valve springs/valve stem seals

[JOHNFAK]

Half way through replacing my valve stem seals. Let me know if anyone wants me to grab pics or wants any info. 

[Me78569]

I'd be interested

[notlimah]

Same!

[JOHNFAK]

Ok. I'll do a mini writeup with links info and pics but let me know if anything you want before she gets buttoned back up tonight. 

[CSM]

If you can look at the play in the valve guides it might be interesting.  I thought about changing my seals but I bet I have enough valve guide play it wouldn't be worth it.

[JOHNFAK]

Hit a snag.

Are the injectors tor hold down bolts 

SAE 1/4" 28NF 

Or 

6mm 1.0 threads

 

Have to tap hole 

[Mopar1973Man]

I normally find a die that fits a bolt. Then I know the tap is that size. I'm going to say its going to be metric but double check me.

[JOHNFAK]

Went and got a 6mm 1.0 tap ....... too tired after today and late night with Kansas Basketball to continue - will hopefully finish

after work tomorrow.

 

So heres some details.

 

I have a constant smoke at idle with this truck. Its not injectors and engine appears to be healthy on compression test as well as blowby. I had thought previously of valve steam seal but many people/threads had told me that its inlikely due to being under positive pressure on startup ....... so I had ignored till now. I was looking at my stem seals and noticed this on the MOST of teh exhaust seals.

 

 

So time for it all to come off.

 

TOOLS NEEDED

 

18mm for spring compression tool (cummins performance parts)

8mm for injector holddown

10mm for valve cover and rockers

19mm  or 3/4 for injection lines

pick magnet for picking up collets around stem

good flashlight

barring tool

 

Remove valve cover.

Remove lines.

Bar engine over until #6 is in valve overlap (exhaust closes and intake opens).

#6 + #1 are at TDC.

Remove rockers.

Remove injector crossover tube

Remove injector

Stick an allen key/screwdriver gently through injector hole and confirm piston at top (for peace of mind).

Install compression tool onto injector holddown holes.

Crank down GENTLY. Stop when starts to bind.

Remove collets around valve stem seal very carefully using pick magent and put aside.

Remove springs and retainer

Remove valve stem seal using pliers as gently as you can. There is a video here.

 

 

After this put springs back and compress back down and carefully put collets back on and uncompress to lock all four springs.

TIP here is to pull on valve stem up to make sure fully up as it will want to fall down a 1/8th inch and cant get collets in.

 

After all this is done, repeat down the firing order and bar engine over to get 2+5 at TDC, then 4+3.

Once that is all done ....... reinstall all rockers.

Bar engine completely over looking for any issues.

Then set/check valves as per normal.

 

 

Other Notes.

 

1) I found a camera with a 6mm video cable extension helped me bar engine over from underneath and I could see when piston was comming to TDC. Very accurate and helped working by myself.

 

2) I hit an issue at #2 where injector holdown hole had rust from moisture at bottom. So when I tried to thread the tool into it I couldnt. I tried to use a shorter bolt that was shorter and I think slighlty off in size. It pulled out and now I have the rethread the hole to ensure I can get a good clean hold for my tool without creating more damage/issues.

 

3) I couldnt think of how to measure valve stem guide issues - I just pushed side to side. It felt farily normal (low play) and consistent bewtween valaves -but I dont know

 

Id say if you can change injectors and set valves you can change springs.

 

Id give those a difficulty of 5/10. Springs around and 8/10 just due to time consuming and having to take so much care with the collets and working with TDS and back 2 pistons are hard etc.

 

 

 

 

Edited March 27, 2016 by JOHNFAK

[IBMobile]

Thanks for the info and good work.  I like how you used the flat washer between the nut and tool so there is no damage to the tool.  

[notlimah]

Nice video! I was jamming out to the tunes as well. I gotta say though, that smudge or whatever it was was driving me nuts! Hahahah I kept thinking it was in my screen and I couldn't get it off! 

 

Really awesome stuff though! One of these days I really want to dig into one of these engines like this.

[JOHNFAK]

Thanks guys.

The link on valve overlap is from ryan ( ISX ).

The video is from someone  else that I found that just showed taking off the valve stem seals themselves.

 

Its really not too bad ....... just need to understand TDC for each firing combo so you dont drop a valve. The rest is just how long it takes working by yourself. Up and down for tools (and breaks) etc. Probably for me it I hadn't hit 2 snags - a full days job. Basically 8-10 hours about 2x-3x the rate it takes me to do injectors (around 3-4hours). Im definately not quick.

 

Hardest part is #5 and #6 cranking down the tool as not much room for a 1/2" drive socket and wrench socket (used an open end wrench) and then working on those collets and being very careful not to let fall down a pushrod hole or injector hole (had a cloth here in injector bore).

 

Now I have to retap the injector hold down on #3 and finish #3 and #4. And button her back up and check lash.
Tonight or tomorrow.

 

 

[Mopar1973Man]

What happen to the head to have that much rust inside?

[JOHNFAK]

22 minutes ago, Mopar1973Man said:

What happen to the head to have that much rust inside?

 

Who knows - PA truck originally.

Could have been some moisture left in during some maintenance or work.

most of the rest of it is obviously in areas that have no moving parts or oil contact .... directly behind the valve cover seal etc

 

 

[CTcummins24V]

The exhaust seals are all messed up. The valve just moves up and down the seal with no oil inside? I know you don't want oil getting in the top of the cylinder, but there's no lubrication on the valve stem seal?

[JOHNFAK]

3 minutes ago, CTcummins24V said:

The exhaust seals are all messed up. The valve just moves up and down the seal with no oil inside? I know you don't want oil getting in the top of the cylinder, but there's no lubrication on the valve stem seal?

 

 

Not quite following.

The seal is seated/pressed.

The valve rides inbetween - there is oil on the top of teh valve .... but it gets wiped "off" 99% by the seal as it drives down into the cylinder.

 

[IBMobile]

1 hour ago, CTcummins24V said:

The exhaust seals are all messed up. The valve just moves up and down the seal with no oil inside? I know you don't want oil getting in the top of the cylinder, but there's no lubrication on the valve stem seal?

This article from Engine Builders may answer your questions.

http://www.enginebuildermag.com/1998/07/valve-stem-seals-materials-and-designs/

[CTcummins24V]

Thanks guys! I learned something today!

Unlikean umbrella seal, a positive seal does not move. It is pressedin place on the end of the valve guide and wipes the oil off thevalve stem as the stem moves up and down. The seal does not actuallymake direct contact with the stem but rides on a thin film ofoil creating a hydrodynamic seal. This allows a small amount ofoil to slip past the seal to lubricate the guide. For this reason,a precise fit is extremely important with a positive seal to getaccurate oil metering.

 

If a positive seal fits too loose aroundthe valve stem, too much oil will get past the seal and floodthe guide. Oil consumption will go up along with all the problemsthat go with too much oil in the combustion chamber. If a positiveseal fits the stem too tight, the hydrodynamic seal may be lostas the oil film is scraped off the stem. This will starve theguide for lubrication causing increased valve stem and guide wear(seal wear, too), and may even cause the valve stem to overheat,gall and stick.