Howard's cam suggestion

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NC Engine Builder

NC Engine Builder

Grumpy Old Man
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Got to do a pretty much stock 340, built to early specs, 9.8 compression, mild bowl ported J heads, LD340 intake, and customer is looking at this particular cam, open to thoughts from you guys...
Screenshot_20201119-085151_Chrome.jpg
 
That cam will run nice...

I would get the compression under 9.5 if he wants to run on pump gas....
 
Agree on compression, probably open the chambers a bit, maybe play with head gasket thickness. He originally was going to use a edelbrock or speedmaster aluminum head, but decided to stick with the iron heads instead
 
j par said:
What rear end gears does he have and what are his expectations...
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It's pretty much a cruiser, zero dragstrip action, 3:23 rear gear, hes wanting a 340 just slightly "optimized" allready has nice headers, 2 1/2 exhaust ect. And like a lot of guys, he wants a little "muscle car" idle, but with no drivability issues..
 
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replicaracer43 said:
It's pretty much a cruiser, zero dragstrip action, 3:23 rear gear, hes wanting a 340 just slightly "optimized" allready has nice headers, 2 1/2 exhaust ect
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I posed that question as that's what Ken at Oregon cam grinding would ask me when I'm asking him to grind a cam for me... More specifically what are my expectations....
Even though he tried to talk me out of it LOL I said I want a cam that's going to set the world on fire and I wanted to barely idle and I want it to this and I wanted to that and again against his recommendation he gave it to me and that's exactly what it was a big pain in the butt... Lol...
I guess what I liked best because I'm a cheapskate is that I could give him my cam and he would grind it into anything I wanted for $79 LOL...
Personally I don't see anything wrong with that for a street cam... And honestly with just high octane pump gas I think you'd be fine...
 
replicaracer43 said:
Agree on compression, probably open the chambers a bit, maybe play with head gasket thickness. He originally was going to use a edelbrock or speedmaster aluminum head, but decided to stick with the iron heads instead
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What kind of cranking will it yield with that cam and 9.8, havent done the math myself.

Be nice to get the open spec closer to .500

An honest .480-.495 will work much better with your peak and average .400 n up flow.
Lets say .470 turns into .450-.460 lift after the push rod angle eats up .012 and then the not perfect geometry eats another .008
You can use those heads up without sacrificing the bottom and manners imo
But if you're just going for a little hotter than stock it will sound and run like with more chop and rpm stretch
 
replicaracer43 said:
It's pretty much a cruiser, zero dragstrip action, 3:23 rear gear, hes wanting a 340 just slightly "optimized" allready has nice headers, 2 1/2 exhaust ect. And like a lot of guys, he wants a little "muscle car" idle, but with no drivability issues..
Click to expand...

Then its perfect.
Decent street porting can raise the .200-.450 port flow by 20+cfm, so he should feel a good kick in the pants when he tips it open. I tend to want to exploit the heads as much as i can, thats where my first thought came from. Fyi i sometimes read the first post and just respond without reading over the other responses.
 
Garrett Ellison said:
Here’s this cam. It was a little small in this application but it’s got a nice idle. The heads may need worked to run the .506 lift, too, but it’s on a 104 ICL so it still makes good lower end.
Howards Cams Camshafts CHRYSLER 5.9L/360 Mopar small block LA - 0.506 int./0.506 exh. Valve Lift with Factory Rocker Arm Ratio
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Thanks for posting this Garrett. 1970 340 with speedmaster CNC heads. LD340 intake and 650 brawler carb. It has Speed Pro 2332 pistons. The heads were milled .030. 8553 head gaskets Compression is 10.2-1. Cam is installed at 104. Comp ultra pro magnum rockers. Kim
 
MOPAROFFICIAL said:
What kind of cranking will it yield with that cam and 9.8, havent done the math myself.

Be nice to get the open spec closer to .500

An honest .480-.495 will work much better with your peak and average .400 n up flow.
Lets say .470 turns into .450-.460 lift after the push rod angle eats up .012 and then the not perfect geometry eats another .008
You can use those heads up without sacrificing the bottom and manners imo
But if you're just going for a little hotter than stock it will sound and run like with more chop and rpm stretch
Click to expand...
I've been waiting on @AJ/FormS to chime in with his math calculations...I always enjoy reading that..
 
I built a stock spec 340 with redone J-heads upgraded to 2.02/1.60 but not ported. Put in a Comp XE268 and could not be happier. It is in a 68 Barracuda and that car pulls hard. Used an RPM Eddy and 750 Eddy carb. It is a 904 Auto, factory "hi-stall" converter, 3.55 gears, cheap headers and 2.5" duals. Very strong, very friendly and sounds great.
 
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