A3 air filter on LDT

[ToddJK]

No soldier B. I’m done anyway. #5&6 exhaust was way too loose. Hopefully this will make a diff. Got it together and ideas good. Will drive it tomorrow.

So how is everything running with your truck? Has the change seemed to make noticeable difference and did you ever upgrade the air filter?

 

[Tracer]

As others have posted the 5 Ton conversion is common. This filter is from an M52A2. I copied the installation from an M35A2 that was modified at the Tooele Army Depot. with an LDS engine.

 

[ldmack3]

So how is everything running with your truck? Has the change seemed to make noticeable difference and did you ever upgrade the air filter?

Lot happened lately. I neglected my property for two years after getting Burt so this year I have/am spending a lot time getting things back to where I want. Mowing, trimming, tree trimmin, tree harvesting, herbicide & fertilizer application and moveing MORE rocks.

So now.
Months ago I cracked 2 pistons and replaced them and liners. While the pan was off I noticed the oil pump idler gear was even more sloppy than when I originally replaced it. So I pulled it again and the locally manuf shaft was worn worse that the origninal and it had only 100 miles on it! So I ordered a NOS shaft ($$$) and new bearing as it was spinning on the shaft and in the gear. Pressed it all together and reassembled.
Also, I installed the recommended LDS rocker arms as recommended and adjusted the valves. I retorqued the heads (slight seepage) and the valves after driving it and getting it up to temp. Did let it cool down before doing the heads. I installed an A3 air cleaner and I turned the fuel down by 4 flats as I never did anything when I did the FDC bypass and my temps were "sensitive".

Runs pretty good but with two new pistons/sleves I have not pushed it yet. Temps much better.

Bad news is the oil pressure. Takes 1-2 seconds longer to come up to 60PSI at start and after driving it, well warmed up, it will drop to 15-20 at idle. I set the idle up to keep it flowing. Only thing I can think of I might have done to cause this is R & R of the #1 main bearing cap. I did use assembly lube on the bearing. I know worn mains will cause this condition, but struggling to believe ONE can (assuming I messed it up) would cause this.

I have no leaks and oil level has not changed. When first start it I am getting white smoke out the exhaust until warm. Also, when winding out 4th I noticed a lot of white smoke. Enough that cars behind me back off. Once I get up to speed and shift, no more smoke unless I repeat.

When I put the oil lines back in I replaced the pump output o-Ring and gasket. Torqued and double checked all connections.

Again no leaks, oil in water or water in oil.

I really don't want to pull the pan again, three time in a year, unless I am missing something. If I do and determine the #1 main is a problem, I'm screwed. So I would conside adding and electric pump with press switch for when the pressure drops below 20-25. This would also pre-lube at start up.

Thoughts, ideas or suggestions?

 

[ToddJK]

Both, my old deuce and the one I have now do similar with oil pressure. Not quick to get up to oil pressure and drops down to 15-20 psi when warm. Could be the oil pump, perhaps the new bearing and such has less tolerance so it doesn't push as much until it's nice and worn in? I would think as long as the truck has oil pressure, things should be good and if oil pressure increases along with rpm, that should be the normal.

The excessive smoke is most likely due to the new piston/sleeve(s) as the rings need to be worn along with the walls of the sleeve to make a good seal. If it doesn't seem to be eating coolant, that would be my assumption, but if it is eating coolant, I would check the gaskets starting with the intake and make sure those are sealing properly. If that's not it, there's always that possibility that either the head gasket is faulty or the bolts need to be retorqued again. You did have the heads resurfaced, correct? If so, I doubt it's to do with the head itself.

Maybe an engine guru might chime in and have better information or an idea of what and why.

 

[ldmack3]

Yea I actually re-torqued the heads twice and they took off .010 to get them true. Both times I got movement in the nuts and I reset the valves which needed it.
Before all this on start up it took 7 sec for 60 psi, after 7 seconds to 60. Before, after road trip psi dropped to about 30. There is something else going on with the oil psi. When at warm itdle I step lightly on the throttle to bump the RPM and the oil indcator not move then suddenly jump up 10 psi. New gage and pressure transmitter so maybe some crud got in the sensor port.
I'll keep an eye on it. I need to haul some top soil so I'll be driving it easy for another month or so before loading it up.

Thanks for the input!

 

[ToddJK]

Yea I actually re-torqued the heads twice and they took off .010 to get them true. Both times I got movement in the nuts and I reset the valves which needed it.
Before all this on start up it took 7 sec for 60 psi, after 7 seconds to 60. Before, after road trip psi dropped to about 30. There is something else going on with the oil psi. When at warm itdle I step lightly on the throttle to bump the RPM and the oil indcator not move then suddenly jump up 10 psi. New gage and pressure transmitter so maybe some crud got in the sensor port.
I'll keep an eye on it. I need to haul some top soil so I'll be driving it easy for another month or so before loading it up.

Thanks for the input!

Anything on that oil sending unit can make readings a little sketchy, I've seen that happen before quite a few times, especially those real sensitive sensors some cars have.

 

[rustystud]

Before doing anything I would use a pressure gauge and check the "main" side pressure. There is two pressure systems in this engine. A high and low side. If the spring is loosing tension on the low side it can cause a loss of pressure. This assembly is located under the turbo just above the oil pan.

 

[ldmack3]

Before doing anything I would use a pressure gauge and check the "main" side pressure. There is two pressure systems in this engine. A high and low side. If the spring is loosing tension on the low side it can cause a loss of pressure. This assembly is located under the turbo just above the oil pan.

I noticed today there is an oil leak from there. Was too hot to look at so will tomorrow or next chance.
Thanks for the advice. 'll pull the TM and read through it.

 

[ldmack3]

Rusty:

Pulled the regulator.
I have the late model style

Per 209-2815-210-34-2-2

Spring lengths
Long - New is 4.650" mine 4.457"
Short - New is 1.620" mine 1.359"
Plunger OD - .8000 - .8010" mine .800 & .800

Can't measure spring tension or piston bore diameter but looks like I need to replace at least the springs.

Thoughts?

 

[Jbulach]

Or can the springs be shimmed the same as most hydraulic regulators to increase pressure?

 

[rustystud]

Rusty:

Pulled the regulator.
I have the late model style

Per 209-2815-210-34-2-2

Spring lengths
Long - New is 4.650" mine 4.457"
Short - New is 1.620" mine 1.359"
Plunger OD - .8000 - .8010" mine .800 & .800

Can't measure spring tension or piston bore diameter but looks like I need to replace at least the springs.

Thoughts?

Jbulach has the right idea. Shim the springs. This way you can control the amount of pressure you want. Just add or subtract shims.

 

[ldmack3]

Easy enough.
I'll post the results for future generations!

Thanks Jbulach!

 

[ldmack3]

Better.
I measured the springs inserted into the plugs and added shims in the plugs to correct the length. Appx .25" and .20" as needed per original spring measurements

Time to 60 psi maybe a little better but first start since dissassembly may not be an accurate assessment.
Cold press on start up increased slightly.
Idle pressure when warm/hot increased by appx. 5 psi. Steady at 20. Happy if thats all I can get but would like 30.

The TM refers to the shorter spring as the piston cooling relief valve spring. So I was hopeing my temps would be better but nt the case.

My question is will any harm be done by increasing the shims/pressure on the piston cooling spring? Wisjhful thinking more oil will reduce my EGT?
What about system pressure? How much pressure is too much? 60 psi max is good but again I would like to see 30 at hot idle.

This is definitely a better/cheaper/easier fix than replacing springs or unit.