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Best Cam Upgrade for stock 360???

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amx73 View Drop Down
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    Posted: Jun/19/2018 at 6:28am
So, I'm thinking about putting a cam in my stock 360. Its got Hedmann 1 5/8 tube headers, Edelbrock Performer intake, Edelbrock 600cfm carb, and HEI distributor. Trans is a stock 727, and I believe the rear is 2.72 or 3.08? A stock 73' 360 with a 4bbl and dual exhaust is 220HP, with my upgrades its probably 250ish HP? Would like something very streetable, with improved throttle response. I'm thinking the Comp 268H grind is the largest I could go without changing valve springs...?

Jake
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Post Options Post Options   Thanks (0) Thanks(0)   Quote WesternRed Quote  Post ReplyReply Direct Link To This Post Posted: Jun/19/2018 at 7:09am
Based on my recent experience, with the stock valve springs, you will see valve bounce around 5,500 rpm, so probably a good idea to throw some new performance springs at it and you should be able to turn +6,000 RPM. Somewhere round 270 advertised duration is probably good, watch the lift, the valve retainers can hit the valve stem seals and or valve guides if you go to high, watch out particularly if you are above 0.500" lift. Aftermarket retainers and locks can give you a bit more clearance here. Depending on which heads you have, you may or may not need some other valve train upgrades.
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Post Options Post Options   Thanks (0) Thanks(0)   Quote Sonic Silver Quote  Post ReplyReply Direct Link To This Post Posted: Jun/19/2018 at 8:07am
Originally posted by amx73 amx73 wrote:

So, I'm thinking about putting a cam in my stock 360. Its got Hedmann 1 5/8 tube headers, Edelbrock Performer intake, Edelbrock 600cfm carb, and HEI distributor. Trans is a stock 727, and I believe the rear is 2.72 or 3.08? A stock 73' 360 with a 4bbl and dual exhaust is 220HP, with my upgrades its probably 250ish HP? Would like something very streetable, with improved throttle response. I'm thinking the Comp 268H grind is the largest I could go without changing valve springs...?

Jake
Your rear gearing is most likely a 3.15, or possibly 2.87. With that, an automatic, stock converter, and 8.5 compression ratio, I wouldn't get too frisky on the cam. I have a Bullet/Ultradyne grind in a 8.5 cr 360 that is very responsive right off idle. It is 262 duration (207 at .050) with .461 lift on 110 lobe centers. It pulls to a bit over 5,000 rpm.
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Post Options Post Options   Thanks (1) Thanks(1)   Quote SC397 Quote  Post ReplyReply Direct Link To This Post Posted: Jun/19/2018 at 9:30am
Comp 268H
Isky 270HL
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Post Options Post Options   Thanks (0) Thanks(0)   Quote gremlinsteve Quote  Post ReplyReply Direct Link To This Post Posted: Jun/19/2018 at 11:29pm
Or a summit 8600
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Post Options Post Options   Thanks (0) Thanks(0)   Quote PHAT69AMX Quote  Post ReplyReply Direct Link To This Post Posted: Jun/19/2018 at 11:47pm
Chet Herbert A4B from late 1980's
'69 AMC Stock Camshaft Reground, Straight Up,
failed to get a Base Circle measurement...
Self Degree Wheel Measured, not guaranteed...

.512" Lift Intake at Valve, 1.6 Rocker
 280* @ .005
 227* @ .050 (? 58* ramps) ( assumed symetrical )
 112* ATDC = Intake CL

.529" Lift Exhaust at Valve, 1.6 Rocker
 295* @ .005
 246* @ .050 (? 61* ramps) ( assumed symetrical )
 112* BTDC = Exhaust CL

IN opens  .050 @   2* BTDC - .005 @  31* BTDC
IN closes .050 @  45* ABDC - .005 @  73* ABDC (DynCR)
          .050 @ 227*      - .005 @ 284*

EX opens  .050 @  53* BBDC - .005 @  77* BBDC
EX closes .050 @  13* ATDC - .005 @  39* ATDC
          .050 @ 246*      - .005 @ 296*

Overlap   .050 @ 15*       - .005 @  70*
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Post Options Post Options   Thanks (0) Thanks(0)   Quote farna Quote  Post ReplyReply Direct Link To This Post Posted: Jun/20/2018 at 5:43am
I'd stick with more of a torque cam and keep stock valve springs. No cam lobe wipe issues running regular oil with no additives. If you go much over 300# on the valve springs you have to use a high pressure additive. Stock springs are under 300#.  With a high gear rear (low number, 2.87-3.15) a torquey cam will feel better taking off anyway. Keep rpm under 6K (5.5K if valves start to float there). A towing/RV cam will work great. You can build an engine for torque and get great throttle response and keep it at moderate rpm. It will feel real strong. Or build for high HP -- which means you need to turn it up in rpm to get the power, and it won't have much throttle response without a higher stall converter (lets engine rev up before moving) and more gear in the back since it doesn't make as much torque at lower rpm either. So the 268H is about the biggest I'd put in -- power is supposed to start at around 1500 rpm. I wouldn't use a cam that doesn't "come in" later than around 1500 with a stock converter and rear gears. A 270 duration is usually spec'd at around 1800 rpm... that's pushing it just a little, but workable. 260-270 would be good for a street/strip car that sees more street than strip use... IMHO. I don't care about a "lopey" idle, but I know some guys like it. I prefer my engines to run smooth. 
Frank Swygert
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Post Options Post Options   Thanks (1) Thanks(1)   Quote amx73 Quote  Post ReplyReply Direct Link To This Post Posted: Jun/20/2018 at 7:06am
This Lunati cam looks like it might do the trick? I also have a 3.54 gear set and a posi I could through in there too!

  • Advertised Duration (Int/Exh): 250/256
  • Duration @ .050 (Int/Exh): 208/213
  • Gross Valve Lift (Int/Exh): .484/.484
  • LSA/ICL: 112/108
  • Valve Lash (Int/Exh): Hyd/Hyd
  • RPM Range: 1000-5200

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Post Options Post Options   Thanks (0) Thanks(0)   Quote Dave Z Quote  Post ReplyReply Direct Link To This Post Posted: Jun/20/2018 at 6:36pm
I'm sure any of the cams recommended here will work fine. But just because everyone has an opinion, here's mine. Call Bullet Racing Cams at (662)893-5670. Tell them what you have and what you want it to do and they will custom grind a camshaft for your specific application. It doesn't get better than that.

Dave Z
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Post Options Post Options   Thanks (0) Thanks(0)   Quote purple72Gremlin Quote  Post ReplyReply Direct Link To This Post Posted: Jun/20/2018 at 6:50pm
Originally posted by farna farna wrote:

I'd stick with more of a torque cam and keep stock valve springs. No cam lobe wipe issues running regular oil with no additives. If you go much over 300# on the valve springs you have to use a high pressure additive. Stock springs are under 300#.  With a high gear rear (low number, 2.87-3.15) a torquey cam will feel better taking off anyway. Keep rpm under 6K (5.5K if valves start to float there). A towing/RV cam will work great. You can build an engine for torque and get great throttle response and keep it at moderate rpm. It will feel real strong. Or build for high HP -- which means you need to turn it up in rpm to get the power, and it won't have much throttle response without a higher stall converter (lets engine rev up before moving) and more gear in the back since it doesn't make as much torque at lower rpm either. So the 268H is about the biggest I'd put in -- power is supposed to start at around 1500 rpm. I wouldn't use a cam that doesn't "come in" later than around 1500 with a stock converter and rear gears. A 270 duration is usually spec'd at around 1800 rpm... that's pushing it just a little, but workable. 260-270 would be good for a street/strip car that sees more street than strip use... IMHO. I don't care about a "lopey" idle, but I know some guys like it. I prefer my engines to run smooth. 
I dont like "towing RV cams". Those have too much duration. Most RVs have 4.56 gears. So they are doing about 3600 at 55. So these so called "RV" cams will idle rough, and not run very well at lower speeds...
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