News:


  • June 16, 2024, 05:53:15 AM

Login with username, password and session length

« previous next »
Pages: [1]   Go Down

Author Topic: Leaking .35 FP-S head  (Read 599 times)

Offline Chucky

  • Trade Count: (0)
  • Lieutenant
  • ***
  • Posts: 92
Leaking .35 FP-S head
« on: April 15, 2011, 10:38:45 AM »
Recently acquired a NIB OS .35 FP-S.  Prior to running it, I checked it over for tightness everything was good.  During the initial run, I noticed  a good sized drop of oil and fuel building up where the heads meets the cylinder on the bypass side of the motor.  After cool-down, I checked head screws and found that each needed about 1/8 turn to return to the same tightness I'd started with.  Tried a couple more times with the same results.  Removed the head and inspected everything and all looks normal.  The head looks clean and straight, the head gasket is in good shape and I can't see any defects in the edge of the cylinder that mates with the head gasket.  Put all back together and ran again with same results.  In all cases, I've used a proper head screw torquing pattern.  Could the head be warped?  Any suggestions on how to remedy this?

Logged
Chuck Winget

Offline Wayne J. Buran

  • AMA Member
  • Trade Count: (0)
  • Admiral
  • *
  • Posts: 1096
Re: Leaking .35 FP-S head
« Reply #1 on: April 15, 2011, 01:02:27 PM »
Well, sounds strange for an engine that is supposed to be NIB. I believe that the FP 35's came with a head shim/gasket. I would check it carefully. Make sure that maybe the leak is not from the gasket area but someplace else. The FP's were still totally machined at least at mating surfaces so maybe there is a hole someplace. If the original Philips screws are what you have get rid of them and get a socket head cap screw replacement which is usually better. Good luck.
Wayne
Logged
Wayne Buran
Medina, Ohio
AMA 14986 CD
USAF Veteran 35 TAC GP/ 6236 CSG, DonMuang RTAFB, Bangkok, Thailand 65-66 North Coast Controliners   "A fine is a tax for doing wrong. A tax is a fine for doing well!

Offline Steve Schlesser

  • 2013 Supporter
  • Trade Count: (0)
  • Ensign
  • *
  • Posts: 43
Re: Leaking .35 FP-S head
« Reply #2 on: April 15, 2011, 02:29:08 PM »
Chucky,
  The head has a relief that fits over a line up pin on the rear portion of the case, just a thought. Good luck
Logged

Offline Frank Bowman

  • Bowman's Rings
  • Trade Count: (0)
  • New Pilot
  • *
  • Posts: 20
Re: Leaking .35 FP-S head
« Reply #3 on: April 16, 2011, 06:14:00 AM »
 :)Tape down 320 to 400 grit sand paper on all sides to really flat surface. Remove liner from block, invert it top down & while holding it down flat on paper, pull it across paper and look at surface. If you don't see 100 % clean flat surface , rotate 90 degrees and repete process until flat. Make sure when you remove liner to look and see if the FP has a tiny pin in block and relief in liner to properly locate liner to block and it is lined up correctly.  See if that will fix problem. Take care & good flying. Frank
Logged
Frank Bowman

Offline Chucky

  • Trade Count: (0)
  • Lieutenant
  • ***
  • Posts: 92
Re: Leaking .35 FP-S head
« Reply #4 on: April 16, 2011, 02:22:58 PM »
Looks like I managed to post this question in the wrong area!  Thanks for the suggestions.  A mechanic friend solved the problem with a little valve grinding compound used to properly seat the head to the cylinder.  Once cleaned up and reassembled with head gasket, the engine runs fine with no leaks or loose screws.
Logged
Chuck Winget

Advertise Here
Pages: [1]   Go Up
« previous next »
Tags:
 


Advertise Here