Cams for 318's

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"HOW TO PICK A CAM" would be the perfect sticky, focusing on usage vs duration vs rpm vs head flow vs lift vs lsa vs cylinder pressure.

Stock heads/stock flow limits lift..
Gears and cylinder pressure restrain duration and dictate lsa etc... hard to make a sticky thats nothing other than gobs of confusion for the average novice. Some things are best left to the professionals... kinda like none of us are gonna do our own open heart surgery's if and when the time comes ;) though I hope this works out.

Maybe a "stage one,two ,three, etc" 318 build recipes would be easier. No matter what, you're gonna see those threads pop up..lol
 
"HOW TO PICK A CAM" would be the perfect sticky, focusing on usage vs duration vs rpm vs head flow vs lift vs lsa vs cylinder pressure.

Stock heads/stock flow limits lift..
Gears and cylinder pressure restrain duration and dictate lsa etc... hard to make a sticky thats nothing other than gobs of confusion for the average novice. Some things are best left to the professionals... kinda like none of us are gonna do our own open heart surgery's if and when the time comes ;) though I hope this works out.

Maybe a "stage one,two ,three, etc" 318 build recipes would be easier. No matter what, you're gonna see those threads pop up..lol
Herbert did a nice mild Can for std or near Std LA318: 195°/205°/110°LCA Bit more lift...wakes up a std 2bbl engine or upgrade with a good COND sp2p 2bbl or 4bbl inlet or Holley Z 4bbl allow & an Economaster 450cfm carb or 1406 Edelbrock (AFB) 4bbl or 80457 square 600 Holley, with a pair of Duals minimum 2" tube ea side or shorty or long tube SMALL DIA headers 1.5" primaries IF you can find them) with a quicker curve in the Dist to match the Can. Old Completion Cams 268H Can us a hotter choice if you like a wee lobe at idle...if your going to wind it up put a 340 hiperf oil pressure (or marine) relief sp4ing in the oil pump.
Off idle to 5,000rpm with ubive combos will leave a smile on your face, so will the sound of a pair of long Glasspacks with louvered cores.
Trev.
PS Mill the heads & bolt on a set of the Speedmaster adjustable roller rocker gear if you want more go & adjustabilty.
 
"HOW TO PICK A CAM" would be the perfect sticky, focusing on usage vs duration vs rpm vs head flow vs lift vs lsa vs cylinder pressure.

Stock heads/stock flow limits lift..
Gears and cylinder pressure restrain duration and dictate lsa etc... hard to make a sticky thats nothing other than gobs of confusion for the average novice. Some things are best left to the professionals... kinda like none of us are gonna do our own open heart surgery's if and when the time comes ;) though I hope this works out.

Maybe a "stage one,two ,three, etc" 318 build recipes would be easier. No matter what, you're gonna see those threads pop up..lol
There are more cam experts out there than there are cams to choose from. Leaving it to the "professionals" is a good idea, and when it comes to small block Mopar engines, that would be Dave Hughes over at Hughes engines in Washington, Il. Just feed him your particulars and you won't go wrong. I have run his cams in everything from stroked and blown small blocks to my present mild build 318 Magnum motor. 309-745-9558. Not sure, but their web site might have a cam form you can fill out.
 
Take a look at
Howards Cams Hydraulic Flat Tappet Camshafts - 255 int./261 exh. Advertised Duration
all three listings have the same .006 seat duration
The bottom listing for the chevy is similar to most chevy .842 profiles at that duration when sold for a MOPAR with 1.5 rockers
The middle listing is similar to the chevy profile but with 1.6 rockers I do not think this is a special for the larger Ford lifter
Now the top show shows the difference when you use a master made for the larger MOPAR/ AMC .904 lifter
.070 more lift and most likely much more area under the lift curve
Not touting Howard here- these three were conveniently on the same page for this discussion
You can find shelf Mopar cams at this duration from Lunati Voodoo, Bullet, Engle etc with various lobe centers (I think the DC/MP has been discontinued)
or you can go custom, like from Jim at Racer Brown (Herbert has none in their catalog but does have some oldy moldie customs they should still work well and the price is usually "right")
My favorite is Mike Jones custom Mopar lobe it is shorter seat to seat and larger at 200
your heads, compression, intake, exhaust and trans/ gears will make a big difference on what you end up choosing
don't but a chevy cam in your MOPAR- like the oldie but goodie 268 comp mentioned above
Here's how you tell- just compare the Mopar grind with their small block chevy grind- if they are the same PASS
 
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For the street, the factory usually got it pretty close...don't stray too far from it.
Now if you are a quarter miler that would be different
 
.480 lift cam is hardly a broomstick
Howard says street /strip for a 318
I'm thinking about as big as I'd like to go on a stock compression/ gears/ converter 318
would run better than the 268 comp in the above build and have more duration @ .200 where the power is made
does not the comp XE268 only have .454 lift?
 
comp XE 268 .477 .480 .224 .230 is way too much for a 318.
go to comps website and get their dyno sheets.You'll see the xe 256 and 262 are better than the xe268 in a warm 350 sbc with Dart heads.
.410 .420 or .429 .444 and maybe .204 .214 would be a good choice for a stock 318, but you didn't want to hear that.
 
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.480 lift cam is hardly a broomstick
comp XE 268 .477 .480 .224 .230 is way too much for a 318.
go to comps website and get their dyno sheets.You'll see the xe 256 and 262 are better than the xe268 in a warm 350 sbc with Dart heads.
.410 .420 or .429 .444 and maybe .204 .214 would be a good choice for a stock 318, but you didn't want to hear that.
This isn‘t exactly true.
What is missed is the fact that duration does two things. It controls the operational rpm range and how long the valves are open to ingest air and fuel.

IF the supporting cast of parts are not employed to make an effective full use of the extra air & fuel, less power can be the result.

A larger duration cam will have a higher operating RPM range as the plus in making more power but has the draw back or not making any decent power in the lower operating RPM range. The larger the duration the more power you can possibly make at a higher RPM at the cost or lower RPM power.

Dave Freiburger said, and I so whole heartily agree, afford the best cylinder head you can.

There is NO magic cam for any engine of any displacement. PERIOD!
 
This isn‘t exactly true.
What is missed is the fact that duration does two things. It controls the operational rpm range and how long the valves are open to ingest air and fuel.

IF the supporting cast of parts are not employed to make an effective full use of the extra air & fuel, less power can be the result.

A larger duration cam will have a higher operating RPM range as the plus in making more power but has the draw back or not making any decent power in the lower operating RPM range. The larger the duration the more power you can possibly make at a higher RPM at the cost or lower RPM power.

Dave Freiburger said, and I so whole heartily agree, afford the best cylinder head you can.

There is NO magic cam for any engine of any displacement. PERIOD!
:thumbsup: to that last line! BTW, Hughes claim to fame is " real Chrysler cams" designed around .904 base circle lifters -verses chevy blanks. You can't have it all, so consider where your engine is going to be spending most of it's time ( rpm wise ), and use that info as part of your choice criteria. Other areas often not considered are where you live ( 5000 ft above sea level or a little closer to the water. Running vacuum accessories? In many cases, smaller can be better.




A larger duration cam will have a higher operating RPM range as the plus in making more power but has the draw back or not making any decent power in the lower operating RPM range. The larger the duration the more power you can possibly make at a higher RPM at the cost or lower RPM power.

Dave Freiburger said, and I so whole heartily agree, afford the best cylinder head you can.

There is NO magic cam for any engine of any displacement. PERIOD![/QUOTE]
 
:thumbsup: to that last line! BTW, Hughes claim to fame is " real Chrysler cams" designed around .904 base circle lifters -verses chevy blanks. You can't have it all, so consider where your engine is going to be spending most of it's time ( rpm wise ), and use that info as part of your choice criteria. Other areas often not considered are where you live ( 5000 ft above sea level or a little closer to the water. Running vacuum accessories? In many cases, smaller can be better.
Thanks.

I have found that the wider the centerline, the more vacuum and better power brake operation I have. While this wider 112 or 114 doesn’t as much as a power maker as a more narrow 110/108, it isn’t a disaster ether. For a smooth driver, look for a cam on a 112 or a 114.

A better performing cam will be on a 110 or a 108. This cam will also have choppy idle. I know most guys die for this.
 
I’d like to add that a lot of people will shun the 318 with a host of complaints and they haven’t even built one. Often I see a mismatch of components and unrealistic expectations.

One way around the big cam blues is to properly combine the right gear ratio and get a good converter with the proper stall for YOUR application. For the smaller engines, this does require a higher stall and gear ratio then a larger engine.

A second way around a lack of torque with a small engine is a roots style super charger. These are regarded as inefficient and use a lot of power to turn, but there instant brut torque can not be denied.
 
This has kept me out of trouble most of my life with a small block mopar, street driven.
Pick a cam that you think is perfect for your application, then buy the next smaller one.
 
This has kept me out of trouble most of my life with a small block mopar, street driven.
Pick a cam that you think is perfect for your application, then buy the next smaller one.
:lol: Here is a 318 Magnum motor I just finished putting together. It's in a 74 Duster with a stock build 727 ( 2500 rpm convertor ) and 3.23's out back. This car is a daily driver. 318 Motor from a 96 Dakota in real good used condition. Completely stock rotating assembly ( including pistons ). Stock heads got new seats, guides. Stock valves ( 1.92 and 1.60 ) were also in good condition. Had them refaced and back cut at 25*. 3 angle valve job got blended to the bowls with some miner bowl work. Roller cam was a Hughes SER0814ALN-10 grind. 110 LSA, installed straight up. .491" / .500" with stock 1.5 rockers. CR came out to 9.14 static with the head gaskets I chose. Intake = a 650 Edelbrock and Edelbrock air gap. Pretty free flowing cast iron exhaust manifolds in to a "Pypes" 2.5" "X" pipe exhaust with chambered mufflers. Plenty free flowing for a little motor. Great combination for my little Duster. Very driver friendly ( 2 grand Daughter chompin at the bit) and probably a low 15 second car near sea level.

IMG_0885.JPG
 
:lol: Here is a 318 Magnum motor I just finished putting together. It's in a 74 Duster with a stock build 727 ( 2500 rpm convertor ) and 3.23's out back. This car is a daily driver. 318 Motor from a 96 Dakota in real good used condition. Completely stock rotating assembly ( including pistons ). Stock heads got new seats, guides. Stock valves ( 1.92 and 1.60 ) were also in good condition. Had them refaced and back cut at 25*. 3 angle valve job got blended to the bowls with some miner bowl work. Roller cam was a Hughes SER0814ALN-10 grind. 110 LSA, installed straight up. .491" / .500" with stock 1.5 rockers. CR came out to 9.14 static with the head gaskets I chose. Intake = a 650 Edelbrock and Edelbrock air gap. Pretty free flowing cast iron exhaust manifolds in to a "Pypes" 2.5" "X" pipe exhaust with chambered mufflers. Plenty free flowing for a little motor. Great combination for my little Duster. Very driver friendly ( 2 grand Daughter chompin at the bit) and probably a low 15 second car near sea level.

View attachment 1715345828
Stock mag rocker ratio is 1.6.
 
Sorry, you are right. That would put the lifts at .523 / .533 respectively. 1.5 and 1.6 lift #'s are both listed on the cam card. Had a chance to give the cooling system a real test yesterday. Drove down to Phoenix where the temp was 100+ degrees. A/C on continuously. Did real good. No over heats, even in stop and go traffic - and the A/C will freeze your *** outa there!:steering:
 
did you have to mill the valve guides/pedestal (what ever they're called) for that .533 lift?
 
did you have to mill the valve guides/pedestal (what ever they're called) for that .533 lift?
Used completely stock valve train, including stock roller lifters ( which were in excellent shape ). Probably could have went with slightly shorter push rods, but didn't bother with this mild of a build. Rocker scrub across the valve tips was still ok.
 
Interesting.

I thought .520 was the accepted max lift before machine work.

I have a Lunati HR cam that is .517 at 1.6 rocker ratio and thought that was pushing it.
 
Interesting.

I thought .520 was the accepted max lift before machine work.

I have a Lunati HR cam that is .517 at 1.6 rocker ratio and thought that was pushing it.
Never heard of such a thing??? Way too many variables involved to make a statement like that.
 
Never heard of such a thing??? Way too many variables involved to make a statement like that.


there has to be a point where the factory casting will not support a given lift (and spring combo) and the guide bosses need to be milled.

you've never heard of that?
 
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