Dodge Cummins Diesel Forum banner
  • Hey everyone! Enter your ride HERE to be a part of September's Cummins of the Month Challenge!
1 - 20 of 21 Posts

·
Registered
Joined
·
242 Posts
Discussion Starter · #1 ·
i was wondering what you guys adjust your valves to. if there is a better number then factory spec, i plan to do it today or tomorrow
 

·
Registered
Joined
·
963 Posts
The proper numbers are on the tag, they are tried and true, use them not some fantasy numbers
 

·
Registered
Joined
·
23 Posts
Spent last 19 HAPPY years at Freightliner

its nice to hear that, im thinkng about applying to there canonsburg location in september when i get out of school... any advice?
 

·
Registered
Joined
·
761 Posts
the rule of thumb is .010 on the intake and .020 on the exhaust. however my truck said . .010 and .026 on the valve cover. I went with the rule of thumb settings
 

·
Registered
Joined
·
658 Posts
06ramcummins- I remember reading somewhere that the spec on the exhaust was changed for the 06s; cant remember where.

If you read in the Cummins manual, it will give an "acceptable range" for valve adjustment. Anything in that range (like, .007 to .015 for intake, IIRC), supposedly wont affect performance. Not entirely true if you factor in fuel consumprion.

I run mine at .009 and .019. If anything, it gives me a little wiggle room on when I have to do my next overhead.

Daniel
 

·
Registered
Joined
·
761 Posts
Since adjusting to the "rule of thumb" settings. The motor does run a lot smother, quieter, heck almost like new. and you are right about the acceptable range, atleast from all the reading that I have done trying to figure out what the best setting could be.
 

·
Registered
Joined
·
1,862 Posts
There are no "rule of thumb" valve settings. Every engine manufactuer does extensive design testing and calculations to determine the appropriate setting for that valve train, things like the rate of lineal expansion of the various compnents at different temps, rate of cooling of the valve head when the valve is closed,length of time the valve is on it's seat, piston to valve clearance etc, etc. Increase in performance and noise reduction (what noise in a Cummins ;)) would be barely measurable and would hardly be worth risking the burnt or bent valves.

It's also interesting to note that high performance camshafts, like GM's 30-30 shafts, are designed for higher valve clearances, not tighter. What does that suggest?
Steve g
 

·
Registered
Joined
·
761 Posts
There are no "rule of thumb" valve settings. Every engine manufactuer does extensive design testing and calculations to determine the appropriate setting for that valve train, things like the rate of lineal expansion of the various compnents at different temps, rate of cooling of the valve head when the valve is closed,length of time the valve is on it's seat, piston to valve clearance etc, etc. Increase in performance and noise reduction (what noise in a Cummins ;)) would be barely measurable and would hardly be worth risking the burnt or bent valves.

It's also interesting to note that high performance camshafts, like GM's 30-30 shafts, are designed for higher valve clearances, not tighter. What does that suggest?
Steve g
As for the "rule of thumb" are those clearances correct for our motors? Please correct if I'm wrong. I'm still learning about these motors.
 

·
Registered
Joined
·
39 Posts
It's also interesting to note that high performance camshafts, like GM's 30-30 shafts, are designed for higher valve clearances, not tighter. What does that suggest?
Steve g
That we don't have 30-30 cams?:rof
.008 in. and .018 ex.
Dyno queen or race truck; as tight as .005 in and .010 ex. with stock cam and valvetrain.
 

·
Registered
Joined
·
242 Posts
Discussion Starter · #12 ·
my factory dodge manual (diesel supplement) claims .10 and .20. i was thinking about calling cummins and asking them.

id rather call international over ford anyday!!!
 

·
Registered
Joined
·
841 Posts
how often are you supposed to adjust valves on 1stgen?
 

·
Premium Member
Joined
·
1,326 Posts
Whenever you can hear them :lol3::rof:rof:thumbsup

Sorry - couldn't resist.
 

·
Registered
Joined
·
658 Posts
I believe the book calls for checking every 24K; could be as much as 36K, though dont hold me to it. Checking never hurts anything.

The sales pitch of the early 24v engines being able to go 150K before an adjustment is pure BS. I adjusted the valves for a guy a while back with 86K on his 00/01. He said it was like driving a new truck, and gained about 3mpg.

DP
 

·
Registered
Joined
·
242 Posts
Discussion Starter · #16 ·
25k miles. dodge/cummins manual
 

·
Registered
Joined
·
461 Posts
I would thiink they are hydraulic lifters. Cummins would know.
 

·
Premium Member
Joined
·
857 Posts
how do you adjust the valves? is there a write up some where? if ther is that woudl be awesome.
 

·
Registered
Joined
·
3,578 Posts
The 24 valves are not hydraulic lifters, so who knows where the 100,000+ miles adjustment interval came from.
 
1 - 20 of 21 Posts
Top