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Captainkirk

Old School Mopar Warrior
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Time to start researching a cam selection for my Duster 340.
The old grind, which really enjoyed the crap out of, was as follows:
Lift .450/.475
Duration 298/308
Overlap 79 deg.
@.050 232/242
This thing had a gloriously lumpy idle and ran like a scalded dog. My only complaint was that with a single plane intake, the idle vacuum was pretty low (under 10" IIRC) for power brakes. But that did not make it un-driveable by any means...
This time around I'll be using a RPM Air Gap in place of the Torker, and CR will be in the 10:1 range rather than the 12.5:1 pistons I ran last time around.
A833 4 speed
3.91 Sure Grip
650 or 750 DP
Suggestions on a good hydraulic cam for this combo?
And, yes...I like the lumpy idle.
 
I had that same grind in my 70 Duster 340, in 1975. I loved that thing, and would run it again if I could find one....lol. I had an LD340 on mine, and Hedman headers. 3.23 Sure Grip and a 4 spd. Ran like a gut shot cat!
 
I had that same grind in my 70 Duster 340, in 1975. I loved that thing, and would run it again if I could find one....lol. I had an LD340 on mine, and Hedman headers. 3.23 Sure Grip and a 4 spd. Ran like a gut shot cat!
I still have mine. Less than 5000 miles since new in 1976, but lifters had rust pitting. Engine shop does not recommend using an "old" cam with new lifters as he says he's seen multiple cam failures with this sort of Mix-n-match. Of course, he could be trying to sell me a cam...
 
My cam was a TRW. I don't think they even make cams anymore. I'm in the process of building a 273 for my 65 Barracuda, and will probably use a hydraulic roller. Haven't found one I like yet....they're all to dang big for an itty bitty motor like a 273.
 
My cam was a TRW. I don't think they even make cams anymore. I'm in the process of building a 273 for my 65 Barracuda, and will probably use a hydraulic roller. Haven't found one I like yet....they're all to dang big for an itty bitty motor like a 273.
Use something for a 5.2 or 5.9 Magnum. You're going to reduce the rocker ratio (and thereby the lift and .050 duration) from 1.6 for the magnum to 1.5 for the LA. For example, that puts this already mild cam from .480 lift to .450 lift. Comp and Crane also has (or used to have, anyway) some ECU friendly magnum grinds that would make this one look like a dragster cam in comparison.
Hydraulic Roller Camshaft; 1992 - 2002 Chrysler 5.2L - 5.9L Magnum 800 to 5000 Howards Cams 770225-14 | Howards Cams
 
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I still have mine. Less than 5000 miles since new in 1976, but lifters had rust pitting. Engine shop does not recommend using an "old" cam with new lifters as he says he's seen multiple cam failures with this sort of Mix-n-match. Of course, he could be trying to sell me a cam...
old cam, new lifters. It's been done many times without failure. some builders put too much voodoo BS out. lol
The likely failure is using old lifters on a new cam
 
My cam is on its third set of lifters
Break in the same as if both were new
Assembly lube and good high zinc oil.
Just my experience.
Next cam will be a solid flat..

I would reuse your cam especially since you liked it so much..
 
That is a lot of adv duration for 232 @ 050. Consider the Comp cams 280 H magnum cam: it has 230 @ 050, but adv duration [ @ 0.006" tappet lift ] of 280*.
Looooooong adv duration gives poor vacuum, & poor low end tq, bad news on a street driver.
 
New lifters on a used cam is totally and 100% acceptable. You simply just break them in like a brand new set. Soon as it busts off 2500-4000 for fifteen minutes. Done.

That said, if it was me and I "just wanted" a new one, I would seriously consider this.

DODGE COMP Cams 20-671-4 COMP Cams Nostalgia Plus Camshafts | Summit Racing

The Comp Nostalgia line is ground to simulate the old purple shafts, but with modern and MOPAR SPECIFIC lobes. This means this line of cams all take full advantage of Chrysler's larger .903 lifter diameter. That's a damn good grind and will probably be about right on top of what you had. Notice they gave it a split duration. Kinda brings the purple cams into the 21st century.
 
That is a lot of adv duration for 232 @ 050. Consider the Comp cams 280 H magnum cam: it has 230 @ 050, but adv duration [ @ 0.006" tappet lift ] of 280*.
Looooooong adv duration gives poor vacuum, & poor low end tq, bad news on a street driver.
If it were I running down this rabbit hole, (LOL, and I kind of am....) I would look for a cam with the lift to near the heads limits, (flow of known) rising as quick a mild race grind on a 108 a line in the duration suitable for the job. The difference between the advertised duration and the duration @050 would be a good bit smaller than a “Comp Magnum” grind. I’d do this in a mechanical cam. Or a roller if it is a Magnum.
 
Want a stout mechanical Howard’s roller @ about the rpm range your dealing with? Check it....
:thumbsup:
Mechanical Roller Camshaft; 1964 - 2003 Chrysler 273, 340, 360 2400 to 6000 Howards Cams 711213-10 | Howards Cams
Damn, now your talking! Nice grind, I may just use that in my 360 LA hydraulic roller block. I’ve not seen any mention of what rockers he’s using yet, but I have the feeling he may be needing to upgrade to adjustable rockers to meet his goals. If you stay hydraulic flat tappet, Howards has a good .904 specific grind for the lift range of your heads, so while the heads are getting worked, get them set up with a 98434 K (I think-32 or -34) kit with 4 groove locks (if you’re using your old valves)
Performance Dual Valve Spring & Retainer Kit; 1.465 10 Degree Howards Cams 98438-K12 | Howards Cams
This cam has 277/283 advertised duration, and is in the sweet spot for lightly modified J heads.
Hydraulic Flat Tappet Camshaft; 1964 - 2003 Chrysler 273, 340, 360 2600 to 6200 Howards Cams 710581-10 | Howards Cams
 
I believe replacing lifters on a good used cam is totally acceptable. I always inspect my camshaft anytime I'm in the motor and replace the lifter of any camshaft lobe that I don't particularly like the wear pattern of I've only done it a few times. I go through a break-in. Just like a new cam, but I will say I've only flattened one lobe in 40 years and run over 300 lb on the nose on the street. None of my camshafts have been ground since 1990 that may have something to do with their longevity I don't know. I am no way saying that a new lifter can remedy a bad cam lobe! But if I have one lobe whose pattern seems to be a little bit wider than all the rest I will replace the lifter I did this on camshafts that I thought were gone but I guess I caught him early enough because a few thousand miles later when I opened it back up it looked good. I have put new lifter sets on good old cams with success.
 
Truth be known I've put slightly used lifters on a new cam. lol
never had a problem, I also used wheel bearing grease a couple times years ago for break in. lol I was young, but it worked. lol
I am in no way recommending my old make do with what I have methods.
 
Truth be known I've put slightly used lifters on a new cam. lol
never had a problem, I also used wheel bearing grease a couple times years ago for break in. lol I was young, but it worked. lol
I am in no way recommending my old make do with what I have methods.

Me too.....all mixed up and on different lobes. Never had a problem. But then we kinda had to do what we had to do. lol
 
@Garrett Ellison ,thank you! Here is my thing.....

A 340, a big bore/short stroke engine will like to rev up and make terrific top end power and being a short stroke engine & as long as the valve train is controlled well, it will hang onto the top end charge very well. If I could find a 1/2 step smaller cam from the Howard’s line up in a solid roller, I would have chosen that one. A solid flat tappet cam would also do well here. But that is if you want to run that SFT vs a solid roller. But with that cam...

Getting stock heads to work with it may increase the dollar amount on the heads final cost. I don’t know for sure, I didn’t check, but the spring seat may need work with the Howard’s valve springs. Then there is always another spring dealer to look at like PAC, Isky, Crane etc... Since the cost is getting up in price for not just a rebuilt stock head but one with bowl porting, (IMO) why not make a little more of a stretch and push to spring for Edelbrock heads, re-equip the head with the proper springs if the OE Edelbrock springs don’t meet the need, add a RPM AG, 750 & 1-3/4 headers. Now the above cam can start taking advantage of the extra air flow the Edelbrock head can support which will add some nice extra top end pop.

With a good intake track like above, getting away with a cam slightly smaller than 230@050 & making 400 hp is entirely possible.
 
I still like my recommendation. Cause it's mine. lol
 
Whatever cam you choose, if your not porting the heads I'd stick with max .500 lift .
Duration is where you want to play.
 
Whatever cam you choose, if your not porting the heads I'd stick with max .500 lift .
Duration is where you want to play.

I agree! It also saves money from extra machine work on the heads and keeps from using expensive valve sprAngs.
 
Absolutely! It’s easy too get carried away with iron to the point of nearly paying out the cost of a set of aluminum heads.
Sticking with Rumble’s budget friendly plan, Rustys cam recommendation would get you there. A set of the recommended Comp 995-16 comp springs
Free Shipping on Orders Over $99 at Summit Racing
should drop right in. So, you may be at worst looking at getting the guides cut down for spring and retainer clearance while doing the larger valves. Doing it like this, I really like Rusty’s cam choice, too!
 
Absolutely! It’s easy too get carried away with iron to the point of nearly paying out the cost of a set of aluminum heads.
Sticking with Rumble’s budget friendly plan, Rustys cam recommendation would get you there. A set of the recommended Comp 995-16 comp springs
Free Shipping on Orders Over $99 at Summit Racing
should drop right in. So, you may be at worst looking at getting the guides cut down for spring and retainer clearance while doing the larger valves. Doing it like this, I really like Rusty’s cam choice, too!
My discussion with the machinist while dropping off the heads went as follows; "Don't actually do anything, other than clean and inspect, until you've worked up an estimate". This, with the notion in mind that if we come close to the cost of a set of Eddy heads, I'd like to make an informed decision at that point. He figured at a glance that we could come in at around half that, which sounded good to me.
 
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