Anybody have pics of 426 Max Wedge Stage ll and lll heads

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Found an ootb test for the first version 518-M vs an untouched 286.
Both are 2.08/1.88 valves-
Tested on 4.375” bore, 28” test pressure, no tube on ex.

518-M(worse than I remembered)-

Lift———I/E
.100—- 66/52
.200—-137/99
.300—-192/136
.400—-226/159
.500—-239/174
.600—-242/181
.700—-244/181

286-

Lift———I/E
.100—- 60/50
.200—-121/93
.300—-179/128
.400—-213/157
.500—-241/177
.600—-264/191
.700—-272/201

While the 286 ex ports flowed better ootb than the early 518-M, the newer ex port has much more potential, and after porting ends up quite a bit better than the ported 286 ex port.

518-M(same ports/valves as above), quick bowl blend only:

Lift———I/E
.100—- 65/54
.200—-143/105
.300—-196/137
.400—-242/166
.500—-254/192
.600—-261/205
.700—-265/218

Both intake and exhaust ports on the 518-M are shaped vastly different that a 286 head.
I’ve never had an OE 518 in my hands to compare to...... so they may or may not be similar to the 518-M’s.
 
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PRH said:
I’ve ported 286’s with 2.14 valves that just tickled [email protected].
That’s a “normal” porting job, not pushing the limits of anything.

I also had a set of them here done by Kaase, they flowed a couple cfm more.

The 286 exhaust port kinda sucks for its size though.
Click to expand...
Yeah, they didn’t have the technology we have today. Pretty damn good for the early 60’s though.
 
Thanks again Dwayne! As an aside, who in the world still has an untouched set of 286.? I have two pairs, and I can guarantee, neither set is untouched, lol.
One more question, if you don't mind.... have you ever flowed a maxwedge crossram?
 
33IMP said:
Thanks again Dwayne! As an aside, who in the world still has an untouched set of 286.? I have two pairs, and I can guarantee, neither set is untouched, lol.
One more question, if you don't mind.... have you ever flowed a maxwedge crossram?
Click to expand...

I’ve actually had two sets of untouched 286’s here.
One set was the later revised version with the added bowl and chamber cuts.

I don’t recall which set of those it was, but one set had all the original hardware with them, including the tuliped intake valves......... which flowed noticeably less than the non-tulip valves.

I’ve never tested one of the intakes.
 
I think my crudely ported (not by me!) 286 still have the tulip intake valves, and I was disappointed by the performance increase compared to a pocket ported 906. The nicely ported set has new normal stainless In them.
 
I think the tulip valves were one of those “seemed like a good idea” things.

At least...... they don’t work in those heads on the flow bench.
The floors on 286 heads are flat as a pancake, and the tulip valve is just in the way.

I remember years ago, a guy who was from down under who used to port heads tried them in some 906 heads.
I don’t recall how much it was, but they really knocked the flow down on the set of heads he was working on.
 
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For those that want to run a MW X ram, but don’t want to cough up the $$ for real MW heads.......
Stealths or Ede’s work just fine:

852C953E-01F9-4C02-A296-1E10683D3B49.jpeg


Although....... the valve cover removal situation is better with raised port heads like TF270’s or EZ/SR’s.
 
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