Please help me Choose: 318 Cam selection Thread
#2755924
03/25/20 04:40 PM
03/25/20 04:40 PM
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Joined: Jul 2007
Posts: 2,554 Maryland
wally426ci
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I am trying to decide on which cam to pick for my 1968 318 with NP435 4 speed (D100 TRUCK) 3:23 GEARS - mostly around town driving with some highway time a few times per year. Occasional hauling loads.
I am going 30 over and keeping the stock crank. I am looking for fuel economy and low end while staying with smooth Idle.
I've seen the Comp 252 recommended but the shop recommended the Lunati 10200700 or the Erson E420101....
BRAND COMP Cams Manufacturer's Part Number CL20-208-2 Cam Style Hydraulic flat tappet Basic Operating RPM Range 800-4,800 Intake Duration at 050 inch Lift 206 Exhaust Duration at 050 inch Lift 206 Duration at 050 inch Lift 206 int./206 exh. Advertised Intake Duration 252 Advertised Exhaust Duration 252 Advertised Duration 252 int./252 exh. Intake Valve Lift with Factory Rocker Arm Ratio 0.425 in. Exhaust Valve Lift with Factory Rocker Arm Ratio 0.425 in. Valve Lift with Factory Rocker Arm Ratio 0.425 int./0.425 exh. Lobe Separation (degrees) 110 Grind Number 252H
BRAND Lunati Manufacturer's Part Number 10200700 Cam Style Hydraulic flat tappet Basic Operating RPM Range 1,000-5,000 Intake Duration at 050 inch Lift 208 Exhaust Duration at 050 inch Lift 213 Duration at 050 inch Lift 208 int./213 exh. Advertised Intake Duration 250 Advertised Exhaust Duration 256 Advertised Duration 250 int./256 exh. Intake Valve Lift with Factory Rocker Arm Ratio 0.454 in. Exhaust Valve Lift with Factory Rocker Arm Ratio 0.454 in. Valve Lift with Factory Rocker Arm Ratio 0.454 int./0.454 exh. Lobe Separation (degrees) 112 Grind Number
BRAND Erson Cams Manufacturer's Part Number E420101 Cam Style Hydraulic flat tappet Basic Operating RPM Range 1,000-4,000 Intake Duration at 050 inch Lift 208 Exhaust Duration at 050 inch Lift 208 Duration at 050 inch Lift 208 int./208 exh. Advertised Intake Duration 280 Advertised Exhaust Duration 280 Advertised Duration 280 int./280 exh. Intake Valve Lift with Factory Rocker Arm Ratio 0.420 in. Exhaust Valve Lift with Factory Rocker Arm Ratio 0.420 in. Valve Lift with Factory Rocker Arm Ratio 0.420 int./0.420 exh. Lobe Separation (degrees) 111 Grind Number RV10H
Last edited by wally426ci; 03/25/20 05:20 PM. Reason: DETAILS
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Re: Please help me Choose: 318 Cam selection Thread
[Re: Sniper]
#2756037
03/25/20 09:28 PM
03/25/20 09:28 PM
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Joined: Jan 2003
Posts: 3,122 Auburn WA
Dave_J
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Auburn WA
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I haven't had any luck finding a new 68 340 4 speed cam for a long time. Yep. But I have a Delta regrind 68 4 speed cam in my 360 and its have been good. They reground my 360 OEM cam core.
Retired, US ARMY 1973-1994 ASE mechanic, Electrical 1994-1997 Retired GTE/VERIZON/FRONTIER 1997-2015
Posting cheap tech help (CRAP) here since Nov 97, 1000's of posts, some may be good.
03 Suzuki Burgman 650(Burger King) Scooter 65 Formula S Cuda 78 Little Red Express Truck 98 Buick Regal (wifes car)
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Re: Please help me Choose: 318 Cam selection Thread
[Re: wally426ci]
#2756148
03/26/20 11:12 AM
03/26/20 11:12 AM
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Joined: Jan 2003
Posts: 14,492 So. Burlington, Vt.
fast68plymouth
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I Live Here
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So. Burlington, Vt.
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The addition of a 4bbl will be a better upgrade than a cam swap.
I like the 360-2bbl cam in a combo like that(works with stock everything).
68 Satellite, 383 with stock 906’s, 3550lbs, 11.18@123 Dealer for Comp Cams/Indy Heads
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Re: Please help me Choose: 318 Cam selection Thread
[Re: wally426ci]
#2756162
03/26/20 11:43 AM
03/26/20 11:43 AM
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Joined: Jul 2007
Posts: 2,554 Maryland
wally426ci
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This is a new rebuild in the stock 318 from the truck
Ok, Comp got back to me. This grind looks very similar to the Lunati that the shop recommended (if so, the question is which between the 2 now):
COMP recommendation
BRAND COMP Manufacturer's Part Number XE250H Summit Racing Part Number Cam Style Hydraulic flat tappet Basic Operating RPM Range 800-4,800 Intake Duration at 050 inch Lift 206 Exhaust Duration at 050 inch Lift 212 Advertised Intake Duration 250 Advertised Exhaust Duration 260 Intake Valve Lift with Factory Rocker Arm Ratio 0.432 Exhaust Valve Lift with Factory Rocker Arm Ratio 0.444 Valve Lift with Factory Rocker Arm Ratio Lobe Separation (degrees) 110 Grind Number
Last edited by wally426ci; 03/26/20 11:55 AM.
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Re: Please help me Choose: 318 Cam selection Thread
[Re: Sniper]
#2756164
03/26/20 12:01 PM
03/26/20 12:01 PM
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Joined: Aug 2007
Posts: 6,095 Valencia, España
NachoRT74
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Valencia, España
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The Comp and Erson cams really aren't much bigger than a stock 360 cam.
My favorite cam for a 318 is the stock 340 cam
Venezuela and Mexico Chrysler sectionals offered a 318 4 bbls engine with the 340 cam and 10:1 pistons ( advertised ) México on their 68-70 GTS versions ( can't recall if laters too ) Venezuela on 70 Coronets and 71/72 Chargers. Venezuelan cars got in fact the engines made in Mexico. 727, 3:23 axle ratio open 8 3/4", with I think 29" Diameter wheels.
With a Charger born in Chrysler assembly plant in Valencia, Venezuela
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Re: Please help me Choose: 318 Cam selection Thread
[Re: NachoRT74]
#2756196
03/26/20 02:29 PM
03/26/20 02:29 PM
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Joined: Jan 2003
Posts: 20,740 A collage of whims
topside
Too Many Posts
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Too Many Posts
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Posts: 20,740
A collage of whims
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A 110 LC will tend to build slightly less cyl pressure than a 112 LC, generally. I'd think in that direction if the CR is 9.5 or more. Lift is, within the limits of springs & architecture, kind-of free power, no driveability downside that I've seen. Adding lift does tend to slightly increase effective duration, but in the range being considered, it shouldn't be a problem. More exhaust duration or lift (vs. intake, aka "dual-pattern")helps with a restrictive exhaust, say full-length 2.5" or smaller duals with tailpipes. The difference isn't huge between those 2 cams, though. Main thing for that application is to build low-mid RPM torque, and be able to use a vac advance curve without detonation under load. Many a wise man has stated "don't over-cam" and/or "pick the smaller one for the street", so again, the CR is part of the equation.
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Re: Please help me Choose: 318 Cam selection Thread
[Re: wally426ci]
#2756222
03/26/20 04:00 PM
03/26/20 04:00 PM
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Joined: Jan 2003
Posts: 3,122 Auburn WA
Dave_J
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Auburn WA
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I just looked at the cam that is in my 1980 cop E58 360 in my 78 LRT. I thought it was a regrind 360 2bbl done to 68 340 4 speed spec's. It is not.
I have a Comp Cams Extreme 262/270 and it is a very good 360 cam. Not much lope on a 360, may be a bit on a 318. With my 3.55:1 gears and the stock 78 LRT's stall it gets down the road good. Not a race truck but snappy.
Retired, US ARMY 1973-1994 ASE mechanic, Electrical 1994-1997 Retired GTE/VERIZON/FRONTIER 1997-2015
Posting cheap tech help (CRAP) here since Nov 97, 1000's of posts, some may be good.
03 Suzuki Burgman 650(Burger King) Scooter 65 Formula S Cuda 78 Little Red Express Truck 98 Buick Regal (wifes car)
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Re: Please help me Choose: 318 Cam selection Thread
[Re: calrobb2000]
#2756651
03/27/20 10:01 PM
03/27/20 10:01 PM
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Joined: Jan 2008
Posts: 2,224 ILLINOIS
volaredon
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top fuel
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yup... COMP 252 and stock 360-2bbl cam almost exact carbon copies of each other.... duration and overlap, etc are identical.... I think the COMP may give you something like 0.015" more lift.... not enough to sweat over but the stock Melling 360 replacement cam is MUCH cheaper.... only without being in the "COMP cams" box.
I put one in an 83 D250 with its original (unrebuilt) 318, but I put a set of EQ heads on it with the Magnum rocker gear.... (your 69 heads had higher compression than the stock 83, 318 heads had so Mag head swap may not be applicable in your case) HUGE difference in that engine.. power and mileage both went UP. I ran a Performer (not "RPM") intake and Carterbrock 600cfm carb... this truck was 727 and 3.55s with 235/85R16s on 8 lug rims.
I also rebuilt a 69 318, and put in a 79 short bed, all stock... but bored 0.030", and a MP cam (at the time they offered the COMP 252 as a "purple shaft" MP part) and I even "chickened out" and went even smaller than a 252 (I think they had a "248" MP cam just below that 252 as well.. I was so afraid of "over camming" back then, wish I knew then what I know now) but even that truck ran freakin great.... A833 OD 4 speed with 3.91s.... I had an Edelbrock "streetmaster 318" intake on there, (it was what I could find at the local swap meet back then) and an identical Carterbrock 600 carb on it as I had on the 83.. when I had the 79, I worked at a dealer, got "employee price" on that cam or any cam I would have wanted out of the MP catalog.
That one got overloaded and USED as a truck (that thing thought it was a 1 ton) and when unloaded I ran it like a slalom toy... especially in town. 4 speed, manual steering and brakes was the last truck I had (before my current one) that came to me with a /6..... cant believe it was nearly 30 years ago. Had that thing for 6 or 7 years, drove the wheels off of it, often with a dragging bumper (way overloaded esp for the 1/2 ton that it was)
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