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so, i bought a 26 foot uhaul truck, with a blown up 454 in it. 2000 c6000.
i guess i figured it would be more simple to do this motor swap, but, its stressing me out. i have to leave this house in a month, scrape up my insane parents, and take them somewhere. its weighing heavy on me. i can work on stuff, but, dont really have the place to do it. and, the thought of having a mechanic who makes mistakes at 100 per hour, is almost too much for my little soul to bear.

i look at remans, and, they are available. new motors,no. i hear things about getting a .3 over, overheating problems!!?? have people also heard this happening? i suppose it could happen, for sure.

labor for this job is 2000 at least. jasper wants 4000 for the motor, others want around 3000. its a huge investment for me, and, im not certain what to do!

it uses a allison 545 trans, btw. i thought about a 350 swap, too!! you can get them new, theyre cheaper, and make even more power!! but, im sure thats not gonna be easy.


this week, im going to try to find a used motor, i suppose. or try to refund the truck and just get another which runs, though it will have 160k on it, at least i can rebulid it on my own time. i dont know if they will refund me, though.

i think im in over my head!! im in NJ. truck is in central NJ. im open to options, i know you guys are masters of motors, and, i wanted to at least throw this out there!

thanks for any thoughts/comments/ideas/offers!!

:p
 

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Discussion Starter #2
ive also been seeking desperately a place i could do this swap, myself, and, spend the extra money on buying tools! anyone open to rent their shop for a couple weeks??!! im in NJ!
 

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I agree that you're in over your head, but you wouldn't be the first guy who has had to rebuild a motor out on the street. Tough time of year to do it though, with winter comin' on.

Let me help you a little with the math. .3 would be three hundred thousandths, or a little less than 5/16ths of an inch. What you mean, I'm sure, is boring and honing the block for 0.030" oversize pistons and rings. (thirty thousandths of an inch) or just a little less than 1/32nd of an inch. Hundred of thousands or maybe even millions of vehicles are running around every day with 0.030"-over pistons and rings and do not overheat. It can happen if the cylinder walls get too thin from overboring the block, but 0.030"-over won't do it.

Smokey Yunick explained why thinner walls lead to overheating. Piston rings do not glide smoothly up and down the cylinder wall, they jerk along in little steps. These little steps cause a vibration in the metal. When there is enough meat in the cylinder walls to cancel these little vibrations, all is right with the world and the motor does not overheat. When the cylinder walls get bored and are too thin to cancel these little vibrations, air bubbles separate from the water and form on the water jacket side of the cylinder walls that will not allow cooling water to get the the cylinder wall to carry heat away and the motor overheats. That's why thin walls can overheat the motor. Smokey found that out by cutting a motor apart, installing glass walls so he could see what was going on and running the motor. My hero, Smokey Yunick. :thumbup::thumbup::thumbup::thumbup:
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by the way.. that is either an L21 or an LP4 motor.. the propane versions use sodium filled exhaust valve stems.

4 bolt main 454.. forged steel crank.. forged rods... topkick motor..

when you go to remove the motor... please DON'T CUT WIRES coming out of sensors and stuff..

please USE extreme care to remove all the sensors.. the coolant temp sensor in the left head is well over 100 bucks if you damage it.. there are knock sensors in the sides of the block and wiring to them.

i added some pictures.. one of the passenger side of the engine by the starter.. notice at the top that the remover and or installer had mashed the knock sensor up really badly.. the other picture is of the crank position sensor in the timing cover. nothing is cheap on this motor and every sensor is needed... it won't work well without it .. you may also want to spend the extra time to clean the fuel injectors and verify they work properly while you have them out. this is not spraying the outside this is building a test harness that runs on a 9 volt battery with a momentary push button and an injector connector.. plus some hoses to hook to the top of the injector and also a spray straw to allow you to spray carb or brake cleaner thru them.. clogged injectors will KILL These motors again and again..

please try to identify what and why it failed in the motor coming out.. was it overheated.. was sand put in the oil...or dropped into the air intake.. sugar in the fuel tank..

buying a truck with no place to work on it.. any truck lots nearby?

throw NOTHING out until after you have the engine running... and the truck driving properly... you never know what you need.. and nothing is cheap on these.. wow... my images would not load again... screwey internet..
 

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by the way.. that is either an L21 or an LP4 motor.. the propane versions use sodium filled exhaust valve stems.

4 bolt main 454.. forged steel crank.. forged rods... topkick motor..

when you go to remove the motor... please DON'T CUT WIRES coming out of sensors and stuff..

please USE extreme care to remove all the sensors.. the coolant temp sensor in the left head is well over 100 bucks if you damage it.. there are knock sensors in the sides of the block and wiring to them.

i added some pictures.. one of the passenger side of the engine by the starter.. notice at the top that the remover and or installer had mashed the knock sensor up really badly.. the other picture is of the crank position sensor in the timing cover. nothing is cheap on this motor and every sensor is needed... it won't work well without it .. you may also want to spend the extra time to clean the fuel injectors and verify they work properly while you have them out. this is not spraying the outside this is building a test harness that runs on a 9 volt battery with a momentary push button and an injector connector.. plus some hoses to hook to the top of the injector and also a spray straw to allow you to spray carb or brake cleaner thru them.. clogged injectors will KILL These motors again and again..

please try to identify what and why it failed in the motor coming out.. was it overheated.. was sand put in the oil...or dropped into the air intake.. sugar in the fuel tank..

buying a truck with no place to work on it.. any truck lots nearby?

throw NOTHING out until after you have the engine running... and the truck driving properly... you never know what you need.. and nothing is cheap on these.. wow... my images would not load again... screwey internet..
thanks for the visuals, they get me thinking. thanks for the heads up on the injectors, as well. i think ive gotten myself in over my head here. i am going to try to retract the bid on the truck... which might not work, but, i will try. im just too afraid of a giant headache!

my motor, the truck was stolen and ran about 10000 miles without an oil change... until it apparently gave up. there are parts sticking through the bottom of the oil pan. there is also nothing left in the power steering, which scares me. the parking brake runs off the PS pump. this motor has seen like 3 PS pumps over its lifetime, too. according to the record, this motor is only about 50k miles old. (uhual trucks get beat up badly, apparently)

im afraid to get a reman motor. is this justified? can anyone tell me what company THEY would trust? jasper seems best... but it gets a little crazy... 4000 plus tax. then, at lesat 2500 install. then... power steering must be dealt with, as well. its all just scares me ALOT because i see the records, and, the techs must SUCK who work on these trucks. they replace an o2 sensor because it burns on the exhaust... but it costs over 100 dollars for the part.... they never just splice the wire... and it just burns up AGAIN and again through the history on the truck!! so... whatever else they "did"... scares me!! im one of those guys who goes through all connections, or most of them. but... my ignitions keep going!! my motors run well! im wishing for a partner to do the heavy work on this, and, i just do all the little stuff, and, make the wires clean, etc. i personally wouldnt chop out sensors, no. but, i can see why you mention it, because ive spoken to alot of guys who "went to school for 2 whole years!!", so they know ALL ABOUT working on stuff... lol.. any other comments are appreciated, sir! thank you!
 

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I agree that you're in over your head, but you wouldn't be the first guy who has had to rebuild a motor out on the street. Tough time of year to do it though, with winter comin' on.

Let me help you a little with the math. .3 would be three hundred thousandths, or a little less than 5/16ths of an inch. What you mean, I'm sure, is boring and honing the block for 0.030" oversize pistons and rings. (thirty thousandths of an inch) or just a little less than 1/32nd of an inch. Hundred of thousands or maybe even millions of vehicles are running around every day with 0.030"-over pistons and rings and do not overheat. It can happen if the cylinder walls get too thin from overboring the block, but 0.030"-over won't do it.

Smokey Yunick explained why thinner walls lead to overheating. Piston rings do not glide smoothly up and down the cylinder wall, they jerk along in little steps. These little steps cause a vibration in the metal. When there is enough meat in the cylinder walls to cancel these little vibrations, all is right with the world and the motor does not overheat. When the cylinder walls get bored and are too thin to cancel these little vibrations, air bubbles separate from the water and form on the water jacket side of the cylinder walls that will not allow cooling water to get the the cylinder wall to carry heat away and the motor overheats. That's why thin walls can overheat the motor. Smokey found that out by cutting a motor apart, installing glass walls so he could see what was going on and running the motor. My hero, Smokey Yunick. :thumbup::thumbup::thumbup::thumbup:
.
thank you for the reply! people have told me that the .030" might pose a problem, but, im going to have to agree, its unlikely. i guess i can run something like water wetter, if i should have a problem? it should help this big block, maybe help alot. i could maybe go for the high flow waterpump, too. so.... i guess im not AS worried about getting the overbored reman motor...

if you were going for a reman motor.... who would you trust?? what do you think would prove the motor was worth the effort... possibly a static turnover, to prove the motor isnt "too tight"?

yes, im in over my head, and, i dont have support behind me, so im going a little crazy over here! thanks, ive got to keep it mind, im pushing it... and i think im going to TRY to retract from this deal, and, get another truck which runs MINT. it will have 155k or 163k on it. it will cost about 6500. but, alas, i may find a low mile motor, still... i think i would trust it more.... and it should come in at less than 2000 dollars, shipped. id probably jump on it, if i can find one... less risk than the reman, dont you think?

i can see what Smokey was talking about! thanks for the visual. it makes sense. air doesnt cool like water does!

any other thoughts are appreciated! thanks for the reply!
 

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find a complete USED motor.. from a crashed truck... hopefully it will be OK..

if rods are thru the oil pan.. and steering parts are gone... somebody put a brick on the gas pedal and blew the motor up... the rev limiter should have caught it.. or they dumped crap thru the intake..

do you have a lot of money invested??

was it yours when it was stolen... or still a uhaul... and you got it for a song..

did they steal the computer out of it also... those get expensive also..

there are issues when engines blow up at full throttle.. or up against the rev limiter... the crank stops.. but the rotational inertia keeps the torque converter rotating.. it will shear the studs right off the front of the converter and it will spin down over the next 30 seconds or so tearing the pilot up on the converter... costing you not just a converter.. sometimes a complete transmission..

you could install depending on smog requirements almost any big block chevy and make it work with a carb and distributor.. you could install a 350 chevy with a Th400 and make it work.. or even a TH350.. but either will work.


as for the steering.. there are truck wrecking yards all over the place..

you can look up parts on this site.. so you know what they cost.. almost..

Search GMC Parts

heck... buy a big block suburban and swap the motor in.. it must be a gen VI motor though.. and DON'T THROW out anything till its running.. and then still don't throw it out if you intend on putting an L21 back in it.

you might find a truck with a damaged box and just move your better box onto that one.. there is just so much to know...

so.. search out an L21 or an L29 they came in buses also.. topkicks.. but its only 98 to 2000 i think..

Chevrolet Performance 19207551: 454ci/7.4L Long Block Replacement Engine 1998-2000 GM Bus Chassis with VIN Code L21, LP4 | JEGS

this really is off thread for this forum.

this offsite thread has some great images also..

GM Performance :: View topic - OEM Distributorless 411-powered 454?
 

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Discussion Starter #8
find a complete USED motor.. from a crashed truck... hopefully it will be OK..

if rods are thru the oil pan.. and steering parts are gone... somebody put a brick on the gas pedal and blew the motor up... the rev limiter should have caught it.. or they dumped crap thru the intake..

do you have a lot of money invested??

was it yours when it was stolen... or still a uhaul... and you got it for a song..

did they steal the computer out of it also... those get expensive also..

there are issues when engines blow up at full throttle.. or up against the rev limiter... the crank stops.. but the rotational inertia keeps the torque converter rotating.. it will shear the studs right off the front of the converter and it will spin down over the next 30 seconds or so tearing the pilot up on the converter... costing you not just a converter.. sometimes a complete transmission..

you could install depending on smog requirements almost any big block chevy and make it work with a carb and distributor.. you could install a 350 chevy with a Th400 and make it work.. or even a TH350.. but either will work.


as for the steering.. there are truck wrecking yards all over the place..

you can look up parts on this site.. so you know what they cost.. almost..

Search GMC Parts

heck... buy a big block suburban and swap the motor in.. it must be a gen VI motor though.. and DON'T THROW out anything till its running.. and then still don't throw it out if you intend on putting an L21 back in it.

you might find a truck with a damaged box and just move your better box onto that one.. there is just so much to know...

so.. search out an L21 or an L29 they came in buses also.. topkicks.. but its only 98 to 2000 i think..

Chevrolet Performance 19207551: 454ci/7.4L Long Block Replacement Engine 1998-2000 GM Bus Chassis with VIN Code L21, LP4 | JEGS

this really is off thread for this forum.

this offsite thread has some great images also..

GM Performance :: View topic - OEM Distributorless 411-powered 454?
very valid points, thank you! i got the truck from uhaul. it was never returned, until they got a call it was on a highway. they retrieved it, and found the motor was blown. the PS parts are there, but, i noted there was no fluid in the reservoir.

the part about the possible issue with the trans.... THAT RIGHT THERE.... scares the crap out of me. and youre right, it could happen!

the guy at the uhaul kinda convinced me to buy it. it sounded good, at the time... im hoping uhaul will simply credit me on another truck. they might. i paid 2800 for this one. the others are going for about 6500. with 160k plus on them. some have... up to 300.. .but mostly a little over 200k...

ive been a fool. if i find a truck with good compression, its a smooth runner, and its got a decent history(i have a couple choices ready to go actually), then put in GOOD oils(they always run crap oils in these trucks) and do all the little things, like initially run marvel in the oil and gas to get rid of some sludge(is this a bad idea??), then dump the oil and put in synthetic... im thinking some 15-50 mobil 1. and the rest probably 10 30 mobil 1. the motor should be fine from there. i mean , i wont drive this thing 50k miles, in even ten years... i just got caught up in the idea of having a NEW MOTOR for close to the price of the truck with 160k on it... but i think ive been stupid. id rather have a well broken in motor! its going to be more predictable.

any other thoughts? and thanks for finding the NEW motor! i have emails to dealers out right now, but, havent heard back yet. im guessing they will suggest that very motor. and, in all honestly, a NEW motor would maybe be worth it.... IF i knew the trans was OK! but, i DONT! this thing BLEW UP! and its weird. i have to hope uhaul lets me slide on this deal. if not, im going to have to hunt for a used motor! or, go for the new one... hmmmm.... the new one looks so yummy!
 
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