valve adjustment?

[Jim Brzozowski]

Sorry, don't have a book on the engine. Can anyone tell me, are there any valve adjustments required? Solid lifters, hydraulic or what on the Dmax? What kind of valve train does an LB7 have?

[DmaxMaverick]

Hydraulic rollers. No adjustment. I guess they could be shimmed, if you had a need to.

[BMDMAX]

The Duramax is not a hydraulic lifter. Cut & pasted from the GM literature:

Duramax 6600 6.6L V-8 Diesel (LB7/LLY)

Type:

Duramax 6.6L V-8 turbo-diesel

Displacement:

6599 cc

Compression ratio:

17.5:1

Valve configuration:

overhead valves (4 valves per cylinder)

Assembly site:

Moraine, Ohio

Valve lifters:

mechanical roller

Firing order:

1 - 2 - 7 - 8 - 4 - 5 - 6 - 3

Bore x stroke:

103 x 99 mm

Fuel system:

direct injection diesel with high pressure common rail

I will have to check my shop manual to see if there is an adjustment procedure or not.

[Nix]

BMDMAX, I was just wondering a few things about some of the accessories on your truck. I have not been able to decipher some of the abbreviations and was wondering if you could clear it up for me.
1.HJAT 145
2.stealth 215
3.KD VA 200+
4.RAS
5.SPA DG211
6.MDP custom fuel system?(sounds expensive!)
Please forgive my ignorance as I recently discovered the joy of diesel performance :D . Also, did you need to lift your truck to fit wheel/tire combo? If so, how much? Thanks for your help.

[Buck]

Sorry Brandon I beat ya to it :D :D ;)

HJAT = Edge Juice with Attitude-Competition program
Stealth 215 = Quadzilla Stealth Tuner for Duramax - 215HP Competition Program
KD VA 200+ = Van Aaken Smart Box E 200+ Competition program
SPA DG211 =
SPA DG-211 Digital Boost with Pyro in 1 gauge.
SPA Digital Boost with Pyro comes complete with probe and pressure sender. Very sensitive and accurate. Stores maximum recorded values for easy recall. Programmable "high limit" warning lights along with outputs for external alarm. Backlight switcable between red and green.

I know what #4&6 are but my memory is failing me :( It's bed time for me


Kennedydiesel.com has all of these things if you want an in depth explanation
:cool:

[BMDMAX]

Yep, you beat me to it! :D The two you could not remember are the RAS = Roadmaster Active Suspension and the MDP Custom Fuel System = the lift pump and secondary filtration designed by JK and myself. It is essentially a high volume, return regulated fuel supply getting 15 PSI to the CP3 with sub 2 Mic filtration and switchable supply/returns to a secondary race tank. To my knowledge there is not another setup like it.

My wheel and tire combo was choosen specifically to fit with no lifting. It is a 2WD for street-only use but the combo handles like a dream and zero rubbing lock-to-lock in turns.

[Buck]

DUH!! Dunno why I couldn't put "RAS" together :eek:

[Nix]

Thanks a lot for clearing that up for me. :cool:
Will that wheel/tire combo work on a 4x4? Who is making good aftermarket front suspension parts? I've already gone through an outer tie rod and an idler, and just wondered if there was anything stronger out there. I haven't worked on a truck front end yet. How tough is it to change these parts yourself? Thanks for the help. This site rules. :D Now I just need more$$$$$ :(

[BMDMAX]

The wheel will work no problem but the tire is street use only. John Kennedy can give you some advice on front suspension upgrades to make it stronger.

[Buck]

Fabtech has some Beefy looking steering parts, I've seen them in 4 wheeler and peterson 4 wheel magazines. Here is a link

beefy steering (http://www.fabtechmotorsports.com/applications/chevy/4wd00-04k2500hd.html)

[More Power]

If this were a flat tappet engine, there might be some sort of service interval for valve lash adjustments, but I couldn't locate a reference to a service interval in the few minutes I spent looking.... Manual says set each rocker to produce .012" clearance when that cyl is at TDC. With roller lifters, it shouldn't change much throughout the life of the engine.

The 6.5TD uses non-adjustable hydraulic roller valve lifters.

MP

[Jim Brzozowski]

MP & BmDmax thanks for that info. I thought I had read somewhere that it had mechanical roller cam. But there is absolutely nothing about valve adjustments in the service section of the owners manual. Since I plan to run this one a million miles or so, just thought eventully I may have to make an adjustment along the way. Had a 90 Taurus SHO that had overhead cam lifter that you had to shim to make an adjustment, put 160,000 miles on that on and never even checked tha adjustment. I figure if you can't hear a rocker out of adjustment, it's probably not. Although I've also learned the hard way on the one volkswagen engine that I owned,when you have to keep backing off the adjustment because its too tight, better look out you are stretching a valve. It eventially broke and stuck into the piston, not a pretty sight. Thats not too likely with such low rpms these Dmaxes run. The thing about a diesel, you can't hear or distinguish a rocker knock from a combustion or injector knock, at least I don't think I could. Sure hope they did a good job setting those clearances when they assembled my engine.

[01max]

Valve Clearance Adjustment




Remove the fan clutch. Refer to Fan Clutch Replacement in Engine Cooling.
Remove both upper valve rocker arm covers. Refer to Valve Rocker Arm Cover Replacement - Upper Left and Valve Rocker Arm Cover Replacement - Upper Right .
Rotate the engine in the normal direction and put the number one piston at Top Dead Center (TDC) of the compression stroke. Number one cylinder is right side front. While turning the engine watch the intake valve to open and close. Align the mark on the crankshaft balancer with the pointer on the engine.



Loosen the valve clearance adjusting screws for the valve being adjusted.
Insert the feeler gauge between the tip of rocker arm and the valve bridge.
Notice: Use the correct fastener in the correct location. Replacement fasteners must be the correct part number for that application. Fasteners requiring replacement or fasteners requiring the use of thread locking compound or sealant are identified in the service procedure. Do not use paints, lubricants, or corrosion inhibitors on fasteners or fastener joint surfaces unless specified. These coatings affect fastener torque and joint clamping force and may damage the fastener. Use the correct tightening sequence and specifications when installing fasteners in order to avoid damage to parts and systems.





Adjust the intake and the exhaust valve clearance to 0.3 mm (0.012 in) with the engine cold. Shown are the valves that can be adjusted at number one COMPRESSION stroke TDC.

Tighten
Tighten valve adjusting screw lock nut to 22 N

[Jim Brzozowski]

01max, thanks. Looks like I'm just going to have to break down and give Helms some money for books, there's just too much I don't know about this engine. All my previous chevrolet engines were NO. 1 cyl. on the left side. Of course I have always specified right and left while sitting in the drivers seat facing forward. I also thought that at TDC on the compression stroke, both valves were closed and you could both I & E at the same time.

[01max]

i was thinking that when a person had to have the injectors replaced, they might be able to talk the tech into adjusting the valves when he had it already torn down that far, you could slip him a $20 or $30 it would be wirth a try