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LLY engine swap - light duty to medium duty

Odlaw

Odlaw

Redneck
Messages
577
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40
Location
Deep in the woods - near Waldo, FL
Hey fellas, this is a question for a friend of mine. He has an 06 medium duty(5500) tow truck with a blown LLY motor. He just purchased a LLY out of a 04 2500 wreck (BTW he got the motor for $1500.00 delivered to his shop - motor has 87k miles on it). Other than the obvious stuff like oil pan, intake and such, is there any other parts he should swap out or anything else that he might need to know? Are the turbos the same type and size on these trucks? The salvage yard he purchased the motor from said he would need to swap the injectors because the med duty has a totally different tune than a light duty. I told him I didn't know but I knew where to find out.... ;)

Thanks
Smitty
 
The blocks are completely different mounting wise. The med duty block has different mounting tabs cast into it that the LD does not... it won't work without fabricating new mounts.

I remember reading this way back a long time ago where a guy with a haulin' ass Kodiak cracked a piston and replaced his with a pickup engine... I'll see if I can find the thread at the other place.

Start reading at post #210:
http://www.dieselplace.com/forum/showthread.php?t=224799&page=21
 
Well, I sent my buddy all the info and the pix from that great write-up and it appears that the LLY motors have the tabs on them for medium duty or light duty trucks...so he dodged a bullet there. The injectors are different between the two so, the salvage place was correct that he would need to swap the injectors. Still don't know about the tune - if/how it will figure into all this. He also got a nice turbo in the deal....and needed it too, his med duty had over 400k miles on it with maybe 10 oil changes total (they never maintain their trucks) - the compressor wheel was rubbing the housing.
 
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OK - new question. The injectors from each of the motors are physically the same but if you look em up they are different part numbers. Does anyone know what the difference is? Here's his dilemma; two injectors got crushed when the 06 LLY came apart. He can't afford (right now) to buy two injectors and was thinking of taking 2 off the 04 LLY and sticking them in the easiest to get to holes until he can replace them. Any ill effects by doing this?

Thanks
 
If the injectors flow at different rates (I believe they do) then the ECM will get all confused because the balance rates will be all over the map. JM2C. I got a feeling there would be other problems as well.
 
Good point. He's decided to leave all 8 of the 04 injectors in and see what happens. BTW, with 87k on the new motor when he swapped the oil pan you could still see the cross hatch on the cylinder walls.
 
Odlaw said:
Good point. He's decided to leave all 8 of the 04 injectors in and see what happens. BTW, with 87k on the new motor when he swapped the oil pan you could still see the cross hatch on the cylinder walls.
Click to expand...
That would indicate regular oil changes. Although the presence of crosshatch at that mileage isn't uncommon, it's always a good sign.
 
btfarm said:
That would indicate regular oil changes. Although the presence of crosshatch at that mileage isn't uncommon, it's always a good sign.
Click to expand...

Yeah, I was trying to point out the fact that it appears he got a nice motor for the price.....or at least a fairly well maintained one anyway.....something my buddy is not accustom to....lol! Surprised he didn't call me after seeing the cross hatch and say something like "man, this motor has abnormal looking scratches on the cylinder walls"

He's paying a mobile diesel mechanic to do the swap (my buddy is assisting) and they made a boo boo... for some reason they opted to leave the 04 cp3 pump on.....truck will only run for about 2 seconds. They're swapping the 06 pump back on tomorrow.
 
OK - truck is back together - will crank and run about three seconds...when it starts. If it does not start the injectors will only fire three times (actually thats probably true when it starts. Here's what is 04 on the truck; long block, cp3 pump /regulator, injectors, turbo, reluctor wheel. 06 parts; ecm, CPS, CS, all wiring, connectors etc. Gettin code P0336 Crank position Sensor circuit a range/perf

Any ideas?

Thanks
 
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In all the jostling and banging around with those motors I wouldn't be surprised to see the CPS messed up. Thus the code.
 
Mine (and his thoughts exactly) so he took the known good CPS off the 06 and installed it with the same results. Are the reluctor wheels different between 04 and 06 maybe?
 
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UPDATE; the reluctor wheels are different between the 04 and 06 one has 57 teeth and the other has 58 (can't remember which right now) but they are swapping them in the morning. This would explain why it would crank briefly - every rotation put it further out of time. Hopefully that will be it.
 
I was about to say the Cam and Crank sensors could be swapped backwards also.. Good luck!
 
Cruel trick indeed! He called me today. Said after they put everything back together she fired right up....she sat there idling (getting smoother buy the minute) then after about 15 minutes it started pouring smoke. They panicked at first then after further investigation, determined the exhaust had a good bit of oil in it from the original engine coming apart. Drove it for a couple of hours and cooked everything out of the exhaust. He was running calls in it as of noon today. He's already picked up another oil filter and oil and plans to change it again after running it over the weekend.

Thanks for all your help fellas.

Smitty
 
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