L18 8.1L swap resource thread

[Larry]

Is there a special too to remove the crank pulley/balancer to swap over to the workhorse style crank pulley/balancer, or will any standard puller work?

Pretty much any 3 jaw puller will get it off. Going back on is a different story. I typically borrow the GM 8.1L tool kit from my GM dealer buddy. The Kent-Moore tool kit is J-44900. Alex and I were watching a tool kit on Ebay over the weekend and it looks like I missed out. It sold for $93

 

[Kay86K5]

Pretty much any 3 jaw puller will get it off. Going back on is a different story. I typically borrow the GM 8.1L tool kit from my GM dealer buddy. The Kent-Moore tool kit is J-44900. Alex and I were watching a tool kit on Ebay over the weekend and it looks like I missed out. It sold for $93

That's what I thought. I remember Alex telling me there was a special tool needed at some point of the removal/install for this, just couldn't remember (and figured others might want to know who were reading this thread). I will need to figure that out.

On a side note I got my old TBI350/TH400 out of my crew cab this last weekend. Going to spend a few weeks cleaning things up. Only have a couple misc items I need to pick up before I can at least bolt in the 8.1/NV4500 into the truck. Hopefully by mid April they will at least be in the truck. Making progress.

Thanks again for all the great valuable info!!

 

[Larry]

If anybody is curious what replacing the rear mail seal on a L18 using the Kent-Moore J-44900 tool kit is all about here you go…

Seal remover installed with several self-tapping screws

Start cranking on the center bolt. About half way off

Taa-daaa

New dealeo

Seal installer. This just one has two thumb screws to secure it to the crank then just presses the seal in. Once the tool bottoms out at the crank the seal is completely installed. Add a layer of oil around the sealing surface to the crank but not to the outside between the seal and block

I didn’t replace the clutch but the pilot bearing looks pretty rusty and sketchy so it got the heave hoe since I was there.

It would be a challenge to replace the bearing type pilot without a pilot bushing/bearing remover tool as it sits so deep into the crank. Seems deeper than older SBC/BBC. This truck only has 68K miles on it but the bearing was toast!

View of the flywheel holding tool that is included in the J-44900 kit. This helps keep the flywheel from spinning while torqueing the flywheel bolts and pressure plate bolts. Both manual and automatics use the same tool

View of the EGR bullchit that is used on the early L18’s. If I had time I would have removed it all and sent the ECM out for tuning. While the clutch looked like new the flywheel had a few burn marks on it so I sent it out to be turned as well.

There you have it….that is where a few of those special L18 tools come into play. I got a new Blackbery PRIV phone last week and it kicks ass with pictures! Even uploads them to Flickr at a push of a button as well. I love this phone!

Oh, and I also discovered the ZF uses a huge diameter clutch alignment tool. It is not the typical ole 10 spline tool that was used on GM clutches for eons. Not sure what size it is but it is huge! Luckily, I had an old universal clutch alignment tool that fit. I hate using that old tool as it never really seems to get clutches aligned perfectly causing issues when you go to stab the trans. It fits everything but nothing well. Guess, I'll find out later today when I stick the trans back in. (to avoid confusion....on my K10 and Burb, I used the typical old 12" clutches GM used for decades which does have the typical 10 spline)

 

[Kay86K5]

Still lots to do and purchase, but progress is always better than no progress

 

[Larry]

Sweet! Nice the hard work begins.

 

[Kay86K5]

For you guys who have swapped the 8.1 into a square....what have you done about the oil cooler lines? Has anyone deleted the lines and if so, what part number did you use for it? Is it the same as the 5.3/6.0 oil delete? If you have kept them, how did you set it up?

 

[Larry]

For you guys who have swapped the 8.1 into a square....what have you done about the oil cooler lines? Has anyone deleted the lines and if so, what part number did you use for it? Is it the same as the 5.3/6.0 oil delete? If you have kept them, how did you set it up?

I ditched the oil cooler lines all together as I am running out of room to mount more things like oil coolers and run lines. Just put pipe plugs in the holes in the block. Some people claim there is some bypass dealeo that must be removed somewhere in the oil filter area. I never did that on either of my rigs and the K10 has been running for 8 years like that with no oil pressure issues.

 

[Kay86K5]

I ditched the oil cooler lines all together as I am running out of room to mount more things like oil coolers and run lines. Just put pipe plugs in the holes in the block. Some people claim there is some bypass dealeo that must be removed somewhere in the oil filter area. I never did that on either of my rigs and the K10 has been running for 8 years like that with no oil pressure issues.

That's what I like to hear. I have heard people talk about the bypass too. I think I'm just going to ditch the oil cooler lines too. Do you remember what size pipe plugs you used?

Edit: Pretty sure I found it. They should be 1/2" NPT plugs that you can get (does that sound correct?)

 

[Larry]

Yeah, I think they were regular ole 1/2 pipe plugs

 

[Kay86K5]

Hey @Larry I had two questions for you regarding your 8.1 you swapped into your burban (cause I know you were running headers on that motor). Did you use a factory oil dipstick that worked fine with headers, or did you get an aftermarket flexible one? The one I had that came with my motor was broke, but even trying to mock it up, it looked like it was not really going to work with the headers. Just wondering what you did there

Also, did you find any clearance issues with the driver side knock sensor to the headers? I know you have shorty headers, and I went with a mid-length set, but I noticed they are really close to the driver knock sensor (passenger side is fine) to where I'm not sure if I can get the plug onto the sensor. Did you experience anything with this, and if so what did you do about it?

Thanks Larry!

Edit: I think I figured out my oil dipstick just fine, but still doing some research on the knock sensor. I noticed on the first page you listed "213-298 Knock sensor - Drivers side (this sensor requires being moved to a different hole in the block)" as one of the parts you used in your swap. Do you have a picture of which hole in the block you use for this sensor?

 

[Larry]

Hey @Larry I had two questions for you regarding your 8.1 you swapped into your burban (cause I know you were running headers on that motor). Did you use a factory oil dipstick that worked fine with headers, or did you get an aftermarket flexible one? The one I had that came with my motor was broke, but even trying to mock it up, it looked like it was not really going to work with the headers. Just wondering what you did there

Also, did you find any clearance issues with the driver side knock sensor to the headers? I know you have shorty headers, and I went with a mid-length set, but I noticed they are really close to the driver knock sensor (passenger side is fine) to where I'm not sure if I can get the plug onto the sensor. Did you experience anything with this, and if so what did you do about it?

Thanks Larry!

Edit: I think I figured out my oil dipstick just fine, but still doing some research on the knock sensor. I noticed on the first page you listed "213-298 Knock sensor - Drivers side (this sensor requires being moved to a different hole in the block)" as one of the parts you used in your swap. Do you have a picture of which hole in the block you use for this sensor?

Sorry for the late reply. For some reason I stopped receiving email notifications when someone posts in one of my subscribed threads or sends me a PM. I just happen to have some time to surf the forums and saw you posted this a few weeks ago.

Glad you got the dipstick figured out. Yes, both the K10 and Suburban use OEM dipsticks although they are different. I believe the dipsticks changed design sometime in 2003 or 2004. The later one is the better one as the earlier design tends to chaf the spark plug wire.

Yes, there are clearance issues with the driver’s side knock sensor which I why I have two part numbers listed. The part number for the driver’s side has a smaller stud to relocate to a different hole. Once you get the engine in there it will be obvious which hole to use. I’ve been running the knock sensors in this location since 2008 on the K10 with no issue.

Here is the driver’s side knock sensor (PN 213-298)

 

[Kay86K5]

Sorry for the late reply. For some reason I stopped receiving email notifications when someone posts in one of my subscribed threads or sends me a PM. I just happen to have some time to surf the forums and saw you posted this a few weeks ago.

Glad you got the dipstick figured out. Yes, both the K10 and Suburban use OEM dipsticks although they are different. I believe the dipsticks changed design sometime in 2003 or 2004. The later one is the better one as the earlier design tends to chaf the spark plug wire.

Yes, there are clearance issues with the driver’s side knock sensor which I why I have two part numbers listed. The part number for the driver’s side has a smaller stud to relocate to a different hole. Once you get the engine in there it will be obvious which hole to use. I’ve been running the knock sensors in this location since 2008 on the K10 with no issue.

Here is the driver’s side knock sensor (PN 213-298)

Yep, perfect. That is exactly what I did. Same part number knock sensor in the same exact location. Thanks for the confirmation!!

Just as an FYI, All I need to do is the wiring harness in mine (went with a stand alone harness from Howell as well) which I already have in my possession and see if this thing will fire up! Hopefully this weekend can make some good headway on it. Maybe in a few weeks I can get this thing to start up!! Thanks again for all the great info in this thread!

 

[Capt Ron]

I picked up an 8.1 today. Bounced some ideas and pics off of our resident 8.1 guru @Larry and pulled the trigger on a 2002 C6500 GMC. Got the engine and trans out today. Cab was burned so I could not here it run. I will do a compression test and go from there. Trying to figure out a way to read the computer to see what the mileage is .




View attachment 222945

 

[Larry]

I picked up an 8.1 today. Bounced some ideas and pics off of our resident 8.1 guru @Larry and pulled the trigger on a 2002 C6500 GMC. Got the engine and trans out today. Cab was burned so I could not here it run. I will do a compression test and go from there. Trying to figure out a way to read the computer to see what the mileage is .

You got a hell of a deal there Ron, especially for the price you paid! You might end up with a free engine and even make money if you play your cards right selling off left over bits. That AT545 Allison, front axle and big Eaton rear axle should be well worth what you paid for the entire thing. Then there are those big 22.5” wheels that usually go for $100+ a piece at the junkyards. I bet the local LKQ would give you decent money for those bits and sell the rest of the truck for scrap iron of you have a way to haul it off without axles under it.

That ECM does not retain miles that I recall or even engine hours but I can tell you the last warranty claim on the truck was in July of 2004 where it had 58,885 miles at that time. That said, it is pretty safe bet the engine has well over 100K on it. Maybe when you pull the engine you notice evidence where someone has already had the engine out before where it may have had a reman by now. Ryder shops are known to be pretty hacky so if they replaced the engine once already you should find half the things loose and misrouted. Ryder mechanics pretty much suck and take no pride in their work, just like U-Haul shops. Either way, the price you paid is worth it.

So now that I’ve had time to study your engine pictures on the big screen, the brackets on this engine are not uncommon at all. Forget what I said in the text. I just didn’t recognize these brackets with the air brake air compressor not present. Hell, we still used these exact brackets today on International school buses with the PSI 8.8L although 90% of ours are sold with air brakes vs. juice brakes.

Your brackets are the same as these minus the air brake compressor. You might be able to use these in your truck but you’re going to have to get creative in finding a way to get rid of that big idler pully (where the medium duty truck fan attaches) as that pully will probably interfere with the throttle body air induction pipe when used in a square body pickup. The water pump on your engine will accept a spin on fan clutch from any late 90’s through current GM truck engine. The bonus of using these brackets is the fact the A/C compressor is on the passenger’s side which makes it easier to make A/C lines and that ZF Power Steering pump is a hoss! Try to keep that if you can. The biggest hurtle will be to figure out how to delete that bigass idler pully. Anxious to see what you do with this. I would sure try to use these brackets if this was my engine. Congrats man!

 

[Capt Ron]

Thanks @Larry I got the engine and trans out yesterday and loaded on my truck just as it started to snow. I also kept the aluminum loading ramp, front steer tires {almost new} with wheels, radiator and a few other odds and ends. I did not have a place to store the chassis so I actually let a friend of my uncles take it for helping me remove all of the parts. We also used his tow truck to pull the motor and trans . Once I sell the tires, ramp, trans and radiator I feel I did OK.
I was wondering about that big pulley also, when I change it over to mechanical throttle body will I have to use a spacer between the intake and the tb?
This cc is being built to haul my goose neck and enclosed car trailer so I would like to get a hold of and use an air brake compressor like in the pic above, space permitting. It would be nice to be able to air up tires etc....
I probably would not have even attempted to do this conversion if it wasn't for all of the info from your 8.1 resource thread and @Kay86K5 s build thread. Thanks again for all of your help, I will keep you posted on my progress.

 

[Larry]

Thanks @Larry I got the engine and trans out yesterday and loaded on my truck just as it started to snow. I also kept the aluminum loading ramp, front steer tires {almost new} with wheels, radiator and a few other odds and ends. I did not have a place to store the chassis so I actually let a friend of my uncles take it for helping me remove all of the parts. We also used his tow truck to pull motor and trans . Once I sell the tires, ramp, trans and radiator I feel I did OK.
I was wondering about that big pulley also, when I change it over to mechanical throttle body will I have to use a spacer between the intake and the tb?
This cc is being built to haul my goose neck and enclosed car trailer so I would like to get a hold of and use an air brake compressor like in the pic above, space permitting. It would be nice to be able to air up tires etc....
I probably would not have even attempted to do this conversion if it wasn't for all of the info from your 8.1 resource thread and @Kay86K5 s build thread. Thanks again for all of your help, I will keep you posted on my progress.

You know, the throttle body spacer had been up for debate several times on the Facebook 8.1L Group. Many people have been successful with not using the spacer at all. Not sure if it is due to their cable routing, a stack up of tolerances or they just aren’t noticing they are not getting a full WOT (5 volts at the TPS). My K10 absolutely could not achieve WOT until the spacer was added just due to the geometry of the way the cable pulled the Vortec L29 454 Throttle Body. When I did the 8.1L in the Polar Bear Suburban I didn’t even look to see if it required the spacer or not, I just threw one on based on experience with the K10. I’d say, give it a shot without the spacer and see if you can achieve WOT. The spacer does make the air induction pipe that much closer to the hood so if you would get away without the spacer that would be better.

Cool idea on the compressor. The only challenge with that is the compressor runs all the time so you would have to figure out a clutch or a “quiet” way of bleeding off the unneeded air when not using it. I will tell, ya those type of compressors are HEAVY beasts, high volume/low psi and they are not cheap. Maybe more weight than you would like to haul around and less performing as you would expect from something so damn big and heavy.

Glad to be a bad influence! . If I get up to Denver anytime soon I’ll have to come check this beast out.

 

[Kay86K5]

Little thread bump of my 8.1 finally running for a little bit

 

[Larry]

Little thread bump of my 8.1 finally running for a little bit

Sweet! It's alive!

 

[Kay86K5]

Been a long road, but finally got it figured out. With the help of Josh at Team 208 Motorsports...he had a scope that we were able to really see what was going on. It turned out that my "new" crank sensor I installed before the swap was junk. It was working, but it was sending erratic signals to the computer. We were able to see that each time the cam sensor was "on", the crank sensor is supposed to go on and off 24 times...but mine was only going on and off roughly about 16 times. So we decided to pull the crank sensor out (and yes you can pull the crank sensor out of one of these when swapped into a square body...it's tight against the firewall, but it pulls out just fine) and replaced it with another brand new one I had. Once we did that both cam and crank sensors were working perfectly, but still wouldn't fire (but was trying to more than ever before). So we moved on to checking fueling and found that my injectors were completely clogged up just from sitting. So we threw some starting fluid down the TB and the thing fired right up! We pulled the rail/injectors out and yeah, they are pretty bad. I ordered up 8 brand new injectors (not reman's) that I'm going to install and should be good to go.

I guess from my research, clogged injectors on any LS swap is a pretty common problem. So anyone doing this swap...this is defiantly something to check before fire up...probably worth just budgeting into the swap to purchase new injectors and call it good.

So it ended up being that I had a couple weird problems going on at once, but I'm happy now to actually know what was going on and know how to fix it now!

 

[Team208Motorsports]

I skimmed and didn't see this covered, thought I would share.

When doing an 8.1 swap and you plug off the oil cooler ports, the oil is then rerouted to the oil cooler bypass valve. I would remove the filter adapter and pull this valve as it is no longer needed. On our most recent 8.1 swap this valve was stuck, which gave zero oil pressure. You can also see the ports in the bypass are not very large. Another thing to keep in mind is the filter bypass no longer works with the cooler ports plugged.