Are those flow numbers BS cause they are too high or too low?
Oh yea according to DD2000 the cam you should use should be .500IN lift and 1.100EX lift with a 240@0.050 duration
Are your springs gonna coilbind with any more lift?Is it solid or hydroller?If those heads really flow to .700 why put a smaller lift cam.Most of those comps are .714 put some lift in it.That is wise to do get your head flowed ,no more guessing games.
Are your springs gonna coilbind with any more lift?Is it solid or hydroller?If those heads really flow to .700 why put a smaller lift cam.Most of those comps are .714 put some lift in it.That is wise to do get your head flowed ,no more guessing games.
no , i set the spring up at 2.1 installed height and at 750 lift, i can still get a quarter between the inner and outter springs. i just like how the cam i have doesn't require 220 or more seat pressure. these procomps are better than 990's but i don't wanna push the castings really hard, ya know , take it easy on the stud bosses. the extended impellor chart had me making alittle over 800hp with the heads on a blown 475 9.2 to 1 compression, i could turn a a.t. dominator b to 6900 runnin 98mph.the pump is fresh, i built it myself and set it up pretty tight(.026) and its not cavatating at wot. i'm just trying to maintain 90-91mph with the 13 to 1 505bbc and spray big when needed.
the cam i have on hand is a solid roller comp blower/nitrous cam with 652 matched pattern lift, 252, 262 duration 114 center with a cast dizzy gear.my goal is peak hp tq at or near 6500-6800.i need good flow numbers for these heads or someone's numbers who've actually had a unported set flowed.
well i started calling around looking for someone to flow these things, and the 2nd call i made was to the machine who's working over my block, they've got a 2yr old super flow bench!!! so , give me a couple wks and i'll let yall know exactly what a procomp bbc head will flow!!
I'm still curious: what your bore and stroke are, solid or hydraulic, roller or flat tappet?
As to the programs accuracy, I've entered several "package combo's" like some advertised on the AFR and Edelbrock. The program comes close to what they advertise, but is on the optimistic side for sure. Simulations have been shown to be very accurate, I've seen firsthand engines on the dyno come within a couple HP of the Sim's calculation. The two programs in question will get close, but there are too many variables that are given a constant value (like rod length), for them to be more accurate. The trend is all I'm looking for while using these, I get frustrated not being able to put all the other important information in.
800 on a single 4bbl 500ci engine is way doable, especially with 13:1 compression. Although, in my experience, it usually occurs at closer to 7500rpm.
the cam doesn't need crazy seat pressure(only needs 155lbs seat, 450open, i set them at 170lbs seat, @500 open).current cam is a 114 center, 652 matched lift, i 252 e262, comp roller.
I'm confused -
Your running a solid roller with 155lb seat springs ?
This has got to be an old street roller cam then....right ?
IMO 252 at .050" is on small side for that much compression and cubic inches.
If I'm understanding what you plan on running is right, you can get a cheaper off the shelf cam that is much more modern and make more power for your apoplication.
BTW: Is $100-$200 more for a non-shelf cam worth a pant load of power and possible engine issues ?
Did I understand this all wrong ?
well i started calling around looking for someone to flow these things, and the 2nd call i made was to the machine who's working over my block, they've got a 2yr old super flow bench!!! so , give me a couple wks and i'll let yall know exactly what a procomp bbc head will flow!!
Make sure they probe it !
Make sure they go all the way to .900" (so you get .700 and up also)
Make sure they have a good ear also !
And then cross your fingers.
Sorry for 3rd post in a row.
Forget my questions. You mentioned cast iron distributor gear. It's a street roller with mild performance in mind. Again, thus the cast gear and low psi springs.
I would not spin this thing hard, that's for sure !
BTW: to answer another question. Without a ton of work and $$$$$, it's hard to get a strong running 750hp+ NA BBC with OEM rect heads. Pretty easy to 700hp. Thus a ton of 454-510 cid 650-700hp motors that run 200+hp of juice on top of that.
HERE'S THE CAM I HAVE:
Camshaft Specification Table
Part Number 11-694-8
Engine 1965-1996 Chevrolet
396ci-454ci
8cyl.
Grind Number CB 300BR-14
Description
--------------------------------------------------------------------------------
Intake Exhaust
Valve Adjustment 0.02 0.02
Gross Valve Lift 0.652 0.652
Duration At 0.015 Tappet Lift 300 308
--------------------------------------------------------------------------------
Valve Timing At 0.015
Open Close
Intake 36 84
Exhaust 88 40
--------------------------------------------------------------------------------
These Specs Are For The Cam Installed At 114 Intake CL
Intake Exhaust
Duration At 0.05 255 262
Lobe Lift 0.3833 0.3833
Lobe Separation 114
--------------------------------------------------------------------------------
Recommended Valve Springs 929-16
i ran it on the camquest tonite with a low head that flows 311cfm at .650 on intake, 238 at .650 exhuast.
with the blown 475 i had it in it was "making" :
736hp@6500
667ftlbs @5000
changed the induction, compression, and cubes to a 13 to 1 505 with at 1100cfm on a mid flow single plane and got, ran the same cam, no nitrous :
775hp @6500
704ftlbs@5000
so this cam i have seems like it'd work great for what i'm doin, hell it has more hp and tq in the na 505 than it did in my blown475
the heads go over to be flowed, hopefully they'll flow at least 310-315cfm @.650 on the intake and 240cfm@.650 exhaust. if they do, i'll run the same heads with the same cam
ran the 505 again with a 400hp shot:
1204hp @6500
2400ftlts@5000 wtf that means
so what's the cam i have look like to you guys? run 110 all the time or could i get away at 100 octane? i appreciate the good advise guys!
[QUOTE=IMPATIENT 1;2914844]
Tom, I can tell you that 800+ hp is a pretty tall order for a 505cid with a single carb and that small of a cam, and unported heads even though those heads flow very well right out of the box. I'm running a set of Pro Action big block aluminum heads and I believe that the Pro Comps-Pro Top Lines-and the Pro Action heads are all the same head. I had mine ported extensivly and they dont flow a great deal better than they did out of the box. If you'd like the flow #s give me a call. With your engine combo. your probably going to be at 725+ lift and 240lb on the seat to reach your hp goals. If you really want your motor and pump combination to run at the max on the nos then its not going to be nowhere near the ultimate when your off the bottle. Its a trade off. If it runs full tilt off the bottle and then you spray it you may get a little gain but it wont run like it could if you had it cammed with the proper compression and pump {impeller} for the nos, but when you cam it and lower the comp. and install a larger impeller all for a large shot of nos then it doesnt run quite as well off the button. Look at Crane cams roller nitrous grind in Doug Herbert , part # cra-138351 This would be a great cam for your engine.
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