Another cam question 361

[qkcuda]

I have bought a 1966 Charger with a 361, automatic and 3.23 gears. It has stock exhaust manifolds and a stock 2 1/4 exhaust system into 2 inch tailpipes. It will have a Performer 383 intake, a 625 Street Demon spread bore type carburetor and MP electronic ignition. It has PS, PB, and factory A/C. I have an extra set of 2.76 rear gears sitting on the shelf. The car is not in my garage yet (long story) so I do not have access to do a compression test or assess the parts that are in it. I have driven it, and as far as I can tell the long block is all stock. Not even sure if the heads have ever been off, I assume they are still 516's.
My question is what would be a good cam to upgrade performance, especially torque? I am wondering if I have to be a little more conservative with the 361 versus a 383, kind of like a 318 versus a 340? My goal would be an honest 300 horsepower and as much torque as possible, which will cruise at 2000-2500 rpm (depending which gears I use) and get decent gas mileage. I just sold an 11 second street car, now I want a cruiser.

 

[440Coronet500]

Lower compression will call for an RV type cam grind. This will give you the low end torque your looking for. 440'

 

[Don Frelier]

A couple things:
1. I think the stock exhaust would be 2" not 2 1/4".
2. The stock manifolds are not real good but between 2,000 and 2,500 they will do.
3. Why are you planning to put a spread bore carb on a square style intake?

Keep the cam small with a wide lobe separation angle.
The small Summit cam is probably a good choice.
Don't change the gears.

 

[qkcuda]

Technically not a spreadbore, just small primaries like one. I figured it would be better for economy at cruise. Actually the manifold will accept either.

 

[qkcuda]

I was looking at the small summit cam. Here are three other candidates. (sorry a bit hard to read, click on them to make larger)

 

[Darter6]

1966 361. 9.0 to 1,compression test 125 to 155 psi,valve lift .392 duration 252*.
The 383 of 1966 shows(4bbl) lift at.435 duration at 256*I and 260*E. From the 1966 service manual.

 

[qkcuda]

Thanks, I only have a 68 service manual at home. I figured the 361 would have the same cam as the 383 2 barrel, which was the second cam you listed. I guess not.

1966 361. 9.0 to 1,compression test 125 to 155 psi,valve lift .392 duration 252*.
The 383 of 1966 shows(4bbl) lift at.435 duration at 256*I and 260*E. From the 1966 service manual.

 

[Darter6]

The Mopar Performance repo 383 HP cam shows specs at lift .450/.458 duration 268*/284* with a centerline of 115*
The Voodoo that is close to those specs should work well.
Yeah, The 4bbl of 66 was a bit hotter.
The 361 and 383 were so close most never knew what engine they had.
I have a 1963 and a 66 361. I plan on building the better of the two as far as wear goes.

 

[Darter6]

The 66 service manual shows that the 361 and 383 2bbl shared the same cam.
The 383 had a .2 more compression over the 361.

 

[qkcuda]

The 66 service manual shows that the 361 and 383 2bbl shared the same cam.
The 383 had a .2 more compression over the 361.

So even the smallest of those cams would be an improvement.

 

[qkcuda]

The Mopar Performance repo 383 HP cam shows specs at lift .450/.458 duration 268*/284* with a centerline of 115*
The Voodoo that is close to those specs should work well.
Yeah, The 4bbl of 66 was a bit hotter.
The 361 and 383 were so close most never knew what engine they had.
I have a 1963 and a 66 361. I plan on building the better of the two as far as wear goes.

The specs on the Summit cam are almost the same. I found a cam with the exact same specs as the Summit cam in a very old TRW catalog that I had at home.

 

[66Satellite47]

The Voodoo cams look good, I'd go for the larger one, a bit more lift helps. Also if you stick with stock exhaust manifolds, I'd look for a set of the HP style, '70?

 

[rumblefish360]

I would use a intake duration @.050 of no larger than 216 and only with the stock size tire. Which is small.
210 would be good with those rear gears.

If you have work on small block 340’s before, I would treat the 361 exactly the same despite the differences. The bore and stroke are very similar. 3.31. VS 3.38, 4.04 VS 4.120, short stroke, big bore.....

 

[qkcuda]

I would use a intake duration @.050 of no larger than 216 and only with the stock size tire. Which is small.
210 would be good with those rear gears.

If you have work on small block 340’s before, I would treat the 361 exactly the same despite the differences. The bore and stroke are very similar. 3.31. VS 3.38, 4.04 VS 4.120, short stroke, big bore.....

I kind of like the description of the Voodoo 701 cam too, good vacuum, works with PS, PB and A/C. The 1000-5500 rev range sounds good too. The tires are 27 inches tall, which gives me around 2500 rpm at 60 with the 3.23's.

Yes I have worked on every size of small block they made, but that was in my racing days, and economy was not one of my goals.

 

[Don Frelier]

I agree with small primaries, the original AFB on my 66 383 had the small primaries and it had terrific throttle response.
68/69 Hi performance manifolds are pretty common and occasionally a nice set shows up here.

 

[rumblefish360]

The 1000-5500 rev range sounds good too. The tires are 27 inches tall, which gives me around 2500 rpm at 60 with the 3.23's.

Yes I have worked on every size of small block they made, but that was in my racing days, and economy was not one of my goals.

I used this Crane split Hyd. in a 318 a long time ago. It was very good and has the same description. My P/B worked excellent. I also had 3.23 gears on stock sized tires on a low compression engine/904 trans, headers, 600-4bbl. NO converter change needed. Good cheap thrills. The lil’teen ran high 14’s. 19 mpg’s Hwy.

https://www.summitracing.com/parts/crn-693941/make/dodge
216/228-.454/.480-112
The Lunati would be chooses now. 1.6 rockers employed.

 

[wyrmrider]

Well let's see
stock compression was listed as 9.2:1 but more likely low 8s
so we want to close the intake early to build dynamic compression and also to the cruiser axles etc etc
stock exhaust does not like overlap so no narrow thumper bullshit , can use slightly narrower lca on very short cams
so that comes down to shelf cams

Lunati 700 or 701 for cams in the 256 range best choices
10200700 253 208 .454 VOODOO best shelf cam 112LCA

Lunati 701 256/262 213/220 .454/.475 108 LCA you do not want the narrow LCA increased overlap
Engle K-52 (ground to order so you pick the LCA and ex duration)
Engle K-52 262 209 .458 can be paired with K54 ex or a lobe with same as K-52 lift and less acceleration which is fine for exhaust

................................006........,050.......lift ...........LCA.. Intake Centerline These are much bigger cams than the above
Howard 721141-08 267 267 220 220 .506 .506 108 104
Howard 721941-12 271 281 224 234 .518 .543 112 108
both are going to get the intake closed about the same place so I'd pick the one with the less overlap


http://www.bulltear.com/forums/showthread.php?17928-AMC-360-build-for-low-end-torque Discusses Engle

For the Howards I'd draw a big circle and map the centerlines and plot the lobe centers and figure out where the intakes close or Howard will send you the timings with an inquiry

IMHO Jones has the best lobe in this class and again you and he pick the exhaust and LCA- which with jones is a result not an input
http://jonescams.com/street-performance/
I built a lot of 361 and 413 truck and industrial motors We worked with the late Bill Jenks at Potvin/ Moon cams and came up with a [email protected] with 430 lift
yes that's short and quick did lots of dyno testing You are not moving a City Bus (City Bus Companies paid for the R and D and Chrysler under warranties)
so you do not have to go that short
I runJones Cam in my 73 New Yorker and have had that motor in a motorhome- great cam I just saw another write up and I'l post it

ok here are excerpts tried to find comparable cu in
Jones 256 202 120 .305 .461 50% fatter @.275 than DC 260 (269 @.006)

H64307-66299 256/264 202/208 .307/299 .491/478 w/1.6 111 I109 ex 114

07-20 38 10 @.050 3 0verlap per Shawn Watson

simillar stroke 3.574 a sMopar 360 but shorter rod

IO same stock 401 IC 5 later stock ex opens and closes 4 degrees earlier than stock

Custom Mike Jones cam, 202 max area intake lobe Jones designed for Chrysler 440s.

More area under the curve than a longer-duration cam like a Comp 268, extremely fat at 250-275 lift, about 50% more than a Mopar Performance 260 cam.

Fast acting, but the nose is big and reduces wear. 521 valve lift with 1.7 Scorpion Rockers. Over 400TQ from 3400 to 4600 and over 375TQ from 2800 to 5000 in AMC 360.

Longer duration style 208 (264) exhaust lobe for high-RPM power,

extrapolating it'll make 350HP to 5500.

 

[qkcuda]

FWIW the 701 is ground on 112 lobe centers also, but installed at 108. I tend to agree though, that the shorter cam may be the better choice, plus the 454 lift will cause less issues with guide clearance if I don't end up removing the heads, and anything over 454 lift on those 516's is going to be wasted effort anyway. I have to try to resist the temptation to go bigger, my drag racing roots are showing.

 

[Darter6]

^^^^^^I understand.It's hard to calm down the Gearhead in us...

 

[rumblefish360]

The 112 will idle nice and smooth and then some when warmed up. I think the 112 & + centerline cams are perfect for a absolute driver with no big muscular intentions or signals for the world at large to pick up on.

On one build I did, (absolute driver that even nasty in laws could not complain about, and thank the Lord I don’t have that problem!) I used an H piped exhaust with long case mufflers. IIRC, I think they were the Dyno Max Sound FX.
https://www.summitracing.com/parts/wlk-18280/year/1979/make/dodge/model/magnum
Not to great for power since they neck down inside but church mouse quite they almost were. Excellent on the inside for a zero drone sound.

Dave Vizard has some interesting thoughts on this subject.

The car still had good power well above a normal 4bbl. optioned car would.