Boss 429 from 429" Windsor Stroker Project Mixed up Boss

[hwoods]

https://youtu.be/clgw6Ak7AaQ

[427LX]

I have been following his build and he should be close to firing it up soon.

[Joey120373]

I’ve also been following the build, I even sent an email to Mr. Brown ( not Jay, think his name is Tim? Can’t remember )
Inquiring about the heads.

To fit a 363 cube sbf with those heads in my 64.5 mustang would require cutting the shock towers,
But I am considering it.
What I don’t know, is weather or not those heads would offer any substantial advantage over a good set of AFRs  on a 363 cube “hot” street engine. My plan was to have a spirited high revving motor, 6500-7000rpm pump gas motor, nothing too wild, but little mustang with a stick needs to rev.

Those ports *look* fairly big, not sure what the cross section is. My thought is that they are better suited to a 400+ cube motor. But I imagine a bit of epoxy in the floors would
Wake them up on a smaller engine. If you look at Mr. Browns engine masters entry ( he won the race engine division ) he put what looks like about 1/2 inch of epoxy in the floor, and raised the roof slightly, maybe .100 to .150, so overall the port looks like it was smaller, and more oval than his as cast ports.

So I was planning on a set of 195 or 210cc AFRs and a roller cam. That combo should get me just north of 500hp without too much fuss.

Not sure those heads would gain a ton at that level, who knows? Would love to see such a dyno test, like Kasse did between his P-56 and Boss 9 heads. Think he gained somewhere in the neighborhood of 100hp.

In any case, HP gains are not the driving factor, it’s the look. Something about popping the hood and seeing that cute little 6 pound 5 ounce baby hemi in there just gives me wood…

[Gregwill16]

Very cool build.

[Joey120373]

very few videos out on this, i can only find a handfull.

One is what looks to be a fairly mild, 416 (ls motor, but who cares.. )

https://www.motortrend.com/features/hemi-ls-yes-real-kicks-ass/

10.5 to 1 with these cam specs :
238/246 degrees at 0.050 with 0.595-inch lift on both the intake and exhaust ground on a 112-degre lobe separation angle
so a fairly mild combo, made 636HP@ 6,500 and 545lb/ft @ 5,500.
That sounds fairly impressive, but not earth shattering.

So digging further, I found this :

https://www.motortrend.com/how-to/1311-ls3-engine-build-part-3-dyno-tuning/

this is essentially the same short block, at 10.7 to 1 , cam specs:
0.605/0.615-inch lift, a duration of 238/248 degrees, and a 112-degree lobe-separation angle.
It made these numbers :

635 hp at 6,700, with a peak torque of 543 lb-ft at 4,800 rpm.

These two short blocks are about as close as one could ask for given they are two completely different motors. One uses the hemi ford heads and the other uses some CNC ported LS3 heads. looking at this, it seems the Hammer head combo has nothing on a good set of in line valve heads.
They look to be damn near identical power wise, the LS has a better spread between peeks, but without being able to see all the data that may not be all that telling. 

And, as someone once said, "the head doesn't care what block is underneath it " or something to that effect....

What i think this shows, is that at the 650HP level, these mini boss heads are good but probably just too much cylinder head for a 650HP combo.

The other video i saw :
https://www.youtube.com/watch?v=HyP_jhv_I-0
article:
https://mooregoodink.com/hammerhead-hemi-peaks-928hp-427ci-sb-ford/

Here it looks like they ported the heads a bit, put them on a much racier 427 Windsor, and cranked out 928hp at 7,700rpm.
Now that's more like it ..
This is where these heads seem to come into their own, I don't know of any standard LS head that can do this. Sure, full race SB2 or Yates heads hit these numbers, but those aren't exactly home gamer units.

Jays heads would seem to hold up well against these.......

[blykins]

You can tell how good a head is by how much camshaft it needs to hit a certain peak hp rpm. 

With 416 cubes, a 6500 rpm peak with 238 degrees of duration is pretty good, but I think it's still inline of the "good" wedge and canted valve heads out there, i.e. TW-R, AFR, CHI 3V, etc. 

I think the fascination of those heads is that they are something different, not belly-button, and look great. 

[chilly460]

Agreed, it's carrying some decent RPM for the cam, my AFR205s peaked at 6300 with a 242/250 cam, although jury is out if a Vic Jr intake is a bottleneck at that level. 

Looking at the episode where they flowed them, they did 395cfm @ .800" (cue the 'flow isn't everything" comments), so that jives with the comments that you'd start to see these heads pick up with a more serious combo.   I haven't built or really researched any small block heads beyond about an AFR220 level, so not sure how much you can get out of an inline head, but seems that's pretty good canted valve territory. 

My thought is, unless you are really married to a small block, seems for the fitment issues and $$ obstacles of these heads, I'd just be building up a Boss headed big block.  I think these heads are $7300ish with the bespoke rockers, and I'd assume it'll need special pistons, headers, etc that are the same obstacles you'd see with a big block, without the huge displacement difference. 

[Joey120373]

Yea, I agree on all points, these heads are awesome looking, but unless I were building a 427 or 460 inch stroker, and a serious one at that, I doubt these heads will fair enough better than a 220 AFR or big TF head to justify the cost.

650 hp on a mild 408 (assuming a stock block 351 stoker here)
With that small of a cam is very impressive. I know you could get there with a set idle 220 AFRs, but I’m guessing it might take a bit more cam and or CR to do it.

[machoneman]

I think the CHI heads on the same short block would be darned close in hp/torque and would only require special pistons and headers to run. Tons of intakes bolt up and no needed for bespoke rockers.

Brent, do you have any CHI headed (or similar canted valve headed) dyno examples to show us?