318 Cam Maybe Not

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I was interested in that Howard's cam, they're fairly local. Might have to rethink my choice AGAIN it's only an extra 50$ to my budget, this is my practice engine so I need to be somewhat happy till I can afford to do a proper 360 or 383 build. I'm basically doing the frieburger/dulchic cougar build. I need a new oil pan so I figured I tear it out and ring it and port the heads a bit and see what happens
 
stroked340 said:
I'd be more worried about blowing up that weakass 7 1/4..when you add more power..
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I'm not too hard on it. When I get around to that, I might have a 360 and 8 3/4 waiting in the wings. One reason I don't want to get too deep in a 318 build.
 
Browncar said:
I was interested in that Howard's cam, they're fairly local. Might have to rethink my choice AGAIN it's only an extra 50$ to my budget, this is my practice engine so I need to be somewhat happy till I can afford to do a proper 360 or 383 build. I'm basically doing the frieburger/dulchic cougar build. I need a new oil pan so I figured I tear it out and ring it and port the heads a bit and see what happens
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I got to thinking after reading through this thread, I have a half dozen cams I tested on my desktop dyno. I kept looking at the peak horsepower (usually at 5500 rpm). When was the last time I revved past 5500? We spend most of our time between idle and about 3000 rpm. I got in the charts and did some comparisons.
 
toolmanmike said:
I got to thinking after reading through this thread, I have a half dozen cams I tested on my desktop dyno. I kept looking at the peak horsepower (usually at 5500 rpm). When was the last time I revved past 5500? We spend most of our time between idle and about 3000 rpm. I got in the charts and did some comparisons.
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I'd be much more interested in that than top end. Clearly the weakness of the 318.
 
toolmanmike said:
Here's a quote from @moparmandan about a Comp he put in his Teen:

" COMP-Cams 20-220-3. 250/260 .432/.444
Took our 318 Scamp with stock bottom end around the block for its first shakedown this past weekend. 7.25 with 2.76 gears. Still did a peg leg burnout for half a block without even getting in it hard. Can't wait till we put the 8.8 in with 3.73 Trac loc and tweak the tune. This is gonna be fun. Cam seems too pull well off idle. Probably too small for a lot of people."
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To me that cam is about on par or slightly hotter than the stock 340 cam. Its about the same lift and duration @0.050" lift.

So if you think of the 4 main choices of the xe line 262,268,275,285 are all big step ups from stock 340 nevermind the stock 318 and 360 ones.
 
273 said:
To me that cam is about on par or slightly hotter than the stock 340 cam. Its about the same lift and duration @0.050" lift.

So if you think of the 4 main choices of the xe line 262,268,275,285 are all big step ups from stock 340 nevermind the stock 318 and 360 ones.
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That's why I'm concerned about throwing a cam in and have it perform worse than the stock cam. Wasted money possibly.
 
273 said:
To me that cam is about on par or slightly hotter than the stock 340 cam. Its about the same lift and duration @0.050" lift.

So if you think of the 4 main choices of the xe line 262,268,275,285 are all big step ups from stock 340 nevermind the stock 318 and 360 ones.
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The stock 340 cam is 268/276 .430/.444 It has 18° more intake duration and 16° more exhaust than the XE250H that Moparmandan used. The lift is about the same. I wish I had the @.050 specs on the 340 cam. May'be someone will chime in with them. The smaller the engine the less they can tolerate duration and still be mild enough on the street without a converter and/or gears. With a stock Teen and say a 4 barrel and dual exhaust I wouldn't go bigger than the XE262H. Do you happen to have the stock specs for the 318 and 360 cams? I don't right off hand. They were pretty anemic if I remember correctly but a 360 cam in a mild 318 is a good step up from what a few said that tried it. Any cam that's bigger than stock specs is a improvement as long as you don't go too far.
 
rustyfish said:
That's why I'm concerned about throwing a cam in and have it perform worse than the stock cam. Wasted money possibly.
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As long as you don't go too big especially if you don't want to mess with a converter and/or rear gear change. If you don't need to disassemble far enough to replace a timing chain and it runs ok now, you might want to just leave it the way it is.
 
toolmanmike said:
The stock 340 cam is 268/276 .430/.444 It has 18° more intake duration and 16° more exhaust than the XE250H that Moparmandan used. The lift is about the same. I wish I had the @.050 specs on the 340 cam. May'be someone will chime in with them. The smaller the engine the less they can tolerate duration and still be mild enough on the street without a converter and/or gears. With a stock Teen and say a 4 barrel and dual exhaust I wouldn't go bigger than the XE262H. Do you happen to have the stock specs for the 318 and 360 cams? I don't right off hand. They were pretty anemic if I remember correctly but a 360 cam in a mild 318 is a good step up from what a few said that tried it. Any cam that's bigger than stock specs is a improvement as long as you don't go too far.
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I think if anything I'll go with Moparmandan's suggestion. It's a nice inexpensive matched package. Did you say you had already run some sticks to see what had the best torque or were you going to do it?
 
rustyfish said:
I think if anything I'll go with Moparmandan's suggestion. It's a nice inexpensive matched package. Did you say you had already run some sticks to see what had the best torque or were you going to do it?
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Keep in mind, with the 7 1/4 peg leg and 2:76's it will be slightly disappointing from a standing start. Once it gets up into the power band of the cam a little, it will seem like a whole different car.

Once you do it, you'll want an 8 3/4 with a suregrip and a minimum 3;23.

I have a 318 in my Dart Sport. I installed a HE268 kit, double roller chain, 4v intake and carb with headers. I put 3:55's out back, and for a 318 it's a fun little car.
 
rustyfish said:
I think if anything I'll go with Moparmandan's suggestion. It's a nice inexpensive matched package. Did you say you had already run some sticks to see what had the best torque or were you going to do it?
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Yep, I ran a bunch of mild small block cams with similar specs. They were all about the same. I like that Howards cam I posted above.
 
Bad Sport said:
Keep in mind, with the 7 1/4 peg leg and 2:76's it will be slightly disappointing from a standing start. Once it gets up into the power band of the cam a little, it will seem like a whole different car.

Once you do it, you'll want an 8 3/4 with a suregrip and a minimum 3;23.

I have a 318 in my Dart Sport. I installed a HE268 kit, double roller chain, 4v intake and carb with headers. I put 3:55's out back, and for a 318 it's a fun little car.
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That's a good combination to go along with that 268 cam. A stock 318 couldn't handle it though, especially with the 2:76's. That XE250 H has 20° less duration and .040 less lift than the 268. It gets the duration well below the 220° guideline for a stock teen with a stock converter.
 
toolmanmike said:
A stock 318 couldn't handle it though
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Mine is completely stock other than the cam and other things I mentioned. It had 84,000 on the clock when I did the swap, never touched the short block or the heads other than to replace the head gaskets.
 
toolmanmike said:
A stock 318 couldn't handle it though,
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I meant a stock, unmodified. Stock intake and carb, exhaust manifolds, possibly single exhaust and a 2:76 rear gear. Although you haven't done anything to the short block or heads you have put together a winning package including cam that works well. Are you running a stock converter? If so did you have any tuning issues to make it idle and have plenty of vacuum for power brakes?
 
toolmanmike said:
Are you running a stock converter?
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Yep.

toolmanmike said:
If so did you have any tuning issues to make it idle and have plenty of vacuum for power brakes?
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Idles fine in drive at around 650 or so, brakes HA! that's another issue. They work the first time but if I hit them a second time in succession they harden up. Right around 13/14 inches of vacuum which is borderline.
 
Bad Sport said:
Yep.



Idles fine in drive at around 650 or so, brakes HA! that's another issue. They work the first time but if I hit them a second time in succession they harden up. Right around 13/14 inches of vacuum which is borderline.
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Bad Sport said:
Yep.



Idles fine in drive at around 650 or so, brakes HA! that's another issue. They work the first time but if I hit them a second time in succession they harden up. Right around 13/14 inches of vacuum which is borderline.
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I kinda wondered if that wouldn't be the case. That 268 is a powerful cam no doubt but i would say borderline too big for a 318. If you had a XE262H it might be closer to perfect for your combination.
 
toolmanmike said:
I kinda wondered if that wouldn't be the case. That 268 is a powerful cam no doubt but i would say borderline too big for a 318. If you had a XE262H it might be closer to perfect for your combination.
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When I first started looking at this, this is where I thought I'd go, XE262H. But for now with the drive line stock, milder is better. And if I end up breaking the 7 1/4 down the road, then I'll consider full on upgrades from there. Right now I just want to have a fun driver that I can pretty up as I go. Don't want to be one of those that doesn't drive it for 7 years.
 
rustyfish said:
When I first started looking at this, this is where I thought I'd go, XE262H. But for now with the drive line stock, milder is better. And if I end up breaking the 7 1/4 down the road, then I'll consider full on upgrades from there. Right now I just want to have a fun driver that I can pretty up as I go. Don't want to be one of those that doesn't drive it for 7 years.
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The 262 and the 268 just have a few degrees of duration and .006 and .010 of lift difference. Bad Sport could probably do with a milder cam. You need a bunch milder than that one. I do too.
 
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This is the Howards cam. Duration below 215° fast ramps. (probably a bit noisy) for the lift. "1400-4800 rpm. Smooth idle, very strong torque. " Worst case I would put it in and I would have to take it back out again. I don't hear many that have tried it though. It's not a mainstream cam though.
 
They do take advantage of the .903 lifter diameter. I agree it may be a little fast rate for an everyday driver. A little valve train noise, and somewhat harder on the valve train than the DEH Comp.
 
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