340 camshaft

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Jason Holt

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I have a 1967 dart gt convertible and I am building a 340 for it. It is .30 over 10-1 pistons, J heads ported. Torker manifold, Holley 750. I need input on camshaft. Either hydraulic flat tapper or hydraulic roller. I would like a nasty idle but also run well between 2,000 to 6,000 rpm. It's a street car so I want it to be driveable. Suggestions?
 
auto ( nasty cam might be to much for a stock torque converter)/manual/power brakes??
all are factors, a decent exhaust system can make a mild cam sound (aggressive)
 
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Something like a Comp Thumper, Hughes and Howard’s Cams have similar versions.

Is the car a auto or stick?
Gear ratio and tire size?
Cars weight?
 
Something like a Comp Thumper, Hughes and Howard’s Cams have similar versions.

Is the car a auto or stick?
Gear ratio and tire size?
Cars weight?
727 auto I will be replacing the converter and reared. Rebuilding the 727 also. Tire size and gears to be determined. Also the heads have 2.02 valves.
 
I wouldn't run any hydraulic cam for love nor money.
 
I was looking at the comp cams xe284h camshaft.
That might be a bit too much for an automatic for mostly street use. You might look at something with just a little bit less duration, the lift is spot on. Make sure you break it in properly and use Synthetic oil to protect it.
 
The gear ratio and tire size should be at least in the ball park for what you intend to use and that helps cam selection.

That xe284 should fit the rpm bill you listed. I myself would rather a bit more stout of a cam lobe. Like the Lunati Voo-Doo Line. There all on a 110 C line. That’s a typical muscle car exhaust rhythm. You could ask for it on a 108 and it will have a nastier rhythm. More racey.

Gear wise, 3.73 - 3.90’s on a 26 - 27 inch tire would be good.
 
If you are really after the idle and are stuck on a off the shelf hydraulic flat tappet I would use the comp mother thumpr. As dumb as the name is it is a good cam, I would use 1.6 rockers if you can.
 
The original Lunati VooDoo cams were designed by Harold Brookshire of blessed memory. None better when it came to cam design. Harold was the owner of UltraDyne some years back. Miss him.

This cam will fit your needs......

Voodoo Hydraulic Flat Tappet Cam & Lifter Kit - Chrysler 273-360 262/268

This cam (see link below) is the next step up, but your engine will be on the ragged edge of being overcammed and I can guarantee you that running low gears and a high stall converter on the street with no overdrive and no lockup converter for highway use gets old real quick. Not to mention loss of drivability and sucking copious amounts of gas but not going any faster. Been there, done that.

And don't get hung up on a rough idle. All that means is that your engine is running 'off cam'...... Inefficiently...... Not within its powerband and subject to reversion and all manner of drivability hassles until you bring (and keep) RPMs up enough to get into the powerband (around 2,400 RPMs with this cam) and at that point, your engine should smooth out. Just cam the engine to run well for your intended purpose and parts combo and let the idle be whatever it turns out to be. All else being equal...... A good running bone stock 318 2bbl engine will outrun an overcammed 340 4bbl engine until you've gotten revs up past 3,500 - 3,800 RPMs or so and the 340 is pulling hard. Don't let this happen to you......

Voodoo Hydraulic Flat Tappet Cam & Lifter Kit - Chrysler 273-360 268/276

Your combo sounds strong overall. If you have room underhood, lose the Torker and go to a good highrise dual plane intake such as the Edelbrock Performer RPM (make sure you get the one with center divider that goes all the way up and keep the left and right side of plenum separated...... No open spacers).

Your 750 Holley with vacuum secondaries should be fine once you sort it out for your new parts combo. If you replace it at some point, consider a 650 double pumper. You'll love the difference in performance.

Hope this helps,

Harry
 
Go solids. Lately the Hydraulics are not staying pumped up. We are on are third set from comp. They said they are having a problem. We tried different preloads with no luck. If the car sits for a little it clatters bad when starting it. Three motors same thing . I grabbed a set of lifters out of a old purple shaft kit problem solved.

20171126_164141.jpg


20171229_123254.jpg
 
Voodoo Hydraulic Flat Tappet Cam & Lifter Kit - Chrysler 273-360 262/268

This cam (see link below) is the next step up, but your engine will be on the ragged edge of being overcammed and I can guarantee you that running low gears and a high stall converter on the street with no overdrive and no lockup converter for highway use gets old real quick. Not to mention loss of drivability and sucking copious amounts of gas but not going any faster. Been there, done that.
Great suggestion, and wise advice (learned the hard way - like most of us...)
Two additional suggestions
CC the heads while its apart. There's no reason to guess what the compression will be. I will never have an engine together again without knowing the actual head CC and piston above or below deck.
Stock heads aren't going to flow significantly more with the valves over .5" open.

I've used the street dominator intake and found it pretty decent single plane at lower rpms. It had a better rep than the Torker but I've not run them back to back. If you want to stay with single plane, I would try both. The Eddy RPM with a Holley 4150/60 will bring the air cleaner close to the hood. Check and double check clearance of stud and lid with clay or aluminum foil. A mild drop base will likely be needed.
 
Great suggestion, and wise advice (learned the hard way - like most of us...)
Two additional suggestions
CC the heads while its apart. There's no reason to guess what the compression will be. I will never have an engine together again without knowing the actual head CC and piston above or below deck.
Stock heads aren't going to flow significantly more with the valves over .5" open.

I've used the street dominator intake and found it pretty decent single plane at lower rpms. It had a better rep than the Torker but I've not run them back to back. If you want to stay with single plane, I would try both. The Eddy RPM with a Holley 4150/60 will bring the air cleaner close to the hood. Check and double check clearance of stud and lid with clay or aluminum foil. A mild drop base will likely be needed.

Thanks, Mattax. Points well taken. I'll add this regarding lower dual plane alternatives, as well.

If a Performer RPM intake is too high to fit underhood, there are quite a few good flowing intakes here......

340 Chrysler intake | eBay

Everything from OEM cast-iron intakes to various aftermarket types. There are even a couple of hard to find and exorbitantly priced LD340 intakes.

Performance wise, the lower priced sleeper would be the '71 AVS intake (run your Holley on it)......

71 72 Mopar Chrysler Dodge Plymouth 340 Thermoquad 4V Intake Manifold - OEM | eBay

The 1969 NOS Weiand intake is not cheap, but performance wise, its the equal of the much sought after LD340. And the seller is taking offers, so you can likely get it for less than the 'Buy it now' price.

This intake is the real deal...... Not what is sold under that brand name now of days......

Nostalgia Weiand Intake Manifold nos 4bbl aluminum mopar 340 Dodge Chrysler NEW | eBay

Don't waste your time on the lower profile Performer spread bore intake. The OEM iron AVS intake will outperform it and the vintage Weiand intake will run circles around it.

Hope this helps,

Harry
 
good advice go solid
or if hyd Lunati or Howard with 15 in the catlog notes column or comp xe274HL
best would be solid
Street Performance | Jones Cams
mike and his brother rick have the best cam selection software (controlled induction) and 40+ years of experience but except for the low compression hyd just 904 solids and rollers
be sure with all vendors to specify .904 lifter profiles
as for UD Harold his and JOnes have completly differnet ideas, no idea what Harold would be doing if alive today
 
or if hyd Lunati or Howard with 15 in the catlog notes column
What are you looking for with note 15?
Catalogs | Lunati LLC
Some info you may have in the old catalog may have been removed.
Interesting they list two advetized durations on tha cam page, but just the longer one in the catalog.
Maybe one (475/.494) is .006 and the other (262/268) at .008
or something like that
 
Save the Nostalgia over priced Weiand intake (or Edelbrock etc) for the period correct NOS crowd. Grab a Weiand Stealth #8022.....same intake, half the price. Spend the savings on a nice custom cam as mentioned and related items.
 
Save the Nostalgia over priced Weiand intake (or Edelbrock etc) for the period correct NOS crowd. Grab a Weiand Stealth #8022.....same intake, half the price. Spend the savings on a nice custom cam as mentioned and related items.
Going fast for cheap is easy if you guys pay attention. 12many has shown a pretty good time slip in running that aero dynamically challenged van.
You don’t always need the best part out there.
Sure the better part makes it easier. But at a price.
As we used to say,
“It ain’t pretty but it gets the job done!”
You can help the lesser performing parts with a die grinder and a few bits with some basic work.

I agree on the custom cam if your not really knowledgeable about them. I’d click the link that @Wyrmrider left up top and fill out as much of the info as you can. Also, personally, I like a solid cam over a Hyd.
 
In the howard on line catalog note 15 shows a mopar special others are universal grinds- compare
Voodoo cams are mopar
others you have to compare catalog with grind list or compare with SBC cams-
if they are the same you loose
some crower and crane are- some art- upto you to tell the differences

there are others that have good questioneers
getting good answers is something else
 
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FWIW lets see then...
Snipped from a 2007 catalog pdf Jegs has on-line.
voodoo
upload_2019-12-11_13-13-16.png


Seems they are not the same.
And in that older catalog there is a lobe list.
For the Voodoo lobes
upload_2019-12-11_13-45-26.png


and
upload_2019-12-11_13-42-57.png

seems like someone's calulator died or their cut and paste skills failed..oops.

And for comparison with 2019 on-line catalog and cam web pages its easier to type into a spreadsheet.
upload_2019-12-11_13-48-52.png


That explains the two different durations. The 262/268 for the Chrysler is almost certainly a typing error or a marketing decision.
The evidence is there that the lobe is designed for the lifter.
Now we can discuss whether its idealized for the rod - stroke ratio.
Just kidding!
That belongs in a different thread....
 
Thanks for the posts
I had not seen those "new lobes"
looks like they roll the nose over at the same valve lift
makes setting up springs easier
and lots of heads do not flow more above these lifts either
since the noses are rolled over a quick check of the MOPAR vs chevy at .200 works
there would be even more difference at a higher checking point
so there are later lobes than UD Harold :)
 
Running a few simulations of the the 220/226 Voodoo it produced more street torque than 3 CC cams with avg similar lift.
Comp cams classic 280480/480
Comp's 'replacement' 268/276; 264/264 (20-309-4, was called Magnum Muscle)
Comp's XE268. 477/480 This was the closest, making more power than the Voodoo starting around 3000 rpm, give or take some.

In terms of top end horsepower, all three above are in the same ballpark, and...
oddly, this Voodoo doesn't create as much top end power as any of them.
I don't if that would stay true using a head that flows better at high lift. The model I set up using a stock X-head.
FWIW the cam with the least lift, .464/.464, showed the highest top end Hp in the simulation.
 
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Running a few simulations of the the 220/226 Voodoo it produced more street torque than 3 CC cams with avg similar lift.
Comp cams classic 280480/480
Comp's 'replacement' 268/276; 264/264 (20-309-4, was called Magnum Muscle)
Comp's XE268. 477/480 This was the closest, making more power than the Voodoo starting around 3000 rpm, give or take some.

In terms of top end horsepower, all three above are in the same ballpark, and...
oddly, this Voodoo doesn't create as much top end power as any of them.
I don't if that would stay true using a head that flows better at high lift. The model I set up using a stock X-head.
FWIW the cam with the least lift, .464/.464, showed the highest top end Hp in the simulation.
I should look on my laptop. I might have ran a few 340 cams on the program.
 
Nope, sorry. Lost them all in the big hard drive crash. Just a lot of 318 info.
 
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