340 cam selection

[npfinegan]

I am new to the group and need help picking out a cam for my 340. This is my first time building an engine myself

I was looking at the Comp Cam Extreme Energy cam. .525/.525 lift, 231/237 duration at .050”, 110 lobe

Background: car used to be drag raced with a massive cam like .557 lift 300s duration. Looking to make one rowdy street car that I can occasionally play on the track. Edelbrock aluminum heads, .030 over, rpm dual plane intake, 750 double pumper, 2950lbs, 4.30 rear gear, 4 speed car

Let me know if this is a good choice or I’m trying to go too big, thanks

 

[junkyardhero]

i wouldn't run anything comp makes if i had another choice. i don't particularly care for single pattern cams, but your duration and the 110 are what i would consider healthy for a hot street car that may see some track time to play around.

 

[Dart Frog]

That extreme energy Comp Cam that you're mentioning is a pretty solid grind for a 340 you could do a lot worse. I have been running 340s for 40 years and would not hesitate to run that grind. It is a fast rate cam for hydraulic so your spring selection needs to be right. You didn't mention if your car is up manual or automatic transmission?

 

[npfinegan]

That extreme energy Comp Cam that you're mentioning is a pretty solid grind for a 340 you could do a lot worse. I have been running 340s for 40 years and would not hesitate to run that grind. It is a fast rate cam for hydraulic so your spring selection needs to be right. You didn't mention if your car is up manual or automatic transmission?

4 speed manual

 

[273]

What's the compression ratio?

 

[npfinegan]

What's the compression ratio?

10.5:1

 

[Dart Frog]

I would be looking at something between 230 and 240 at 50 in the 500 lift range on a 108 centerline. I'm not a big comp fan either.

 

[Dart Frog]

Here's one that would fit the bill

 

[Scody21]

I have the 285 comp in my 340 now, basically the same build you have but with 3.91 and being a stick car it’s not so great for the low side of RPM. The cam I have sitting on the shelf kicking me in the *** to swap out is a Howard’s 236/236 on a 107 in at 105. But mine is more for auto X / corner carving…. Should be a ripper…

I think your in the ballpark, and as others said I would not use comp and really for only a few more dollars you can have of the cam places grind one for you. Howard’s, Bullet, Jones, Oregon.

 

[mderoy340]

Do yourself a favor and go SFT with an EDM lifter.
I ran this Lunati Vodoo cam in my 3200 lb Dart with a 999 low gear set, tight 3400 converter, 4.30 gear, 28" tire and ran a best of 11.64 in good air, 11.80 hot summer air.
Edelbrock group bought Lunati and all the mopar cams are deleted from the web site.
30200741 60441 2600 - 6800 .546"/.566" 243/251 272/280 110/106 .016"/.016"
High performance street/mild bracketcam with good mid range to high endtorque and HP. Needs 3000 RPM stallconverter, headers, 10.5:1+ compression, 3.73-3.90 gearing. Lopey idle

 

[PRH]

340’s like to rev.
High rpm and fast rate Hyd cams aren’t a great pairing.

Put a solid cam in it.

 

[Dart Frog]

340’s like to rev.
High rpm and fast rate Hyd cams aren’t a great pairing.

Put a solid cam in it.

Yep I run a solid lifter 285 advertised 525 lift on a 106 centerline. Works for me.

 

[ph23vo]

340'S LOVE SOLID CAMS.. SOMETHING CLOSE TO YOUR SPECS IN A SOLID WILL MAKE IT A FAST REVVER..

 

[Garrett Ellison]

What’s your compression ratio?

 

[npfinegan]

10.5:1

 

[BSB67]

I would not put any fast rate hydraulic cam in a motor that will need to rpm.

Get a solid flat tappet cam.

 

[Garrett Ellison]

Sounds like enough of a ripper that I'd call and check availability and lead time on this piece.
Howards Cams, Mechanical Flat Tappet Camshaft, Chrysler SB LA, 250/256 @ .050, .525/.535, 106 LS - Competition Products
With 285/291@.050 and a 106 LSA for 76 degrees of overlap, it would be plenty rowdy to pull "ALL the RPM's." The 102 ICL would help maintain decent low rpm cylinder pressure, but that's not going to be too much concern with the 4.30 gears.

 

[273]

You hear of issues with hydraulic flat tappets wiping cams do solids have a similar problem ? if not that would be another reason to go this route.

 

[ValiantRacing]

Howards has a good selection for off the shelf cams, i will never run Comp in any engine i build, unless the box says Competition Cams, and that box is about 35 years old.

 

[Garrett Ellison]

While expensive, high quality EDM (electric discharge machining) solid lifters that directly oil the lifter face sure don't hurt matters with solid lifter reliability...
Anything that sees a lot of idle time is a good candidate for these.
DODGE Howards Cams 91718 Howards Cams Direct Lube Extreme-Duty Mechanical Lifters | Summit Racing

 

[Dart Frog]

There's nothing wrong with a good hydraulic lifter setup if the parts are quality. They work well in mild to mid power level setups. But when the velocity of the cam increases to a certain point it begins to get out of the range of a hydraulic making sense because the amount of spring pressure that is needed to control the valve train with the quick opening and closing valves gets high enough that it begins to work against the hydraulic system. No problem for a mechanical lift.

 

[tvt59]

Everyone here will bash me for this. But if you can afford a good hyd roller cam you'd be very happy if you put one in it.

 

[Illahe]

Schneider SFT 278/86F 248/256@ .05 and .558/.550 on 110

 

[Garrett Ellison]

That Schneider is a very good piece!

 

[AJ/FormS]

I'm running a similar cam, on the Street; a Hughes 230/237/110 in a 68 Barracuda@3650/me in it, but in a 360 with Alloy heads at 11.3Scr. She was a DD at one time.
IMO for a manual trans it is borderline too much. It worked ok with 4.30s, But not so good with 3.55s. I've been waiting for like 20 years for it to die, but she's like the energizer bunny.
My peeve is trying to drive slowly with it...... like in parades. Even with a 3.09 low gear, 4 mph is only 550rpm and with a 750DP, it was a bit of a challenge to tune.
I cruise it geared at 65=2240 in overdrive, but that cam and carb combo likes it's gas.