small block 360 cam selection

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yellow rose said:
IIRC Edelbrock changed the Venturi or something (maybe the booster...I didn't pay a whole lot of attention when it was being discussed) on the 750 and it makes getting the fuel curve in shape a bit of a buggar.

Now that I typed that, I *THINK* they changed the booster.

Either way, it can be more difficult to tune.
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Are you thinking of the avs2 with the annular boosters, or something else?
 
The booster issue is all the carbs have the same exact booster in the same exact place over the venturi. When you look at a stock AFB or AVS, take note to the boosters place over-in the venturi. There all places in different spots. Another thing is all the booster parts in the carb are the same. Take the EDELBROCK poster out and compare it to a few other Carter boosters. You will note the amount of holes, where there placed and how big the holes are. The last thing is the 750 secondary booster has a limited orifice to let fuel up into the ring over the booster which limits jetting to that tubes size. Just cut the bottom off and you should be good to go.
 
texas360 said:
i have a 360 with stock bottom end, 596 heads and Weind stealth intake.. gonna run eddy 750 and not sure on distributor yet cause i haven't found one... it will have long tubes and be in a 3600 lb car with reverse manual transmission with 2500 stall and 3.55 gears.. looking for suggestions for a decent street cam with a nice thumpy choppy idle, still has enough vacuum for brakes but has some decent power. Engine is my profile photo
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Ottmundr said:
You may consider something like this.
I have the Lunati 10200701 in my 318, and wouldn't use it again.
There are a few here withe 703. @72bluNblu is running the 10200704.
If I go with a hydraulic flat tappet, I'd go with the 703 listed below.
Voodoo Hydraulic Flat Tappet Cam - Chrysler 273-360 268/276

I am more likely to go with the solid, linked below. I've got 4.10 gears, 2400 stall (I know the TC doesn't match real well, being 100 less than the cam manufacturer recommends but I did talk with them and they said it'd work ok. I want better than ok but it's what I have right now). 308 heads and an RPM Airgap, I'd like to run a 750 AVS2 on this motor, but I have a 650 Holley sitting around, so I may just cheap out and use that instead. Doug's D453 headers. I'll probably just slap in the Unilite dizzy I have sitting on a shelf. I doubt I'll be using the stock bottom end, but I'll stick with the 3.58 stroke. In the next couple of months, the block is going in to the machine shop.
Voodoo Solid Flat Tappet Cam - Chrysler 273-360 264/272
Click to expand...

I run the 100200704 in my Duster, which is a 9.8:1 340 with a Holley 750 DP, Edelbrock AirGap, Doug’s D453’s and ported 308 heads flowing 264 CFM @.500 lift. I’m now running 4:30 gears in the back with a T56 manual.

That cam needs close to 10:1 for compression and at least 3.91 gears. I ran mine with 3.55’s for awhile and it made taking off a little rough for a daily driver. It was fine if I was driving it like I stole it but in traffic it took a little clutch slip. With 4.30’s it’s awesome but then you need an overdrive gear for the freeway. Vacuum at idle is like 10-11, I run manual disks and it’s a little low for power brakes IMO. It’s super fun for a weekend car but it takes a little work as a daily driver especially in traffic.

I think the 100200703 would be a better choice based on the engine specs so far. Better idle, better vacuum, won’t take as much gear, it’ll work with lower compression and stock heads better, etc. I like the 704 but I don’t think it’s a good fit for the OP’s combo. That’s just my opinion, I’m not really an engine builder or big tuning guy or anything. Just know enough to get myself in trouble. Like running a cam a step too big and compression too high to be able to go to a smaller cam and still run on 91 octane and installing a 6 speed to run the gears I need and still have a freeway capable car kinda trouble.

idles mean though :D
 
i remember when the xe-268 came out...number one selling cam for 3 years in everything from 383 mopar to 350 chev. but that was all marketing like every new performance piece is. But have a look at the numbers from comp's website for a warm Dart headed ( I know) chev sm blk.
The strong bottom end little xe-256 really shines for street only applications.It's a shame we don't see figures at 800 rpm. and it actually holds its' own past 5000rpm
YR...i am in full agreement with you on the modern converters but the op asked for a cam recommendation. At 8.1 compression i can't suggest anything with much duration.Even 218 - 220 might be pushing it on the intake.
And like you said...i may be wrong.

xe256.JPG


xe268.JPG
 
Wyrmrider said:
no 268 anything, no 270
his build and what he wants
why keep suggesting big cams
let's see the compression but we know what it's going to be
no matter what converter he needs big fat torque curve
he can afford to give up no grunt on the lower end with those gears and tires
you note the 250 lunati has about the same lift as the 268 or 270 comp but closing the intake 10 degrees earlier makes a lot of difference
the 256 howards closes the intake within degree of the lunati as it is on a narrower LCA
256 comp is a girlie cam
the lunati and especially the Howrds require careful attention to detail- but then they all do
Click to expand...
cylinder pressure changes about 1.5psi per degree Ica; so 10 degrees later is about 15psi. On an engine that currently cranks 145, the new cam will crank close to 130psi, which in my view with a 2600TC is gonna be a bit,scratch that, a lot lazy until around 3500rpm, which with 3.55s and 27s is 31mph.
To get rid of that laziness you got one choice which is more static compression ratio.
Or you can just get a higher stall TC, and not operate in that soft zone.
However, the TC does not solve the laziness afterwards. Without matching Dcr, it will still be lazier than it would be with the correct pressure. Thankfully, at the power peak the laziness is down to perhaps 4% powerloss. On a 300hp engine, that is ~12hp or ~ one cam size,lol.
Like WormRider said
Wyrmrider said:
imho choppy idle and power curve does not compute with a low compression motor
Click to expand...
And post 15 is just chock full of great remarks
yellow rose said:
If the OP wants a 2500 converter than that's ok. But when I see what he's doing that pops up as a big red flag. The car is heavy, has a fairly tall gear and isn't making a bunch of torque. So handicap it with no converter and then buy a cam to try and cover that up. Then it will be a ***** to get the tune up correct so it doesn't rattle its brains out trying to get it to move, and every time you get to tip in it does the same.
So you retard the timing (power loss) and then to get the rattle out at tip in you end up unplugging the vacuum advance (another power loss and the fuel mileage goes straight in the crapper) and where did the OP end up? With a confused, hard to tune, no fun to drive fuel gulping pig.
Click to expand...

The bottom line is this; It's all about the combo; everything is connected to everything else
 
texas360 said:
Isn't 3500 a bit much for a street cruiser?
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No. Here's "why". The stock 340 converter was "about" 1000 RPM over stock. Guess what stock stall is? 1500-1700 RPM. That's one of Chrysler's trademarks. They "really got it" when it came to converter stall speed. They knew how to get the mass of a car up to speed quickly and make it feel snappy. So that puts the stock 340 converter stall speed "somewhere" around 2500-2700 RPM. And that was "back then" when converter technology was in its infancy. Today, you can have a custom converter built that will lock up plenty good enough to ride around town, on the highway, "whatever", get decent mileage, not have that "slipping transmission" sensation converters of yesteryear had, BUT flash to 5000 RPM "if that's what you want. I know that's not what you want, but it's what you will need in order to have a "performance" Chrysler converter. Of course, you don't need to flash to 5000 RPM, but 3200-3600 is a GREAT place to be. With modern converter technology, the converter does not have to see its flash stall to lock up enough to pull the car down the road with minimal slippage. That's because at part throttle, the converter is "tight". Now, you have to actually TELL the converter company this is what you want, but they will make it happen. If I ever build another automatic street car, It's probably going to have a 3800-4200 converter, but I won't run a 3.55 either. More like a 4.30 which would be a better match. You could even stand a 3.73-4.10. While I know mileage would suffer, that car could be blindingly quick for a mild street car with smoe more gear.
 
Oh, yeah, one more thing; 8/1 Scr was too low even with the stock 2bbl cam. and putting the 268 in the 8/1 engines with 3.23 gears, IDK who dreamed that up. I'm guessing the advertising department had a hand in that. Anyway, that's why the 340 got the rep. and the 360 got the rap.
GeeWhiz, my LawnBoy 2-stroke lawnmower has 7/1Scr, and won't cut anything past 3 day growth. Then I have to roll out the big boy Briggs OHV. I love that old LB. It's quiet, lightweight, my wife finds it easy to push and vibration free, if you get my meaning. But the head is integral with the cylinder, so can't mill it, and the only piston available is the stock one. So.......7/1 it will stay.
But when you consider that a snotty cam in the 8/1 360 will need a TC and probably gears, then for less money you can pop the Scr up to whatever you need, and probably still use the 2600 and 3.55s........ maybe even with whatever cam is in it; which is sure to have more low-rpm torque than anything you put into it.
To whit; a 2800TC in a stock long-block smoggerteen-4bbl, with an A998 and 4.30s, was a big-ol' bag of fun, in my 3650 Barracuda; me in it. Was it fast?
Fast compared to what?
Sure it was faster than the 2bbl same engine with a 904 and 2.76s, you bet it was. But the stocker was insanely boring, compared to the A998/4.30s, which was insanely amusing.First gear was all done by 5000=32mph. Second by 58, Third by 89mph. It cruised at 50=2670 @ zero-slip. With 4.30s you'd never have thought that you were driving a 3650 pound tank(me in it). Gears are the great equalizer.
Need I mention passing-gear? ! lol; there was none, cuz top of second was 58 mph, and a smoggerteen at 5000 with the factory cam was done a long, long, time ago.
 
Last edited:
UD Harold designed both the comp xe line and the MOPAR Lunati Voodoo line
here" what he says
"The Mopar VooDoos are true Chrysler profiles, designed for the .904" tappets. "
"That 213/.454" profile is about 5 or 6 degrees fatter at .200 than the Chevrolet one."

5 or 6 degrees at 200 is huge- you can feel it
The comp xe lobes were designed after General Kenetics and before Ultradyne and the Lunati Voodoo Mopar hydraulic lobes after Ultradyne
anyone think that Harold did not learn anything over the years. The Lunati lobes are more modern than the xe lobes- which are much more modern than the H (270h) lobes
Simple as that
from another thread Harold gives more on the "213/454 profile he mentions above
"60400 250/256@ seat 208/[email protected] .454"/.454" valve lift, 112 LSA
60401 256/262 213/220 .454'/.475" 112 LSA."

"The 60401 makes about 19" of vacuum in a 360, so you should have plenty in a 408."
UDHarold"

Stan Weiss adds FYI
" for a flat tappet max velocity is around

.842" - 0.00717 inch / deg

.875" - 0.00746 inch / deg

.904" - 0.00771 inch / deg"

Stan
 
Wyrmrider said:
UD Harold (RIP) designed both the comp xe line and the MOPAR Lunati Voodoo line
here" what he says
"The Mopar VooDoos are true Chrysler profiles, designed for the .904" tappets. "
"That 213/.454" profile is about 5 or 6 degrees fatter at .200 than the Chevrolet one."

5 or 6 degrees at 200 is huge- you can feel it
The comp xe lobes were designed after General Kenetics and before Ultradyne and the Lunati Voodoo Mopar hydraulic lobes after Ultradyne
anyone think that Harold (RIP) did not learn anything over the years. The Lunati lobes are more modern than the xe lobes- which are much more modern than the H (270h) lobes
Simple as that
from another thread Harold (RIP) gives more on the "213/454 profile he mentions above
"60400 250/256@ seat 208/[email protected] .454"/.454" valve lift, 112 LSA
60401 256/262 213/220 .454'/.475" 112 LSA."

"The 60401 makes about 19" of vacuum in a 360, so you should have plenty in a 408."
UDHarold (RIP)"

Stan Weiss adds FYI
" for a flat tappet max velocity is around

.842" - 0.00717 inch / deg

.875" - 0.00746 inch / deg

.904" - 0.00771 inch / deg"

Stan
Click to expand...

There, I fixed it for you. Harold (RIP) was one smart man. I used to run General Kenetix cams in my Chevelle race car in and shortly after high school All the guys laughed. Until they saw my tail lights.
 
u got that right RRR we ran their Mushroom in the trans am car
Then went to Engle- why the factory switched their R&D $$$ IDK
 
Wyrmrider said:
UD Harold designed both the comp xe line and the MOPAR Lunati Voodoo line
here" what he says
"The Mopar VooDoos are true Chrysler profiles, designed for the .904" tappets. "
"That 213/.454" profile is about 5 or 6 degrees fatter at .200 than the Chevrolet one."

5 or 6 degrees at 200 is huge- you can feel it
The comp xe lobes were designed after General Kenetics and before Ultradyne and the Lunati Voodoo Mopar hydraulic lobes after Ultradyne
anyone think that Harold did not learn anything over the years. The Lunati lobes are more modern than the xe lobes- which are much more modern than the H (270h) lobes
Simple as that
from another thread Harold gives more on the "213/454 profile he mentions above
"60400 250/256@ seat 208/[email protected] .454"/.454" valve lift, 112 LSA
60401 256/262 213/220 .454'/.475" 112 LSA."

"The 60401 makes about 19" of vacuum in a 360, so you should have plenty in a 408."
UDHarold"

Stan Weiss adds FYI
" for a flat tappet max velocity is around

.842" - 0.00717 inch / deg

.875" - 0.00746 inch / deg

.904" - 0.00771 inch / deg"

Stan
Click to expand...

Harold never had anything to do with the comp xe lobes.he would roll over in his grave at this bullshit.
 
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