Starting a Major on a 1975 GT4 | Page 2 | FerrariChat
Buy

Starting a Major on a 1975 GT4

Discussion in '308/328' started by greggbferrari, Oct 29, 2011.

This site may earn a commission from merchant affiliate links, including eBay, Amazon, Skimlinks, and others.

Page 2 of 2
  1. Brian Harper

    Brian Harper F1 Rookie
    Owner Silver Subscribed

    Feb 17, 2006
    4,078
    San Jose area
    Full Name:
    Brian Harper
    #26 Brian Harper, Nov 16, 2011
    Last edited: Nov 16, 2011
    I'd be inclined to run if it it seems to be otherwise in spec. It is a relatively low-stress bearing surface and it is well lubricated. If iit sn't gross wear that will let all the oil squirt out the side it will probably be ok.

    And using a hone will only make it rounder by making the bore bigger. That's not really what you want. Unlike piston rings or brake piston seals, the cam will not grow to fit the new slightly bigger bore. It will just be looser in the hole and that's not good. And I'm not sure honing bare aluminum is quite the same as honing cast iron or even Nikasil. I suspect you'd get nasty results.
     
  2. greggbferrari

    greggbferrari Karting

    Jan 4, 2010
    121
    Seattle, WA
    Full Name:
    Gregg Brown
    #27 greggbferrari, Nov 16, 2011
    I think I will take a cabinet scraper (essentially a straightedge with a square edge) and run it VERY LIGHTLY on the inside of the cap to see if there is a high spot. Then as Pete suggests, measure the inside (torqued in the factory position) and the cam when the cam is out. If it’s not too bumpy, or too big a clearance, I’ll leave it alone.
    If I ever rebuild the motor I can line bore the caps. If I’m thinking right, the nice thing about belts is they are a little more tolerant of changing the centerline to cam to crank distances than a gear or some short chain drives.
    In one sense it looks like I got lucky, at least compared to Geno!
     
  3. yelcab

    yelcab F1 World Champ
    Consultant

    Nov 29, 2001
    13,674
    San Carlos, CA
    Full Name:
    Mitchell Le
    #28 yelcab, Nov 17, 2011
    I hope your mechanic paid for that...
     
  4. Sledge4.2

    Sledge4.2 F1 Rookie

    Oct 19, 2007
    4,789
    Marin
    Full Name:
    Geno
    #29 Sledge4.2, Nov 17, 2011
  5. Sledge4.2

    Sledge4.2 F1 Rookie

    Oct 19, 2007
    4,789
    Marin
    Full Name:
    Geno
    #30 Sledge4.2, Nov 17, 2011
    i wonder what the seat of the cam looks like. In my situation, it was scarred just like the cap...
     
  6. greggbferrari

    greggbferrari Karting

    Jan 4, 2010
    121
    Seattle, WA
    Full Name:
    Gregg Brown
    #31 greggbferrari, Nov 17, 2011
    What I can see doesn't look too bad. I'll pull the cams this weekend...watch this space. Thanks for the link to the other thread.
     
  7. Sledge4.2

    Sledge4.2 F1 Rookie

    Oct 19, 2007
    4,789
    Marin
    Full Name:
    Geno
    #32 Sledge4.2, Nov 17, 2011
    will be interestnig to see the bottom cradle condition.

    The mechanic that botched mine spend hours making sure any high spots were smoothed off (he had a little hand tool or some sort), then installed the cams and spun them to see if it was smooth before reinstalling.
     
  8. chrismorse

    chrismorse Formula 3

    Feb 16, 2004
    2,150
    way north california
    Full Name:
    chris morse
    #33 chrismorse, Nov 17, 2011
    Last edited: Nov 17, 2011
    Having done just one Major on my 77, i have a couple of thoughts;

    1)go back and have a good look at some of the parts you have already pulled to determine if anything needs to be ordered before reassembly starts, stuff like plug extenders & boots, plug wires, caps, ignition parts, special coolant hoses, thermostat, air and oil filters...........

    2) Try to define the extent of your "major", by giving the car a real good once over and looking at the service records. This is a big job in its own right. Is it due for a front wheel bearing pack are the balljoint or rack boots torn, how about the CV boots, brake hoses and brake pads. Do the tires indicate the need for an alignment. How are the fuel and evap hoses, the filler and cross over hoses. If you are doing coolant hoses, how are the aluminum pipes, (mine had chaffed almost through in a few places. I had them heliarced, then used rubber hose and tie wraps to provide running clearance).

    3) Once you have "THE LIST" of parts you need, you can do a bit of shoppping, looking for better prices, but beware, there is some junk out there.

    4) While studying the list and availability, you might look at some of the seriously improved parts now available, like Scuderia Rampante's coolant and fuel hoses, double lip cam seals, better cam cover gaskets, (with the two parallel red sealant beads), constant torque clamps.

    5) You might stock up in advance on new nyloc nuts, Parker Stat-o-seal washers, gasket remover, tie wraps and 6,8,10mm helicoil kits for the inevitable stripped bolt holes.

    6) Some of the "As long as i am in there items": Oil and water temp sensors, pressure sender, clutch disc+ rear main seal, motor mounts, recharge the ac, all of the coolant hoses and clamps, A arm and sway bar bushings, shocks, radiator fans, all of the light bulbs, relays and fuse box, lower stiffer springs, bigger bars and brakes, a super charger, Nitrous.......sorry, was getting carried away there.

    7) And, if you aren't burned out at the end of the day, peruse the threads for the operations you are about to undertake for the inevitable golden crumb of knowledge that our more experienced contributors freely recount.

    8) Once you open up the engine, (get the cam covers off), you really need to be meticulous abut the nuts and washers, multi compartmented plastic trays are a big help.



    hth,
    chris
     
  9. chrismorse

    chrismorse Formula 3

    Feb 16, 2004
    2,150
    way north california
    Full Name:
    chris morse
    #34 chrismorse, Nov 17, 2011
    Last edited by a moderator: Sep 7, 2017
    Hi Greg,

    Have a good look at the cam pulleys. One of my old fiber pulleys were starting to seperate at the lip.

    chris
    Image Unavailable, Please Login
     
  10. greggbferrari

    greggbferrari Karting

    Jan 4, 2010
    121
    Seattle, WA
    Full Name:
    Gregg Brown
    #35 greggbferrari, Nov 18, 2011
    ...and thanks for the link, Geno. "Plastiguage is for lawnmowers and weedwhackers..." Ouch, but of course he's right.

    I'll get the cams out this weekend and send some pics.
     
  11. david

    david Formula Junior

    Feb 21, 2001
    810
    Northwest
    Full Name:
    david
    #36 david, Nov 18, 2011
    Oh jeez. That looks scarily familiar. I had that happen to mine. It turns out that the bearing(s) for the pulley shafts that gear off the crank were wearing out. That caused the belts to start to move out to the ends of the pulleys, which probably is what tore off the lips. I would check to make sure you aren't hearing any bearing noises and make sure your belts are staying where they are supposed to. I had my fiber pulleys replaced with aluminum ones.

    Sorry for the quick hijack, but I didn't want to be reading about a timing belt disaster. Now back to our regular program.....
     
  12. Sledge4.2

    Sledge4.2 F1 Rookie

    Oct 19, 2007
    4,789
    Marin
    Full Name:
    Geno
    #37 Sledge4.2, Nov 18, 2011
    Looking forward to the pics and solution...
     
  13. Artvonne

    Artvonne F1 Veteran

    Oct 29, 2004
    5,379
    NWA
    Full Name:
    Paul
    #38 Artvonne, Nov 19, 2011
    I would turn it back the way its supposed to be (numbers to the outside), and figure out to get it line bored or something equally adequate. This isnt a place to save money or mickey mouse it, if the cam bearing siezes it can snap the cam in half, and/or stop the whole show and your mashing all the pistons and bending all the valves, or it can cascade even further.

    To fix it correctely, it really should have a line boring tool run through it. Anything less is a guess and a crap shoot.

    Just an FYI, all engines usually have index or "match" marks, numbers, dots, hash marks, something to point the way in which things are assembled. You should always look for and identify parts orientation and placement BEFORE removal, so as not to confound things like were seeing here. If there are no recognisable match marks, you should carefully make some even if its magic marker. Be careful with stamps and punches, you can cause more harm than good sometimes. Pictures are pretty benign as are drawings.

    The problem here is the cap was number matched to its position and orientation first, then cut for the line bore the cam takes through the head. By flipping the cap around, the cap may only be off a couple thou, but its enough to bind the cap against the cam and start cutting. Aluminum is a wonderful bearing material, but once damage occurs, the steel imbeds in the aluminum and then becomes a cutting tool. It can rapidly go from happy to destroyed in minutes.

    No one said, but you caught this just in the nick of time. You are very lucky.
     
  14. greggbferrari

    greggbferrari Karting

    Jan 4, 2010
    121
    Seattle, WA
    Full Name:
    Gregg Brown
    #39 greggbferrari, Nov 19, 2011
    Last edited by a moderator: Sep 7, 2017
    Removed the cams and you can see a matching witness mark diametrically opposed to where the cap was tight. It really just looks polished; you cannot feel any ridge or roughness with a bare finger or a fingernail. The next picture is the cam itself. It looks ok, although there is a very fine mark corresponding to the worst polish on the caps. None of the journals look that great in the area that is not directly fed by oil as you can see in the last picture.

    Reading the thread Geno provided, the consensus seems against a line bore, although I'm sure it's the best thing to do. I really don’t want to take the head off at this point. I think I’ll dress it with a straight scraper, polish everything with grey Scotchbright and put it back together. Crazy?
    Image Unavailable, Please Login
    Image Unavailable, Please Login
    Image Unavailable, Please Login
     
  15. greggbferrari

    greggbferrari Karting

    Jan 4, 2010
    121
    Seattle, WA
    Full Name:
    Gregg Brown
    #40 greggbferrari, Nov 20, 2011
    Last edited by a moderator: Sep 7, 2017
    Separate question: The 36mm fixing bolt came out easily enough, but the balancer did not just slide off as you can imagine. I put a two-jaw puller on the back of the balancer, but as I tightened it I noticed the gap between the weight and the back of the pulley closed up—where the red arrows are in the picture. That means the elastomer is getting sheared. Is there any danger of tearing the elastomer and wrecking the balancer by using a puller?

    Should I put a shim between the weight and the pulley? All the threads I searched just say “remove the balancer.”
    Image Unavailable, Please Login
     
  16. Sledge4.2

    Sledge4.2 F1 Rookie

    Oct 19, 2007
    4,789
    Marin
    Full Name:
    Geno
    #41 Sledge4.2, Nov 20, 2011
    I am very interested in what the experts say here, but would think the risks equal regarding putting the cap back on the correct way vs the way it came off. Regarding your proposed solution, I believe that is exactly what my mechanic did.

    If you would like, i can call him and ask, he STILL owes me :)

    He did make a mistake, but he is a fairly well respected old Ferrari wrench...

    Ps, clean those carbs :)
     
  17. Sledge4.2

    Sledge4.2 F1 Rookie

    Oct 19, 2007
    4,789
    Marin
    Full Name:
    Geno
    #42 Sledge4.2, Nov 20, 2011
    Looking back at my notes, I could feel scar marks on the cap ...so you are better off than I was
     
  18. PRS

    PRS Formula Junior

    Jun 1, 2011
    715
    Issaquah
    Full Name:
    Pete S
    #43 PRS, Dec 8, 2011
    Hey Gregg, how is the major coming?
     
  19. greggbferrari

    greggbferrari Karting

    Jan 4, 2010
    121
    Seattle, WA
    Full Name:
    Gregg Brown
    #44 greggbferrari, Dec 10, 2011
    Last edited by a moderator: Sep 7, 2017
  20. greggbferrari

    greggbferrari Karting

    Jan 4, 2010
    121
    Seattle, WA
    Full Name:
    Gregg Brown
    #45 greggbferrari, Jan 15, 2012
    Last edited by a moderator: Sep 7, 2017
    OK, back at it. I have a really tiny garage, and I was getting to the point where I was dirty all the time and tripping over everything. Basically pulling off the balancer kicked my a**. I also discovered that I needed to replace the water and vacuum lines; I’ll post about that separately if anyone is interested.
    So here’s what it looked like once I got the balancer and the two drives off. The drives were a huge PITA just like the balancer. I thought I could just dimple the nuts on the cam drives and crack them off with a sharp cold chisel. Instead they are really soft and apparently badly corroded. I ended up using a very small diamond burr and essentially cutting the nut off.
    Cleaned up you can see that the seal is in pieces on the rear drive, the front seal was the same. I popped the seal out with one a double-hooked seal puller, and you can see the retaining circlip. Both of these came out cleanly. Next I packed the bearing with axle grease to catch chips, and drilled through the bearing cage. Once cut I used a small hooked scribe to peel back the ball bearing cage. I used the T&E puller available from Amazon, and it works very well, pulling the bearing out cleanly. (I used the middle set of ends, just like the on Draper samba-lee and other used.) The bearing is tight on the shaft of the drive, so you need to use the puller all the way to the threads.
    One note: The Bellville spacer behind the bearing and in front of the circlip (retaining ring) for the rear bearing was oriented convex, unlike the one samba-lee removed in his excellent post. http://www.ferrarichat.com/forum/showthread.php?t=248319&highlight=cam+seals+308&page=2. You can see the difference if you compare the pictures. Both drives were like that, so I’ll put them back that way.
    Last picture is the rear seal as it came out. No wonder the bearing looked good, it had continuous flow-through lubrication.
    Image Unavailable, Please Login
    Image Unavailable, Please Login
    Image Unavailable, Please Login
    Image Unavailable, Please Login
    Image Unavailable, Please Login
    Image Unavailable, Please Login
     
  21. greggbferrari

    greggbferrari Karting

    Jan 4, 2010
    121
    Seattle, WA
    Full Name:
    Gregg Brown
    #46 greggbferrari, Jan 16, 2012
    Last edited by a moderator: Sep 7, 2017
    OK, now I have a problem. I tried to pull the bearing in with the gland nut, first with an oversized washer (first picture) and then with a 2" washer that catches both the inner and outer race (second picture.) It went in as far as the last picture and won't go an further. I tried a little extra persuasion with a breaker bar, and the Superperformance hex nut started to strip. You an see the threads on the drive shaft are gettng pretty shiny, even though I greased everything.

    I made sure the bearing spacer wasn't tangled up in the inner circlip by putting a little grease on it to "glue it the right spot. I suppose it could have slipped and interfered with the bearing.

    Next step is to destroy this new bearing pulling it out and check everything. I put motor oil on the bore and the shaft, anything else I shoud know?
    Image Unavailable, Please Login
    Image Unavailable, Please Login
    Image Unavailable, Please Login
     
  22. greggbferrari

    greggbferrari Karting

    Jan 4, 2010
    121
    Seattle, WA
    Full Name:
    Gregg Brown
    #47 greggbferrari, Jun 7, 2012
    Last edited by a moderator: Sep 7, 2017
    Finally “finished” the major on my 1975 308GT4. You may notice that the first post was at the beginning of October 2011, so I beat Brian’s 20 month estimate by a full year! I want to thanks to every one for quick and accurate advice throughout. Ferrparts and Superformance were great as well.

    I’ve been heads-down on the car since my last post in January. I ended up replacing the vacuum and heater lines to the front, I used the Aeroquip 1503-10 line from Murdock Industries for the vacuum. (If you buy 17 feet you can use the extra piece for the vent line from the sump to the oil vapor collection canister.) That meant moving the driver-side tank, which meant fabricating a replacement for rusted panel and bracket, which meant cleaning and painting the chassis and inside of the sheetmetal. I also replaced all of the heater hoses, and then all the water hoses, all the fuel hoses; you get the picture. I think there are 36 hose clamps in the cooling/heating system.

    One change from stock: I used aluminum tube for the line from the fuel pump to the firewall and a short rubber line to the carbs, and another aluminum line to replace the vent cross-over. (They are normally 5/16 or 8mm fuel line.) The aluminum lines looked too futuristic when I first installed them, so I pulled them and covered them with black heat shrink. Tell me what you think. I also used Gates latest “barrier” fuel line, it has a liner that reduces weep and resists methanol. Replaced the fuel filter and stripped and checked the pump, and replaced wiring to the pump. Replaced the fuel tank cross-over with Marine fuel line, also with a barrier and double wire reinforcement. Three Band-Aids for that one.

    I had the alternator rebuilt and made a new heavy gauge jumper to the starter post.

    I ended up cleaning up the #10 cam cap with superfine gray Scotchbrite and turning it around to its correct position. We’ll see.

    I finished replacing the cam-drive bearings, seals, crank seal, air-pump-drive seal and of course the cam seals and adjusted the valves. Oh I did actually replace the timing belts and bearings, clean and lube the tensioners, etc. I used the Verell tensioning method (thanks Birdman), and I don’t want to hear about it. Hylomar blue on the gaskets on the cam covers, Loctite 518 on all the seals.

    I couldn’t resist cleaning up the cam covers, which then looked so much better than the cam belt covers that I painted them. That made the air filter box look so bad I painted that with Eastwood wrinkle paint. Twice.

    I did not touch the carbs.

    Of course all the other fluids were replaced so I bled the brakes, running a liter of fluid through, and replaced the gearbox oil with five quarts Redline 75W/90 NS.

    Replaced the spark-plug wires since one had burned out a plug connector and filed and re-set the points. When I got to them, the front points opened .004” maximum, remember this was a running car when I started.

    Static timed the disti’s and it started and idled right away, which quite frankly amazed me. After I set the advance with the timing light I drove it around the block and left it idling while I showed-off the engine of to my neighbor.

    Then he noticed the fire.

    I have never used a dry powder fire extinguisher before, but I can highly recommend them. Turns out I left a 3” square piece of t-shirt wiping cloth wedged on top of the rear header. No damage I can see, but I’m really glad it didn’t happen when the engine was covered in oil with missing vent lines, etc. The engine bay cleaned up with just compressed air.

    Anyway, thanks again to all for the advice. I found a single drip under the rear exhaust cam, and one on the air-pump drive, and a drip on the floor. I’ll chase them down, but nowhere near the superfund site the thing used to be. Here are a few “after” pictures.

    Next up: Petronix, and Birdman fuse blocks. This winter rebuild the rear suspension, maybe a clutch…

    Cheers, Gregg
    Image Unavailable, Please Login
    Image Unavailable, Please Login
    Image Unavailable, Please Login
    Image Unavailable, Please Login
     
  23. Brian Harper

    Brian Harper F1 Rookie
    Owner Silver Subscribed

    Feb 17, 2006
    4,078
    San Jose area
    Full Name:
    Brian Harper
    #48 Brian Harper, Jun 7, 2012
    I did the same for the vent line on my GT4. The rubber line sagged from zip-tie to zip-tie under the back window and just didn't look tidy. The hard line is ruler straight and looks proper. I bent up the ends a little with a tubing bender to make a nice transition to the rubber hoses.

    Looks good!!
     
  24. Bad Dogg

    Bad Dogg Formula Junior

    Sep 29, 2006
    433
    Avon, CT
    Full Name:
    Howard
    #49 Bad Dogg, Jun 8, 2012
    Awesome! Great job!
     
Page 2 of 2

Share This Page