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L18 8.1L swap resource thread

I will take the evap advice, my truck is all stock so I still have all the emissions stuff.

I was pretty excited to get the van engine, all the good stuff and its an '02 so adjustable fuel pressure. It was a musicians tour van down in Denver. Van was hit hard in the passenger side by a drunk while the guy was playing a show in the bar. He only had liability on it, drunk guy took off. I gave him $1000 for it and then used 2 rolls of duct tape to seal the bent door up. Drove it up to Wyoming on US85 with no issues. Great score.

I talked to Howell this afternoon. They were able to answer any questions I had and were very helpful. I see no reason to reinvent the wheel here and will likely get the harness and tune from them. Do you think the "hot" tune you have is worth needing to run 91 octane all the time? I would prefer to run regular gas but we all want max power. Its not my daily driver so a bit of extra cash at the pump might not be terrible.
 
Seeking cam and crank sensor clarification - Should I order year-specific units or go with the updated/latest year engine model?

Specifically:
I have a 2001 8.1L - should I order AC-Delco 213-1063 Cam Sensor and 12575172 Crank Sensor and do these include the upgrade for durability mentioned in page 1?
 
2Dogs said:
Seeking cam and crank sensor clarification - Should I order year-specific units or go with the updated/latest year engine model?

Specifically:
I have a 2001 8.1L - should I order AC-Delco 213-1063 Cam Sensor and 12575172 Crank Sensor and do these include the upgrade for durability mentioned in page 1?
Click to expand...

There is only one Crank sensor, as the earlier design crank sensor was superseded many years ago so no issue there. 2001 is kind of an odd duck on the Cam sensor side, which RayLar has a nice write up on that. If the engine is out and you have time on your hands, I would update the cam sprocket and timing cover to the later design and use the later design cam sensor. If you have a truck dead in the water, I’d just replace the sensor. For a while 2001 sensors were completely unavailable as stated on RayLar’s website but Rockauto now lists some for 2001
 
To my knowledge, with the crank sensor, it doesn't matter what year you put in when ordering, all of them are the updated sensor, so you should be fine there.

As far as the cam sensor goes, that is year specific. There is a 2001-2003 year/style sensor, and a 2004+ year/style sensor. There has been some debate on the interwebs on the availability of the 2001-2003 style sensor and if you can get it. Some say you can't get it anywhere, others have said if you take time to look, you can find the sensor, just maybe not at your local parts stores. Most, if they start to have an issue with their 01-03 year sensor, opt to swap out the whole system our for a 2004+ style system, which includes swapping the timing gear, timing cover, and cam sensor (I'm pretty sure the chain itself is standard across all the years, but could be wrong).

I may be missing something with this, and I'm sure someone will correct me if I'm wrong
 
A snow day at work means I finally got a chance to check out the 8.1 I bought from @ktmoutfront
It's pretty clean inside and the intake runners were taped off to keep foreign objects out. I don't see anything out of the ordinary but this is the first 8.1 I have been into. It is a bit land locked right now and I cannot get to it with a crane/forklift to pull the pan. Looking good so far! Damn those intake ports are huge!

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yes there HUGE intake runners . i got a old school friend who stopped over a few months ago and asked what in the hell is this engine i had on a stand ? ? ?

i told him a factory 8.1L or 496cid and he was blown away with the intake size of the ports.

also as said propane = clean engine inside as its a cleaner burn over dirty dino oil .
 
Hey @Larry

I have a question for you. My dad and brother just picked up a 2003 C5500 with an 8.1 in it. On the way home with the truck my brother noticed the truck felt very under powered. So he called me to pick my brain and I told him maybe a tune up and a fuel pressure bump would help the truck. But today while checking his VIN and RPO codes for this truck, we came across an option code of LQR POWER OPTION GMPT V8, 8.1L, 225 NET HP @ 3800RPM GM V8 225 HP(LQR). Is this a factory detune for gov't vehicles?

To me that shows ~100hp loss.
 
GWeakland620 said:
Hey @Larry

I have a question for you. My dad and brother just picked up a 2003 C5500 with an 8.1 in it. On the way home with the truck my brother noticed the truck felt very under powered. So he called me to pick my brain and I told him maybe a tune up and a fuel pressure bump would help the truck. But today while checking his VIN and RPO codes for this truck, we came across an option code of LQR POWER OPTION GMPT V8, 8.1L, 225 NET HP @ 3800RPM GM V8 225 HP(LQR). Is this a factory detune for gov't vehicles?

To me that shows ~100hp loss.
Click to expand...
Sounds like a cool truck! Ya, there were some fleet options on the Medium Duties to lower the power rating. I don’t believe there were any hard part differences such as cams, etc. but more on the calibration side. Sounds like some tuning is in their future.
 
Larry said:
Sounds like a cool truck! Ya, there were some fleet options on the Medium Duties to lower the power rating. I don’t believe there were any hard part differences such as cams, etc. but more on the calibration side. Sounds like some tuning is in their future.
Click to expand...
Awesome. Thanks for the help sir!
 
So I did a compression test on my 8.1 last night and all cyl were between 155 and 170 psi. I will soon start collecting the necessary gaskets {intake/oil pan, etc} and start rounding up things like updated intake bolts and cam/crank sensors.
As I am not really adding any resources to this thread I will post future updates in my 28 day build thread as that is where this engine will probably end up.
 
Just throwing it out there - If anyone happens to have one of the stock cast type 12558927 PS/AC brackets for the Express vans / medium duty / Workhorse rigs available for sale please let me know! I can get one with the ZF type pump locally, but it seems the supply is dried up on them as well at GM. I will be running this in a non-AC vehicle, so I will need the ability to put an idler on for the AC delete. I've sent a message to the guy who fabricates the replacement brackets to see if he can supply one with provisions for the idler but haven't heard anything back from him.

I've just bought an 01 3500 cab and chassis for it's engine to swap into my Chevelle, so it's time to get serious about ordering some parts up.
 
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I've been searching for a while in our Heavy Truck LKQ yards to try and find one of those brackets. If I happen to stumble across more than one, I'll shoot you a message. But I have been working on this for 2 months now.
 
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