L18 8.1L swap resource thread

[ZooMad75]

The tools are too expensive to buy. If they're absolutely necessary then I have to find a place to rent or pay somebody to change it. I see guys on Youtube pulling the old one with sheet metal screws and installing with various objects like automatic transmission clutch steels. Just seems like with the rear cap loose the whole job becomes very easy, but I'll look it over more closely.

There is no doubt this is a case of the right tool for the job. The gm tool makes install of the seal a snap and hard to do wrong.

I'm sure there's a way to do it without the tool but I'd want the crank in place to aid in centering the seal and prevent the seal from inverting possibly.

I've got access to the correct tools since I work at a dealer so I'm somewhat spoiled. If Larry needs them for his stuff I just grab it and let him borrow it.

I don't know how well you know anybody at a local dealer, but knowing how infrequently we use the 8.1 tools at our shop I wouldn't be against loaning them out with a deposit I'd return if the tool comes back.

 

[RootBreaker]

The tools are too expensive to buy. If they're absolutely necessary then I have to find a place to rent or pay somebody to change it. I see guys on Youtube pulling the old one with sheet metal screws and installing with various objects like automatic transmission clutch steels. Just seems like with the rear cap loose the whole job becomes very easy, but I'll look it over more closely.

i did the rear main via a backwoods ghetto redneck way. i used a slap hammer dent puller.. lol.. drilled holes, screwed into it and lightly slap hammered.. did this a few times at 3, 6, 9, 12 o clock positions..
but first i cleaned the back that i could see and applied oil to help seal slide off..
took time but no need for those expensive tools.

 

[SpeedlabDan]

I'd recommend using the tool if you could find one. I did mine while the engine was out bc it was starting to leak slightly after 197k but I installed it the same way I would install Rockwell hub seals with grease packed in the spring side to help retain it. Unfortunately I didn't know the spring had fell off the back side once installed and it wasn't until driving the truck I realized it had failed.

 

[RootBreaker]

Swap info:

- The L18 8.1L has the same foot print as older BBC engines and will bolt in the same as any other older SBC and BBC. In fact, the L18 will accept any exhaust manifold or header from older BBC engines. The starter motor from any older SBC and BBC for use with a 168 tooth flywheel will also fit the L18. Any transmission from an old PowerGlide, TH350, TH400 to Allison, to NV4500, etc. will bolt on to it as well.

Today I am going to run out and get the flywheel bolts to put my 1991 sbc 350 flywheel/clutch and pressure plate on....

I tried putting my starter on, and the holes on my starter dont seem to take the bolt. ill have to post pics later but i found it odd that i couldnt get my starter on. i have to dig up my sbc 350 starter bolts out to take a look at the difference.


now my engine didnt come with an alternator. So, what would be a desired alternator to add?

 

[RootBreaker]

Sadly, I've pro been chasing these issues due to this the entire time. It has been a long road but at least at this point I know everything except the block at brand new... Here's the part number and application I ordered. It covers a lot of models but should be correct for my application.

View attachment 347987

View attachment 347988

is this part needed for the swap into our trucks? wow did I miss this?
while my first engine i bought came with wiring harness and ecu, it did not come with this...

but this second engine.... HAS IT!!!!!!
so i best save it.. i was looking at it last night going.. i have no clue what this is.. and if i need it...

 

[RootBreaker]

As I’ve been prepping @ZooMad75 8.1 the past few days I was able to grab a few clear photos of the method to remove the oil bypass valve for those that chose not to run engine oil coolers…or just simply don’t have the real state to mount a cooler anywhere. The update is at the bottom of Post 24 on Page 2 of this thread

so is there a reason to not run the cooler? that is my next thinking.. my current engine has the cooler lines and they were not cut. Now I dont know if they will be long enough to stretch to wherever I may need the cooler to be..
just thinking ahead if its worthy of doing it or removing it.. as im prepping my engine slowly...

 

[RootBreaker]

check this link out.. they put them in a corvette and one guy drilled the heads to put his valve covers on!!!!

https://www.digitalcorvettes.com/threads/8-1l-496-its-a-done-deal.151094/

 

[ZooMad75]

Today I am going to run out and get the flywheel bolts to put my 1991 sbc 350 flywheel/clutch and pressure plate on....

I tried putting my starter on, and the holes on my starter dont seem to take the bolt. ill have to post pics later but i found it odd that i couldnt get my starter on. i have to dig up my sbc 350 starter bolts out to take a look at the difference.


now my engine didnt come with an alternator. So, what would be a desired alternator to add?

You'll need a big block flywheel. Specifically gm 12582964 and 12563485 for 6 bolts as they are one time use.

Your small block clutch and starter should bolt up.

The cs144 is a non-pcm controlled alternator is what Larry and I use on ours.

 

[Larry]

so is there a reason to not run the cooler? that is my next thinking.. my current engine has the cooler lines and they were not cut. Now I dont know if they will be long enough to stretch to wherever I may need the cooler to be..
just thinking ahead if its worthy of doing it or removing it.. as im prepping my engine slowly...

The reason not to run a cooler is when you don’t have room for one, like mine. The trucks that these engines were made for were made to be tow pigs where added cooling and capacity was needed. If you have room, certainly use the cooler but don’t bother with those factory cooler lines. They suck and if they aren’t leaking now, they will be in 10 minutes. Make lines out of AN hose and fitting instead if you decide to use a cooler.

 

[RootBreaker]

The reason not to run a cooler is when you don’t have room for one, like mine. The trucks that these engines were made for were made to be tow pigs where added cooling and capacity was needed. If you have room, certainly use the cooler but don’t bother with those factory cooler lines. They suck and if they aren’t leaking now, they will be in 10 minutes. Make lines out of AN hose and fitting instead if you decide to use a cooler.

thx..
since i now need a flywheel.. im skimpin on funds so will keep the oil adaprer to possibly use in the future

 

[RootBreaker]

You'll need a big block flywheel. Specifically gm 12582964 and 12563485 for 6 bolts as they are one time use.

Your small block clutch and starter should bolt up.

The cs144 is a non-pcm controlled alternator is what Larry and I use on ours.

Yes I tried my flywheel and the crank hole isnt big enough. oh well.. gotta get one.

well starter bolts go into outside bolt holes but too big to go through holes on block side. safe to drill out?

so what alternator did you two go and get? ill have to go through the entire thread again and catch all new notes I may need. in my build thread, i put together a lot of stuff for me. I will have to add to my list.

in addition, I didnt have the TAC before.. so since it is $185-$250 for one... and one came with the engine I got, guess I cant complain about the need of a flywheel.

 

[ZooMad75]

Dude, go back and read the details. It's pretty evident that you don't have all the facts straight.

I gave you what he and I use in my previous post.

The cs144 is a non-pcm controlled alternator is what Larry and I use on ours.

To be more specific, 96-99 k2500/3500 with the L29 454.

Don't drill the block out. The 8.1 bolts are metric.

 

[RootBreaker]

Dude, go back and read the details. It's pretty evident that you don't have all the facts straight.

I gave you what he and I use in my previous post.


To be more specific, 96-99 k2500/3500 with the L29 454.

Don't drill the block out. The 8.1 bolts are metric.

hah thanks.. i need it spelled out as im a very slow person!

I needed that exact that you gave... thanks..

i wasnt saying drill the block out.. but the actual starter holes. like I said... the 8.1L starter bolts will go into the starter but then the holes are smaller on the next spot the bolts need to go through... so i was wondering if it was ok to just hone them a bit.

 

[RootBreaker]

8.1L starter bolts...
96 sbc starter

 

[Larry]

8.1L starter bolts...
96 sbc starter

Yes, you can drill out the starter to make clearance for the fatter bolt but be careful…….if the starter is not mounted straight you’ll have a fangled up gear mesh issue that will eat the ring gear.

 

[RootBreaker]

Yes, you can drill out the starter to make clearance for the fatter bolt but be careful…….if the starter is not mounted straight you’ll have a fangled up gear mesh issue that will eat the ring gear.

i will buy the correct started. was told mine will work and i dont see that happening

 

[RootBreaker]

My cousin said there is a difference between flywheels on a 2500 and 3500.. never knew that.. i did order it so had to cancel .

 

[SpeedlabDan]

You'll need a big block flywheel. Specifically gm 12582964 and 12563485 for 6 bolts as they are one time use.

Your small block clutch and starter should bolt up.

The cs144 is a non-pcm controlled alternator is what Larry and I use on ours.

How come you guys run the cs144 alt? I missed that. I ordered a stock alt and it plugged right in to my Howell harness

 

[SpeedlabDan]

is this good? half the price..

https://www.ebay.com/itm/392400412406

Is there an actual difference in a 2002 8.1L between a chevy and gmc... ? 2500 and 3500?
in that link.. if you select
2002, chevy, silverado, 2500hd, ls extended cab 4 door it says not compatible but they list all the 3500s as compatible.

I never trust eBay listing or most companies from Amazon either I'd get the part numbers and do the research yourself just to be sure.

 

[ZooMad75]

How come you guys run the cs144 alt? I missed that. I ordered a stock alt and it plugged right in to my Howell harness

Main thing is it's not pcm controlled. The 8.1 stock alternator is. Not that it's a bad thing. But like running cable throttle to simplify things, this simplifies the charging system. Plus it's widely available everywhere in 124amp and higher versions.