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Thread: Project Minne - a 72 build thread

  1. #171
    mad scientist
    Join Date
    Apr 2007
    Location
    Austin, TX
    Posts
    537
    yes, Craig has the heads and my oil console. I am modifying the 72 console for thermostat and external AN16 fitting.

    I am about to start working on the engine. I am expecting to have the heads back in a few weeks. Would be great to have the shortblock ready for them.

    Yes, life has been getting in the way for the past few years. Right now I Have some time so its time to use it.
    1971 911T SWT - Sun and Fun Machine
    1972 911T - "Minne" painted and undergoing assembly.

  2. #172
    mad scientist
    Join Date
    Apr 2007
    Location
    Austin, TX
    Posts
    537
    Let's see. Where did I leave off last...

    Rear suspension. I spent some time doing the initial setup. I Had to shim the spring plate bushing covers, bolt down the spring plate to the trailing arm, set the initial torsion bar angles and finally install the brake rotor.









    During the day I started cleaning and prepping parts. First was the oil tank. This needs to be test fit so that I can start to run my oil lines.

    While the oil tank is ready to install, I can not install it. There were some non-S package 911T delivered without the oil level gauge. This meant that the tank does not have a provision for an oil level sender. Even more important is the lack of external oil cooler inlet on the bottom of the tank. New to me. This means I Have to either modify the tank or get a new one. I am currently weighing options.



    Next up on the cleaning list was the brake calipers. Those 930 brakes that have been collecting dust are now ready to bolt on. I will have to make some new supply lines but that would not be much of an issue.



    And lastly, there was a set of cookie cutters that are my roller wheels. They have dry rotted tires and have been sitting on the side of the house for a few years collecting leaves. They are clean enough to install.




    wait... Did you catch that? I said, INSTALL...
    1971 911T SWT - Sun and Fun Machine
    1972 911T - "Minne" painted and undergoing assembly.

  3. #173
    mad scientist
    Join Date
    Apr 2007
    Location
    Austin, TX
    Posts
    537
    And so, with some suspension and some wheels I had to set her down. I fully admit that I was humming the theme to 2001 A Space Odyssey.

    Minne is on 4 wheels. Minne has seen the light for the first time in about 15 years. Minne rolls easily and I think she thanked me for reaching this point.













    You know... I think its time to start building an engine.
    1971 911T SWT - Sun and Fun Machine
    1972 911T - "Minne" painted and undergoing assembly.

  4. #174
    aka techweenie Eminence Gris's Avatar
    Join Date
    Dec 2003
    Location
    West Los Angeles
    Posts
    3,091
    Bravo, Jamie.

    I'm going to send you a billet oil door hinge piece for Minne...
    techweenie.com

    My parts fetcher: 2016 Tesla S | Currently building: 73 RSR tribute and 69 RS tribute

  5. #175
    Longhoods forever! silverc4s's Avatar
    Join Date
    Apr 2003
    Location
    Somewhere in Texas
    Posts
    439
    Kudos to you, Jamie,
    That is going to be one beautiful coupe. see you in Kerrville��
    Bill Conway, Early S Registry member #254
    1970 S, 2.2L Silvermetallic Coupe
    1973 T, 3.2L Black Carrera Targa
    1969 T, 2.4L Silvermetallic Targa

  6. #176
    mad scientist
    Join Date
    Apr 2007
    Location
    Austin, TX
    Posts
    537
    Thanks Bill and Bill.

    Yes, I hope Minne will be finished to attend HCR19. At least mechanically the car should be running by then. Though there may not be an interior.
    1971 911T SWT - Sun and Fun Machine
    1972 911T - "Minne" painted and undergoing assembly.

  7. #177
    mad scientist
    Join Date
    Apr 2007
    Location
    Austin, TX
    Posts
    537
    Picking up where I left off. The past 2 weeks have been busy. All the first of the year job commitments take some time. So, garage time has bee limited.

    There has been a lot of behind the scenes working going on. Parts cleaning has taken most of this time. And so, if you have clean parts, you might as well do something with them. In this case, it was time to start the engine build.

    Let's see... The crank is cleaned. I also polished using 1500grit paper, a few drops of oil and a leather strap. Old school but works in the garage. To be honest the crank was clean and didn't need it. All the crank and rod journals measured out near the new diameter spec.



    If you have a crank you need something to put the rods on. Of course, there are bearings that fit in there too. I Dry Film Lube (DFL) coated the rod and crank bearings. They were then buffed and measured for clearance. Rod clearance came out right where I want it.



    And if the crank is clean and rods are attached I just needed to lay the main bearings in place and set the crank on top of it. So far, so good. Oh yeah, Don't forget to check the intermediate shaft backlash. This was the same set I pulled out and showed zero wear. So, yes, it still measured in spec.




    At this point I was a few seals and bolts away from closing up the case. A thin coat of Threebond on the perimeter, some 574 on the bearing webs and then it was time to torque it up. Took me 35 min to seal the DS of the case, install the bearings, mate the two, install the through bolts, drop on some perimeter nuts and torque it all down. Almost routine...



    While the sealants were setting I needed to clean more parts. The cylinders were media blasted on the exterior and then scrubbed thoroughly to get rid of any residue. There are nice and clean.



    Oh, and if you have cylinders you might want to put some pistons in them. Of course, these needed some modern technology too. DFL coatings on the skirts and ceramic thermal barrier coatings (TBC) on the piston crowns.



    Next I will gap the rings to individual cylinders and CC the piston crows so I will know exactly what my compression ratio is. And, I also have to install some head studs and reapply epoxy to the oil galley plugs.

    I am expecting my heads back from the machine shop in the next week. I am hoping to be ready for them when they arrive.
    1971 911T SWT - Sun and Fun Machine
    1972 911T - "Minne" painted and undergoing assembly.

  8. #178
    Very cool Jamie! Thanks for sharing with us.
    See you at HCR!
    Couple of 911s and some projects.

    ES #2013
    RG

  9. #179
    mad scientist
    Join Date
    Apr 2007
    Location
    Austin, TX
    Posts
    537
    This week has been entirely focused on the engine build. Specifically getting the pistons ready for installation. Yeah, I know many just snap on some rings and slide them in the jugs. But I prefer to spend the extra time. This is one of the reasons a 911 build gets expensive. It just takes time to pull together the details.

    Let's start with the CC process. In order to accurately know what your compression ratio is you have to measure piston dome volumes and cylinder head chamber volumes. These are JE aftermarket pistons. They were ordered with a nominal 10.5:1 Compression Ratio (CR). I bought them used/uninstalled a few years ago when a particular engine build changed direction.

    To measure CR you have to determine the piston dome volume. The easiest way is to pour some liquid in the top. If you know the piston over volume - you can do a little math to determine the crown volume.

    I setup a chemistry burette. I have a 100ml glass burette with 0.2ml graduations. This is accurate for my needs and will give you a calculated CR down to 0.01CC. Yeah. splitting hairs here. The process is not well defined on the board so here is my method.

    First you have to install a piston into a cylinder. I will often install a single top ring to help keep it from sliding down. The cylinder is then turned upside down on a flat surface. The piston is pushed down until the crown stops at the same height as the ceiling surface. I used my kitchen countertop. (My wife was already asleep. Make sure to clean up before you go to bed). While the piston is in place, smear a small layer of grease around the perimeter to seal and prevent the measurement liquid from leaking out. I use normal grease and a cotton swab to distribute. This position means that any added liquid will only measure the volume above the piston. The piston is then covered with a clear plate with two holes - a fill hole, and a air escape hole.


    Using the burette you deliver a measured quantity of liquid into the piston void space. The liquid goes into the fill hole. When the air bubbles are gone, you read the volume and use this to calculate the CR. If you don't know how to read a burette, go back to your HS chemistry class and refresh your memory.




    In my case, I measured a few pistons coming up with an average of 50.1ml of over piston volume. Now, you also have to measure the piston depth. In this case, you measure the distance from the sealing surface to the top perimeter edge of the piston or the lowest spot on the valve pocket, This measurement allows you to calculate an effective piston crown "cylinder" so that you do some subtraction.

    AFter the piston over dome volume is measured you have to determine deck height. I install a piston (no rings) and slide a wrist pin in place. Then drop a cylinder on top with no base gasket. You measure the height of the piston edge to cylinder sealing surface. This allows you to calculate the thickness of your base gasket to achieve the desired deck height. In my case, I will use a stock 0.25mm gasket to acheive a deck height of 1.19mm (average). I target just over 1mm for performance builds.

    Here are my pistons that are marked with the weight group, the cylinder number to be installed and a directional arrow indicating position in the engine. The two heavier ones are at the flywheel end. The two lighter ones are at the crank pulley end. Done.





    I will show the same results on the cylinder heads once they arrive back from the machine shop next week. They are currently on a truck between here and there. The chamber volume is the remaining number to calculate CR accurately.

    Next, I weigh pistons and adjust the groupings for position. My scale measures to 1g. That is close enough. After a short period of time there will some carbon buildup and the 100mg tolerance is quickly awash. So, weigh pistons and wrist pins individually. Make a table of their weights. Mix and match until you are close in weight. These JE were close. Pistons were +/-1g and wrist pins were 2 g tolerance. I put a heavier pin with a lighter piston and end up with a group of pistons and pins that are 1g deviation across the group. I am totally fine with reaching the tolerance limit of my scale. Here are the pistons and pins grouped together.



    Oh, I forgot to mention. The wrist pins are also coated. I use a different product here. Basically, Tungsten disulfide powder. I make a slurry and wipe it on. Noticeable reduction in friction. This coating only works well on highly polished surfaces like the new piston pins. There. Secret spilled.


    Next up, you have to size and gap the rings. Due to combustion heat the rings will heat up and expand. If the gap is too tight, the ends of the rings will meet and then bind against the cylinder wall. This causes excess friction and wear and yes, more heat. Its a downward spiral to wearing out your engine.

    So, Again I install a piston in the cylinder. I use a small spacer block underneath to raise the piston so that the ring is seated about 20mm below the surface. Then insert a ring and push it down so that it seats against the top of the piston crown. This is just using a piston as a locator.




    when you remove the cylinder the ring is now parallel to the sealing surface and the ring gap is easily measured.




    I use two feeler gauges to measure ring gap. You can calculate the ring gap based on manufacturer specifications. In this case, JE specifies a formula that is cylinder diameter (measured) x a tolerance factor. The result is a target gap. The gap is different for top and middle rings. Make sure you measure both and keep track of them. I take them out of the package, measure and write the gap value on each package. I also keep a table on my notes.

    The feeler gauges are setup like a go/no go. One is at the gap I want. The other is one size larger. Here you can see that the as-delivered new ring is a no-go.




    The ring comes out and ready for adjustment. I use a very small, fine, flat file. Its wide and easy to hold.


    The new ring has a coated surface on the edge. This is the dark coating.




    AFter a few passes with the file the edge is gone meaning I took off a few 0.0001".




    You keep fitting and filing until the ring gap is set to your liking. Here is my ring gap set. In this case, the specified value was 0.018".




    The rings were then installed on the pistons and rotated such that the ring gaps are properly oriented. oil ring gap goes up, and compression rings are lateral and opposite. A few drops of oil on the rings make sure they rotate freely and with no binding. I will be installing them in the cylinders this weekend.
    1971 911T SWT - Sun and Fun Machine
    1972 911T - "Minne" painted and undergoing assembly.

  10. #180
    member #1515
    Join Date
    Mar 2009
    Location
    San Antonio, Texas
    Posts
    4,239
    If you like this project vote for Jamie over on Pelican!

    http://forums.pelicanparts.com/off-t...vote-here.html
    David

    '73 S Targa #0830 2.7 MFI rebuilt to RS specs

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