CIS to ITB EFI conversion

[dannichols1474]

Hi Nick,

I went out and removed the rain hats from the ITB's and took a couple of photos of engine wiring harness.

Harness connector that plugs into the back of the electrical panel in the left rear corner of the engine bay:


Overview shot of the harness from the distributor running diagonally across the engine towards the starter:


This shot shows the wires coming along the cooling fan shroud to the oil temp and oil pressure sending units:


This shot shows the harness connecting to the oil pressure warning light switch and then heading out the back of the engine bay and down to the starter solenoid:


Keep up the DIY spirit!

[dannichols1474]

My car is running great after the CIS to ITB EFI conversion, but I'm not getting any younger and the engine and transmission have almost 72k miles so I decided to rebuild my engine and make it even more of a hot rod.

After talking with Al at x-faktory and Don at Don's Autowerks, I decided to go with 9.5:1 92mm JE pistons, 92mm Nickies cylinders, MFI S-cams from Web Camshafts with ARP studs and hardware throughout the case (not just the head studs) and use Ollie's Engineering for the case, crank, rod, and flywheel and Craig at G2 for the heads and cam towers machining work.

Before starting and at Al's recommendation I bought Wayne Dempsey's book "How to Rebuild and Modify Porsche 911 Engines 1965-1989". After looking through the book, I also bought Wayne's "101 Projects for Your Porsche 911" which has a detailed description of how to drop the engine/transmission out of the 911. Both books are available on PP (not a paid spokesperson :-)).

The following are some photos of the drop and disassembly process (not all as I took many, many photos to have a chance of putting this Swiss watch of an engine back together).

Must have tools:


I removed the ITB EFI to keep it safe in the trunk and I removed the back bumper to make more clearance for the engine before I dropped the engine/transmission:






An important note: the yellow "foot" I used with my floor jack to drop the engine/transmission depends on the weight being balanced on the floor jack. The above photos show the engine with the muffler removed, but the muffler must be in place (if only loosely attached) to get the weight balance correct so the engine/transmission will drop down level. I initially tried the drop with the muffler off and the engine/transmission was nose heavy at the transmision end.
The yellow "foot" worked great at holding the engine/transmission steady and I was able to safely drop the engine/transmission by myself (on PP it is P/N PEL-PW-2563 and it is called "Engine/Transmission Removal Jack Adapter Tool, for 911 engine with sump plate").

[dannichols1474]

Once I got the engine and transmission removed, I rented a knock down engine hoist so I could get the engine on the engine stand after I separated the transmission and attached 911 engine stand fixture to the crankcase.

Important note: I attached the 911 engine stand fixture to the 1,2,3 crankcase half. That was incorrect as the oil pump is bolted to the 4,5,6 crankcase half which needs to be rotated to the bottom and facing up when you go to separate the case halves so you can lift the 1,2,3 case half off and expose the crankshaft and intermediate shaft.

I did the engine tear down with the fixture on the 1,2,3 case half, then rented the engine hoist again so I could put the crankcase back on the floor, move the fixture to the 4,5,6 case half and remount the crankcase back on the engine stand so I could continue the tear down with the case halves separation and removal of the crankshaft (with connecting rods) and the intermediate shaft.

[dannichols1474]

Once the engine was on the engine stand, the engine tear down began starting with the camshafts. If your engine uses nuts to hold the cam timing chain sprockets to the end of the camshafts, then you will need a pair of special tools the get the camshaft nut loose. The tools are described in Wanye's engine rebuilding book. One tool is a double D shaped socket that holds the camshaft steady and the other tool is a beefy 46mm crows foot to grab the camshaft nut from the side. The tools are 1/2 inch drive and my 1/2 inch drive ratchet is 24 inches long and my 1/2 inch drive breaker bar is 30 inches long. With the ratchet attached to the 46mm crows foot and the breaker bar attached to the double D socket, I was able to hold the camshaft from rotating while loosening the camshaft nut by myself. I point is the nut is on pretty tight and you need a long lever arm to get the nut loose.

Once the camshaft nut was loose, I removed the nut holding the chain tensioner in place and used a pry bar to gently persuade the tensioner to slide forward out of the chain housing and disengage the tensioner sprocket. That released the tension on the camshaft timing chain so the sprocket, etc can to removed from the end of the camshaft.

[dannichols1474]

With the cam sprocket, chain tensioner, idler sprocket, etc removed, I could remove the 5 nuts holding the cam chain housing to the case. But in order to get the housing off, the head/cam tower assembly needs to be lifted up about an inch so the cam chain housing can be slid off its mounting studs and rotate to clear the end of the camshaft.

But before removing the head/cam tower assembly, the oil return tubes need to be removed. Then you can remove the barrel nuts and their washers from the head studs. Once the nuts are removed, the head/cam tower assembly can be lifted up about 1 inch, then the cam chain housing can be removed, and finally the head/cam tower assembly can be lifted off the engine exposing the cylinders and pistons.

Next I removed the tin pieces that channel air flow around the cylinders. Then using a rubber mallet and tapping on the base of the cylinder I was able to slide the cylinders off the head studs exposing the pistons.

Using 90 deg curved pliers and a small flat blade screwdriver, I removed one of the wrist pin retaining clips from an outboard piston and tapped out the wrist pin with a punch and rubber mallet to remove the piston, then repeated for the other two pistons on that bank.

Repeat all of the above for the other side of the engine. Remove everything that attaches to the crankcase (breather cover, oil cooler, oil pipe, oil thermostat, flywheel, crankshaft pulley, intermediate shaft cover, etc.

Now I was at the point I described above where I rented the engine hoist and moved the engine mounting fixture the 4,5,6 case half. Then I proceeded to remove the through bolts and all of the nuts that hold the two case halves together and finally split the case halves.





Plastic wedges I used to help separate the case halves

[dannichols1474]

It is important to note that while I was removing items from the engine and taking photos I was also tagging and bagging all of the removed items. So I bought a couple of big boxes of zip lock bags: 1 quart size for small items and 1 gallon size for larger items.

It was at this point that an old friend of mine pointed out it might be a good time to get the transmission rebuilt given it was out and I was going thru all this work to rebuild the engine, so transmission rebuild got added to the list. I did some internet searching and contacted California Motorsports Inc. (CMI). Fortunate for me Ollie's Engineering and CMI are both located in Lake Havasu City, AZ so I could make one trip to drop off parts to both.

With the cases separated, I removed the crankshaft and the intermediate shaft / oil pump. I removed the connecting rods from the crankshaft. I got some giant zip lock bags and bagged the crankshaft and the case halves.

I loaded the trunk of my car with the transmission, case halves, crankshaft, rods, intermediate shaft, oil cooler and flywheel/pressure plate and drove from Milpitas, CA to Lake Havasu City, AZ (9 hours). Tim at Ollie's told me it would be 4 months to complete the engine work (middle of June) and Sean at CMI said they would complete the transmission in 8 weeks (middle of April).

[al lkosmal]

Dan,
I admired your approach when you installed and tuned the EFI kit. you focused on learning and understanding the system.........and it turned out right.

And, once again, you have done the research, gathering the info required to gain an understanding of the work ahead....and then rolled up your sleeves and got to it.

Good luck with the project....you will very happy with the results.

regards,
al

[dannichols1474]

With the engine parts at Ollie's and the transmission at CMI, it was time to turn my attention to the head/cam tower assemblies. The first step was to remove and bag each rocker arm assembly and label the bag with the cylinder # and I(ntake) or E(xhaust). Once all 12 rocker arms were removed, the camshaft was easily pulled out of the cam tower - I pulled the camshaft out carefully so as to not bang the camshaft against the journals in the cam tower.

Next, I removed the nuts and washers that secure the cam tower to the heads. Then using a rubber mallet, I tapped on the head studs of one head at a time to release the head from the cam tower. I repeated this process for the remaining two heads.

With the heads separated from the cam tower, I used a Dremel tool with an engraving bit to engrave the cylinder number on each head and either 1 or 4 on the cam tower in a non machined area.

I repeated this process for the other head/cam tower assembly.








Next I carefully wrapped each head, rocker arm assemblies, and cam tower with bubble wrap. I put the three heads in one giant zip lock bag and the cam tower and rocker arm assemblies in another giant zip lock bag. Then I packed the heads, the cam tower and the rocker assemblies into a heavy duty cardboard box with plenty of packing material and used fiberglass reinforced packing tape to seal up the box. I packed a second box for the other set of heads, cam tower and rocker arm assemblies.

I took the boxes to my local FEDEX shipping center and had them shipped to Craig Garrett at G2 Performance in Grand Rapids, MI. Craig will do machining work on the heads, rocker arms and cam tower.

[dannichols1474]

I just realized a skipped over a very important bit of info: head stud removal.

When I contacted Tim at Ollie's we discussed using Case-Savers versus Time-Serts to strengthen the attachment of the head and case perimeter studs in the magnesium case. The practice at Ollie's is to use Case-Savers on the 10mm head and case studs and Time-Serts on the 8mm case studs. I am having all of the case stud threads strengthened not just head studs. I also supplied Tim with the ARP 504-9501 911 & 930 Turbo Crankcase Stud kit to replace all of the existing case studs.

Back to head stud removal: After a bit of research I found the preferred method is to soak the threads with penetrating oil for some time, use a stud extractor, and heat the case around heads studs with a MAP gas torch. I applied this technique and was successful with all 24 head studs on my engine. I found that the studs came out easier when I applied heat not only around the surface of the case, but also in spigot of the case next to the stud.

[dannichols1474]

While engine parts and the transmission are off-site getting worked on, I am hanging out in the garage on a rainy Sunday night planning my next "to do" item. I have ordered a bunch of parts, some of which have been delivered and others that I am still waiting on.

The next move, once we get a break in rain, will be to start scraping off old gaskets and cleaning parts to be ready for reassembly.

I also plan to completely unwrap, inspect, repair as necessary and rewrap the original engine wiring harness now that I have full access to it (something didn't have when I did the CIS to ITB EFI conversion).

[dannichols1474]

Back 16 years ago when I installed SSI heat exchangers, I noticed that the exhaust manifold studs on heads 1,2,3 were different in appearance (the stud necks down / is thinner in the length between the threaded portions) from the studs on heads 4,5,6.




This difference in studs leads me to think the 4,5,6 heads had been worked on in the past before I bought the car in Dec 2006. Not only are the exhaust studs different, but when I disassembled the heads from the cam towers I found residue of red crayon marks on the 4,5,6 heads, but not on the 1,2,3 head /cam tower assembly.

So my question for the experts is: are the exhaust studs from heads 1,2,3 (thin in the middle) original as installed by the factory?

I removed the intake and exhaust studs from the heads before I shipped them off to Craig for machining and the exhaust studs on heads 1,2,3 were much more difficult to remove than the exhaust studs from heads 4,5,6. In fact, one stud from head 1 and one stud from head 3 were "welded" in place and the studs broke in half in the thinned area of their length and that was with penetrating old, MAP gas torch heat and my stud extractor tool which worked so well with the head studs in case halves.

[dannichols1474]

Tonight, I got busy working on the engine wiring harness. When I did the CIS to ITB EFI conversion, I removed no longer needed CIS components: warm up regulator, warm up regulator relay, cold start thermo switch, cold start valve, throttle switch. Since I had chosen x-faktory's Option 2 (EFI + ECU control of ignition timing advance), I also removed the factory CDI module. In addition, several years back Ralf at Don's Autowerks had installed a new higher output alternator with an integrated voltage regulator and had removed the original discrete voltage regulator. That said I cut and hacked on the engine wiring harness leaving no longer needed wires in the harness.

With the engine and transmission removed, I now have full access to the engine wiring harness so I could finally "clean up" the wiring.

Engine wiring harness as removed with the engine / transmission:


Engine wiring harness unwrapped:


Next, I dis-assembled the 14 pin wiring connector that connects the engine wiring harness to the electrical panel in the left rear corner of the engine bay. I made a diagram of the wire colors by connector pocket. Then I removed no longer needed wires from the wiring harness and the wiring connector:


Then I carefully re-populated the wiring connector and began re-taping the wiring harness. I only got partially done when a I ran out of black vinyl electrical tape:


Once I get more electrical tape and some plastic corrugated wire sheathing, I can finish wrapping and preparing the engine wiring harness for the engine / transmission installation. The plastic corrugated wire sheathing will replace the original wire sheathing for the wires that run down out of the engine bay to the starter and to the reverse light switch at the back of the transmission next to the speedometer cable connection.

BTW, collecting more essential supplies for the engine re-assembly:

[Tony V]

Funny how things escalate! My ‘74 911 engine is with Al now getting rebuilt to RS specs. It’s one of the “Current Projects” in Al’s posts.
Figured I’d have the transmission done at the same time. Since the engine was out, I started looking for a shop to paint the car. Dropped it off yesterday, to a shop in Scotts Valley, for a repaint in single stage Lime Green (current original color) Now I’ve got a 6 month wait for the car to be completed. Sure snowballed into a major project. We’ll have to get together after we’re both done and compare notes. We’re only about 15 miles apart.
Tony

[dannichols1474]

Hi Tony,
Yes, in for a penny, in for a pound. Sounds like a great idea to get together. I’ll send you my email in forum message.
Dan

[TheBrokePilot]

This is my favorite thread on the forum. Love the way you are documenting your work.

How accurate is the wiring diagram you purchased from colorwiringdiagrams.com? I'm trying to follow the factory Current Flow Diagram but with the mess of wiring that I am dealing with it is making it difficult to fix the PO's botch job.

[dannichols1474]

Finished cleaning up and re-wrapping the engine wiring harness:


Next job is to clean up fan shroud, air ducting and engine tin pieces.

[dannichols1474]

Hi TheBrokePilot,

I have found the wiring diagrams for my car from colorwiringdiagrams.com to be very accurate. The wiring diagram is on B size sheets (nice and LARGE) and it is in COLOR so I can actually make out which color wires are connected where. As I stated at the beginning of this thread, a detailed, color, easy to read wiring diagram is MUST for this job.

Good luck with your project!

[dannichols1474]

I have always thought the cooling fan and fan housing on my car needed a refresh, but I just didn't know how it was put together (fan, alternator & housing). On pages 61-63 of Wayne Dempsey's "101 Projects for Your Porsche 911" there is a clear explanation, so I started by tapping the bolts that were exposed when I removed the inner air duct to gain access to the alternator electrical connections:




That released the fan housing from the fan / alternator. I had already removed the nut, washer, outer pulley half and spacer shims from the front of the fan / alternator:



Then I suspended the backside of fan with some wood blocks with the backside of the alternator about 1/2 inch above the garage floor (being careful to contact the inner ring of the fan and not the fan blades - fragile, don't to break a blade and then have to buy a new fan). Then I carefully tapped on the threaded end of the alternator shaft with a rubber mallet and the alternator dropped down to the floor, releasing the fan from the alternator shaft. The alternator shaft is keyed to the fan with a woodruff key which I put in the labelled zip lock bag so I won't lose it.

Now the fan / alternator assembly is separated and I can get on with cleaning the fan and fan housing and hopefully restore their appearance:

[NickW21]

You're really going all out on the engine rebuild, Dan. Pretty impressive. Hey, I had a quick question for ya. I took off my engine shroud and fan, etc. to do some restoration on them as well. I'm at the point where I am starting to put it all back together, but now with the EFI setup vs. the CIS. So, I was going through this thread again recently and noticed that I have a hole in my shroud with no apparent corresponding item to go into it. No plug or whatever is supposed to go there. I saw in one of your photos, that there is a hose coming out of that hole in your setup. Can you tell me where that goes? Does that hook up to the charcoal filter in the back corner of the engine bay? If so, that does not exist in my setup and depending on what it's supposed to be doing, I'll either need to get that hose or just find a suitable plug for it

Here's a picture of the hose I am referring to:

[dannichols1474]

Hi Nick,

I was working on my daily drive (05 MB C55 AMG, I am the original owner) that has 212k miles and I am changing the driveline carrier bearing and changing the differential gear oil since both have not been replaced yet (front and rear wheel bearings and front and rear flex joints on the driveline have all been replaced within the last 50k miles).






Anyway, back to your question. Yes, the hose connected the fan shroud on my car does connect to the evaporation charcoal canister. I think it serves as the canister purge source - fast air / lower pressure. Here are a couple of photos: