|
Hi Nick,
Looking good! For the shielded twisted pair (black and white wires in grounded sheath), connect the white wire (pin 24, TACH IN) to the black signal wire from the Pertronix igniter. Leave the black wire (pin 1) disconnected. The wire sheath is already grounded at the ECU. Connect 12V switched to the red, power-in wire from the Pertronix igniter and make sure you put a 1k ohm pull up resistor between the 12V switched power and the TACH IN signal wire so you get a good high/low/high... signal from the Pertronix to the ECU. |
Yesterday, I made the 1100+ mile round trip to Lake Havasu City, AZ to pick up my rebuilt transmission from California Motorsports (CMS).
It is a long drive, but I find the section through the Mojave National Preserve (from Barstow to the Colorado River along I-40) to be majestic. Excellent spirit recharge. I also took the opportunity to stop in at Ollie's Engineering to see how the engine case, crankshaft,... work is progressing - Tim says he is on track to complete the engine work by mid June. Rebuilt Transmission: http://forums.pelicanparts.com/uploa...1713037190.jpg CMS gives you all of the replaced parts: http://forums.pelicanparts.com/uploa...1713037335.jpg Some clearly worn parts: http://forums.pelicanparts.com/uploa...1713037395.jpg http://forums.pelicanparts.com/uploa...1713037395.jpg I had the original open differential replaced with a Wavetrac locking differential - here is the old unit: http://forums.pelicanparts.com/uploa...1713037631.jpg I also had the differential side cover replaced with CMS's billet aluminum unit. Roger at CMS has seen many of the original magnesium side covers crack over time. My cover is not cracked, but I had it replaced just to be safe. http://forums.pelicanparts.com/uploa...1713037874.jpg |
Hi Dan,
I was reading through your thread for the 20th time and I had a question about power for the EFI system. I was wondering why you chose to tie into the former blower fan circuit at the rear fuse block instead of something like the former CDI power lead? Thank you for writing up everything in such detail. It is really helpful. Sean |
Hi Sean,
I chose the blower motor circuit because it was fused at 25 amps and ran off a relay which indicated to me that the wiring in the existing wiring harness was large enough to handle all of the circuits that would be attached to the EFI power panel especially the fuel injector circuits. In hindsight, now that I am more familiar with the wiring in my car, the power wire to the original CDI module may also be suitable. But I would want to check the CDI module specs and see that its input current spec was in the 25 amp range before I tied the EFI power panel to it. |
It's a good day....
Today I received the pistons and cylinders for my 2.7 rebuild (9.5:1 92mm JE pistons, 92mm Nickies). Thank you LN Engineering.
http://forums.pelicanparts.com/uploa...1713383275.jpg |
While I wait for parts....
Today I decided to fabricate the rod (Porsche tool P221) and chain (Porsche tool P222) holder tools that Wayne D describes in the engine assembly chapter of his 911 air cooled engine rebuilding book. I went down to the local Home Depot and purchased a 24in x 36in sheet of 28 gauge galvanized sheet metal and used the tool template dimensions on page 130 (figure 3-17).
The sheet metal cost $48 and I used 1/6th of the sheet, so the tools cost me $8 plus about 1 hour of time. Below are a couple photos of the process: http://forums.pelicanparts.com/uploa...1713726953.jpg http://forums.pelicanparts.com/uploa...1713726953.jpg http://forums.pelicanparts.com/uploa...1713726953.jpg |
Hey Dan! Things are looking amazing with your engine rebuild!! Quick Q: Did you end up cutting the length of the injector wiring that came with Al's kit? Those wiring harnesses are really well done, but are just extremely long for where they need to be connected. If you didn't cut them, did you just circle them up and zip tie them in the back somewhere? Not a ton of space in that engine bay and would love to not have tons of extra cabling just lying around back there...
|
Hi Nick,
Sounds like you are on your way. Regarding the fuel injector and TPS wiring, I did trim the wires once I mocked up where the wires were going to be routed. I found that using scissors and cutting that stretchy fabric sheathing up its length, then pulling the wires out of the sheath and cutting off the excess sheathing worked well. Yes, my engine build is coming along. I have (I think) all of the parts, supplies (sealant, lint free wipes, cleaner, etc.) and tools that I need to put the engine back together once Ollie's gets finish with the crankcase, crank, rods, etc. I have been reading and studying the engine assembly chapter of Wayne D's 911 engine rebuilding book and asking Al lots of questions. Al has been great, very supportive and has given me a lot of tips on procedure and suggested specialty tools to make the build go smoothly. I have made multiple visits to Stomski Racing (stomskiracing.com) for specialty tools. Have fun with your project! |
Cleaning up the EFI wiring
While I wait for parts... it's a perfect time to clean up the EFI wiring as there is ample room with the engine and trans out of the car.
I decided to replace the 8 bay and 6 bay connector blocks that connect engine side EFI wiring to the ECU side EFI wiring with moisture resistance connectors like I had installed back in December. A 2 pin connector replaces the right connector block that make ECU ground connections for fuel injector banks 1 & 2. http://forums.pelicanparts.com/uploa...1714432612.jpg The 8 bay connector block is replaced with a 2 pin connector for Pertronix power and signal (crank position signal) between the distributor and the ECU / EFI power panel and a 6 pin connector that handles engine temp sensor, O2 sensor, ignition trigger to MSD box, and the throttle position sensor. http://forums.pelicanparts.com/uploa...1714432948.jpg Notice the 1 kohm pull up resistor between 12V and crank position signal. I soldered wire leads onto the resistor leads and covered with heat shrink tubing. http://forums.pelicanparts.com/uploa...1714432948.jpg http://forums.pelicanparts.com/uploa...1714432948.jpg http://forums.pelicanparts.com/uploa...1714432948.jpg Next up will be to replace the 10 gauge main power and ground wires that were left overs from my home solar power project with some automotive grade 12 gauge wire that will be more flexible and better able to handle vibration. |
Replace the main power and ground wires for the EFI
With new moisture resistance connectors installed, I turned my attention to the main power supply and ground wires for the EFI; as well as, the high current power and ground wires for the MSD CDI box.
When I originally installed the ITB EFI system I used 10 awg solar system wire that I had left over from the solar power installation at my house. The solar wire has high heat and UV tolerance and plenty of dielectric stand off strength, but the insulation is thick and pretty stiff so it was hard to work with. In its place I used 12 awg automotive grade copper wire. Unfortunately, the main wires were buried beneath the rest of the EFI wiring so replacing them meant unwrapping and taking apart the EFI wiring. The upside is I get to improve the wiring layout and should end up with a more tidy installation. Following are photos of the tear down and re-assembly: http://forums.pelicanparts.com/uploa...1714457328.jpg http://forums.pelicanparts.com/uploa...1714457328.jpg EFI wiring harness unwrapped and main EFI power wire removed: http://forums.pelicanparts.com/uploa...1714457328.jpg Removed the fuel filter and disconnected the MSD CDI high current wires: http://forums.pelicanparts.com/uploa...1714457328.jpg http://forums.pelicanparts.com/uploa...1714457328.jpg Old MSD CDI high current wires are removed: http://forums.pelicanparts.com/uploa...1714457899.jpg Main EFI ground wire where it attaches to the chassis ground lug behind the fuel filter: http://forums.pelicanparts.com/uploa...1714457899.jpg Old main EFI ground wire removed: http://forums.pelicanparts.com/uploa...1714457899.jpg New MSD CDI high current ground wire installed at chassis ground lug next to the transmission shift rod tunnel: http://forums.pelicanparts.com/uploa...1714457899.jpg |
More photos:
New MSD CDI high current ground wire installed: http://forums.pelicanparts.com/uploa...1714458695.jpg New MSD CDI high current power wire installed: http://forums.pelicanparts.com/uploa...1714458695.jpg New EFI main ground wire connected to chassis ground lug behind the fuel filter: http://forums.pelicanparts.com/uploa...1714458695.jpg Starting to re-assemble the EFI power panel and wiring: http://forums.pelicanparts.com/uploa...1714458695.jpg |
Cleaning up the EFI wiring continued.
More photos:
Old tach wire connection to MSD tach out wire: http://forums.pelicanparts.com/uploa...1714510039.jpg New tach wire connection to MSD tach out wire: http://forums.pelicanparts.com/uploa...1714510039.jpg Tidied up the ground connections at the left rear engine compartment electrical panel: http://forums.pelicanparts.com/uploa...1714510039.jpg Getting the EFI engine harness straightened out and held in place with cable ties: http://forums.pelicanparts.com/uploa...1714510039.jpg Making power and ground connections at the EFI power panel and re-wrapping the EFI engine harness: http://forums.pelicanparts.com/uploa...1714510039.jpg The EFI engine harness is wrapped and secured in place. I decided to keep the new EFI power wire outside the wrapped harness for easier access: http://forums.pelicanparts.com/uploa...1714510039.jpg EFI wiring all back in place with new moisture resistant connectors replacing the original connector blocks. The fuel pressure regulator, fuel supply, and fuel return lines are re-installed. The back of the engine compartment is still pretty busy, but at least to me it is more organized. Now I will update my EFI wiring documents to match the new configuration: http://forums.pelicanparts.com/uploa...1714510039.jpg |
Hey Dan, That is not a good ground location..Yes Porsche used it but was the cause of the CDI box failing when these cars were new, lots of headaches for PNA. I was a tech at HBL Porsche at the time and got to drive home a new 911 everyday to check for faults.
|
Old H2S: Are you referring to the ground stud that's just forward of the relay panel? On my 1973, that stud is brazed to the body, so it "should" be a very good ground point. Not so?
|
No Pete, that forward stud is good. I was looking at the picture of the wires attached to the mounting panel using a long bolt through the panel into the sheet metal behind it. Porsche did the same thing grounding the CDI to the panel rather than a wire to the grounding stud that was 6" away.
|
Grounding concerns
Hi H2S,
Thank you for your concerns about CDI module grounding to the sheet metal electrical panel. While the original CDI box used this point for ground, after the CIS to ITB EFI conversion the original CDI module was replaced by an MSD CDI module and the main ground for it is taken at the grounding stud on the chassis next to the transmission shift rod tunnel (see photo #3 below). The main ground for the rest of the EFI system is taken from the grounding stud on the inside of the chassis beneath the fuel filter (see photo #2 below) - also note the webbed ground strap directly beneath my new black ground wire. The ground wires I was referring to in the photo below (photo #1) are for 2 low current circuits and not the ground for the MSD CDI module - note the webbed ground strap beneath my ground wires which is originates at the chassis ground stub in photo #2). Photo #1: http://forums.pelicanparts.com/uploa...1714595466.jpg Photo #2: http://forums.pelicanparts.com/uploa...1714595466.jpg Photo #3: http://forums.pelicanparts.com/uploa...1714595466.jpg |
Quote:
|
Hi pmax,
I had the underside of the car steam cleaned like 10 years ago and I stopped driving it in wet conditions so it has stayed pretty clean. |
Wiring Documentation for CIS to ITB conversion
Deciding to rebuild my engine and transmission 1 year after I converted from CIS to ITB EFI has given me the opportunity to go back and review / modify / improve the EFI wiring connections.
For anyone thinking about or in the process of this conversion, I will share documents I used with the EFI wiring. In the software documentation that Al @ x-faktory.com provided with the CIS to ITB EFI conversion kit there are 2 documents that I have found to be very helpful in properly wiring up the EFI so it plays as advertised: 1. The EFI wiring schematic: http://forums.pelicanparts.com/uploa...1714628144.png |
2. The Megasquirt2 (ECU) pin out definitions:
http://forums.pelicanparts.com/uploa...1714629158.jpg And then I documented how I actually made the wiring connections between and ECU wiring harness and EFI engine wiring harness. Here is the original wiring connections from June 2023 using the wire connector blocks: http://forums.pelicanparts.com/uploa...1714629334.jpg And here is the new wiring connections from May 2024 using moisture resistant wire connectors: http://forums.pelicanparts.com/uploa...1714629455.jpg In my opinion, clear documentation is a must for success. Good luck with your DIY project! |
Checking piston and wrist pin weight
Checking piston and wrist pin weight prior to assembly:
Set up and data collection: http://forums.pelicanparts.com/uploa...1714866793.jpg Data summary (all weights are in grams): http://forums.pelicanparts.com/uploa...1714866793.jpg Identification of items: http://forums.pelicanparts.com/uploa...1714866793.jpg |
While I wait for parts....
I am (hopefully) 5 weeks away from being able to pick up engine parts from Ollie's and I am trying to make good use of the down time by carefully re-reading Wayne D's 911 engine rebuilding book chapters 4 (mods & upgrades) and 5 (engine reassembly).
My engine already has the upgraded chain tensioners (later Carrera 3.2 style with oil feeds), but not the updated idler arms (p/n 930.105.509.00 (left) & 930.105.510.00 (right)) so I ordered those. Also, my engine still has the original camshaft housing oil line hardware and I do have nearly 0 gauge oil pressure at idle when warm, so I ordered the camshaft housing oil pressure restrictors (p/n 901.105.361.03 - Wayne's book lists .01 which has been superseded by the .03) Lastly, I modified the engine air baffles as discussed on page 81 (figure 4.10) to allow the air cooling to more evenly spread between the cylinders, see the photos below: Section from Wayne's book describing the modification: http://forums.pelicanparts.com/uploa...1715575420.jpg Air baffles before modification: http://forums.pelicanparts.com/uploa...1715575420.jpg Marked up air baffle: http://forums.pelicanparts.com/uploa...1715575420.jpg Modified air baffle: http://forums.pelicanparts.com/uploa...1715575420.jpg Modified air baffle set: http://forums.pelicanparts.com/uploa...1715575420.jpg http://forums.pelicanparts.com/uploa...1715575420.jpg |
Head Gasket or No Head Gasket?
I have been getting conflicting input about whether my 75 2.7L engine uses a head gasket (sealing ring) or not - the two experts I asked said yes ("there's a groove in top of the cylinder that a sealing ring sits in..."), Wayne's 911 engine rebuilding book says no in one section and yes in another, the internet generally says no, and when I disassembled the engine I didn't any sealing rings or other evidence of a head gasket between the cylinders and the heads.
A head, piston, and cylinder from my engine: http://forums.pelicanparts.com/uploa...1715725704.jpg So I decided to do a little engineering mock up / experiment. I set a head upside down on my workbench and then took one of my new cylinders (which do not have a groove in the machined surface that mates to the machined surface on the head) and placed it upside down onto the head mating the two machined surfaces. They fit together precisely and in fact there was a noticeable suction when I pulled the cylinder away from the head. http://forums.pelicanparts.com/uploa...1715725835.jpg I have concluded that my engine does not use a sealing ring between the cylinders and heads. Another subject I have been undecided about is how to measure deck height. Wayne's book says if you have flat top pistons then measure the distance from the top of the piston @ TDC to the machined sealing surface of the cylinder. But if the piston is domed then use the hollowed out piece of solder technique from Walt at Competition Engineering. Again, I performed an engineering mock up / experiment. With the head still sitting upside down on my workbench, set a piston top side down onto the head inside the annular machined sealing surface to see what part of the piston contacted the combustion area of the head. http://forums.pelicanparts.com/uploa...1715726283.jpg It turns out the 2mm wide flat annular ring on the OD of my 9.5:1 JE pistons contact the beveled annular ring adjacent to the machined sealing surface on the head. That fact leads me to conclude measuring the deck height directly between the piston and the cylinder will be satisfactory. |
Dan,
The stock Mahle 90mm cylinders and the Mahle w/JE pistons sets I use all have the sealing ring groove in the cylinder.........the Nickies, as shown in your pix do not use them. Both configurations seem to work well. |
Al,
Thanks for the info. I only know about the parts I have in front of me. Now I know the question of sealing ring or not depends of the part manufacturer as Porsche used both configurations. |
Updated Spocket Supports
Today I received the updated sprocket supports and I switched the sprocket from the old support arm to the new support arm. The process was pretty simple: tap out the rolled pin, tap out the sprocket shaft, remove old support arm, then do the reverse with the new support arm.
Starting with the 1,2,3 side: http://forums.pelicanparts.com/uploa...1715800878.jpg Tap out the rolled pin: http://forums.pelicanparts.com/uploa...1715800878.jpg Tap out the sprocket shaft: http://forums.pelicanparts.com/uploa...1715800878.jpg http://forums.pelicanparts.com/uploa...1715800878.jpg Install new sprocket support arm: http://forums.pelicanparts.com/uploa...1715800878.jpg http://forums.pelicanparts.com/uploa...1715800878.jpg Switching to the 4,5,6 side: http://forums.pelicanparts.com/uploa...1715800878.jpg http://forums.pelicanparts.com/uploa...1715800878.jpg |
Crap! Just realized I put the sprocket shaft 180 deg out on the 1,2,3 arm - the oil pick up cup is wrong. Back to the garage...
This is why it is important to take lots of photos. Here is the engine during disassembly showing the correct orientation of the cut outs / oil catch cups on the chain tensioner sprocket arms. The catch cups have to face up to feed oil to the sprocket bearings. I initially put the sprocket shaft in with catch cup facing down which would have lead to oil starvation and early sprocket bearing failure on the 1,2,3 side - a real bummer. http://forums.pelicanparts.com/uploa...1715803233.jpg Again, original 1,2,3 sprocket support arm with catch cup facing down/right: http://forums.pelicanparts.com/uploa...1715803233.jpg After correction, 1,2,3 sprocket support arm with catch cup facing down/right: http://forums.pelicanparts.com/uploa...1715803233.jpg If I wasn't documenting my work with this forum thread, there is a good chance I would have missed this error. Just dodged a bullet.... |
Piston and Cylinder Assemblies
Today I got busy and put together the piston and cylinder assemblies.
Workstation: http://forums.pelicanparts.com/uploa...1716440463.jpg Storage container for completed assemblies: http://forums.pelicanparts.com/uploa...1716440463.jpg Clean station 1 for carburetor cleaner on the left and clean station 2 for isopropyl alcohol on the right: http://forums.pelicanparts.com/uploa...1716440463.jpg Installing C-clip for right side of pistons with the C-clip insertion tool from Stomski Racing - it took me half a dozen tries to get the hang of using the insertion tool successfully and I had to use a wrist pin as a back stop: http://forums.pelicanparts.com/uploa...1716440729.jpg Measuring piston ring end gap. Here I am using a piston to set the ring square in the cylinder bore: http://forums.pelicanparts.com/uploa...1716440729.jpg Top compression ring end gap measured .011 inch (0.279mm) for all cylinders: http://forums.pelicanparts.com/uploa...1716440729.jpg http://forums.pelicanparts.com/uploa...1716440729.jpg Bottom compression ring gap was a little wider and measured .016 inch (0.406mm) for all cylinders: http://forums.pelicanparts.com/uploa...1716440729.jpg |
Piston and Cylinder Assemblies
After inserting the C-clip in the right side of the pistons and measuring the ring end gap, it was time to start the assembly process.
The assembly process consisted of cleaning the cylinder, cleaning the piston, cleaning the rings, installing the rings on the piston, applying clean oil to the cylinder bore / piston & rings / ring compressor tool, tightening the ring compressor tool around the piston & rings, pressing the piston down in the ring compressor tool so the piston skirt protruded beneath the tool, setting the piston / compressor tool onto the top of the cylinder with piston skirt inserted into the cylinder bore, then using the handle of a ball peen hammer to drive the piston & rings down into the cylinder bore. Once the piston was inserted into the cylinder, I pressed the piston down the cylinder bore until the piston skirt was protruding from the bottom of the cylinder an amount sufficient to allow me to insert the wrist pin into the piston. Then I placed the piston and cylinder assembly into the storage container then repeated the process for the next piston and cylinder. This band type ring compressor tool was a bad Amazon buy. The band would flex open as the ring was reaching the top of the cylinder and the ring would pop out. Fortunately I didn't push a bad position and break or crack any rings. This ring compressor tool went to the recycle bin - I went to the local auto parts store and purchased a wind up style ring compressor that worked well and saved the day: http://forums.pelicanparts.com/uploa...1716443170.jpg http://forums.pelicanparts.com/uploa...1716443170.jpg http://forums.pelicanparts.com/uploa...1716443170.jpg Sequence of installing the piston & rings into the cylinder bore: http://forums.pelicanparts.com/uploa...1716443463.jpg http://forums.pelicanparts.com/uploa...1716443463.jpg http://forums.pelicanparts.com/uploa...1716443463.jpg http://forums.pelicanparts.com/uploa...1716443463.jpg http://forums.pelicanparts.com/uploa...1716443463.jpg http://forums.pelicanparts.com/uploa...1716443463.jpg http://forums.pelicanparts.com/uploa...1716443463.jpg |
Piston and Cylinder Assemblies
Last photo in sequence of installing the piston & rings into the cylinder bore:
http://forums.pelicanparts.com/uploa...1716444153.jpg Another completed assembly: http://forums.pelicanparts.com/uploa...1716444153.jpg Final completed assembly: http://forums.pelicanparts.com/uploa...1716444153.jpg Completed assemblies in the storage container safe in the passenger side seat away from dust and foot traffic: http://forums.pelicanparts.com/uploa...1716444153.jpg |
Fan, Fan Housing & Alternator Assembly
Back in March I had gotten the cooling fan and fan housing bead blasted, polished up and clear coated, then I mock assembled the fan to the alternator and the fan / alternator to the fan housing. At the time, I knew I would need to redo the assembly because I wasn't sure which way the spacer was supposed to be installed between the fan and the alternator. I didn't realize it at the time, but the woodruff key that locks the fan to the alternator shaft was loose rattling around inside the alternator - turns out when I clear coated the fan, the clear coat reduced the width of the woodruff key groove in the fan hub and the woodruff key no longer fit in the groove.
So today I disassembled the fan / alternator / fan housing assembly to correct the above issues. Spacer between the alternator and the fan. The raised shoulder on the spacer goes down facing the alternator and contacting the inner race of the front alternator shaft bearing: http://forums.pelicanparts.com/uploa...1716513367.jpg The spacer between the alternator and the fan properly installed: http://forums.pelicanparts.com/uploa...1716513367.jpg The woodruff key on the alternator shaft: http://forums.pelicanparts.com/uploa...1716513367.jpg Filing the the woodruff key groove in the fan hub: http://forums.pelicanparts.com/uploa...1716513367.jpg Verifying the woodruff key fits properly into its groove in the fan hub: http://forums.pelicanparts.com/uploa...1716513367.jpg Verifying the woodruff key is properly installed after the fan is pressed onto the alternator shaft: http://forums.pelicanparts.com/uploa...1716513367.jpg Alternator / fan / fan housing parts from disassembly in marked bags: http://forums.pelicanparts.com/uploa...1716513367.jpg Thankfully I took lots of photos during disassembly so I can figure out how to put the fan belt pulley back together. Spacer shims for the fan belt pulley installed: http://forums.pelicanparts.com/uploa...1716513367.jpg Outer half of the fan belt pulley installed: http://forums.pelicanparts.com/uploa...1716513367.jpg |
Fan, Fan Housing & Alternator Assembly
Extra fan belt pulley shims installed:
http://forums.pelicanparts.com/uploa...1716515222.jpg Conical thrust washer installed: http://forums.pelicanparts.com/uploa...1716515222.jpg Fan belt pulley nut installed: http://forums.pelicanparts.com/uploa...1716515222.jpg Installing the fan housing onto the alternator / fan, but then I realized I didn't have the alternator oriented properly with respect to the ignition coil mounting studs on the fan housing - back to disassembly photos to determine the correct alternator / fan housing orientation: http://forums.pelicanparts.com/uploa...1716515222.jpg Fan housing correctly oriented with the alternator: http://forums.pelicanparts.com/uploa...1716515222.jpg Using the fan housing mounting nuts to pull the fan housing down evenly onto the alternator / fan assembly: http://forums.pelicanparts.com/uploa...1716515222.jpg Catalogued new fasteners for the engine rebuild: http://forums.pelicanparts.com/uploa...1716515222.jpg Updated the new fastener inventory to reflect the 6 new M6 nuts and washers that I used to secure the fan housing and air deflector to the alternator / fan assembly: http://forums.pelicanparts.com/uploa...1716515222.jpg Backside view of completed alternator / fan / fan housing assembly: http://forums.pelicanparts.com/uploa...1716515222.jpg Frontside view of completed alternator / fan / fan housing assembly: http://forums.pelicanparts.com/uploa...1716515222.jpg |
Deck Height and Compression Ratio
I have been struggling to understand and determine the correct deck height target for my engine build. Wayne D's book references Walt at Competition Engineering with a 1.25mm to 1.50mm target using the hollowed out solder method. Wayne also says builders looking for higher compression go down to 1.00mm deck height. Then I researched through this forum and the early 911 registry forum and the consensus seems to be that deck height from the factory was set to 1.00mm, with the caveat that the various tolerances must be known and accounted for, and the valve to piston clearance must be checked and verified to be at or greater than the minimum (1.5mm intake & 2.0mm exhaust) thru the stroke of the piston approaching, at and falling away from top dead center on the overlapping stroke.
Anyway, that all got me to thinking about the compression ratio (CR) and the effects of deck height and shaved heads on the CR. So I started working on some calculations which I share below - please check my work: http://forums.pelicanparts.com/uploa...1716861147.jpg I also calculated CR at deck height of 1.25mm (CR = 9.3) and 1.50mm (CR = 9.1) without the heads being shaved 0.25mm. |
Originally Posted by davis911s
"Dan I am doing the same ITB install in my 911 that you did. Mine is a 77 and I also bought the kit from Al. I am up in Canada. I have a few questions if you don't mind helping me since you did this already. First is the dizzy part. You wrote this... "Next I rotated the engine manually to TDC on cylinder #1 making sure the distributor (dizzy) rotor was pointing to cylinder #1. I marked the position of the dizzy relative to the engine and then marked the position of the rotor on the dizzy. Then I removed the dizzy and again marked the position of the rotor on the dizzy. Once out, I disassembled the dizzy to reveal the mechanical advance and then used steel wire to wrap tightly around the posts holding the return spring on both sides of the dizzy thereby locking out the mechanical advance so that the ignition timing advance would be controlled entirely by the ECU. The dizzy was reassembled and reinstalled into the engine. " My question is , is this part necessary? If so do you have photos of the dissassembly of the distributor and procedure once in there of what you did ?" Hi Shawn, Good question about the distributor. In the book "Performance Fuel Injection Systems" by Cramer & Hoffman (from DIYAutoTune.com the big USA distributor of Megasquirt ECU's), the authors state that if you are going to have the ECU control the ignition timing advance, then you need to disable the mechanical advance mechanism in the distributor. That way there is only one master of the ignition advance curve. I achieved the disabling of the mechanical advance by taking the distributor (Bosch in my car) and removing the springs and replacing them with steel wire, see page 6 of this thread (post #106 & 107) for a step by step procedure with photos. |
Ignition Timing Set Up - More Info
From Page 1, Post #12 of this thread:
"I opened the hand throttle a bit and cranked the starter and the engine started albeit it didn't sound very good but it was a beginning. In TunerStudio, I selected Ignition Settings, then selected Ignition Options, then selected Fixed Advance and selected Fixed Timing. Then from Cranking Advance, I entered 6.0 (6 deg BTDC) and selected Burn. I connected my timing light and the timing was no where near 6 deg BTDC, so from TunerStudio, I selected Ignition Settings, then selected Trigger Wizard and pressed the "+" button next to the Ignition Offset angle box until the timing as measured with my timing light measured the same as the timing advance the ECU was commanding. For my engine with a Pertronix ignitor in the dizzy, that required Ignition Offset angle turned out to be 61.5 deg, so I burned that value in the Trigger Wizard. At this point, the engine sounded more composed but still off key. Next I went back to Ignition Settings, then Fixed Advanced and selected Use Table and selected Burn. A pop up message stated the ECU would need to be reset for the changes to take effect, so I turned the ignition switch to off, then turned the ignition switch back on and restarted the engine. I checked the timing with my timing light at several rpm levels and the physical timing was now tracking the ECU timing correctly." Here are a couple of photos of the Tuner Studio app showing the location of the Ignition Timing Wizard: http://forums.pelicanparts.com/uploa...1717547280.png http://forums.pelicanparts.com/uploa...1717547280.png From my earlier post: "I connected my timing light and the timing was no where near 6 deg BTDC, so from TunerStudio, I selected Ignition Settings, then selected Trigger Wizard and pressed the "+" button next to the Ignition Offset angle box until the timing as measured with my timing light measured the same as the timing advance the ECU was commanding." So more details might be helpful: I had set the Tuner Studio to command 6 deg of advance. I set the timing advance setting on my timing light to 6 deg so when the actual ignition timing was 6 deg BTDC the "Z1" timing mark on the Crankshaft pully lined up with timing mark on the fan housing (which matched the crankcase halves parting line): http://forums.pelicanparts.com/uploa...1717548461.jpg But when I starting checking the timing with my timing light the Trigger Wizard was set to 0.0 deg so the timing mark on the crankshaft pulley was way off to the left (counter clockwise) from the timing mark on the fan housing - see photo below (an added benefit of having the engine torn apart for a rebuild is I can now clearly see many things that were hard to see when the engine was together and I was doing the ITB EFI conversion): http://forums.pelicanparts.com/uploa...1717549171.jpg So by pressing the "+" button on the Trigger Wizard and adding more offset, the timing mark on the crankshaft pulley moved right (clockwise) until finally the "Z1" mark on the crankshaft pulley lined with the timing mark on the fan housing (with my timing light set to 6 deg advance AND the ECU (via the Tuner Studio app) commanding 6 deg of timing advance). And like I said before, once the correct timing advance offset was entered into the Trigger Wizard, the engine sounded a lot better, but still needed the ITB's to be balanced to get the engine to a good sounding rhythm. Hope this additional info is helpful. |
This is an amazing write up. Much much appreciated!
Does anyone have details photos or a link to a video of the fuel line set up? Lines from filter to engine bay gauge to fuel distribution and then off to the injectors? Also detailed vacuum lines would be much appreciated too |
Fuel Lines & Vacuum Lines
Hi Shawn,
Here are some photos: Yellow arrow is the fuel supply line from the fuel filter to left side fitting on the fuel pressure regulator (FPR). Orange arrow is the fuel return line from the bottom fitting on the FPR to the existing nylon fuel return line back to the fuel tank. Important caveat! You will using a 3/8in to 1/4in brass barbed union to connect the fuel injection hose supplied with your x-faktory kit to the existing nylon 1/4in return line. Make the connection of the barbed union to the existing nylon line first - you will need a nylon fuel line press (I bought a Dorman 800-301 Fuel Line Repair Tool on Amazon) and a heat gun. If you have worked with nylon fuel lines then you already know the drill, I had not, so I watched the how-to videos first. Once the connection of the barbed fitting to the nylon line is done, then the connection to the 3/8in fuel injection hose is easy: put a hose clamp over the line, press the barbed fitting into the hose and secure with the hose clamp. From Page 1, Post #11 of this thread: " Then I plumbed in the fuel lines using 3/8 inch ID Gates Barricade Fuel Injection hose (note: it is important to use fuel injection rated hose that can withstand the higher fuel pressure compared to fuel hose used with carburetors). I used a Dorman 800-301 fuel line repair tool to press a 1/4 inch to 3/8 inch barbed connector onto the factory installed 1/4 inch ID nylon fuel return line (I used a heat gun to soften the nylon line while I pressed on the barbed connector). For all the other connections (fuel filter to fuel presure regulator (FPR), FPR to fuel return, and FRP to injector fuel rails), I pressed on by hand the 3/8 inch barbed AN-6 fittings supplied with conversion kit and secured them with hose clamps." http://forums.pelicanparts.com/uploa...1717992342.jpg The white arrows point to the fuel lines that run from the right side fitting on the FPR to the injector fuel rails for each bank of ITB's. http://forums.pelicanparts.com/uploa...1717992342.jpg This photo includes the intake manifold vacuum plenum (with RHD marking) sitting to the right of the FPR. http://forums.pelicanparts.com/uploa...1717992543.jpg The blue arrow points to the intake manifold vacuum plenum. There is a 9/32in vacuum hose running from the barbed fitting at the base of each ITB to the barbed fitting on the plenum (6 total). The small 1/8in vacuum hose connects to the smaller barbed fitting on the plenum and runs along with the ECU wiring harness back to the Mega-Squirt ECU and connects to the fitting on the ECU which is your connection to the MAP (manifold absolute pressure) sensor. http://forums.pelicanparts.com/uploa...1717992342.jpg Hope this is helpful - let me know if you have any questions. |
|
:)
davis911s- Here is what I offer for the PMO ITB setup..... http://forums.pelicanparts.com/uploa...1718012626.jpg It uses the SC & 3.2 Fuel Filter and will work with the Factory Polyamide Tunnel Lines. Everything is made to order, and can be assembled to your specifications. For info please email me. NO PM's as box is most likely FULL. len.cummings @ verizon.net but without the spaces. :) |
Parts are back from Ollie's
I made my third trip out to Lake Havasu City, AZ to pick up engine parts from Ollie's. Tim and Andrew have been a pleasure to work with and Tim completed the work in the 4 months that he originally estimated.
http://forums.pelicanparts.com/uploa...1718863250.jpg Evidence of balancing the connecting rods: Tim removed material from the top and the bottom of the rods as necessary. http://forums.pelicanparts.com/uploa...1718863250.jpg http://forums.pelicanparts.com/uploa...1718863250.jpg Measuring the weight of each rod: http://forums.pelicanparts.com/uploa...1718863250.jpg Recording the rod weight data and assigning the piston / wrist pin / con rod combinations to their cylinder position: http://forums.pelicanparts.com/uploa...1718863250.jpg Bagged up each con rod with it's assigned piston / wrist pin number and cylinder position: http://forums.pelicanparts.com/uploa...1718863250.jpg Next will be washing the crankcase halves with soapy water as per Tim's recommendation. |
| All times are GMT -8. The time now is 10:45 AM. |
Powered by vBulletin® Version 3.8.7
Copyright ©2000 - 2025, vBulletin Solutions, Inc.
Search Engine Optimization by vBSEO 3.6.0
Copyright 2025 Pelican Parts, LLC - Posts may be archived for display on the Pelican Parts Website