4 Wheel Parts
4WD
ALLDATAdiy
JC Whitney
Off-Road Tires
Dodge Parts
Canadian insurance for your Charger


Author Topic: Cam timing on a 90 318  (Read 1196 times)

0 Members and 1 Guest are viewing this topic.

Offline JohnB

  • Newbie
  • *
  • Posts: 128
  • RCC Rules!
    • Deep-Blue-Sea.org
Cam timing on a 90 318
« on: June 28, 2007, 08:42:20 AM »
I have a 90 ramcharger with a 318, has 150k miles on it.
The timing chain has quite a bit of play in it, and I can get a speedpro indexed key set for 30 bucks, so I am thinking about changing it.  I have done some reasearch, and there seems to be a thought that 4 degree advance on the cam would help the engine out.  It has great compression, and I use it primarily to tow 6000 pounds of boat around.
Anyone ever advanced the timing on one of these? and what did you find?

Offline Dodge 85 RC

  • Official Backwards Transmission Rebuilder
  • Mopar Nut
  • ******
  • Posts: 8938
  • Gender: Male
  • Its not a Bronco or a Blazer, ITS A RAMCHARGER!
    • Dodge R/C
Re: Cam timing on a 90 318
« Reply #1 on: June 28, 2007, 09:33:35 AM »
In order to find out if you need to advance it or not you need to degree it when you install it.  A stock timing chain may or may not be made right in regards to actual cam timing.  Sure advancing it can help.  You also need to remember that 4 degrees at the crank is only 2 degrees at the cam.
85 R/C 367/manual v/b'd 727/208, 4.10's ,Modified 4 inch RCC lift, 3 inch body lift 52 inch springs up front HD 3/4 ton 52 inch springs out back. About 10 inches of lift 35x12.50R15 M/T Baja Claw Radials 15x10 Black Rockcrawlers Custom HD bumpers
99 merc sable-wifes car
02 merc grand marquis

Offline JohnB

  • Newbie
  • *
  • Posts: 128
  • RCC Rules!
    • Deep-Blue-Sea.org
Re: Cam timing on a 90 318
« Reply #2 on: June 28, 2007, 10:15:00 AM »
In order to find out if you need to advance it or not you need to degree it when you install it.  A stock timing chain may or may not be made right in regards to actual cam timing.  Sure advancing it can help.  You also need to remember that 4 degrees at the crank is only 2 degrees at the cam.
Thanks, I am just putting a new chain on the stock/original cam.  I am looking to put 4 degrees advance on the cam.  These motors had the cam retarded from the factory, along with some other "retardation" to make them "smog" complient, and gave up some torque, and a little hp in the process.  I didn't know if anyone one here had tried this.  I am planning on rolling the distributer a few degrees forward too.

Offline ToxicDoc

  • Lifetime Supporter
  • RCC Nut
  • *
  • Posts: 10071
  • Gender: Male
  • RCC Rules!
Re: Cam timing on a 90 318
« Reply #3 on: June 28, 2007, 01:05:44 PM »
Thanks, I am just putting a new chain on the stock/original cam.  I am looking to put 4 degrees advance on the cam.  These motors had the cam retarded from the factory, along with some other "retardation" to make them "smog" complient, and gave up some torque, and a little hp in the process.  I didn't know if anyone one here had tried this.  I am planning on rolling the distributer a few degrees forward too.


Unless you're custom grinding a cam (thereby advancing/retarding intake/exhaust separately) all you are doing is shifting the power band up or down.  That may not be a bad thing for a truck however...

I've done it before and liked the results.  It let me run a "big" cam yet still be streetable with my old rod.

http://www.lt1howto.com/articles/camshafts.htm

"Advancing a cam means you are moving the valve events earlier in the cycle. If done when installing the cam you will be moving both the intake and exhaust events earlier in the cycle. This generally boosts low speed torque at the expense of peak HP. Retarding a cam does the opposite, it will improve peak power by delaying valve events, which will increase peak HP and move the peak HP rpm up, but at the expense of low-end power."
'85 W150 SB, 408 stroker, Magnum manifolds, Performer RPM, 670 Truck Avenger, HEI ignition, Auburn LSD 9.25 and '82 D44 (non-CAD) with 3.55/3.54,  NV4500/NP241

Offline hrhitter97

  • Newbie
  • *
  • Posts: 199
  • Gender: Male
  • RCC Rules!
Re: Cam timing on a 90 318
« Reply #4 on: June 28, 2007, 01:37:53 PM »
Hey Toxic,
     I have the edelbrock performer plus cam with their performer roller timing chain and gear set, It has 4 deg adv., 4 deg retard and straight up.  I have it installed at the straight up position, How would changing it to 4 degrees advanced work in conjunction with advancing the timing by rotating the dist. cap.  Is it the same process, just doing it two different ways, or are the two adjustments completely differerent with different results?

1985 dodge ramcharger Royal 150, 4WD
360 Edelbrock Carb & Intake, 727, np208
9.25 Rear, D 44 Front, 4.10 Gears
15x10 Eagle 089 wheels 35x12.50x15 Truxus Mt's
4" Skyjacker Suspension Lift with Rear Springs
borgeson steering shaft, adjustable drag link
custom fabbed rear bumper with tire carrier

Offline JohnB

  • Newbie
  • *
  • Posts: 128
  • RCC Rules!
    • Deep-Blue-Sea.org
Re: Cam timing on a 90 318
« Reply #5 on: June 28, 2007, 04:26:28 PM »
ToxicDoc,
That is exactly what I am trying to do.  This vehicle spends it's entire life towing a 23' boat, about 5500 pounds.  I don't care about hp, just torque. 

Offline McGuyver

  • the prodigal son returns
  • Full Member
  • ****
  • Posts: 1717
  • Gender: Male
  • Ahnuld Truckzenneger
    • McGuyver's homepage!
Re: Cam timing on a 90 318
« Reply #6 on: June 28, 2007, 10:54:12 PM »
hrhitter97,
Advancing the distributor only advances the ignition timing.  It has no effect on the valve timing at all.  Advancing the valve timing involve one of several different methods of changing the cam orientation relative to the crank position.
Great whits are oft to madness allied.

Offline ToxicDoc

  • Lifetime Supporter
  • RCC Nut
  • *
  • Posts: 10071
  • Gender: Male
  • RCC Rules!
Re: Cam timing on a 90 318
« Reply #7 on: June 29, 2007, 12:00:09 AM »
Hey Toxic,
     I have the edelbrock performer plus cam with their performer roller timing chain and gear set, It has 4 deg adv., 4 deg retard and straight up.  I have it installed at the straight up position, How would changing it to 4 degrees advanced work in conjunction with advancing the timing by rotating the dist. cap.  Is it the same process, just doing it two different ways, or are the two adjustments completely differerent with different results?


No it's different.  Ignition timing sets combustion relative to the piston/crank location.  Cam timing changes valve position relative to the crank/piston - independent of ignition/spark.

  Earlier ignition can give you more power across the the rpm range.  Whereas cam timing shifts that curve up or down.  So you can advance your ignition timing more more total power.  However, your peak power will occur/remain at whatever rpm it already is. 

If you would like to have some more of that power occur earlier (more off the line) you can advance your cam.  Towing or rock crawling might be good examples of good application.  A lot of "rv" or "towing" cams already have an advance ground in so if you put it straight up it's like another cam that has been advanced a few degrees (in addition to the other changes).
'85 W150 SB, 408 stroker, Magnum manifolds, Performer RPM, 670 Truck Avenger, HEI ignition, Auburn LSD 9.25 and '82 D44 (non-CAD) with 3.55/3.54,  NV4500/NP241

Offline chrysler300le

  • MO Chapter Leader
  • Mopar Nut
  • ******
  • Posts: 5484
  • Gender: Male
  • RamchargerCentral.Com Rules!
Re: Cam timing on a 90 318
« Reply #8 on: June 29, 2007, 03:53:18 AM »
ToxicDoc,
That is exactly what I am trying to do. This vehicle spends it's entire life towing a 23' boat, about 5500 pounds. I don't care about hp, just torque.

In your case I would say just advance it 4 degrees.  it won't hurt anything.  You could probably go 8 degrees and still be happy. Cam timing was retarded starting in the 70's for emission reasons. 
2005 Dodge Neon SXT
2003 Dodge 2500
1981 Dodge Mirada
1979 Chrysler 300
1977 Dodge M885
1976 Dodge M884