Cam selection - 500HP 360

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Moparmal

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I have aguy who Im importing some parts down under for - He is using ported 587 360 heads, pacemakers, Air Gap and a 650 DP Holley and wants to make 500HP!!

I dont think he'll gte there with what he's using....my guess is the heads wont do it with what he's spending on them, and the carb will struggle as well -

I really dont think he's concerned about ET - He's also only running 3.5 gears and 3000 stall.

I think he just wants a torquey fairly hi HP motor.

He wants me to suggest a camshaft - so I thought Id ask you what the most "streetable" stick you could suggest would be to get him near that- assuming the heads flow around 270cfm ?

Obviously he doesnt want a pig - and a roller is out of the question.

Lets aim for 450HP and see what people think is a nice stick - Over to you guys......:clock:
 
Comp Cams 305AH-8 camshaft with .525"/.540" lift and 305/312 degree advertised duration, 253/260 degrees @ .050", 110 lsa, installed at 108 intake centerline.

Be kinda unfriendly in a 360 for the street. He's better off with a 408. 500 street friendly h.p is much easier.
 
Your freind needs to stop dreaming and get a reality check. The HP level isn't a hard one to perscribe parts for, but with those gears, I'll be at the finish line with less power before he gets into second gear.

Everything he has is completely off balance so far.
 
rumblefish360 said:
Your freind needs to stop dreaming and get a reality check. The HP level isn't a hard one to perscribe parts for, but with those gears, I'll be at the finish line with less power before he gets into second gear.

Everything he has is completely off balance so far.
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Exactly!!

You have to match things up to make it work right. If the heads are ported to flow 270cfm they'll make the 500 hp he wants but to make that kind of horsepower he'll need a really big cam, at least a 750 carb, and a single plane intake, and it sure ain't gonna be very torquey down low and work well with them 3.55 gears. Tell him he needs to think more in the lines of 400-425 hp if he wants good low end torque and something to work with those gears. I'd say have him call Jim at Racer Brown and tell him what he has and what he wants to do and he'll suggest his best options. His # is 410-866-7660 and you can catch him after 2 pm eastern time.
 
fishy68 said:
Exactly!!

You have to match things up to make it work right. If the heads are ported to flow 270cfm they'll make the 500 hp he wants but to make that kind of horsepower he'll need a really big cam, at least a 750 carb, and a single plane intake, and it sure ain't gonna be very torquey down low and work well with them 3.55 gears. Tell him he needs to think more in the lines of 400-425 hp if he wants good low end torque and something to work with those gears. I'd say have him call Jim at Racer Brown and tell him what he has and what he wants to do and he'll suggest his best options. His # is 410-866-7660 and you can catch him after 2 pm eastern time.
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The phone thing may not happen as he's in Australia - but I agree, his proposed combo is out of balance - Thanks for the heads up on this guys - I knew it was going to get stinky -

Lets try something different, lets say its a 408 - same gears etc and same heads.....is it possible to get 500HP with a DP intake and a less "piggy" cam?

If so..what cam would you suggest? (Duration and lift will do.....)
 
A nice cam for a low 400HP motor would be a Comp XE274H or an equivalent Lunati Voodoo grind.
 
Lets try something different, lets say its a 408 - same gears etc and same heads.....is it possible to get 500HP with a DP intake and a less "piggy" cam?

If so..what cam would you suggest? (Duration and lift will do.....)
Click to expand...


You deffinatyely can get there stroking it,i'd go with more gear though.. a dual plane will work great something along the lines of an Air Gap or performer rpm,heads properly preped,and i'm a big fan of Lunati voodoo series of cams,i'd suggest the 60404 .513/.533 lift...
 
Yup,I'll vote again for the stroker! Easy 500 H.P and loads of torque too. Dont need a really loose torque converter and the stroker will tend to make a big cam seem mellower and much more driveable. Lots of vacuum to run power brakes and decent fuel mileage (as long as you drive sane), I believe 16 mpg from a 408 is reasonable and all the while having that power!

Someone else may chime in here, mileage may be better or worse.
 
I truly doubt that any 500 hp engine, new or old, will give you 16 mpg. Nor will you get lots of vacuum to run power brakes with the cam necessary to make 500 hp.
 
10:1 CR you could go with the RB ST21 - solid - 254*@ @50 .544/520 vlift with 1.6/1.5 rockers. I have it in my 388 (3.79 stroke) and it hauls street or strip. Jim also runs it in his 360 Dart. he needs at least a 750cfm carb or it will run out of air near 5000rpm.
 
Thanks for the replies - so in nutshell:

MID 250 DURATION / .540 LIFT SOLID should get close on the Dyno with 270 cfm heads?
 
Unfo - that I cant say......all I can say is that they wont "stall" at .500......

Im getting the feeling he doesnt have enough info yet to make a decision, am i right?
 
Granted its a 340 but the engine I built up in my cuda pulls 433 HP. I run a 6-pack setup and an edlebrock performer RPM cam. The heads are 202/160 and ported and polished to flow with T/A heads. I have a lot invested but well worth it. I tried the .508 Purple Shaft cam but it was way less streetable and in my opinion far less responsive. Even with the 4-speed and 3.23 gears I can still run a 12.89 @ 115 mph. Im with the rest of these guys if its 500+ HP you almost have to go with a stroker if you dont want to run a Super or Turbo. Im between switching to a 440 and building the 360 in my duster. But im shooting for around 400 HP on this one. Good Luck.
 
Mal,
Can you get the flow #'s from him? Or post them? It's not the peak flow it's the amount of flow under the peak lift. Add the flows up that are or will be under peak lift and only add the flows that are at the hundreds, like 100, 200, 300 and so on. Then divide by what ever amount of lifts added and then divide by 1.67 for HP correction. Then multiply by 3.44 and this is what the HP for the engine will be. It's the average of flows not peak and whats below peak lift that counts. This is where small valves and port velocity comes in, as most small valves will flow more than a large valve at low lifts up to .400 lift.
 
Dave - thanks for the links - useful tool.

Bobby - thats really interesting info - I can use that for myself.:read2:

unfortunately it seems the guy I was asking for was simply trying to get me to do his "leg work".....he's not contacted me for over a month.

If he had been "up front" with me and just said he was after information - I wouldnt mind, but I really dislike being lied to.:angry7:.........So

- he can stuff it :thebirdm:

- and Ill keep your info for people who are genuine. Thanks for your interest and advice.
 
I've got two around 500 hp 360's both with rpm air gap intakes and stock heads

1.360 block .60 overbore
stock crank
eagle i beam rods
340 j heads 2.08 intake valve fully ported and the larger valve opens the port quite a bit they flow 287 @ 600
lunati mech cam
Cam Style Mechanical flat tappet
Basic Operating RPM Range 4,200-7,500
Intake Duration at 050 inch Lift 256
Exhaust Duration at 050 inch Lift 268
Duration at 050 inch Lift 256 int./268 exh.
Advertised Intake Duration 292
Advertised Exhaust Duration 302
Advertised Duration 292 int./302 exh.
Intake Valve Lift with Factory Rocker Arm Ratio 0.550 in.
Exhaust Valve Lift with Factory Rocker Arm Ratio 0.571 in.
Valve Lift with Factory Rocker Arm Ratio 0.550 int./0.571 exh. lift
Lobe Separation (degrees) 106
Intake Valve Lash 0.024 in.
Exhaust Valve Lash 0.026 in.
Computer-Controlled Compatible No
Grind Number SPI2-292-302

indy ported rpm air gap intake
motor is 13.5:1 comp ratio w kb pistons

it made 522hp @7100 and 435 ft lbs @5700
the car its in has 4.56 gears and 26 in tires
and it has a 5600 stall for a big block that will flash to 4800 with the smallblock

That motor will blatenly not run on the street even if I changed the converter and gears then it would just be a turd it doesnt clean out the miss from the cam until almost 3500rpms


2. 360 block .30 overbore
4.00inch crank=408
eagle h beam rods
340 x heads fully ported with 2.02 intake
a comp thumper cam which is less lift and duration and more lobe seperation (basically a smaller cam)
a port matched (not fully ported) rpm air gap
motor is 9.7:1 comp ratio

this motor made 455hp @ 5600 and 510ft lbs @ 3800

4.10 gears
3600 stall converter


the 360 is actually faster at the track by .6 seconds but its not a fair comparison the stroker is faster down low or from a roll 20mph or higher
but you can actually drive it who needs 500 hp when you can have 500 ft lbs?

oh yea and the 360 cost more to build to that power cuz of the heads valve size and the extra port work on the intake and heads and the stroker has a roller cam and was still cheaper
 
almost forgot the 408 gets a recorded best avg. 8 mpg on a 140 mile round trip kinda babying it one small burout and cruising at 60-65 mph @ 3000-3200
 
340dart.812 said:
I've got two around 500 hp 360's both with rpm air gap intakes and stock heads


340 j heads 2.08 intake valve fully ported and the larger valve opens the port quite a bit they flow 287 @ 600
Click to expand...

Those heads are far from stock...
 
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