Valve Lash

[obert]

I know I don't necearily need to adjust my valves yet, but i cant keep my hands out from under the hood. ( already run them once & im only at 72k now! )

But im just wondering if anyone has experimented with the effects of the adjustment.





ie: should both (I & E) be set tight?, or will this create more valve overlap resulting in loss of boost? Or perhaps set intake skin tight and exh. somewhere in the middle?

Are there even any tricks here at all? ( Yeah, i know... set'em & forget'em)



I did notice last time though, giong by the data plate at . 010" and . 020" the engine seemed to have a better performance feel, and the valves were just a little loose before i stuck my hands in.





Am i putting way to much thought into this or am i working on a viable point here? Is 3000rpm fast enough to start getting down this specific? Any thoughts?

 

[BigCarl64]

Yes, supposedly there is a performance setting on the valve lash. When I had my head off for a blown head gasket, Rubberneck reset my valve lash to a certain spec. I can't remember exactly what he set them to, but he mentioned something about a particular setting that would yield a better performance. Maybe he can chime in and give us the scoop.



Hey Rubberneck, where you at?

 

[LSMITH]

I set mine about 3 thou tight of mean on the intake and about 5 tight on the exhuast and picked up some low end torque with no loss on the high end. It sounds better under load too. What is kinda weird is that EGT seems to have gone up 50-75 degrees with more valve lift. Maybe it is burning the fuel better and that is the reason, I really don't know

 

[obert]

lsmith, your exaust valves are tighter, thus open sooner. i am a deisel machanic, all be it a young one. when the valves open sooner you loose exh. heat out the manifold. this is similar to how a " jake brake" works and is why your exh. sound so sharp(mine is the same ) . i am wondering to what degree this can effect you power out put. i confuse my self if i think on this to much. does heat out the exh. mean power loss, or do the escaping gasses spin the turbo more and make up for lost gasses? im pretty well set on running down the intakes to the limit.



I know that lash = timing, so where to put that exh. valve???

 

[LSMITH]

That makes sense that the exhuast is a bit hotter as it is let out earlier. At any rate it runs a lot better now than it did with the valves on the loose end of the range.



You have a reuseable gasket on the valvecover, run it with several settings and see what happens. Doing just the exhuast valves would take the time down to a half hour at the most. If I have a little time this weekend I will set mine at mean and run it, then go 4 thou or so loose of mean on the exhuast and see what happens.

I know the intakes need to be a tad tight of mean to get the best out of the engine, but am not sure on the exhuast either. I am thinking tight would mean that more of the exhuast could get out making room for more cold air to get in as the temp in the cylinder should be lower and the valve will be open longer? I really do not think that power output is lowered by tight exhuast valves as the energy of the gas is spent well before the valve begins to open, but that is just MHO. If you do any testing let us know.

 

[obert]

I plan sunday to set intakes at . 005 and exh at . 018 or so. we'll see what happens.

Im crashing late nite here because i want to get this wrapped up on sunday morning. I have to go out west to Piqua OH to Bobcat factory training all next week, and being a true turbohead/in love with my truck as much as my fiance, it must be running 110% and have that show shine to make evryone drool. :-laf



The open exhaust also draws attention, as the last time i went out to training no one new my name but rather i was the "kid with that loud a** truck" Evryone likes to hear that turbo bark when i shift gears



One way or an other, tractor pulling season is comming and ill be pulling the big loads again. And I'll shurly irritate the better half by spending hours on end out under the hood of the truck and not under another hood... ... ... ... .



I''l keep posted,and further input is always welcome

 

[rubberneck]

I set the intakes to 0. 010 and the exhaust to 0. 023, My cousin is a heavy truck mechanic, and he had an old magazine lying around, (cant even remember title, wish i knew where it was). Any way, it had a listing of optimal valve settings for many of the light and medium duty diesel engines. It listed the above specs for our motors. The factory service manual states to set them at 0. 010 and 0. 020. Can you tell the difference between 3 thousands?? I dont know.



One thing to make note of if you are going to run tight valve clearances. Remember that the valves are going to get tighter with time not looser. If you decide to run them tighter keep an eye on them. would hate to see someone burn a valve.

 

[obert]

Thats a good point of view. I still want to set the in takes tight, but ill stay at least 20 with the exhaust.



The core of my theory lies in throwing the valve as far open as possible, only lately has timing come in to my mind... ...



And dont worry, ill keep an eye on the valve train... ... as i said above- i cant keep my hands out of the thing



Also, ( i bet some of you can relate ) im a young man startng out and soon to be married, I find the electronics to be rather expensive, especialy knowing i need a clutch before upgrades. I'm just trying to streach my mechanical abilities as far as possible... Oh well. I set out to get this Deisel odessy when i was 14 when the old man drove one home-- it took till i was 20



maybey Ill add those ponys( and bells and whistles ) by 27... .

 

[R Anestis]

I Second that!!

Obert:

I couldn't help but notice your sig. Yep, Red ones are definitely better. By any chance do you make it to the Canfield Fair for the Smoker Series? Just wondering, that's becoming a tradition of mine.

-Ron





PS: don't you just love it when those Green Weenie Wanna Be's end up like this: :--) :{ :-{}



Oo.

 

[obert]

We run antique NEARLY stock pulls. A Farmall 400 ,did well in 5500# and 6500# division 2. Also an Oliver super 99 GM:--)

It did well, too. Id like to go to open class (div. 4) but no one has 8500# open. the 99 goes in 8500, 9500, and at the steam show pull dad and i put on it weighs about 11,500.



p those not into tractors-- 99 GM is powerd by a 371 detroit diesel, and is VERY loud )