made plenty of runs. 3 weeks ago I went to a T/T and made 7 very good runs with no overheating or signs of any problems. 1 week later I started it in the driveway and had a bunch of steam out of one bank. Oh well - live and learn. Since then I've found a clean set of TW 170 castings for practically nothing. I'm putting new guides , valves, valve job and surfacing down to 54cc's to reach 11.5:1 CR. And yes, I'll be porting them but only lightly- clean up and gasket match to 1262's. Will only have $600 into these when I'm done. Hoping to see high 10's in the 1/4. Opinions Welcome... I will also be checking PV clearance!
10SECFox
You might be able to Polish a Turd but in the end its still a Turd...Same goes with stock heads...The Twisted Wedge heads should make a nice addition compared to the polished Turds.
once you have the aluminum heads to compare to the heavy ass irons, youll never look back. $600 isn't bad for a set of TWs, does that include pushrods and rockers?
Heads came with 3/8 studs and guide plates -no valves or pushrods. I'll be installing new valves and guides, transferring my 7/16 studs and rockers. I'm hoping that my comp cams 8.2 push rods will transfer also.
TW heads need chamber work, to pick up noticeable gains in flow. You can increase flow some without chamber work, but not near as much as with the proper chamber work. Also the exhaust ports don't need much work, it does not matter what Ford head you are working with.
Going to the track today for some T/T runs and an index race with the new TW170's. Hoping to see close to a 6.95 in the 1/8. I'll post results later.
Let us know how it does. My original 351 combo was really close to yours, and if I'd have stuck with it, I think it would've easily ran mid 10's on motor.
contrary to common thought, adding flow to the inlet side does not guarantee power increases. I have done several experiments with this, much to others' chagrin. There is a definite line between valve events and flow parameters. Flow does not equal horsepower, flow equals horsepower capability. There are other very significant players in the puzzle.
Though not the case in this thread's set-up, you can take a very well assembled (and properly cammed) 5.0L stock eliminator engine combination and add some good heads and good intake, the motor will fall on its face. Why? the cylinder does not have proper phasing and access to the increased flow capability.
In your case, with that cam, a swap to the TW wedge heads may require additional exhaust help. I have been around a lot of ported 125cc (289/302/5.0L) and 140cc (early 351W L heads), and have yet to see a set of ported 351 heads really flow much beyond 225 cfm. And even if they do on the bench, the resulting power output does not align to the measured flow potential. Likewise, I do not know the extent of your current 351W heads porting, but if it is like most very worked small block ford heads, there is a lot of focus on the exhaust (also evidenced by your exhaust port problems) which brings the low to mid liift exh/int ration very high. sometimes near 90%. Even the original 60's HD/TransAm/GT40 head (1.88/1.625 valves) ran E/I near 90%. If your vehicle is running 1 3/4 to 3" exhaust system, then the change to the significantly larger inlet capability is going to fit in quite nicely and likely show some decent improvment (and actually may have been a tad too much flow for the previous combo with the cam). However, If the vehicle is running a 1 5/8 to 2 1/2 system, it could rock the other way, so that improvement is nearly non-existent. Not because the heads are bad, but because the valve events are just not right for the motor.
In the early 90's, I took a well optimized small headed motor, and jumped on the band wagon of larger heads and quicker ET's. To put it bluntly, I lost about .15 in the 1/8th mile. I played and played and played and just never recovered performance. The E/I balance was just not working the cams that I typically used. This was pretty much the straw that broke the camels back, with me, that got me looking far more in depth with valve event calcs, and what is really going on.
I dont know what your current compression is, but if you are seeing an increase in compression, with the new TW heads (cut to 54cc's), then that can buffer the short comings of a mismatched set-up. Typically it works way better when the exhaust occurs very early, but other scenarios can benefit too.
Though not the case in this thread's set-up, you can take a very well assembled (and properly cammed) 5.0L stock eliminator engine combination and add some good heads and good intake, the motor will fall on its face. Why? the cylinder does not have proper phasing and access to the increased flow capability.
In your case, with that cam, a swap to the TW wedge heads may require additional exhaust help. I have been around a lot of ported 125cc (289/302/5.0L) and 140cc (early 351W L heads), and have yet to see a set of ported 351 heads really flow much beyond 225 cfm. And even if they do on the bench, the resulting power output does not align to the measured flow potential. Likewise, I do not know the extent of your current 351W heads porting, but if it is like most very worked small block ford heads, there is a lot of focus on the exhaust (also evidenced by your exhaust port problems) which brings the low to mid liift exh/int ration very high. sometimes near 90%. Even the original 60's HD/TransAm/GT40 head (1.88/1.625 valves) ran E/I near 90%. If your vehicle is running 1 3/4 to 3" exhaust system, then the change to the significantly larger inlet capability is going to fit in quite nicely and likely show some decent improvment (and actually may have been a tad too much flow for the previous combo with the cam). However, If the vehicle is running a 1 5/8 to 2 1/2 system, it could rock the other way, so that improvement is nearly non-existent. Not because the heads are bad, but because the valve events are just not right for the motor.
In the early 90's, I took a well optimized small headed motor, and jumped on the band wagon of larger heads and quicker ET's. To put it bluntly, I lost about .15 in the 1/8th mile. I played and played and played and just never recovered performance. The E/I balance was just not working the cams that I typically used. This was pretty much the straw that broke the camels back, with me, that got me looking far more in depth with valve event calcs, and what is really going on.
I dont know what your current compression is, but if you are seeing an increase in compression, with the new TW heads (cut to 54cc's), then that can buffer the short comings of a mismatched set-up. Typically it works way better when the exhaust occurs very early, but other scenarios can benefit too.
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