Camshaft suggestions

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Michael Paselk

Michael Paselk

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Hello All,
I’ve been utilizing this forum for the last couple of years and this is my very first post.
I am looking for Camshaft suggestions for the following:

1976 Mopar 360
Stock crank and pistons
915 J heads with I/1.88 E/1.60 valves
Combustion Chamber 65.0-73.5 cc’s
Ignition converted to HEI
QFT slayer 650
Edelbrock performer RPM w/ spacer
Hooker headers with 3 inch Flowmaster series 40s
Looking for the correct duration and lift limits. Obviously I’m looking for max hp and drive ability for what I currently have.

Thanks in advance!
 
Mike - assumption is your asking what the current engine will handle, meaning J Heads and stock springs? Question, have your heads been re-worked at all?
 

Mopar 340 Cam

Mopar Performance P4452782AE


  • Chrysler 273, 318, 340, 360
  • Advertised Duration: 268°/276°
  • Centerline: 114°
  • Lift: .429"/.444"
  • RPM Range: Idle to 5800

Nice running, great performance, no headaches . . .
 
I would do two things. 1. Pull the heads and install 2.02 intake valves and hardened exhaust seats. 2. Buy a Comp Cams Extreme Energy 268 cam. My 340 has J heads with 2.02 intakes, Edelbrock Air Gap, headers and the Extreme Energy 268 cam kit (cam, lifters and springs). It's good for 375 HP. Send me a PM with an Email and I'll send you a video of how it sounds.
 
Welcome Michael
max hp and drive ability tough goal at what rpm do you want max HP
have the heads/ guides been cut for viton stem seals and what lift
do you have springs
you are looking at 340 springs or better stock 360 springs will not do much
stock 360 you have very low compression so we have to close the intake early to get any torque
yes you can close it later but then you have no low end
perhaps AJ will point you to some of his analysis which is the first place to start
you need to post weight or body, gears and converter and reg or premium fuel and how do you want to drive daily drive back and forth to work or saturday night special

I just posted this in a 318 thread but
if we are thinking of a cam in the 256-260 range (would not ever use old comp 260h in 2018 no lift)

650 AVS carb is about right

I posted a whole list of short cams in the 340 cam thread which we can look at with different LCA's check it out
340 cam specs? see post 27 and 37 & 38
post 27 reads from shortest on the bottom the 256 comp is there and several others listed by duration but nothing from Bullet or Engle or Crower but you can get the idea
you are looking at short duration and high lift
Aj what DCR would he have with a Intake Close of 54-56 @.006? about right on the DCL?
could he use more DCL (earlier intake closed)depending on a fuel the fuel gotcha?
of course if this is a Saturday night special hot rod with low gears, loose converter
268 comp cam has all the problems of the 340 cam then it depends on how nasty and un-driveable you want it

we can get to the proper DCR either way
 
Quick and easy Dynamic compression calculator.
Wallace Racing: Dynamic Compression Ratio Calculator
I figure about 8.2-8.5:1 depending on which head gasket is used. Gear, rear tire diameter, and converter is going to be the deciding factor. Going to have to keep it very mild, unless you want to go ahead and do what it takes to get to 9-9.5:1. Stock J heads stall out around .500 inch of lift. I know this is just a cam selection thread, and this isn't a budget friendly way of doing it, but if the bottom end is fairly fresh with low wear and good ring seal, this is really a case where stepping up to a set EngineQuest magnums ( Efficient 62 cc chambers for a bump to 9:1 and much better O.O.T.B. flow) with the early intake pattern and associated valvetrain hardware would make your goal of "Max Hp and Drive Ability" a lot more attainable. As stated, if the heads are stock or close to it and you elect to sink $$$ into them for springs, seats, and 2.02 valves as mentioned, your probably going to be a lot happier going to the next step and upgrading and then matching the cam to the existing hardware.
 
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Correct? Good luck with that here.
 
Holy Cow! That why I love this forum! Thank you so much for everyone’s response it is very much appreciated! Hello Cazbah362, heads are currently at the machine shop. They are going through the heads and I am waiting for the results to see what direction we want to take.
Cazbah362 said:
Mike - assumption is your asking what the current engine will handle, meaning J Heads and stock springs? Question, have your heads been re-worked at all?
Click to expand...
 
Mike, the direction Garrett is suggesting with EQ Dual style heads is a good suggestion. J heads are are well liked in the SB world, so selling them would be easy to make up some of the cost? Adding a thinner head gasket and/or possibly shaving the EQ's a little would help in this area as well. Also, you can have the shop measure guides and springs to tell you max lift/load available for that setup.

You would have to change to Magnum type rockers, there are pros/cons to this as well. Pros better selection on rocker type, better/easier geometry setting, cons losing the rigidity of the valve train (quick glance, not detailed). I sway towards the Magnum in this area - but you will get different opinions. Nice thing about this setup is it is portable to both Magnum and LA's, so something happens opens the short block selection down the road.

Once this is sorted, then I would start determining cam - I am a fan of roller system, but then you are getting into cost.
 
Well as luck would have it....Machine shop called and the J Heads are cracked.... I am left with the 318 heads and the 360 engine. That cant be a good mix?!
Any other suggestions?

Thanks again!
 
FWIW, 360 heads are a dime a dozen, at least in my world anyway... Do you currently have the heads off of the engine? If so, does it have the 7 cc open dish piston or a four valve relief? How deep in the hole are your pistons from zero deck? Attainable compression is going to be the deciding factor. Early closed chamber or high swirl 318 heads would be good on a 360 for compression, but wouldn’t flow enough to support a 360 past 4500 rpm on a good day...
 
Michael Paselk said:
Well as luck would have it....Machine shop called and the J Heads are cracked.... I am left with the 318 heads and the 360 engine. That cant be a good mix?!
Any other suggestions?

Thanks again!
Click to expand...
Not a good combination. The 318 heads have small ports and small combustion chambers.
 
These latest camshaft recommendation posts bring up a different point altogether. What we really need for all these usable low compression 360s is an affordable head with magnum ports and 58-62cc heart shaped chambers set up for shaft rockers. I’m not going to hold my breath, though.
 
Garrett Ellison said:
FWIW, 360 heads are a dime a dozen, at least in my world anyway... Do you currently have the heads off of the engine? If so, does it have the 7 cc open dish piston or a four valve relief? How deep in the hole are your pistons from zero deck? Attainable compression is going to be the deciding factor. Early closed chamber or high swirl 318 heads would be good on a 360 for compression, but wouldn’t flow enough to support a 360 past 4500 rpm on a good day...
Click to expand...
Thanks Garrett in response to your previous question... ive attached pics of the 318 heads (Casting# 2843675) and the current stock pistons.
360_Heads.jpg
360_piston.jpg
 
318 heads can work real good with some port work (are you up for some minor DIY porting?)(larger intake valves)
the 302 318's have smaller wedge chamber and better exhaust- intake could also use some work see posts above for stock
the EQ heads are available with shaft rockers most likely your best value
or Magnum heads with magnum lifters and pushrods
basically those are your choices without going aluminum
the piston shown is the stock (non HD truck) piston- no way to get any quench or compression with it but if you have to keep it we can do the best we can
I would not buy 360 heads and start there- money pit with no future big chambers etc
 
Garrett Ellison said:
FWIW, 360 heads are a dime a dozen, at least in my world anyway... Do you currently have the heads off of the engine? If so, does it have the 7 cc open dish piston or a four valve relief? How deep in the hole are your pistons from zero deck? Attainable compression is going to be the deciding factor. Early closed chamber or high swirl 318 heads would be good on a 360 for compression, but wouldn’t flow enough to support a 360 past 4500 rpm on a good day...
Click to expand...
What is that like 45 MPH ?
 
Again, a lot of great information. Thank you all! Will have to go back to the drawing board and decide where to go from here. At this time we will probably throw back together. That being said, will it at least be able to cruise around in? forgot to mention that the current cam is a summit 6900.
Capture_Sum.PNG


Before the motor was recently tore down we could never get the timing right.

Things we found:

-318 Heads were not torque down. AT ALL!!!
- Distributor Drive had a lot of play
- Major dead spot on initial acceleration
-Timing impossible to set
- Timing Chain Loose
I guess at this point just looking to be able to cruise around for the rest of the summer.
Again... Any suggestions to help me achieve that goal would be greatly appreciated

Wow...the bar just hit an all time low. LOL!

Thanks again everyone for your help!
 
Thats the really old school "204-214" cam spit out on the automated camgrinders by the thousands
lots of private labels as Summit and Edelbrock
sorta looks like the 340 cam but it's not- it's worse
the 278-288 is at .004 whereas the 340 cam is at around .008 so do not compare durations
you can compare the .204 and lift to the cams in the 340 list I posted
 
With adequate porting and 1.88 or 1.94 valves in the 318 heads, they’ll rpm quite a bit better. Are yours leaded fuel 675 castings? If so, going to need hardened exhaust seats, which if so, is more $$$ that would be better spent on a good head. Depends on year rear axle ratio. Tell us about the rest of your car, four speed/automatic, if automatic, what converter, rear axle ratio. The math on mile per hour is tire diameter X RPM / 336 X axle ratio.
 
Michael Paselk said:
Again, a lot of great information. Thank you all! Will have to go back to the drawing board and decide where to go from here. At this time we will probably throw back together. That being said, will it at least be able to cruise around in? forgot to mention that the current cam is a summit 6900.View attachment 1715358359

Before the motor was recently tore down we could never get the timing right.

Things we found:

-318 Heads were not torque down. AT ALL!!!
- Distributor Drive had a lot of play
- Major dead spot on initial acceleration
-Timing impossible to set
- Timing Chain Loose
I guess at this point just looking to be able to cruise around for the rest of the summer.
Again... Any suggestions to help me achieve that goal would be greatly appreciated

Wow...the bar just hit an all time low. LOL!

Thanks again everyone for your help!
Click to expand...
Sorry for your issues but I wouldn't trust any of it. The whole thing sounds like a accident waiting to happen.
 
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73 dodge dart Sport originally a 318-904 Transmission
Now:
360 with 318 heads casting (675)
7.25 with 2.76 gears
904 trans/ stock converter
Running P255/60R/15 on rear.
Garrett... Yes the current heads are set up to with hardened seats to run unleaded.

Thanks!
 
I agree. I think the 318 heads can be made to work quite well. If they are not cracked, you are at an advantage because you HAVE THEM.
 
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