F-Head Troubleshooting And Repairs

Discussion in 'Flat Fender Tech' started by william_cj3b, Jan 14, 2017.

  1. Jan 14, 2017
    william_cj3b

    william_cj3b Sponsor Sponsor

    Milton, FL
    Joined:
    Nov 17, 2003
    Messages:
    340
    Last week the f-head in my 3B started running bad after a high speed run on the way home from work (65 mph on a 3 mile stretch in o/d, about 3000 rpm).

    Basic troubleshooting showed the ignition and fuel were ok. The compression test results were ugly - 85 on #1, 30, 40 & 70 for the rest. I did a crude leakage check by applying 50 psi air to each hole at TDC. No evidence of significantly leaking valves. All of the cylinders leaked a considerable amount of air into the crankcase, but #2 leaked enough to levitate the dipstick! I thought I detected some cross cylinder leakage as well, so this could be rings and/or head gasket issues. Another clue to internal engine problems was the oil on top of the carb. BTW, I do not have an oil bath air cleaner. Or, at least I didn't :susp:

    [​IMG]

    This will be my first attempt to rebuild an f-head, assuming it requires a full rebuild. This is also my first build thread. I'm stoked! I'll post as many pics as I can. You guys follow along and tell me what I'm doing wrong.
     
  2. Jan 14, 2017
    Glenn

    Glenn Kinda grumpy old man Staff Member Sponsor

    Apopka, Fl
    Joined:
    Sep 21, 2002
    Messages:
    7,421
    You don't have an oil bath air cleaner? Did you take the mesh out of yours and replace it with a paper filter?
     
  3. Jan 14, 2017
    william_cj3b

    william_cj3b Sponsor Sponsor

    Milton, FL
    Joined:
    Nov 17, 2003
    Messages:
    340
    PO did it. I have the write up for it somewhere. I was planning to do the same thing.
     
  4. Feb 26, 2017
    william_cj3b

    william_cj3b Sponsor Sponsor

    Milton, FL
    Joined:
    Nov 17, 2003
    Messages:
    340
    Well, after work shipped me around the country for the last month like a lost FedEx package, I finally started work on the B yesterday. My 5yo daughter 'helped' me disconnect everything: drive shafts, wiring, fuel & oil lines, etc. I noticed it takes about 4 times as long to do anything when trying to keep a fearless 5yo from getting hurt :rolleyes:. I still have to pull the trans/t-case/OD shifters, then decide whether to pull everything as an assembly or separate the engine.

    I need to find a new option for image hosting. I refuse to fight with the ridiculously aggressive ads on photobucket any longer:mad:
     
  5. Feb 28, 2017
    GeoffreyL

    GeoffreyL Active Member

    moorestown, nj
    Joined:
    Aug 1, 2012
    Messages:
    1,461
    Are you rebuilding the other stuff as well as the engine? I would start with the engine, get it back in and if all runs well with that and I'm happy move on to the trans/tease/od. Don't bite off more than you can take at once, Thats how you get discouraged and lose interest.
     
  6. Feb 28, 2017
    william_cj3b

    william_cj3b Sponsor Sponsor

    Milton, FL
    Joined:
    Nov 17, 2003
    Messages:
    340
    Yes. I'm going to go through all of the mechanicals now.

    The trans will need synchros at the very least. The t-case will get a new intermediate shaft and some output seals. I'll also disassemble and inspect the overdrive which I rebuilt about 7k miles ago. The steering box will come out and get an overhaul as well.

    I'm an industrial mechanic and automation tech by day. I rebuild gear pumps and gear reduction boxes every week, so I'm pretty confident with the drive train. I can rebuild the overdrive in a couple of hours. The F-head is the unknown for me only due to lack of familiarity. I've built several Ford V8's, a couple of inline Chevy 6's and a Nissan Z24.

    Loss of interest and becoming discouraged are, for me, easily overcome by setting the right goals. Getting the jeep back on the road is too generic as a goal. Getting the jeep in as new mechanical condition by a specific date in order to drive it somewhere special is the right goal to motivate me. Don't laugh, but I have a Gantt chart for the project with individual timelines for each sub-project. So, my stated goal is: "Complete mechanical restoration of the 3B by mid-April. Semi-daily driving it to facilitate testing and tuning for 3-4 weeks. Drive it and the T3C from Florida to Indiana for the Willys Reunion in mid-May."

    It's an agressive plan, but failure just means setting a new goal. I like working on the jeep and I like driving it even more. The Willys Reunion is something I've wanted to do for years. What better way to get there than in a stock CJ3B?(y)

    The engine is out. Tools are on the way and the machine shop knows it's coming. Pics to follow this evening.
     
    GeoffreyL likes this.
  7. Feb 28, 2017
    GeoffreyL

    GeoffreyL Active Member

    moorestown, nj
    Joined:
    Aug 1, 2012
    Messages:
    1,461
    I'll definitely subscribe to your build, I've got a 53 3b i've been hunting parts for to redo one of these years.
     
  8. Feb 28, 2017
    75 DJ

    75 DJ Member Sponsor

    Des Moines, IA
    Joined:
    Sep 12, 2016
    Messages:
    54
    I hadn't thought about the Gantt chart, but it makes perfect sense. Makes me think I need to do one...
     
  9. Mar 1, 2017
    william_cj3b

    william_cj3b Sponsor Sponsor

    Milton, FL
    Joined:
    Nov 17, 2003
    Messages:
    340
    I finally got the engine and transmission out of the jeep last night. Here it is just before hooking up the crane. Every thing is disconnected and the engine is just sitting on the frame. [​IMG]

    My recollection of interference was wrong. The assembly comes out quite easily. The biggest interference was between the exhaust manifold and the horn. I'll leave the manifold off on the way back in.
    [​IMG]

    [​IMG]

    And it's out. You'll notice I'm doing this in a one car garage/laundry/storage unit. My barn still has a dirt floor. The hoist is all the way back against the washer and dryer and the jeep is against the door. Barely enough room to lower the engine to the floor.
    [​IMG]

    Had a 14 hour day at work today. I'll post more tomorrow. Yawn...
     
  10. Mar 1, 2017
    oldwillys

    oldwillys New Member

    NJ
    Joined:
    May 13, 2006
    Messages:
    8
    Looks easy when looking at the photo, but it does make the job harder when you do not have enough space to move around,
     
  11. Mar 1, 2017
    william_cj3b

    william_cj3b Sponsor Sponsor

    Milton, FL
    Joined:
    Nov 17, 2003
    Messages:
    340
    Preparing the jeep for storage in the barn. Plastic bags are there to keep the dirt daubers out.
    [​IMG]

    What was one has now become two. That sounds backwardso_O
    [​IMG]

    Look Ma! No pilot bushing! And no trace of one either. Rough measurements show the diameter is about 0.030" larger than the trans pilot. Anyone ever see something like this.
    [​IMG]

    Strange looking plug in the back of the oil galley.
    [​IMG]

    New toys came in last night. These replace ones that never came home after loaning them out. My valve spring compressor should be here tomorrow.
    [​IMG]

    I'll disassemble the engine, inspect and measure this weekend, then drop it off at the machine shop on Monday. It'll take 2-3 weeks to get through the machine shop and then at least a week to get parts before assembly. That gives me 4 weeks to refresh the brakes, rebuild the steering and go through the gearboxes.

    Alright, I have to get back to work now. Somebody has to pay for the jeep parts!
     
  12. Mar 1, 2017
    Glenn

    Glenn Kinda grumpy old man Staff Member Sponsor

    Apopka, Fl
    Joined:
    Sep 21, 2002
    Messages:
    7,421
    Glad you got it out easier than was anticipated. :coffee::)
     
  13. Mar 1, 2017
    Keys5a

    Keys5a Sponsor Sponsor

    Joined:
    Jan 23, 2014
    Messages:
    1,092
    Pilot bushing should be in the flywheel. Looks like a good time to replace that too as it can be a cause of jumping out of 2nd gear on deceleration. Try out some of those new measuring tools to see if your original is worn.
    Just the beginning of project creep....
    Looking good!
    -Donny
     
  14. Mar 1, 2017
    jpflat2a

    jpflat2a what's that noise?

    Riverside CA
    Joined:
    Jul 30, 2003
    Messages:
    7,471
    I'd remove the tapered bolts/pins from the crankshaft before sending crankshaft to machine shop. Don't lose them.
     
    47v6 likes this.
  15. Mar 1, 2017
    GeoffreyL

    GeoffreyL Active Member

    moorestown, nj
    Joined:
    Aug 1, 2012
    Messages:
    1,461
    What size/brand are those tires? Look like swamper she but I don't think they mad them that skinny
     
  16. Mar 1, 2017
    william_cj3b

    william_cj3b Sponsor Sponsor

    Milton, FL
    Joined:
    Nov 17, 2003
    Messages:
    340
    Yeah, only I didn't remove it! Strange thing is I don't think the crank is drilled to accept one. I didn't take precise measurements yet, but hole seems to be only about 0.030" bigger than the input pilot.
    Definitely. Thanks for the tip!
    Super Swamper TSL 29x8.5 on 15x4.5" Kelsey-Hayes wheels. The wheels are too narrow but the combination works pretty well. I've run 18-20 psi in them. Some wear on the fronts makes me think I need to increase the pressure some.
     
  17. Mar 1, 2017
    Howard Eisenhauer

    Howard Eisenhauer Super Moderator Staff Member Sponsor

    Tantallon, Nova...
    Joined:
    Nov 22, 2003
    Messages:
    4,535
    The pilot bearing doesn't go in the crank, it does actually belong in the flywheel.

    H.
     
  18. Mar 1, 2017
    william_cj3b

    william_cj3b Sponsor Sponsor

    Milton, FL
    Joined:
    Nov 17, 2003
    Messages:
    340
    Doh! (Head slapping forehead):oops::D That makes a lot more sense. I didn't even look at the flywheel before I pulled it off :whistle:
     
  19. Mar 1, 2017
    Glenn

    Glenn Kinda grumpy old man Staff Member Sponsor

    Apopka, Fl
    Joined:
    Sep 21, 2002
    Messages:
    7,421
    Good catch Howard! It didn't even dawn on me either why something didn't seem right. :oops:
     
  20. Mar 1, 2017
    PeteL

    PeteL Member Sponsor

    Joined:
    Aug 3, 2003
    Messages:
    5,230
    [QUOTE="william_cj3b, post: 1325793, member: 1544"

    My valve spring compressor should be here tomorrow."=QUOTE]

    [​IMG]



    Can't you use the blue valve spring compressors in that wooden box?
    Can I borrow them?

    :D
     

Share This Page

New Posts