J4 crank breather with JP4 head - quick question

  1. #1
    I'm using a JP4 head on a J4 vts bottom end. There's a breather pipe which comes out of the block above the oil filter housing which usually goes into the head iirc. However, the JP4 head does not have the fitting for this.

    I beleive, from other threads, that this breather can be blocked off? Is this right? If so, how have people blocked it? Tap a thread in and wind a bolt into it? Or core plug or similar?
  2. #2
    Yes mate, tap the hole and then find appropriate bolt! make sure you remove the sump (if already fitted) as the swarf will need collecting and removing from the engine.

    i did the same with my jp4 block which has a breather hole just above oil fiter fitting. worked a treat

    think mine was m10 thread -may be wrong though was a little while ago now

    edit - does this mean your making progress?
  3. #3
    Ok cheers mate

    I ideally wanted to avoid having the sump off as its all sealed on. WOndered if a core plug would do the job instead, but if tap and bolt is a better way, that is what I will have to do. Recommend we some sump sealant? lol

    M10 sounds about right. Decent sized hole.

    Progress? No thinking about it though lol
  4. #4
    think i used a loctite product to seal the sump, cant remember the number though there are a fair few depending on application

    a core plug type fitting may work, i may be wrong but i dont think that section is under much pressureso may be an option?!

    less thinking more doing!!
  5. #5
    was it the 5910 stuff? black in colour?
    Sure I've read about a blue one somewhere before as well?

    thinking is this week, doing is next week, hopefully
  6. #6
    Its a 3/8 hole dude.
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  7. #7
    Quote:
    Originally Posted by Dom View Post
    Its a 3/8 hole dude.
    what do you know you southern bell end? or did you hear me mention that to mike in one of your brief waking moments?