It is. It will also take the 901 spring which is cheap and you can even still use the stock rockers.
318 Cam Maybe Not
- Thread starter Rustyfish
- Start date
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It is. It will also take the 901 spring which is cheap and you can even still use the stock rockers.
I'm used to a little clatter with my 273. It's kinda cool!
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And I will agree, the more I look at the DEH specs the more I like it.
Since some were originally solids, that's kinda expected. lol
nm9stheham
Well-Known Member
I'll add my vote for this one. The OP is street cruising.... it would be foolish to make the low RPM's bog by going larger on duration. And yes on the moderate rate ramps to keep things easy on the valvetrain.
If you lool at the 0.050" spexs both 340 and xe250h cams are similar. Think of the xe250h as a fast ramp tighter LSA version of the 340 cam.
Im sure the 360 cam in a 318 gives a nice little bump but I think its to conservative.
I totally agree with you when you say idle to 3500 is a very important powerband for a street engine. In normal driving my tach rarely goes above 2000 rpm.
And especially if you got everything going against you eg. Heavy car, small engine, high gear, low stall etc..
But I think people shouldn't just go super conservative either.
Take the two mopar magnum create engines which I basically own both. 300 has stock cam and the 380 has a fairly stout cam.
I got magazine dyno of both below.
*note the 300hp one does start to 3000 rpm but looking at the curve both are probably the same or close at 2500 rpm.
I got the 380hp in a 68 Valiant with 2800 stall, 2.96 gears and 27" tires with an effective gear ratio of 2.63.
And I dont exactly have 300hp create but a 98 5.9 jeep which is pretty much the same besides 4bbl and headers. Its heavier and 3.73 gears and 32" tires with an effective gear ratio of 2.80.
If you compare the two dyno charts the 380hp engine meets or beats the 300hp from 2500 rpm plus except one point. Which is the peak torque of the 300hp has a slight advantage.
Driving both the valaint is a little soft under 2000 rpm. Which I blame more om the intake, single plane M1 then the cam.
Theres a dyno shoot out between the M1 and Airgap an the airgap made 20-30+ lbs-ft all over the bottom end.
Where the 5.9 jeep pulls hard from idle and if weighed the same as the Valiant would definitely be the better under 2500 rpm choice.
But doesn't mean the stock cam is the winner for a daily driver or down low performance. Theres a big cam difference between the two. Lots of choices, Im sure something like a 265 or 268 cam would give 90% of top and bottom. Basically having your cake and eatting to.
I think the trick is finding the cam thats gonna give you the most top end with out effect bottom end too much. Or a compromise that works for you.
The modified Hp and Tq is eddy heads and bigger cam something like a 275
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I really never gave an option to the OP about what cam to get. He ask was it worth it and I said yes, and gave an example of a basic combo 4bbl headers and xe262h = 282 hp.
Showing whats possible out of a stock long block 318.
I usually dont give a cam recommendation.
Theres no shortage of that. I like to give them info so they can pick their own cam.
Generally Id say no more than xe262h for 273/318 and xe268h 340/360 unless deep gears and stall is in the cards. But really depends on peoples level of compromise.
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With your parts listed and a mild pocket port on your 302 heads and with 1.88 and 1.60 stock 360 valves and the 255DEH I recommended installed at 106 and headers, Desktop Dyno says 323 HP and 360 LB FT torque. I called compression 9:1 and that's probably close with the 302 heads.
Some say the program is pretty liberal but I think it's close. What people do not think of is, Desktop Dyno uses SAE gross HP figures and not net.
That should make for a snappy little 318.
Rustyfish
Member
Thanks for that Rusty, but that combo gets me in trouble with fitment. I have power steering and column shift so headers are unlikely.
Why? I put them in my car. Just had to dent one of the tubes slightly to clear the steering knuckle.
Deh cams are designed to work with manifolds.
Rustyfish
Member
What headers did you use? Only seen one set that could get through that and they were semi custom
Cheap Summit headers.
Rustyfish
Member
I had column shift when I installed them, and yes power steering. It required flipping the bar that the linkage hooked to, but that was it.
I have since removed it and installed a Cheetah.
I'm not up to speed on what you are working on, mine is a 74 Dart Sport.
Rustyfish
Member
Cheetah?
I guess "cheap" is relative. The least expensive ones for my application on Summit are $450.
I guess "cheap" is relative. The least expensive ones for my application on Summit are $450.
Rustyfish
Member
'66 barracuda
I see someone at least mentioned the Comp 256 in passing.
When I was doing a lot of SBM cam research, I ran a whole bunch of the comp ones on their simulator app with the closest to my stock roller LA spec as I could program.
The XE256 vs the XE262 came out with the 262 only being 10HP prak higher in a MUCH narrower peak. The 256 had a whole lot more torque under the much broader HP curve.
To me that said 256 MUCH better street cam while only giving up 10 HP.
Did the OP say he had a stock LA 318 cam?
IIRC the lift is .399-.400.
The cams I did research on were all in the .450-ish and under range.
That should be a very noticeable improvement.
When I was doing a lot of SBM cam research, I ran a whole bunch of the comp ones on their simulator app with the closest to my stock roller LA spec as I could program.
The XE256 vs the XE262 came out with the 262 only being 10HP prak higher in a MUCH narrower peak. The 256 had a whole lot more torque under the much broader HP curve.
To me that said 256 MUCH better street cam while only giving up 10 HP.
Did the OP say he had a stock LA 318 cam?
IIRC the lift is .399-.400.
The cams I did research on were all in the .450-ish and under range.
That should be a very noticeable improvement.
dartfever
Well-Known Member
@ .050" specs for the stock 340 cam are 208 intake, 214 exhaust.
Then run the early 340 manifolds, OR the large outlet Dakota Magnum manifolds. I am pretty sure they will fit.
megavites
Well-Known Member
I wound up going with the Whiplash cam. It retains the low end torque and the idle I was looking for.
It no slouch on the top end either.
It no slouch on the top end either.
Exactly why I like recommending the DEH grinds from Comp. They are ground in a similar fashion and are not very expensive.
To the OP, don't fret yourself with details. Will this work with manifolds? Is this one right? Is this one wrong? A camshaft doesn't know if it's breathing through headers or manifolds. Will one work better with manifolds or headers? Probably, but are you looking for every ounce of HP? I doubt it. You will drive yourself crazy with details. For your application, all you need is a cam with no more than about 226 @ .050 duration (that's actually gettin a little big) and ground on either a 108 or 110 LSA. I would keep lift conservative, so you can continue to use stock rockers. So that means IMO .470 and less. Then you can also take advantage of inexpensive valve springs like Comp's 901 spring. You can do this all on an extreme budget if you stay away from snappy names like Thumpr and Whiplash.........not that those cams don't work, they do, but there are cams that can do just as well for less, so why not save the money?
One last note, there's no need to drive yourself insane on a decision. Just stick with the guidelines I posted and you will win. There's no need to try to micromanage this. You're not lookin for every last HP you can find. All you want is something snappy and reliable. You've been given that info already. Use it.
No need to make this difficult, because it is very simple.
That’s the biggest problem.
Fretting over the possible 5hp loss from a bad choice.
And such....
Fretting over the possible 5hp loss from a bad choice.
And such....
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