318 cam shaft selection/upgrade for stock engine

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RustyRatRod said:
No, That's not a VooDoo grind. The VooDoo grinds are split pattern cams, which I believe will work better.
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How about this one

Brand:Lunati

Manufacturer's Part Number:10200701LK

Part Type:Camshaft Kits

Product Line:Lunati Voodoo Cam and Lifter Kits

Summit Racing Part Number:LUN-10200701LK

UPC:788120732703

Cam Style:Hydraulic flat tappet

Basic Operating RPM Range:1,000-5,500

Intake Duration at 050 inch Lift:213

Exhaust Duration at 050 inch Lift:220

Duration at 050 inch Lift:213 int./220 exh.

Advertised Intake Duration:256

Advertised Exhaust Duration:262

Advertised Duration:256 int./262 exh.

Intake Valve Lift with Factory Rocker Arm Ratio:0.454 in.

Exhaust Valve Lift with Factory Rocker Arm Ratio:0.475 in.

Valve Lift with Factory Rocker Arm Ratio:0.454 int./0.475 exh.

Lobe Separation (degrees):112

https://m.summitracing.com/parts/lu...se1-_-lunati&gclid=CI3uqYritNMCFdS6wAodYaUD2A
 
273 said:
I'd just run stock 340 cam.
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I ran a stock 340 cam with Rhoades lifters in a 72 318 block with 10.5 forged pistons and 360 heads and Holley 600 vac secondary carb and got 22.5" Hg at idle and 17.75 MPG highway with 2.76 gears in a 68 Barracuda....

I had 24" Hg at idle with stock 318 heads, but it had too much compression and would detonate, I had to lower the compression a bit with 360 heads and it was fine....
 
toolmanmike said:
No one around has a old Crane book. Too bad. We could have some old numbers reground and make a fortune. I hope someone comes up with some old info. I managed a speed shop in the 70's and don't remember many Crane cams with that combo. Many cams back then were heavy on the duration side and low lift.
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You're right on the standard cams of the day; hot rodders have not changed: MORE HP OR DIE!!! LOL But I used an HE series cam that I bought in 1974 and it worked like I described, and used it because my first performance build was in the wake of the oil embargo; I was still traveling around with 5 gallons of gas in the back 'cuz sometimes, you just could not find a station with gas. I still have the cam card.

Actually, cams like the VooDoo are sort of the modern incarnations of that type of cam profile. The end ramps are different though. Nothing is new under the sun....
 
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AJ/FormS said:
Wait!
221@050 and 248 advertised? that's 27* from seated to .050. That is the fastest FTH I have ever seen. What's the PN?
I just gotta have one of those. Every teener should have one of those.
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AJ, it's [email protected] and 248 advertised, that makes it 37* from seated to .050. and it makes 16" of vacuum
 
d1970 said:
AJ, it's [email protected] and 248 advertised, that makes it 37* from seated to .050. and it makes 16" of vacuum
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That's still amazingly steep (too steep); mid-40's degrees difference between advertised and .050" duration is normal for a steep hydraulic flat tappet cam ramp. (Like the VooDoo or XE.)

JEGS shows 221* at .050" but that has to be wrong. It is almost certain to be in the low 200's or even high 190's duration at .050" TAPPET lift, considering the 248* intake advertised duration and intake valve lift of .410". MP cam ramps are not typically the steepest around.

Plus, if anyone measures a cam .050" VALVE lift, THAT number is going to be a lot shorter than .050" TAPPET lift. But 'at the valve' is not the standard for .050" lift numbers.
Camshaft Choice - Camshaft Specifications - Guidelines - Hot Rod Magazine
 
JEGS shows 221* at .050" but that has to be wrong. It is almost certain to be in the low 200's or even high 190's duration at .050" TAPPET lift, considering the 248* intake advertised duration and intake valve lift of .410". MP cam ramps are not typically the steepest around.

chart (3).gif
 
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Gotcha and thanks very much; I was looking for something like that. Where is that from? The source document may explain how they measure .050" lift.

I am willing to bet a bunch that the MP .050" numbers are a .050" valve lift, which would be at .033" tappet lift. Other similar cams are listed below for Adv duration/.050" tappet lift duration/difference:
Crane H-248-2 248/192/56* (softer ramps)
Lunati Voodoo 253/208/45* (fast ramps)
Comp XE 256/212/44* (fast ramps)
Racer Brown EH-4 250/200/50* ('kinda' fast ramps)

Regardless, the MP is heading in the right direction for a cam for the vacuum the OP wants...'cept for the 110 LSA.
 
Thanks, I never can find that site. It does not say how the .050" is measured that I can see.
 
Yup. That's a goodun.

MObarracuda said:
How about this one

Brand:Lunati

Manufacturer's Part Number:10200701LK

Part Type:Camshaft Kits

Product Line:Lunati Voodoo Cam and Lifter Kits

Summit Racing Part Number:LUN-10200701LK

UPC:788120732703

Cam Style:Hydraulic flat tappet

Basic Operating RPM Range:1,000-5,500

Intake Duration at 050 inch Lift:213

Exhaust Duration at 050 inch Lift:220

Duration at 050 inch Lift:213 int./220 exh.

Advertised Intake Duration:256

Advertised Exhaust Duration:262

Advertised Duration:256 int./262 exh.

Intake Valve Lift with Factory Rocker Arm Ratio:0.454 in.

Exhaust Valve Lift with Factory Rocker Arm Ratio:0.475 in.

Valve Lift with Factory Rocker Arm Ratio:0.454 int./0.475 exh.

Lobe Separation (degrees):112

https://m.summitracing.com/parts/lu...se1-_-lunati&gclid=CI3uqYritNMCFdS6wAodYaUD2A
Click to expand...
 
273 said:
I'd just run stock 340 cam.
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It would be "ok". The reason I stopped recommending it has been covered in the posts previous to this. No one really knows what the specs "are" for that cam. In fact, I have measured more than one and gotten something different. Quality control? Proprietary grinding? Operator error? I am FAR from perfect, but since I have friends who have had similar results, I sorta think operator error ain't it.
 
Say Moby, what are you putting this into?
If you are sticking to the high vacuum thinking the booster needs 18", you may be cheating yourself from some extra power.
See, the big-cam engine may idle with a low vacuum, but you don't drive the car at idle! You can pick a cam with only a little lower idle vacuum, but pops right up as soon as the engine hits say 1800rpm,the typical stall speed. So by the time you are 1 car length out of the gate, the booster is fully charged. And if the check valve is working right, and the booster is working right, it will store plenty of vacuum, to provide plenty of assist.
So, depending on your current cylinder pressure, you may be able to move up a bit in camming. Not much room tho with the stock compression ratio and heads.
 
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I have power brakes. They work. I'm running the lunati 10200701 in my 318 with a performer manifold and 600 cfm carb I am happy so far. The bad is that I have yet to install my ministarter, 302 heads, d453 headers and better gearing than 2.76. In spite of that, it's nice.

Go here. (It should be linked to the welcome wagon forum and mandatory reading.)
RustyRatRod's Guide To Hot Rod Bliss
 
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AJ/FormS said:
If you are sticking to the high vacuum thinking the booster needs 18", you may be cheating yourself from some extra power.
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That is eventually the question that was going to come up.... why 18" of vacuum? Where does that number come from? It is pretty high....
 
AJ/FormS said:
Say Moby, what are you putting this into?
If you are sticking to the high vacuum thinking the booster needs 18", you may be cheating yourself from some extra power.
See, the big-cam engine may idle with a low vacuum, but you don't drive the car at idle! You can pick a cam with only a little lower idle vacuum, but pops right up as soon as the engine hits say 1800rpm,the typical stall speed. So by the time you are 1 car length out of the gate, the booster is fully charged. And if the check valve is working right, and the booster is working right, it will store plenty of vacuum, to provide plenty of assist.
So, depending on your current cylinder pressure, you may be able to move up a bit in camming. Not much room tho with the stock compression ratio and heads.
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What???? That is funny you call me Moby! Good point on the vacuum at 1800 rpm
 
nm9stheham said:
That is eventually the question that was going to come up.... why 18" of vacuum? Where does that number come from? It is pretty high....
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I work for Cardone (nations largest family owned auto part reman company) and had my booster rebuilt by my company. The Manager of the custom rebuild department told me the small diameter boosters need 18-20 of vacuum to work properly. My old 273 could barely muster 15-16 and the assist was marginal.
 
Ottmundr said:
I have power brakes. They work. I'm running the lunati 10200701 in my 318 with a performer manifold and 600 cfm carb I am happy so far. The bad is that I have yet to install my ministarter, 302 heads, d453 headers and better gearing than 2.76. In spite of that, it's nice.

Go here. (It should be linked to the welcome wagon forum and mandatory reading.)
RustyRatRod's Guide To Hot Rod Bliss
Click to expand...
Thanks for pointing me to that link...good reading!
 
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That is true of the dual diaphragm units.
Not of the Larger single diaphragm 73 up units.
And the cure for the little ones is a 15/16 M/C . When the boost goes away you will hardly notice it.
But my 73Dart booster works just fine with a 230@050 cam that idles right around 10 ish in neutral (4speed car).
BTW, I'm not encouraging you to buy more cam than you need; Just to entertain a bigger cam than one that idles at 18. If you are looking for performance, there are probably 2 or 3 cam sizes between stock and too-big-for-that-booster.And another 2 sizes until the bigger booster starts to go soft.
But,if you are at stock CR,you will run out of compression first.There's just not a lot of room before the take-off gets soggy. And then you need to increase your stall-speed in compensation, and shortly after that, you will need rear gears. So, it's kindof a balancing act,between adding performance at higher rpm with a bigger cam, and loosing bottom end to get it. The only way to get the bottom back is with compression.And when that gets too high , you run outta room with insufficient octane to suppress detonation.
Everybody is pushing and shoving,and then you run outta cubic inches and get to stroke that thing,lol,and start over.By everybody,I mean;compression,cam, octane,TC, gears, and finally, cid. And eventually you run outta head.
 
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MObarracuda said:
I work for Cardone (nations largest family owned auto part reman company) and had my booster rebuilt by my company. The Manager of the custom rebuild department told me the small diameter boosters need 18-20 of vacuum to work properly. My old 273 could barely muster 15-16 and the assist was marginal.
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OK, that is good info and makes all the sense in the world.

One thing you might want to consider is a vacuum reservoir; it is just a family size pork 'n beans can thing with a check valve that 'stores' vacuum (i.e., stores 'nothing' LOL) and so you will always a have some high level of vacuum ready to go. It will store vacuum at the level that you had when last decelerating with the throttle closed, which, with a decently tuned carb, is easily in the low to mid 20's with a 268-ish cam. I've used one on a turbo rally car and they work fine; they just run out of 'nothing' if you pump the brakes real fast a few times.

Of course, the vacuum reservoir won't fix low compression pistons....
 
Rumor on the street (and this forum) is that those Summit cams are the Crane cams from years ago.....
 
If you are doing a cam look for a used performer intake while you have it off anyway.Very easy to overcam a 318.Lots of good suggestions already.
 
I wouldn't recommend summit brand hyd. lifters. I've got a half turn of preload on them, and they chatter like hell if the car sits for a couple days and even worse if it sits longer.
 
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