Ok adding my section to this. Was going to do my own but figured id stick it in here as it is not a high traction 5 million post thread. anyway.. I got through 3 pages to answer some of my questions. Got 13 more to go but gotta cook on the grill and family/eating time.be back later but thought I would share my notes I am taking.
correct me if I have some things wrong please..
this is jotted notes and all over the place. Tried keeping it somewhat organized and will clean it up later when things are confirmed...
8.1L questions...
Fuel
* High Pressure fuel pump - EP381 Fuel pump
* hoses - 2002 so fuel supply and return
* regulator - built into motor
* I worried about the 1987 pump assembly as it is just hose clamps but Larry said..so im good
1987 Fuel TBI fuel tank. The TBI fuel tanks are different from the older carb tanks.
now on the fuel lines. As I said I was worried and now read what I thought. Ok so my truck has a dual saddle tank setup and both lines go to the passenger side then go from solenoid up passenger side to motor.
I guess I can do what larry has listed here...
supply from motor 4-5 feet then put a filter in, click it in then take another hose and click it in and run back but
* What is the best way to connect to the tank unit? will a hose clamp hold?
* return - is it also a high pressure return or would it be just fine with a hose and hose clamps?
Fuel lines - (No pictures of these). I used supply and return fuel lines for a Workhorse RV application. These are really nice high quality steel braded lines about 4 or 5 ft. long with quick connect fittings on both ends. You will need to get creative with connecting the quick connect fittings to the lines on the frame. I used a GM fuel filter with a built in quick connect fitting (late model Silverado application) then made up something to connect the quick connect fitting on the fuel line to connect to the frame line. The Workhorse part numbers for these lines are W0000539 Supply, W0000540 Return.
Mounting Engine
* Big Block Motor Mounts - Energy Suspension engine mounts - which ones p/n?
8) There is a small nub on the driver’s side of the engine that will need to be ground down just a tad so the engine mounts will bolt to the engine.
* Motor Cross Mount - taken from thread and chopped for me
When swapping one of these engines into 73-87, the ORD HD engine crossmember works perfectly to address oil pan clearance.
7) You will need to rework the engine cross member to clear the oil pan.
* GU32005
* Trans - SM465 - pull guide pins and will bolt to motor
* Clutch - use current sbc 350 pressure plate, clutch, etc? read need to drill holes for metric bolts for clutch? gotta read
read this but what if you already have a manual in truck - still use parts or need these?
* I ran a SM465 behind mine for the first 2 years as well but you will need an 8.1L specific flywheel and pilot bearing (12582964 is the flywheel, 12563485 flywheel bolts & 12557583 pilot bearing).
If not then need
12582964 Flywheel
12563485 Flywheel bolts
* Exhaust - will come with stock manifolds - hear hits frame so either notch frame or bbc shorty headers - which? answered in thread from Ben as well pg1
5) I don’t recommend using the 8.1L exhaust manifolds as they will hit the frame on an older truck. Any big block header or exhaust manifold (396, 402, 454, etc) will fit the 8.1L.
* Alternator - wire for charge goes where? gonna be bigger than my 60a I assume...
* Reading that low mount AC hits frame, but I do not need AC and have this style bracket - just remove and smaller belt?
Wiring
I am new to this but was told it is a stand alone harness pretty much so I am guessing just supply some basics like power, ground and go?
Will have to tie into the gauges so more to do then. I understand that it is great to get a clean howell harness but for now i need to
get it installed, up and running then in 1-2yr would pull motor to rebuild and do clean harness if it is needed...
* Where to mount pcm
The Workhorse W0000393 ECM housing is the plastic piece the ECM snaps into.
These part numbers make up everything in this picture below that the ECM is mounted to. This is actually a Workhorse ECM mounting setup with provisions for an Allison TCM on top. I just used the TCM bracket as a cover per’se.
15764028 BRACKET - PCM
W0007848 BRACKET - TCM
15003790 x2 BRACKET - TCM legs
* Is mud going to be ok to get on it - you saw my stuck
* EGR REmove and block plate - need to do
What to replace on motor before installing or after installing but immediately?
(answered to Ben's question on pg1 - yes I am reading it!!!)
1) I would replace the spark plugs, wires, and crank sensor and that’s it. These engines are simple and usually free of any oil leaks. The Early 8.1L crank sensors have a habit of failing so definitely get a new one. All crank sensors from GM parts have been superceeded to the new design. Once you put the 8.1L engine in an old truck you will not be able to replace the sensor without removing the engine so do it now. The sensors are around $65 but I don’t have the part number for it.
* Crank Position Sensor? - $50
* Plugs/Wires - ? meh run it for a bit
* Oil / Filter - no brainer
Gauges -
* currently 1960's dump truck setup with fuel/tach (5k but going to change to 7k later)
* Mechanical oil gauges
*stock fuel/tach combo
http://www.summitracing.com/parts/MSD-8913/
future:
Idea is to get one and installed. Later can worry about clean harness, rebuild, leaky motor, dual tanks, etc..
side notes
Russell said - The 8.1L PCM is capable of managing dual fuel tanks. Get a tune from a cab and chassis 8.1L truck equipped with dual tanks, provide a fuel level signal from each tank and the PCM will operate your existing transfer pump to maintain the level between the two tanks. The fuel tank module you speak of is old technology. The PCM just controls a fuel pump relay for the transfer pump.
Russell again as I have a manual - I do have a dual tank cab and chassis OS but it is for a ZF6 manual transmission truck.
Larry notes
* My suggestion is to have them toggle off Torque Management, Toggle off EGR (and remove it from the engine), then add their “Hot” tune.
* Then when you get it running bump the fuel pressure up to about 67-68 psi and you’ll have a very strong runner that will start to find weaknesses elsewhere in your driveline .
* I ran a SM465 behind mine for the first 2 years as well but you will need an 8.1L specific flywheel and pilot bearing (12582964 is the flywheel, 12563485 flywheel bolts & 12557583 pilot bearing).
I have a 1991 caprice police hydraulic roller 350 in the truck now..nothing special just an L05 block. could this be an internal balanced setup which is a 1 piece rear main...?
You know, I wouldn’t be surprised if an internally balanced 1 piece rear seal 5.7L flywheel would work on an 8.1L just fine. I’ve never had one laying around to test fitment on the 8.1L. The only real difference I recall noticing on the 8.1L flywheel vs. the typical 350 flywheels was the 8.1L used large metric holes for larger bolts to fasten the pressure plate to the flywheel as well as the dowel pins to center the pressure plate. Those two things may be what make an 8.1L flywheel a specific part number. You would need to hog out the holes in the pressure plate to fit the 8.1L pressure plate bolts and the dowel pins need to be removed in order to use an older clutch anyway. It might be worth trying a 5.7L flywheel. That would save me money in a few months too as I could reuse the 5.7L flywheel in my Burb when I do the 8.1L swap in it. If you go that route, let us know!
I remember in the old days my dad used a 350 flywheel on an internally balanced 396 big block then later on an internally balanced 427. He ran that setup for decades. Maybe we'll get lucky with these modern engines too
