Cam Choice

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SoulSurvivor

SoulSurvivor

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Hello guys. I was hoping you could give me a little guidance on what cam I should install in my '69 340. This is my first rebuild. Its a blast.

The 340 has been hot tanked and magnafluxed and has passed inspection. machinist says I can get away with .020 over bore. The crank survived and just need a polishing. The rods and caps are all Ok but the cap bolts should be replaced. The engine was in really good shape upon disassembly.
The J heads (2.02/1.60) have also been hot tanked and magnafluxed. I had them fitted with a set of Manley severe duty stainless valves and comp cams valve springs rated up to .530 lift(just in case). I will be using the stock type rocker arm assembly.
I am thinking of a set of 10.5:1 forged pistons(correct me if you think something else will work better) and was given a new M1 dual plane manifold.
The engine will go in my 69 Dart Custom(my sig picture).
The trans will be my 904 with a Trans-go kit and 2400 stall(suggestion please)
I also have a just rebuilt 8-3/4 with 3:91 Sure Grip(742 case).
Headers will be mandatory. The car already has a 2-1/2 in system and Flowmaster Super 40s.

So...what cam should i use. I'm old school and remember Racer Brown, Isky, Direct Connection and Crane were the big cam manufactures back in the day. I would like to use the most aggressive without it overheating or having to machine anything. And i don't want to use a roller assembly. But I want my car to snarl and haul ***. If I can get it to run 12 1/2 seconds every couple of months at the drag strip that would be a plus.
I truly am looking for your guidance and tell me if I am on the right track with my combination. I have not bought any parts except the head assembly stuff.

Thanks in advance. I know you will have good suggestions.

Doug
 
I JUST PUT A SOLID COMP. 20-231- 520 540 LIFT DURATION IS 244 252 IN MY 340 40OVER X HEAD SUMMIT STAGE 3 DUALPLANE 750 HP HOLLEY 3200 STALL WITH 4.11 IT HAS AWESOME TORQUE WITH KB PISTONS APPROX.10.25 COMPRESSION. FIRST COMPLETE MOTOR REBUILD. IM HAPPY WITH IT SOUNDS AWESOME TOO. CHECK OUT CAM QUEST ON COMP CAMS WEB SITE, PLAY WITH THE CAMS FOR A FEW HOURS, IT WILL GIVE YOU YOUR TORQE AND HP #s AND THERE AVERAGES. MY MOTOR ON SIMMULATED DYNO IS 477 AT 6500 470 TORQUE AT 4500 . BRIAN IT SHOULD RUN 12 TEENS.
 
A mid 12 second car is a pretty stout car but your on the right track with the 10.5-1 pistons, 3.91 gears, headers, and good intake. You need compression to make the power your after. The high compression will work good with a pretty good sized cam like the one Brian mentioned above but note the one he mentioned is a solid which would require you switching the rocker arms to adjustables. A solid is worth the effort because they make more power (comparable to a roller) so you may think about it. Also note that if you go that big on the stick you probably also need to do some head porting work to get the flow up to make good power because the stock ports usually stall out anything over .500 lift and to make it produce power to propel you in the mid 12's needs more air flow. You might also need to have the valve guides machined down cause allot of stock heads wont allow a cam bigger than .500 lift before the retainer hits the guide. You'll also need a higher stall than 2400. The stall speed is dependant on allot of factors including car weight, engine cubic inches, cam selection, intake manifold, rear gears, tire size, etc. Since you allready said what you want the car to do and have 10.5 to 1 pistons and 3.91 gears something in the 3000-3400 range will probably suit you good but remember you'll need to run an extra trans. cooler when you run a high stall converter. Last thing is the intake. The M1 is a very good intake but on your little 340 will be way down on torque below 3500 so I'd sell it or swap it for a Edelbrock Air-Gap. It'll make more power all the way to 5,000 then even out with the M1. The M1 will probably make more power above 6500 but that's not where your going to be 95% of the time.

Oh yeah to run mid 12's you need traction. Expect to at least have to install a pinion snubber and some sticky tires. If not all that power will just go up in smoke.

BTW: Have you considered throwing a 4" crank in it to make it a 416 c.i.? If you did that you'd have gobs of power and it would be less choppy and a better street driver.
 
If you are dead set on stock rockers, an XE274 is about the limit. I'm not sure you have enough convertor to pull a 274 without bogging it down slightly.

If you go adjustable like on a 273, then a solid is in the picture.

Sell the M1 and get an air gap, LD340 or RPM performer. Better manifolds IMHO.

It's not tough to get a car like yours to run 13.00 with some very basic parts as long as it hooks. My 4 speed dart runs 101-102 with a 68 style 4 speed, stock 10.5 pistons, 3.91, LD340, holley 750, MSD and headers. Real basic.

Here are some builds using a 360:
http://www.geocities.com/alwest_83/dyno
 
crackedback said:
If you are dead set on stock rockers, an XE274 is about the limit. I'm not sure you have enough convertor to pull a 274 without bogging it down slightly.

If you go adjustable like on a 273, then a solid is in the picture.

Sell the M1 and get an air gap, LD340 or RPM performer. Better manifolds IMHO.

It's not tough to get a car like yours to run 13.00 with some very basic parts as long as it hooks. My 4 speed dart runs 101-102 with a 68 style 4 speed, stock 10.5 pistons, 3.91, LD340, holley 750, MSD and headers. Real basic.

Here are some builds using a 360:
http://www.geocities.com/alwest_83/dyno
Click to expand...

Although I like what I hear I think some of your suggestions are a bit over my head. Can I assume that this cam XE274 230-236-.488/.491 is about as big I can go with the stock rocker assembly(hydraulic flat tappet is like the stock setup?)and no valve guide machining? I notice that Competition Cams is preferred. Why is that?
And you all agree the M1 is out. I can get my hands on an air-gap. Will I be able to close my hood with an air gap intake?
If I go with this setup what stall TQ should I look at? I already have the pinion snubber and the SS springs. Sorry for the questions. But I think I am close and just want to match up all the componants.
 
SoulSurvivor said:
Although I like what I hear I think some of your suggestions are a bit over my head. Can I assume that this cam XE274 230-236-.488/.491 is about as big I can go with the stock rocker assembly(hydraulic flat tappet is like the stock setup?)and no valve guide machining? I notice that Competition Cams is preferred. Why is that?
And you all agree the M1 is out. I can get my hands on an air-gap. Will I be able to close my hood with an air gap intake?
If I go with this setup what stall TQ should I look at? I already have the pinion snubber and the SS springs. Sorry for the questions. But I think I am close and just want to match up all the componants.
Click to expand...

I'm running an air gap on my 340 topped by an Edelbrock (Webber) 750 with a black wrinkle Mopar Performance air cleaner. Was nervous about clearance but the hood closes fine, no problems.
 
The springs good fro .530 lift are not going to cover the cams i would recommend. They are usable on the XE268 cam, but dual springs are preferred for it, and required for anything bigger like the XE274. I would not run stock arms on the XE274. They flex a ton with dual springs and frankly it isnt worth doing. Wait until the pushrod drives thru the rocker..ugh. For a true 10.5:1 to run on pump fuel, you'll need a serious cam in it. A bit more than what you mention. I would go flat top pistons at zero deck.(I'd use KB hypers for a budget deal, but they would need the tops milled slightly to drop the compression down) Diamond also has a nice flat top but to get to zero deck might take additional decking on the block. In any case, I'd keep static under 9.5:1 and run a smaller cam for torque. I think the XE268 or the "268" family from others might be a good match for your usage. When in doubt, smaller is better.
 
moper said:
The springs good fro .530 lift are not going to cover the cams i would recommend. They are usable on the XE268 cam, but dual springs are preferred for it, and required for anything bigger like the XE274. I would not run stock arms on the XE274. They flex a ton with dual springs and frankly it isnt worth doing. Wait until the pushrod drives thru the rocker..ugh. For a true 10.5:1 to run on pump fuel, you'll need a serious cam in it. A bit more than what you mention. I would go flat top pistons at zero deck.(I'd use KB hypers for a budget deal, but they would need the tops milled slightly to drop the compression down) Diamond also has a nice flat top but to get to zero deck might take additional decking on the block. In any case, I'd keep static under 9.5:1 and run a smaller cam for torque. I think the XE268 or the "268" family from others might be a good match for your usage. When in doubt, smaller is better.
Click to expand...

Like this one?:

Xtreme Energy XE268H Hydraulic Flat Tappet Camshaft & Lifter Kit
Lift: .477''/.480''
Duration: 268°/280°
RPM Range: 1600-5800
 
Here is a reply I just posted on another thread..... I am a big fan of the XE268. I would use the comp springs they recommend and set them at the right height......

I copied this build up for my dad's 68 barracuda convert and I am VERY pleased with the outcome..... The car has great street maners, runs on pump gas, and pulls hard to 6K rpms. If I were going to build another stock stroke 340, I would do this again in a heart beat.

http://compcams.com/Community/Articl...?ID=-738676943

I am runnin this with a 904 and MP 166K converter. It stalls in the 2400 range. Also the car is running 3.55's
 
I've run Comp, Lunati, crane, Erson, isky.... they are all pretty much the same IMHO. Find a grind that would work and run it. For this type of build, you could run a Lunati 60402 or 60403... another good camshaft. You may have to machine the guide to insure no interference when increasing lift. Just a requirement to play the game.

One place I would spend a few extra dollars is to get the 273 adjustable rocker arms and decent pushrods. That decision opens up more potential cam choices.

I've run a 274 with stock rockers and it's right on the edge. Stock style rockers don't like more than ~300# open pressure. As moper noted, once you get past that point, they start to pop apart. The nice thing about the 268 is that it use a simple single spring/damper set up and not a double spring. Thus no machining required to the head for the springs.

You can find 273 rockers for as little as $50/set. I've seen sets advertised here for that price.

The build Haney mentioned should get you close to mid 12's. The westech dyno is a bit happy on numbers compared to others that were just about spot on for weight/mph computations. Build that engine and slap a Holley instead of the ede carb and you'd be in the 400hp range. Enough to go 12's.

I had trouble with Haney's link. Try this and go to the very bottom of the mopar section "340 Dyno derby"
http://compcams.com/Community/Articles/
 
crackedback said:
I've run Comp, Lunati, crane, Erson, isky.... they are all pretty much the same IMHO. Find a grind that would work and run it. For this type of build, you could run a Lunati 60402 or 60403... another good camshaft. You may have to machine the guide to insure no interference when increasing lift. Just a requirement to play the game.

One place I would spend a few extra dollars is to get the 273 adjustable rocker arms and decent pushrods. That decision opens up more potential cam choices.

I've run a 274 with stock rockers and it's right on the edge. Stock style rockers don't like more than ~300# open pressure. As moper noted, once you get past that point, they start to pop apart. The nice thing about the 268 is that it use a simple single spring/damper set up and not a double spring. Thus no machining required to the head for the springs.

You can find 273 rockers for as little as $50/set. I've seen sets advertised here for that price.

The build Haney mentioned should get you close to mid 12's. The westech dyno is a bit happy on numbers compared to others that were just about spot on for weight/mph computations. Build that engine and slap a Holley instead of the ede carb and you'd be in the 400hp range. Enough to go 12's.

I had trouble with Haney's link. Try this and go to the very bottom of the mopar section "340 Dyno derby"
http://compcams.com/Community/Articles/
Click to expand...

It is almost like that article was written for me. Thats all I'm looking for. Thank you very much.
 
SoulSurvivor , I hope you don't mind me asking a question while everyone is on board about cams. It is along the lines about cams.

I have a 360 with a .474/.474 MP hydraulic cam. I have adjustable roller rockers so can I install a solid cam with solid lifters, adjust the rockers, install everything and be done? I noticed that just by going solid that the cams really do "pop" in HP and TQ. I have ran the numbers on some solid cams that aren't much bigger in duration and lift on Comp Camquest compared to the cam I have now and gain 4 more HP and 21lbs of TQ. Wow. Why does the solid cams make such a jump when compared to other hydraulics?
 
mullinax95 said:
Why does the solid cams make such a jump when compared to other hydraulics?
Click to expand...

The ramps on the cam, no hydraulic loss, gets the valve off the seat faster.

Yes you can swap in a solid, break it in, and let it rip.
 
mullinax95 said:
SoulSurvivor , I hope you don't mind me asking a question while everyone is on board about cams. It is along the lines about cams.

I have a 360 with a .474/.474 MP hydraulic cam. I have adjustable roller rockers so can I install a solid cam with solid lifters, adjust the rockers, install everything and be done? I noticed that just by going solid that the cams really do "pop" in HP and TQ. I have ran the numbers on some solid cams that aren't much bigger in duration and lift on Comp Camquest compared to the cam I have now and gain 4 more HP and 21lbs of TQ. Wow. Why does the solid cams make such a jump when compared to other hydraulics?
Click to expand...

I am probably not the one to ask seeing as I have been asking all the cam questions. But appreciate the fact that you would ask me. This my first rebuild and know just enough to get me in trouble.
 
SoulSurvivor said:
I am probably not the one to ask seeing as I have been asking all the cam questions. But appreciate the fact that you would ask me. This my first rebuild and know just enough to get me in trouble.
Click to expand...


Hey sounds like you're heading in the right direction from reading about your plans for the motor. Thing will move pretty good. I wanted a 360 stroker motor from the beginning but when I started pricing and doing a A-1( ported heads, etc.) build I was over $5000 very fast. I figured I have little over $1500 dollars in the plain 360. I bought a 360 short block from a friend of mine. But I had most of the parts already.

What Moper said about the KB pistons and milling them down is what was done to the motor I have now. A cam with a lot of overlap will bleed off the compression. A Performer or Air-gap would be a excellent choice either way.
 
mullinax95 said:
Hey sounds like you're heading in the right direction from reading about your plans for the motor. Thing will move pretty good. I wanted a 360 stroker motor from the beginning but when I started pricing and doing a A-1( ported heads, etc.) build I was over $5000 very fast. I figured I have little over $1500 dollars in the plain 360. I bought a 360 short block from a friend of mine. But I had most of the parts already.

What Moper said about the KB pistons and milling them down is what was done to the motor I have now. A cam with a lot of overlap will bleed off the compression. A Performer or Air-gap would be a excellent choice either way.
Click to expand...
I hope it turns out alright. All this talk of zero decking, milling, and grinding is driving me to drinking. I don't know what all that means. Like I said lots of these terms are over my head. But that Comp Cams article made sense to me. Bolt on and in and I'm good to go.:munky2:
 
I have used Comp Cams in my last few engines.They seem to work real well.I have never had any trouble.Call Comp Cams they have a great tech line and will give you the right cam.Remember to small or to big will not help you at all.I would stay away from Hughes Cams they are junk I have tosted a few.And the last one I had Dave Hughes himself put it in.I live only ten miles from Hughes engines and I don't buy anything from him anymore.
Jim
 
68383GTS said:
I have used Comp Cams in my last few engines.They seem to work real well.I have never had any trouble.Call Comp Cams they have a great tech line and will give you the right cam.Remember to small or to big will not help you at all.I would stay away from Hughes Cams they are junk I have tosted a few.And the last one I had Dave Hughes himself put it in.I live only ten miles from Hughes engines and I don't buy anything from him anymore.
Jim
Click to expand...

I have never heard anyone just bust and say that they love the Hughes cams. They seem odd to me. They have higher lift with short duration. On the other hand there has been some bad luck with the Comp Cam lifters here recently. I don't know if it is cheap lifters or bad break in procedures.
 
mullinax95 said:
I have never heard anyone just bust and say that they love the Hughes cams. They seem odd to me. They have higher lift with short duration. On the other hand there has been some bad luck with the Comp Cam lifters here recently. I don't know if it is cheap lifters or bad break in procedures.
Click to expand...

I have only heard a couple guys mention they run Hughes cams and both liked them. I just bought one so in a couple months when I get my new 408 finished I'll see if their what their cracked up to be.

I'm one of the guys that posted problems with Comp lifters. I put a new Xe274 and lifter set in my new 360 a couple yrs. back and the cam held up fine but 150 miles later I had 2 lifters that wouldn't pump up. They sent me a new set of lifters and I went through the whole speil of breaking it in again (remove inner springs, break it in, change the oil and re-install inner springs) and that set lasted about 550-600 miles and 2 more would no longer pump up. Took it apart and everything looked fine but the lifters were just junk. Reolaced cam and lifters with a Lunati 60404 and it runs much stronger and haven't had any problems with it in over 2,000 miles.

Also had a problem with extremely noisy comp lifters in a big block chevy I rebuilt for a guy. It was ok when we broke it in with just the outer springs but as soon as we installed the inners the lifters seemed to bleed by so bad they wouldn't stay pumped up. Oil pressure was 35 psi at idle at 700 rpm and 60 as soon as you hit the gas so it wasn't an oil pressure problem. Were getting ready to install a Racer Brown cam and see how it does.

Most guys that have problems with cams going flat did something wrong or had a machining problem. I've installed numerous cam and lifter sets and the only one that went flat was in a 454 I did for a buddy that absolutely refused to remove the inner springs for break in. Guess what, he got to do it 20 miles later when the cam went flat. Tried to tell him but he wouldn't listen.

As far as Comp cams tech line being great. They may know what their talking about but their smart azz know-it-all you know nothing attitude turns me off.
 
fishy68

If I was going to go with a Comp Cam I might pick up the hydraulic lifters some where else and avoid the Comp lifters all together. If you read the top posts by me I was amazed by the solid cams that Comp offers over my hydraulic Mopar cam. The Comp Cam XS268S would gain me 7 more HP and 21lbs of TQ!
 
Doesnt matter who you buy the lifters from, They come from 1 or 2 manufacturers.
 
You can get a set of lifters for $58 shipping included from Summit (Summit brand). That's where I got mine and have not had a problem. If I went with the solid cam kit from Comp I don't think I would have to worry about the lifters giving me trouble. LOL
 
i believe its either comp or crane making the actual cams for summit, so im pretty sure they are probably making the lifters too...what i dont understand is if the cams are made by a namebrand company, why they are cheaper with the summit name....are they cheaper quality maybe? just a thought
 
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