Hey guys.....I am rebuilding a 340 and besides the .030 that it needs, I’m looking for a camshaft suggestion just over stock specs. I want to DRIVE this car, take it 100 miles without worries....USE IT!! I have go-fast cars, but I want a “daily driver” if you want to say. Semi-Quiet and dependable. I’d like some thing maybe a step over the ‘68 340/4speed cam,(.444/.453) but with an awesome formula of duration, lift and overlap! Maybe I’m dreaming, but I’m willing to listen to what your suggestion is. Thankyou in advance!
Ok....here we go AGAIN!!! Looking for a 340 CAMSHAFT
- Thread starter V24x2
- Start date
-
lil red
Well-Known Member
if the engine is mostly original, ie - heads, intake, compression I would use the trusty purple shaft probably 268 272 - .450 .455 lift. It performed well in a 68 340 I had.
Then put a 340 cam in it. Stop trying to make this WAY more difficult than it is. There's no magic bullet that's gonna give you 50 HP above stock, so go with stock.
Yes, actually want to keep it stock, but the manis were gone when I bought it so I’ll have headers just because. So that was a decent performer huh lil red? I’ll certainly check into it, waiting to hear somebody with a Hughes, or a lunati cam, etc. I have about a month to make a choice but I don’t want to wait til the last second! Thx for your input!
It just may come down to that! I have some time to figure this out tho, so I’m open to tried and true suggestions. Thx
The 340 cam is about as "tried and true" as it gets. Although thanks to @krazykuda and another member Oregon Cam Grinders now offers the 68 340 4 speed grind. It is a little healthier than the 69 and up camshafts that were all the more docile automatic grind. I think it varies by only a few degrees, but that's nothing. It's a dead match as far as I'm concerned.
A stock 340 cam works from 1000-5000 rpm, every step up from that is gonna gain like 10-15 hp and move the powerband up a few hundred rpm eg. 1200-5200 1400-5400 etc.. the further you move the powerband off idle the more your gonna need to step up rear gear and stall in similar fashion . above 5000 rpm isn't too useful on the street especially with 3.55 or higher. So you could go with stock 340 cam or a step or two in cam level. Stock I think is like 205-210 @ .050"
Shorty Medlock
Roads Scholar
The 340's, when new, were able to punch way above their weight class The perfect combination of bore/stroke, carburation and camshaft and in the perfect size chassis. Kind of like a 327 in a Chevy II.
I street raced a bundle of them with my '64 GTO, '70 Cyclone GT, '63 421 Gran Prix and others that went thru my hands. Tough to beat in any situation.
If I were to build a street friendly daily Mopar with a small block the 340 cam would be what I'd want. Just enough snot to make your opponent think twice especially if some $$$ is on the line.
I would call Howards, Lunati, maybe Comp, Bullet and see if they can grind you a custom copy of the 340 4-speed cam...maybe with a touch more lift and duration. Just a touch... not too much.
BUT... get it ground on a Mopar .904 lifter friendly core. It makes a difference. The factory thought so. The Brand X guys regularly use .904 lifters for a reason. Anything less is going backwards.
Sounds like a fun deal... burn some rubber for me when you are done.
I street raced a bundle of them with my '64 GTO, '70 Cyclone GT, '63 421 Gran Prix and others that went thru my hands. Tough to beat in any situation.
If I were to build a street friendly daily Mopar with a small block the 340 cam would be what I'd want. Just enough snot to make your opponent think twice especially if some $$$ is on the line.
I would call Howards, Lunati, maybe Comp, Bullet and see if they can grind you a custom copy of the 340 4-speed cam...maybe with a touch more lift and duration. Just a touch... not too much.
BUT... get it ground on a Mopar .904 lifter friendly core. It makes a difference. The factory thought so. The Brand X guys regularly use .904 lifters for a reason. Anything less is going backwards.
Sounds like a fun deal... burn some rubber for me when you are done.
Like to add, I'd find a cam with the highest lift for a given duration if you looking to gain some power with little loss to drivability. eg. say there's two cams at 215 @ .050" one .460" lift vs .490" lift. I'd go with the .490" lift.
Hey Shorty, Thankyou for the interesting post! Good to hear from your “tried and true” past, who doesn’t like an ol street racing story! Thankyou for the input also, I might have to check into those Oregon guys because yes, I do want something street friendly first and foremost, but would still like to kick a little azz if need be!
Thankyou R3, I just might have to look into that.
Here's two engine with very different cams which I basically drive both.
To show what a cam can do to power and drivablity.
The Base Hp/Tq is a 300 hp crate engine basically stock 5.9l with 4bbbl and headers, cam is like 200 @ .050" & .400' lift.
This is a 380hp crate basically the 300 hp engine with a single plane and a 230 @ .050" & .500" lift.
I got a 5.9l jeep basically the 300 hp crate and a 68 Valiant with the 380 hp crate with 2.96 gears with 26.5" tires a 2800 stall, the jeep has similar overall gear ratio cause of the 31" tires. The Valiant is pretty soft under 2000-2500 rpm have to drive in 2nd in town 40 mph or slower or it lugs. The jeep pulls a lot harder under 3000 rpms.
If you look at 3000 rpm they both make the same power but the 380 hp engine must drop off under way more than the 300 hp engine, between 3500-4000 the 380 hp engine is making stock 340, hp numbers. Above that the 380 hp crate engine power really pulls away from the 300 hp engine.
A 215 ish cam with a .500 probably will lose some top end hp but keep most of the 300 hp engines bottom end, Thats the route I'm picking for my car. plus going with rpm air gap intake instead of the single plane.
* The Modded Hp/Tq numbers is the 300 hp short block with Eddy heads and a 275 comp cam hydraulic roller.
To show what a cam can do to power and drivablity.
The Base Hp/Tq is a 300 hp crate engine basically stock 5.9l with 4bbbl and headers, cam is like 200 @ .050" & .400' lift.
This is a 380hp crate basically the 300 hp engine with a single plane and a 230 @ .050" & .500" lift.
I got a 5.9l jeep basically the 300 hp crate and a 68 Valiant with the 380 hp crate with 2.96 gears with 26.5" tires a 2800 stall, the jeep has similar overall gear ratio cause of the 31" tires. The Valiant is pretty soft under 2000-2500 rpm have to drive in 2nd in town 40 mph or slower or it lugs. The jeep pulls a lot harder under 3000 rpms.
If you look at 3000 rpm they both make the same power but the 380 hp engine must drop off under way more than the 300 hp engine, between 3500-4000 the 380 hp engine is making stock 340, hp numbers. Above that the 380 hp crate engine power really pulls away from the 300 hp engine.
A 215 ish cam with a .500 probably will lose some top end hp but keep most of the 300 hp engines bottom end, Thats the route I'm picking for my car. plus going with rpm air gap intake instead of the single plane.
* The Modded Hp/Tq numbers is the 300 hp short block with Eddy heads and a 275 comp cam hydraulic roller.
Last edited:
JDMopar
Well-Known Member
I have the MP cam below in the 360 in my Challenger. It's a little more than stock, hits a good lick at idle, idles well in gear with the J converter. I drove the car to FL and back a few years ago, and it averaged 20 mpg with 3.23 gears. I have had one in a 340 also, and it performed pretty much the same.
Mopar Performance Purple Camshaft Kits P4452761AE
Mopar Performance Purple Camshaft Kits P4452761AE
That's a goodun! IF you can find it.
harrisonm
Well-Known Member
The 68 340 manual tranny cam is a good choice if you want a healthy stock cam. If you want a very drivable cam with a slightly lumpy idle and a good power increase over stock, take a serious look at the Comp Cams XE (Extreme Energy) 260. I have that cam in my 340. I also have headers, New Comp Springs, and an Edelbrock Air Gap intake. It sounds great and runs great. PM me and I can send you an Email of how it sounds idling.
Wyrmrider
Well-Known Member
you may not make much more hp but you can pick up a ton of torque
why would anyone get a stock 340 cam from a big grinder?-loosers thats who
for a 59 year old stock cam get an elgin, wolverine blue racer, speed pro- great quality- you deserve it
save some serious coin
you did not say if you have a low or high compression 340 so all suggestions so far are bogus
only clue is that with headers you do not need a hugh spread between intake and exhaust
stock heads just a medium split, portef or afternaeket heads eveb less
so how about some details
thats a good cam but $$$$$ and eventhough it has the same duration as stock it breaths much deeper
post up your ompression gears etc before asking for cam advice
btw 340 cam is 210-220 @ .050
why would anyone get a stock 340 cam from a big grinder?-loosers thats who
for a 59 year old stock cam get an elgin, wolverine blue racer, speed pro- great quality- you deserve it
save some serious coin
you did not say if you have a low or high compression 340 so all suggestions so far are bogus
only clue is that with headers you do not need a hugh spread between intake and exhaust
stock heads just a medium split, portef or afternaeket heads eveb less
so how about some details
thats a good cam but $$$$$ and eventhough it has the same duration as stock it breaths much deeper
post up your ompression gears etc before asking for cam advice
btw 340 cam is 210-220 @ .050
Johnny Dart
Well-Known Member
The Mopar .450/.455 would be a good choice.
Or check out a mild cam from Lunati.
Or check out a mild cam from Lunati.
One of my old Duke's Drive In cruising buddies, Hemi Greg, used to describe the 340 as "the small block that doesn't know it"... They keep pulling into the high RPM's instead of tapering off like most engines....
Yep, Ken Hoard at Oregon is the guy that we worked with... The cam that they have is dead on the factory specs, but the exhaust lift is .006" less, but the intake is right on for lift... Every other spec on that cam is dead on, duration, lobe center, and lobe separation....
Thanks. I cannot ever remember what the discrepancy was......and it sure ain't much.
-
