Forward head MUST come off again, 79 308 Valve problem | FerrariChat
Buy

Forward head MUST come off again, 79 308 Valve problem

Discussion in 'Technical Q&A' started by dan the man, Apr 11, 2005.

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

  1. dan the man

    dan the man Karting

    Nov 5, 2003
    146
    Alabama
    Full Name:
    Daniel
    #1 dan the man, Apr 11, 2005
    I started the 308 up Friday night, it ran 20 SECONDS and #6 intake valve siezed open and the piston hit it. the engine was barely idling and there seems to only be a bent valve issue, no piston damage. the valve quickly unstuck and poped up. It did this as I was turning the car off. I had cranked it to get my oil pressure up, and make sure the engine would run. I pulled the carb off and you can see the valve is not closing all the way. maybe .100 of an inch. It just barely bent it.


    The question is,


    has anyone been successful in roling the engine and removing the forward head without removing the engine? pics, etc, would be useful.

    I will most likely remove both heads and make sure I do not have any other problems. the rear head is easy to remove.

    Needless to say, The machinist mostlikely screwed up the valve job, and Unfortunatly it was the forward head that this happened to.


    thanks for any help

    Dan
     
  2. Rifledriver

    Rifledriver Three Time F1 World Champ

    Apr 29, 2004
    37,288
    Cowboy Capitol of the World
    Full Name:
    Brian Crall
    #2 Rifledriver, Apr 11, 2005
    The front head will come off in the car rather easily. Some times you have to take off the forward row of valve cover studs or you may have to remove the motor mount bolts.

    It's been done many times by myself and others.
     
  3. Nuvolari

    Nuvolari F1 Veteran
    Owner Silver Subscribed

    Sep 3, 2002
    6,663
    Toronto / SoCal
    Full Name:
    Rob C.
    #3 Nuvolari, Apr 11, 2005
    Sorry to hear about the valve trouble. There are lots of recent threads on head removal (I have no links so a search is best) Some say it can be done without pulling the engine and others say it can't. If your heads went on recently chances are they are not stuck in place so it is likely you can remove it without yanking the engine. One thing to check well is the piston to make sure you did not crack it when the valve stuck. Good luck with it.
     
  4. dan the man

    dan the man Karting

    Nov 5, 2003
    146
    Alabama
    Full Name:
    Daniel
    #4 dan the man, Apr 11, 2005
    Rifledriver,

    are you saying that I should be able to remove the belt, remove the cams, remove the cam studs, remove the exhaust, remove the motor mount bolts, slide the engine back some and then the head should be able to be worked out? that would be great!

    As for the reason, do you have any indications as to why the valve would sieze? I am assuming that the Machinist overlooked a guide issue, or gaulded the guide when he installed the valve.

    Thank you
    Dan
     
  5. Rifledriver

    Rifledriver Three Time F1 World Champ

    Apr 29, 2004
    37,288
    Cowboy Capitol of the World
    Full Name:
    Brian Crall
    #5 Rifledriver, Apr 11, 2005


    Yes. But the lower row of valve cover studs are the main ones that get in the way. We used to that quite often but it has been years. Either the 2 or 4 valve needed to remove motor mount bolts and slide motor back but I cant remember which.

    You are going to have to take a look at the guides/ valves to see. They do need a little lubrication when assembled. Good seals don't allow any in. Also sometimes the fit can be too tight and stick with a little heat, debris, whatever. Seen it happen.
     
  6. ferrarifixer

    ferrarifixer F1 Veteran
    BANNED

    Jul 22, 2003
    8,520
    Melbourne
    Full Name:
    Phil Hughes
    #6 ferrarifixer, Apr 12, 2005
    That's bad luck Dan.

    As said, the std stem seals can be sticky when new, and I now use rubber ones instead of the white plastic Ferrari ones.

    Firstly, the std ones require little plastic condoms to be used when intalling them, to prevent the collet ring from damaging the seal... which is just a pain in the ar5e to do as you can do nothing about removing them without damage.

    They are also fiddly to fit anyway, as it's easy to tear them with impatience!

    So I use generic rubber stem seals to allow more flex for dummy build and then final assembly, also, rubber ones can be more easily found and replaced. I just get the guides made to suit their size for a tight push fit.

    The head can be removed in situ quite easily, so good luck..... maybe it's an omen to re-check the valves properly for installed spring height and internal retainer/bucket clearance....... it's never too late to do a job properly.
     

Share This Page