P-51 Flow Numbers?

Over 400 cfm

Michael Enright said:

Was wondering if anybody has any flow numbers or have seen what you can get out of a set if P-51s? Thanks!

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It might seem like Jon is just advertising so, I can answer this one...

Maximum air flow is not the beauty of these heads - the air flows at .400", .500" are tremendous and it's over 400 cubic feet of air at only .600" of valve lift.
These are absolutely the best "Street/Strip", moderate valve lift heads of any brand I have yet seen; (excluding the hemi's).

Although, personally with extensive porting I have gotten a maximum of 434 intake and 260 exhaust at .750" valve lift. I have seen maximum air flows a little better than that with a steeper angle valve job but, then air flow somewhat goes away at the mid valve lifts.

EDIT: Lately some people have put these heads on some 550" or so racing only engines and gotten some very good, eye opening results.

562 cid p-51

1.05 60 ' time no spray naturally aspirated around 2370-90 #'s
last saturday rough track out of the grove and hot .

http://www.youtube.com/watch?v=lCWrInhEthI

The reason i was asking was i have a 521 with bme rods, bryant crank, and diamond pistons.. got the heads from lem, and as you all know, competition never gets slower so i was seeing what a port-job will gain me! We got almost 400 out of a set of scjs, i just didnt know if i could get that much jump up with p-51s or not. From what im seeing, im gonna port them for sure! Ill let the dyno tell us for sure! Thanks Guys

What dia. is your intake valve?

intake is 2.25 and ex. is 1.76 right now. planning on a small shot of nos also. probably will change valves, just not sure to what size yet.

The P51 heads start pretty much where MAX ported SCJ ends. The mid numbers are fantastic out of the box.

i have just ordered a set of p51 i couldnt resist especially with the dollar being so good, cant wait to see them in the flesh

I got the Double D version.........

Want some

I would like the part number for those, so I can order them.

parkclay

parkclay said:

I would like the part number for those, so I can order them.

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look on jon kaase website there is heaps of info there or maybe ask lem evans on here about them
also thanks pfsracer for the pics it makes the hair on m y neck stand up

That rocker system looks like a sweet set up!

Curt said:

That rocker system looks like a sweet set up!

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shaft!

p-51

wanting to build a 521 also with the p-51s was thing of the some cam jon used in the 460 he did for the engine challenge(will the same top half but with a 521 with a flat top piston im thinging 12:1 compression what do u guys thing as far as horse power #'s

Hi Blake,

What valve set angles are you using on those heads?

Thanks, Steve

68xr7cat said:

Hi Blake,

What valve set angles are you using on those heads?

Thanks, Steve

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Not Blake, but just plain 'ol 45* seats.

henry b. said:

Magazine numbers

Cylinder Head
Flow Comparison
Super Cobra Jet vs. Kaase P51
Valve Lift: Super Cobra Jet: Kaase P51:
INTAKE: EXHAUST: INTAKE: EXHAUST:
.100 70 52 72 52
.200 154 103 152 107
.300 202 139 234 151
.400 248 185 306 183
.500 274 200 350 202
.600 298 208 368 215
.700 309 212 388 229
.800 318 214 395 239

Jon Kasse web site numbers

Flow Chart as Delivered @ 28" Superflow 600
P51
Intake .100 105
.200 175
.300 258
.400 330
.500 375
.600 395
.700 401


Exhaust .100 103
.200 137
.300 170
.400 199
.500 223
.600 242
.700 251

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magazine # are just that depending which mag ya pick up the numbers are all over the place, for the scj's summits ad says 330-225 then jons site says 345-225 then on his same site the p51 vs. scj add says the scj flows 318-214 so i guess the flow is whatever writeup ya want to believe in.