John Bzdel's

1988 Monte Carlo SS

LS1/T56 Change-over page

August 2001 Project Updates

08/05/01  Clutch pedal assembly final installation

I want to get everything ready now for the final installation of the drivetrain.  I needed to get the clutch pedal assembly installed first.

• First I needed to locate the two holes for the clutch master cylinder.  For some reason (maybe because I haven't been focused here for over 3 weeks!) I had difficulty locating the holes from the bench top clutch pedal fixture to my firewall.  I created a simple "Junkyard Wars" style locating tool based on several metal pieces lying around the garage.  I located two holes from the steering column plate that mounts the column to the firewall and then one stud into the lower right-hand brake booster hole for a third reference.
• This view shows the locating tool and this one shows it set up on the bench top mock-up.  I used the bolted it in place in my car and it worked perfect!  The holes were located to within 3 decimal places of the bench top fixture (overkill but oh well!).
• This view shows the clutch master cylinder being fitting through the old cruise control hole after I slightly elongated the top and bottom of it about 1/16".
• The LS1 clutch hydraulic line to the slave cylinder has a restrictive orifice which limits fluid travel down to ~1/16" and can cause issues with apparent grinding of 2nd & 3rd gears at high RPM since the clutch may not fully dis-engage or engage fast enough during shifts.  This view shows a discarded line cut-off (to reveal the restriction) where the fitting installs at the clutch master cylinder.  I drilled this hole in the line out to 7/64" to eliminate a potential problem here.  I had to use a stock F-body discarded slave cylinder (with the bleeder nut cut) to back bleed the line with compressed air to remove the metal shavings.
• Installation of the pedal assembly was a breeze.  Here is the completed installed clutch and brake pedals with new OEM rubber pads installed!  Nice!
• I mounted the clutch master cylinder reservoir onto the power booster with a 3rd Gen Camaro OEM booster bracket.  Looks like the Monte came that way now!
• I also needed to cover the holes in the floor created for the 200R4 shift linkage.  I used a piece of metal from where the shifter boot was cut and welded it in place and then put a quick coat of paint over it.  I will seal this area also.

Next I am moving to the AC/heater shroud for removal of my damaged unit.  This thing is a pain!

08/12/01  Begin final assembly

I am really trying to get serious this week and see if I can get the car ready to fire-up this next week so I apologize in advance for having limited updates and pictures this week.  I will go back after the fact and add pictures with text for this weeks' update since I will be spending a lot of time in the garage.

• I finished building a locating/weld jig for close tolerance motor mount fabrication.  I test fitted a completed pair of mounts in the chassis to verify jig accuracy and the LS1 motor was a perfect fit.  I will be offering these motor mounts which are specifically designed for the G-body for $145 + shipping.  I will later verify if they fit other vehicle applications too.  This pic shows a completed motor mount.
• The AC/heater shroud has been removed and replaced.
• I removed the F-body fuel rail and replaced it with the '97-'98 C5 dual line unit.
• The oil pan was re-installed with a new gasket.
• I found a location on the LS1 (same location as a std. SBC) for an oil pressure sending unit.  I had to drill a fitting on the block which is left unused on the F-body but appears to be an oil temperature sending location in the C5 LS1.  I drilled the fitting with an 11/32" drill and tapped this unit for 1/8" NPT threads and installed my L69 oil pressure sending unit.
• I also added a temperature sending unit to a spare hole location in the passenger cylinder head directly adjacent to the #8 cylinder head.  I oversized the hole using a 37/64" drill bit and tapped the hole for the correct 3/8" NPT threads.   I then installed the stock L69 temperature sending unit.  Not knowing if the LS1 PCM oil and water temperature lead wires provide a digital signal or not I will have the analog sending units available just-in-case!  This view shows the original cylinder head threaded plug, compares it to the sending unit and shows the sending unit installed.
• I re-installed the modified LS1 wiring harness back onto the motor.
• Since I had taken out my power steering box when I painted the engine bay I elected to take this opportunity to replace it with a 3rd Gen F-body IROC "XH" steering box designed with adjustable stops to prevent the front tires from rubbing at full turn.
• I installed a new throttle cable from a '99 F-body.  The F-body unit is a lot longer to reach the throttle body up front.  This view compares the L69 vs. the longer LS1 cable.  I had to slightly enlarge the existing firewall hole using a 13MM drill bit (just over 5/8") to fit the round shaped retaining clip as opposed to the stock G-body rectangular shaped unit.
• The motor mounts were bolted in the chassis using (4) 10M x 1.5 bolts for each mount.
• I replaced the stock F-body pressure plate, clutch disc and flywheel with P/N 12562765 from the 2001 LS6.
• Prior to connecting the transmission to the motor I went ahead and also replaced the clutch hydraulic slave unit located on the front of the T56 with an upgraded P/N 15046288 which is from a 2001 F-body.
• With the engine and transmission bolted together as a unit I carefully lowered the assembly into the chassis.  I left the driver side exhaust manifold and starter off of the motor to make the installation a bit easier since this provided additional clearance at the rear of the motor mounts since with the transmission attached I needed a steep installation angle to clear the front radiator support with the oil pan and transmission yoke at the firewall/transmission tunnel.  I installed the rear Crossmember brackets, rear Crossmember and installed the engine mount through bolts.

08/13/01  Final assembly continued

Final mechanical assembly continues....

• The modified (shortened) Driveshaft was re-installed completing the drivetrain installation.
• I found an 18MM x 1.5 stubby bolt that I could use to plug the OEM oxygen sensor hole on the drivers side exhaust manifold.  This pic will show a view of it.
• Using a new OEM gasket I re-installed the drivers side exhaust manifold to the motor.
• I installed the starter motor.
• With some very minor tweaking (slight downward bend in the line) I installed the power steering lines to the new IROC steering box.
• I connected the throttle linkage to the throttle body.
• I attached an F-body ground wire located from behind the alternator (attached to the block) to the frame.

8/14 through 8/18/01 Final assembly continues

• I refused to use any portion of the worthless crimped stock F-body drivers side Y-pipe after the CAT on my car so I mocked up the proper fit of the exhaust routing between the CAT and my existing G-body exhaust pipe with a piece of 2-1/4" flex-tube. This view shows how I tack welded a couple metal strips to the flex-tube so that it would retain its shape long enough to enable a local muffler shop to properly bend a replacement pipe.
• This view shows where I had to cut the stock G-body Y-pipe and how the new head pipes and CATs will look once installed. I also needed about a 5" section of pipe to splice together the passenger side exhaust. I proceeded to weld the pipes together under the vehicle. The exhaust system is now complete.
• I had the flexible stainless steel fuel lines fabricated to connect the frame mounted hard fuel lines to the intake manifold mounted C5 fuel rail at the same local Industrial Hose supply shop that brazed the ends of my frame mounted hard fuel lines This view shows the stainless flex lines installed.
• Since I was not installing the EGR valve (interfered with my A/C bracket & when I modify the motor with the LS6 intake manifold it doesn't use an EGR valve either) I had to plug the EGR tube inlet hole at the intake manifold behind the throttle body. I stopped by the local hardware stock and bought a tapered rubber plug which fit perfectly into the EGR intake manifold tube end fitting once I cut off the EGR tube. I installed this rubber plug with high temperature silicone sealant where the tube was removed to prevent a potential vacuum leak. I then installed this assembly back onto the intake manifold with the OEM O-ring and 8MM bolt
• I still wasn’t really satisfied with the minimum clearance (about ¼") between the rear of the passenger coil bracket and the A/C-heater shroud. I removed the passenger side valve cover and ground away part of the raised boss which retains the coil bracket to gain about an additional 3/16" of clearance. I also ground part of the bracket here and the attaching bolt face adjacent to the shroud to maximize clearance.
• Since the #8 coil was now turned approximately 45* to again maximize clearance, the spark plug wire was about 1" too short. I went to the local Chevy Dealer and bought one new spark plug wire for a ’99 & newer 5.3L truck since they are ~2.5" longer than the F-body OEM wires and have the exact same special connector end for the coil.
• Next in I installed the A/C condenser with the passenger side A/C hose connection fittings which came out of the mid-‘80’s Olds G-body in front of the radiator.
• To save a few more pounds up front I installed a new aluminum (as opposed to the stock heavy brass) radiator designed for an ’89 IROC Z. This unit also comes with lightweight plastic side tanks and virtually bolts right in without any modifications required.
• I installed an ‘86/’87 GN/TR electric fan and top radiator trim plate which retains the radiator. This is a two speed fan which has the speed controlled by routing the power feed through a large resistor for slow speed operation and directly to the fan for high speed. Two relays are required to operate the fan in the two speed mode.
• I found a pair of electric relays with the correct wiring connector for the GN/TR fan on a wrecked ’88 Midsize Olds. I mounted the relays on top of the A/C-heater motor blower with an existing bolt. I also found an ’85 Monte Carlo OEM  passenger side inner fender mounted battery terminal power junction block which attaches to pre-existing piloted holes on the engine compartment side of the fender to provide positive12V power to these relays. I connected the 12V positive PCM lead for the fan to these relays and also the correct low speed and high speed PCM fan leads to the corresponding relay.
• Trying to determine placement of the F-body PCM was a little frustrating because of the limited length of the stock F-body engine wiring harness so I would not be able to locate it inside of the passenger compartment where the L69 computer resided. I determined which wires I wanted routed to the interior passenger compartment and then installed the passenger side inner fender with a new battery box too since my original one showed severe signs of corrosion. I really couldn’t find a good place to put The LS1 PCM "out of sight" so I elected to mount the PCM on the passenger side inner fender top directly adjacent to the A/C accumulator where the stock G-body radiator overflow bottle is mounted. I will have to relocate the overflow bottle next to the radiator and find another overflow bottle to work here.
• I found a mid-‘80’s Celebrity overflow bottle which could be fitted in front of the battery next to the radiator. I will use this as a temporary set-up until I have time to determine what other options exist.
• The re-wired LS1 engine harness came with a fuel pump relay and positive lead wire for the tank mounted electric fuel pump. I extended this line back to the fuel pump by grafting an OEM fuel sending harness body mating end and integrating this "+" lead, attaching a ground wire and splicing the fuel sending unit wire to connect to my OEM body harness connector.
• I installed my fabricated A/C bracket and LT1 compressor after I had the aluminum bracket bead blasted and clear satin lacquer finished for a nice protective finish which matched the look of the other aluminum engine components.
• The original mid-‘80’s G-body V-8 Olds A/C hoses didn’t want to fit now due to the computer location. I found an A/C hose assembly from a mid-‘80’s V-6 Olds set-up that seemed to work just fine now except I later found out that the connection at the compressor is different even though it appears to bolt up properly.
• The intake system in front of the throttle body required some specialized pieces to function properly. I went to my local fuel line fabricator and found a special 90° rubber elbow which had a 4" diameter end to fit the throttle body on one end and a 3.5" end for the Mass Airflow Sensor (MAF). I also found a 3.5" to 4" diameter reducing sleeve that would connect to the balance of the metal intake tract and air filter. I went to a local muffler shop that has Mandrel pipe bending capabilities and had a 4" metal tube specifically bent per my specifications to route the intake air from the MAF through the radiator support for fresh air to the motor. I attached a 4" inlet diameter K&N conical filter end (P/N R-40-0008 RAM) to this intake pipe. It looks very intimidating in the flesh!
• Since I did not plan on using the F-body OEM Intake Air Temperature (IAT) Sensor due to my intake tract plumbing I inserted a 4.7K ohm 1/2 watt resistor into the wire harness end to simulate a constant 57° air intake temperature and then sealed the end with electrician's tape.
• I waited until the intake system was installed to judge clearance requirements for the upper radiator hose. I had a local Auto Parts store get a stock ’99 F-body upper radiator hose (w/o power steering cooler) for me so that I could verify fitment. It was too short on the end where it needed to connect to the LS1 water pump. I used this as a data point and went back in their stock room with an idea of what I wanted and found a hose which I believed would fit (NAPA P/N 7620). I then test fitted the hose and cut each end to fit properly.

• For the lower radiator hose I ordered up a hose designed for a ’99 & newer 5.3L truck. I trimmed it to fit on both ends and it worked out just fine. I used the plastic protective shield that came with this hose and installed it on the upper radiator hose next to the MAF sensor to prevent potential contact during engine torquing.
• I pulled the PCM wires into the passenger compartment where the L69 computer sits and connected a 12V "+" continuously hot lead for PCM memory and a switched 12V + to the PCM.
• I debated on what to do with the existing Monte Carlo engine wiring harness. I finally decided to just eliminate the wires which were no longer required. The only remaining wires that I used are the starter leads, water temperature sending unit, tach lead, volt gauge lead for the alternator, oil pressure sensor and a power and ground lead for the A/C since it has the correct connector end to mate with the existing A/C wire harness which comes through the A/C-heater shroud.
• I routed the vapor canister hose around the brake booster and connected it with a ¼" reducing plastic connector to the LS1 vent valve vacuum solenoid located on the intake manifold.
• The 1/8" vacuum line for the A/C-heater was routed and connected to the 1/8" vacuum line which came off of the rear of the LS1 intake manifold.
• The heater hoses were connected and I elected to route these under the A/C bracket to keep the engine bay looking less cluttered directly to the fittings on the water pump.
• Work in the engine bay is basically complete now with the exception of connecting the A/C hoses properly connected and system charged. Since I need to be able to have the water pump functioning properly I elected to install the stock F-body serpentine belt which would not activate the newly located A/C compressor until I have the system finalized.
• The stock ’99 F-body battery cables that came with the motor were a perfect length and bolted right up to the battery.
• At this point the hood was re-installed by aligning the scribe marks that I made on the underside of the hood at the hinges prior to removal. This made the fitment perfect.
• Moving on to the interior, I made a cardboard template based on the ’93 F-body console boot to cut out the stock Monte auto shifter console trim piece to accommodate the T56 shifter. I proceeded to cut the hole out with a die grinder and then finished the net trim with a reamer attached to a drill. The boot assembly now just snaps in place! I temporarily fit the C5 T56 shift knob onto the shifter end by forcing it onto the stick until the undersized threads were ready to engage. The stock console bolted down in the rear in its stock location! I will still need to install the front bracket to anchor the front half of the console.
• The proto-type 200 MPH speedo and 8000 RPM tach were installed and the rest of the gauge cover components. I noticed that my OEM plastic bracket which secures the light knob was cracked and actually broken in all three mounting locations. I bought a new piece (GM P/N 14086212 for ~$3) through my local Chevy Dealer. I would recommend getting this part while it is still available! I will still need to connect a speedometer adapter/calibration box which uses a VSS signal from the PCM to drive a mechanical cable for the speedo to work correctly. More details here will be forthcoming soon.
• The brakes were bled since I had installed the 8.5" rear end and disconnected the brake lines.
• The hydraulic clutch was also bled to remove air in the system caused by drilling out the restriction point and installing the new slave unit in the transmission.
• Fluids just need to be filled now for the trans, engine, power steering, brakes, clutch reservoir & radiator!

08/19/01  My LS1 breathes it first air in a G-body!

First off let me say that I apologize for the lack of detailed updates this past week.  I was on a mad rush to get the car ready to go to the local Pacific Northwest High Perf Chevy Show at Seattle International Raceway (SIR) today and missed attending by about 6 hours :>( oh well!  Working on the car and posting web updates just didn't give me the time I needed.  This next week I'll try to get all of the updates from this past week updated and current.  Now on to the good stuff!!!

• After filling all of the fluids as a safety precaution I rolled the car out of the garage before attempting to start it.
• Once the wiring was connected with the proper "hot & ignition on" for the PCM I turned the ignition key to only the "on" position, heard the fuel system & pump relay run for 2 seconds like it is supposed too, cranked the starter and NO START!  I thought, what the heck is up with this?
• I blew the 10 AMP Ignition/ECM fuse after I could hear the fuel pump prime the fuel system.  I replaced the fuse several times and blew several more.  Hmmmmmmmmmm.......very frustrating after getting the mechanical portion of the installation this far.
• I consulted long distance with "Crazy Bill" (as he is affectionately know on the "Monte Mailing List" since he is a "Jedi Master", well seasoned TPI/LT1 G-body retrofitter) to explore my concerns regarding the LS1 PCM wiring and fuses and he suggested a 20 AMP fuse based on the LT1's.  The PCM/ignition fuse in a G-body has only a 10 AMP OEM fuse for the L69 ECM and the LS1 PCM apparently needs a larger fuse too! 
• Installed a 20 AMP fuse and music to my ears!!!!!!!!   The LS1 fired up and ran smooth as silk!  It is very, very quiet even with real dual exhaust.  Very different tone as compared to the SBC too.
• I checked for leaks and noticed that everything seemed fine with the exception of a small oil leak where I had located an external oil pressure sensor above the LS1 oil filter.  Since this was dripping oil on the drivers side CAT I elected to not test drive the car until this is fixed.
• I washed the car and took this pic while still wet so that you can see it in running condition!
• I also snapped this interior view of the Shifter, pedals and although hard to see clearly, the killer proto-type 200 MPH speedo & 8000 RPM tach installed.
• Once dried off, I engaged the clutch and LS1 self-powered the car into the garage!

The debugging process will begin now to ensure everything performs as expected.  I know that I have trouble codes since the SES light is on (as expected) so I will need to isolate all of the issues so that the car will run properly.   I purchased an ATAP to aid in the diagnosis.  I will also have to get the A/C a new set of hoses and have the system charged before installing the pulley belts.  I'll be driving shortly!!!

I was up until 3:30 AM last night trying to get things ready to go and was up before 9 AM this morning and it is pushing Midnight now so needless to say I am a bit tired.  I have spent a lot of time with the car this past week so I will spend some quality family time this week too so please be patient with updates.   And yes it feels great to have it running!!!!!!

8/25/01 The LS1/T56 takes it’s first flight!

I was able to fix the oil leak by removing the driver side CAT and tightening the fitting into the oil pan side adapter fitting. I also discovered a very minor leak at the fuel filter inlet, which required a slight turn on the fitting to stop. I was cautious tightening everything early on to ensure not stripping any threads. I always figured that I could give things a final tightening if leaks were discovered. As it turned out these were the only two leaks of any kind and were easily fixed!

• Just installing the L69 oil pressure sending unit as I initially did directly into the adapter caused an interference with the CAT.  This view shows the plumbing (1/8" NPT 90° street elbow, 2.5"L threaded tube & female connector) required for the oil pressure-sending unit to clear the CAT. 
• The attached harmonic balancer for the front input shaft on the Driveshaft did not want to adequately clear the factory body pan brace. I took this opportunity to fabricate a Driveshaft safety loop to bolt in its place. This view compares the stock sheetmetal brace with my welded ¼"Tx2"W unit that bolts into the same underpan factory bolt holes using longer bolts to compensate for the added thickness.
• In order to secure the air intake tube/filter assembly properly I welded on a 1/8"Tx1/2"W metal tab to the side of the intake tube and attached it to the upper radiator support using an existing hole and placing a nutplate here for an 8MM bolt.
• In order to obtain full throttle I had to unbolt the accelerator pedal and put it into a vice to enable bending the top cable receiving end about 1-1/4" to take up the additional slack caused by the longer F-body throttle cable. A quick re-installation verified full throttle now with the accelerator fully depressed!
• I was concerned that the radiator fan didn’t come yet since the water temperature (according to the factory gauge) was about 220°. I shut things down to prevent overheating and consulted the ’99 F-body service manual and noted that the primary electric fan was supposed to come on at 223°. I fired up the motor again with a cooking thermometer in the radiator and sure enough, at the designated temperate the fan came on! Now we’re ready to drive!
• I backed the car out of the garage wheeled around the driveway, stopped, then and turned onto the street. As I eased out the clutch again and gave it only a small amount of throttle the car accelerated very smoothly and quietly. As I upshifted I noticed that the T56 shifted effortlessly!
• After a quick stop at a local gas station I proceeded to run the car through the gears at a somewhat brisk ¼ to 1/3 throttle acceleration. WOW!!!! The sound created by the huge 4" intake tube/K&N filter assembly is wicked and actually overpowers the sound of the DynoMax dual mufflers and the combination of the two emitted the sweetest high performance authoritative roar that sounds similar to a NASCAR type sound that just brings the biggest grin to my face and has made this whole effort worth every dime spent and hour worked!!!!!!!!!!
• Next I went onto a lightly travel local the freeway for a few full throttle blasts. I ran the car in 2^nd & 3^rd gears until rev limiter kicked in to determine where I should guestimate shift points on my tach face since my tach currently reads about 60% slow until I install and have the Abbott Electronic Ratio Adapter box connected and calibrated to account for the LS1’s unique square wave tach signal. I ran the car again at full throttle and noticed a very nice pull throughout the upper RPM range…..definitely 13 second ET material!!! YEHAW!!!!!!!!
• I stopped by a local weigh station while I was out driving around to establish the race weight of this combination. The car with the LS1/T56 (without driver) now weighs 3380 with ¼ tank of gas (3580 w/driver) compared to 3480 (w/o driver) with the L69/TH200R4 drivetrain. The LS1/T56 changeover accounted for an overall reduction of 100 pounds, all off of the front end!!!
• I probably need to wait a few weeks for the suspension to settle properly up front because right now the front end of the car sits about 1" higher than before. Additionally, I also noticed that now with the IROC steering box installed that my front tires no longer touch the rear of the lower A-arms (courtesy of the huge P275/40x17 tires!) when the steering wheel is fully cranked.
• Before calling it a day,  I went ahead and also installed the C5 Fuel Rail Covers (FRC's) and they make the motor look awesome!

Next up on the agenda is to finalize the remaining details. This will include getting the tach calibrated, speedometer connected and calibrated and the Air Conditioning lines fabricated to fit the LT1 compressor properly and connect to my existing A/C condenser and accumulator. I will also be going back and updating this web page with the remaining pictures and details missed this past two weeks.

8/28/01 Updates to Web page

I added in pictures and updates for the days between 8/13/01 and 8/19/01 above and inserted them into the proper chronology date-wise above. 

8/28/01 PCM SES trouble code diagnosis

I installed my AutoTap software onto a laptop and connected it to my PCM ADL connector. I received the following trouble codes:

• PO107 Manifold Absolute Pressure [MAP] Sensor Circuit Low Voltage
• PO405 EGR Valve Position Sensor Circuit Low Voltage
• PO412 AIR Solenoid Relay Control Circuit
• PO418 AIR Pump Relay Control Circuit
• PO449 EVAP Emission Control System Vent Valve Circuit
• PO452 EVAP Pressure Sensor Low Voltage
• PO463 Fuel Level Sensor Circuit High Voltage
• PO645 Air Conditioning [A/C] Clutch Relay Control Circuit

I expected all of these codes except for the PO107 based on my installation. After further analysis of what causes PO107 with the MAF, it could be caused by problems detected with the EGR system so this makes sense. My first reaction is to want to delete all of the PCM functions for these codes with the exception of the PO107 for the MAF and the PO645 for the A/C since I don’t have the A/C connected properly. I was waiting for the release of LS1_Edit™ Software to do this myself, however, I understand it is still being BETA tested. I am reviewing my options for reprogramming the PCM now.

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© 2001 by John Bzdel