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P-51 Flow Numbers?

36K views 31 replies 21 participants last post by  Michael Enright 
#1 ·
Was wondering if anybody has any flow numbers or have seen what you can get out of a set if P-51s? Thanks!
 
#3 · (Edited)
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.
 
#5 ·
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
 
#17 ·
426 cfm at .600 lift 430 cfm at .840 some ports were higher than that.

Hp and torque numbers in my sig.


 
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#20 ·
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.
 
#25 ·
went 4.80s in a 3200 ss mustang without bars with p51s on radials
 
#28 ·
Ok, so it's been a long time with my P-51s coming. I got 436 out of mine finally, and that looks like to me that would be the Max that can be done. Took the time to raise the exhaust ports and yes they do have T&D shafts on them, has taller valves and different angles. The cam is in the 850's and will be on fogger. if the ol' 521 don't see 900, I'll be dissapointed. I will post the dyno sheet for you guys. Thanks for the help!
 
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