Project Minne - a 72 build thread

[jpnovak]

Been a while since I updated this thread. So... Let's play some catch up.

In the last installment I was working on the engine.

My heads came back from the machine shop. Craig Garrett (G2 Racing - Cgarr on the board) does an amazing job at a reasonable price. The usual stuff was done. Valve guides, seats, resurface, twin plug, etc. I also had the CIS ports welded up and the intake drilled for MFI ports.



The heads were then ported to clean up the casting around the valve guide and to remove casting flaws through the intake and exhaust tracts. They were opened up slightly to match the cam spec, peak HP rpm and overall gas flow rate (velocity). I have my favorite target numbers. Let's just say I usually favor smaller ports even if it slightly limits peak HP. The area under the curve is where its at.

Eventually the longblock was finished. Cams are timed. Just waiting on a few ancillaries to button it all up.




Since the longblock was finished I have to move quickly to start dressing the engine. I have opened up the throttle body and stack diameters to match my heads. They are tapered from top to bottom to help optimize flow and feed the Horsepower beast.

Along the way I have been test fitting the intake, fan and shroud. So far, so good.



And yes... Its a totally stock 72T engine. That's my story and I am sticking to it...



Under the car I have finalized my brake setup. 930 brakes front and rear. All new brake lines from the MC to calipers have been installed. Can't have enough brakes.





I also spent some time and refinished my cookie cutter wheels. This is a media blasted finish with satin clear coating. I thought this was well matched to the car.




However, in case anyone want to know... Cookie cutters will not clear 930 brakes unless you use at least 12mm of spacers. The internal support rib on the backside of the spokes hits the caliper. And it doesn't hit the fins. It hits the caliper half bolt. No shaving possible here. So... I had to get some different wheels. A local friend gave me a great price on some 15x7 Fuchs. The forged wheels have a flat backside of the spoke and clear with no issues. I knew this but didn't want to spring for new wheels at this time. Oh well. The paint is mostly stripped for the first step in the refinish process.



On the body I Have been working on panel installation. The front and rear bumpers are installed. I think they came out great. The oil cooler ducts and rear venting on license panel are well proportioned to the car. So far, its a winner to me.






I also installed the passenger door. I was waiting for some new hinge pins. One of mine was slightly bent and I didn't want to install it and not be able to get it out.

Here is the car on Fuchs with almost all the panels installed. So far, so good.



I am into a 6 week window to make HCR19 in March. Its going to be tight. I wish I Had more time so that I could finalize a few details of the build. But, I would also rather be driving it.

Next up is to finish dressing the engine, mate it to the transmission and get it in the car. Then I can wire the EFI and finalize my oil cooling system.

All these projects are converging at a rapid rate. I just have to remember to take pictures and document along the way.

[jpnovak]

So, Where did I leave off in the last installment?

Some parts came in. Here is my Twin plug cap and rotor. I build my own twin plug distributors. Yes, the engine is twin plugged. CR came out at 10.7:1. It better have that extra plug.



And with the extra plugs you need a few extra holes. Here are my twin plug valve covers before they were finished.



Oh, I needed some exhaust parts. Digging through my parts closet I found an old set of SSIs. They needed some scrubbing to make them look somewhat clean before bolting them on.


At that point the engine was basically done. It was time to mate the transmission. I am using a type 911/01. I prefer the early shift pattern. Plus the 901 variants shift easier and faster. An additional plus is decent gear ratios matched to my cams and desired power band. I use a stock steel flywheel and Sachs aluminum sport pressure plate.



Of course, once bolted together it takes up a lot of floor space. Might as well hang it in the car with those, oh.. so... important 4 bolts. Unfortunately, my low-rise lift is not tall enough to clear MFI stacks with the bumper on. So, the induction system had to come off for installation. Easy enough to put back on. Yes, the drive train is installed in the car. This marks another major milestone.



Now comes the fun task of wiring and oil system.

The first part is modification of the oil filter console. I had Craig Garr (G2 motorsports) bore out my oil filter assembly. There is a 3rd port that is capped off on the factory systems. The job requires boring to fit a factory engine style oil thermostat. The 3rd port is then uncapped and will be connected to my external oil cooler using a 16AN adapter.

[jpnovak]

Since the car was back on 4 wheels and sitting at ride height it was time for some of the last interior modifications before the headline. One of these mods is an integral 3rd brake light. I bought a roll of LED strip. This was 10mm wide and had a black background. It uses fairly bright red LED and 12V direct input. I used closed cell foam inside the vent and then pulled the LED strip in front. It will be very discrete until I press the pedal. Then it's high and bright. Exactly what is needed with today's inattentive drivers.

[jpnovak]

Well, I finally made some time to get back in the garage and get some work done. The current focus is the oil system. Starting with a basket case car you are never quite sure of how many missing parts until you really put it together. I did not fully mock-up the oil system prior to paint.

Let's start with my install items. The front nose cooler is based on an RX-7 cooler. I welded 16AN fittings and mounting tabs to the cooler and it sits in a recess air dam box in the nose. The oil lines are routed following what Matt did many years ago.

http://forums.pelicanparts.com/porsc...r-install.html

100R5-16 hoses are exterior braided and have internal steel mesh. They are rated to 500F and 800psi. Yeah, should have plenty of margin for my 911. I drilled holes in the rockers and test fit oil hoses prior to paint. At this point in the build it was a matter of pulling hoses, routing them, cutting to length and installing fittings. I used reusable fittings rather than the crimp on.

After pulling the hoses I connected to the front cooler. Install is nice and clean. I still need to install hold downs on the hoses. That will happen after the engine is running and leak free.




Here the hoses exit the rockers behind the fender and go up and over the wheel well. They pass across the top of the strut and then enter the body high enough for wheel clearance.



The hoses exit the rockers and go to both the tank and the oil console. The upper hose is the return and goes to the bottom of the tank. The tank has an M30-16AN adapter and then a 90deg hose end fitting. The hose attaches straight into the tank. Easy.



The supply line to the oil cooler attaches to my modified oil filter console. The upper rear port is the access after the newly installed thermostat. Clean.




In the best news. I thought I was missing the NLA lower oil suction tube hardline. NLA everywhere and very difficult to find used. I was digging through a box of stuff that came with the car and found that I had that hardline. Woohoo! I just need 2 new rubber end connection hoses.



The oil console to tank line is still available. it has been ordered and on the way.

The lower 72 oil line is part of the engine cross-over. Its crazy expensive. I already have a mid-year oil backdate line installed. I have a solution to mate these two that will be in another thread.

More progress will be made later this week when the rest of my oil line parts arrive. I should have the full oil system installed by the weekend. Then on to finalize the fuel system.

[jpnovak]

I finished up my primary oil iines and vents hose today. Good feeling having it all tuck up high and tight in the wheel well. Starting from the filter console there are three lines. The top is the oil cooler supply line. It tucks next to the oil cooler and enters the rocker. The forward line is the tank supply line when the thermostat is closed. It goes to the top of the tank return fitting. The rear line is the engine scavenge line from the oil pump to the filter console. I am pleased how nice this came out.









I am still waiting for two rubber hoses to connect the lower supply line. Should be here this week.

Now I can move on to the fuel system.

[jpnovak]

Oil Lines Part 2.

One of the challenges with the 72 oil lines is the seemingly complex arrangement.

The engine cross-over line is one of these. The 72 line goes from the pressure scavenge side by Cylinders 2/3 forward to the engine, under the transmission bell housing, and then transitions to a rubber line that goes rearward, then upward, then attaches to the lower rear fitting on the oil console using a 90 deg hose end. Wow, that's a mouthful.

Now, if you are not using the original 72 cross over line, what do you do? How do you adapt the system for a later engine? here is how I did it.

The engine cross-over line is the 74-77 hard line. It follows the same path ending in a M30 threaded male fitting by the engine oil cooler. This is the same line that ships when you by the early line upgrade if installing SSIs.

The hard line has to make a connection to the oil console. I bought a 78-79 oil line that connects to the oil thermostat. This line has a double, offset 90 deg bend so that the hardline section clears the longitudinal and goes forward through a rubber hose section to the hardline connecting to the thermostat. Many of you are familiar with this line.



Step one: Cut this new oil line in half. Yeah, nothing like buying new parts and cutting them up. I admit I hoped this would work rather than wasting money down the drain.



Step two: bend the hard line section backward and inward. This is to provide clearance in the vertical plane. I put the end of the fitting in a fence post and then used a pipe to lever the oil line carefully into position. This will make sense in another few pictures.

Step three: Offer up the oil line by attaching the lower threaded nut to the engine hard line. Then mark the length of the remaining hose to the engine console.

In this example, I cut about 4" off the hose. The hose end will then be attached to one of my leftover early car, reusable oil fittings. The factory did use reusable fittings on quite a few of the early cars. If you have them. Save them. They are easy to install. In this case, the old oil fitting is a M30, 90 deg elbow. You can see all the parts here.



To install this fitting the outer collar screws onto the hose. Then the elbow section threads into the hose and collar. Tighten all the way down. Once tight you have to make sure you clock it in the right orientation to mount to the car. Here is my completed hose.



What's next? Put it in the car. Everything fits nicely. New rubber suction lines on the lower section. I have about 3" of inward clearance on the tire with 225s. And there is about 6" rearward clearance to the line. I will eventually have some protection on this line though it is probably not needed. The factory never covered these lines.


You can see here how I moved the vertical angle outward for clearance on the longitudinal section. This angles the hose outward to meet with the 90deg elbow fitting. Overall, short oil path. minimal bends. Clean, simple, effective.







And yes, I have the same picture rotation issues as everyone else. These show up on my PC in the correct orientation, set somehow they rotate out phase after upload. Use your imagination...

[jpnovak]

OK. I realize I have not updated in a long time. Work and life have been crazy. Definitely the balance tipped in the wrong direction. I have been slowly chipping away at my long punch list as time allows. However, in the past 2 weeks I Have started working more consistently on the car.

First, I want to say thank you to everyone who voted in Pelican's DIY Build contest. Third Place thanks to all of you! Got my gift Certificate. More on that in another post.


After completing the oil system I worked on the fuel system. First, I started cleaning the original tank. I stripped the exterior and started etching the inside. I ran into issues getting the inside clean after about 2 weeks of trying. The tank was approximately 1/4 full when it was last parked. So, You can imagine the thickness of varnish residue. I am a chemist and tried everything short of mechanical cleaning but could not cut through it. So... I replaced it.

The new Dansk repo tank had to first be inspected, measured and checked for fit.



There have been issues in the past about flange locations and width preventing them from sitting in the chassis correctly. These issues must have been corrected in current versions. The new tank fit fine.



Since the tank fit correctly it was time to prep and coat. The factory E-coat was scuffed down and then coated with 3 layers of Upol Gravitex gray. The shutz gun running 48psi seemed to be about right.

This is as close as you can get to the factory Wurth coatings. It all came out nice. I was happy with color and texture.




Once coated it was time to put it back in the car. The tank really fills up a huge hole up front and I am glad to see it in place.

[jpnovak]

Since the tank was in it was time to connect my lines. I ran 6AN nylon braided line through the tunnel. It was just waiting for some fuel fittings on the other end. The supply line got an M22-6AN adapter. The return line uses the factory banjo with a clamp. I did not have enough room to the steering rack to clear a return fitting and 90 deg hose termination. The factory clamped the return line. There is no pressure on the line so I do not see any issues.



I installed a generic 044 sized fuel pump. Way overkill. But I am fine with that. Again, 6AN lines and fittings throughout the system.




Fuel pump mounted above the stock location. I used a 60mm fuel pump clamp bolted to the underside of the seat pan. This is because the pump did not quite fit in the stock tray. It was long enough to cause concern with trailing arm clearance under compression. We have enough bumps that I don't want any issues.



Fuel lines were then run up into the tunnel following the factory emissions hose tabs.
The fuel lines enter through the bulkhead/shock tower gap on the DS of the car.

Not pictured is a 6AN inline 50micron filter on the supply line before the pump. It is also mounted in the seat pan area and very easy to access to change out when needed. Serviceability is a good thing.



The supply line then enters the flexible fuel line distribution manifold. The flex lines are for my RSR style EFI connections. More on that later.



The supply line then goes across to the fuel pressure regulator. I mounted this on the passenger side shock tower reinforcement. This makes the gauge easy to see and adjust with the MFI stacks in place. Sometimes quick checks on fuel pressure are needed during initial EFI setup.

[jpnovak]

With the fuel lines run it was time to pull some wires. First step is the main harness through the body. I am running a Microsquirt ECU. These have more than enough features to control spark and fuel on an old 911 and the package is small enough to fit inside the tunnel under the shift coupler.

The wiring harness is pulled through the speedo cable hole. There is room for both the speedo cable and harness. From the tunnel exit the harness routes up across the DS undercarriage following the same basic path as the fuel lines. The wiring enters the engine bay at the DS rear corner behind the shock mount.

At first the bundle of wires is daunting... So many colors.



The wires are all clearly marked and get divided into 3 categories.

1) unused - Which means they get cut off and secured out of the way.
2) car side connection - these are 12V, ground, O2 sensor and ignition outputs.
3) engine side connections - these are all the engine mounted sensors and injector connectors.

I separate the engine side connectors with Deutsche 12 pin connectors. Waterproof, easy to install and gives single disconnect point for all EFI should I need to drop the engine.



The main connector is the focal point for the engine wiring harness. You can see here some of the different directions electrons must go. I leave the wires out until it is time to secure and cover.




Based on the position of the 12 pin connector, I use a CAD (Cardboard Aided Design) layout for my wiring harnesses. Simple really. Binder clips in injector and sensor locations. I can clip a connector, cut a wire to length, crimp a terminal and assemble the proper connector with heatshrink as needed. And... I can work in an Airconditioned space. This is most important in July in TX. I think my wife is amazing considering she will walk out in the morning to find wires and tools all over the kitchen floor. Love her for sure...








The EFI needs ignition control. I am a fan of big spark. If there is ever a fault in the EFI you need plenty of spark to keep it going. Case in point... Years ago my MAP sensor failed one a drive. I was 2 hours from home. The car thought it was at WOT all the time. This meant I was running AFR7 under cruise. The twin plug driven by dual Crane Hi-6 boxes never fouled a plug as I drove home. Yeah, I put them back into this car. I mounted them clean on the backside of the rear deck.



A few other items were added. I run a secondary relay and fuse panel in place of the stock CDI unit. I also mount the wideband O2 controller in the same location.

Once everything was mounted I was able to go back and tie up the wiring harness.



The engine bay is getting more busy but it certainly stayed as clean as possible.

[jpnovak]

Next it was time to work on ignition delivery. I am using EFI with integrated ignition control. But I don't like the look of COP, coil packs or other spark delivery methods on a vintage car. It should be a 12 plug distributor for twin plug. I only use the body, rotor and cap since the ECU controls everything. But I took out the least reliable parts. Caps and rotors tend to last a while. So.. Here is the process to build my twin plug distributor.

First I strip the distributor down. This donor had bad bearings so I pulled the gear and shaft out as well.

The body is turned on a lathe to make the top concentric and reduce the diameter for my adapter cap. You can see the cut lines. The distributor bodies are not round. They are oval at the casting parting line. The top sections are not machined and don't have to be - unless you are adding a part on top.



the machined body is then placed in the freezer while the twin plug adapter cap goes in the oven at 200F. 15 min later they are mated. A few soft blows with a dead blow hammer and the body drops into the adapter cap. The result is a twin plug distributor body.




Next, It was time for new bushings. I bought these from a supplier in AZ (PK) since Pelican does not carry them. Again, Heat the distributor body, freeze the bushing and then press in. I used a 12" C clamp to press them in. They did not fit in the vise and my press didn't want to hit the inner bushing.



Lower bushing pressed in.


Once the bushings are pressed in you have to ream them to 12.5mm. I used a long drill bit to also make sure they were parallel and that the shaft spins freely.


If you have 12 spark plugs and 2 ignitions you need two coils as well. So, I wanted an adapter plate to mount them on the top of the fan. I just like the look. A section of flat stock was drilled with mounting holes and cut to length. Then it was painted black. This will all make sense in another post.



I bought two cheap coil brackets that were silver zinc in color. These were trimmed at the mounting holes and then I converted the clear to yellow zinc.



The two coils will mount side by side on top of the fan. The brackets were trimmed to get them to mount closer and reduce clearance. Have to keep it tidy.

Lastly, I Have to prep the twin plug rotor. I make an adapter pin that offsets the rotor to match the height of the cap adapter. I used to use a mounting screw but had issues with high rpms and the screws not being secure enough. Now I epoxy them into place.



I will show the completed assembly soon in another post.