| Author |
Message |
Mike Dawson (Miked)
New member
Username: Miked
Post Number: 33
Registered: 2-2001
| | Posted on Saturday, August 10, 2002 - 9:18 pm: | |
Terry, I think just about every 308 owner has gone through the same adventure. The thread is 12mm as Steve said, with a very fine thread count (maybe .75 or .8 mm per thread). I found bolts at the local Ace Hardware out in the country so they shouldn't be too hard to find. I had to cut them shorter to fit but they worked great. I bought the appropriate bottom tap at an industrial supply house to chase the treads. Unfortunetly most POs just crank in a bolt that is "close enough" rather than doing the job correctly. |
Steve Magnusson (91tr)
Member
Username: 91tr
Post Number: 904
Registered: 1-2001
| | Posted on Saturday, August 10, 2002 - 11:26 am: | |
Terry -- here's the info/data on the F part that is best used IMO to seal the exhaust CO ports:
http://server.ferrarichat.com/~ferrari/ferrarichat.com/discus/messages/112/73413.html
As Peter said, you'd probably still need to remove the manifold to restore/chase the M12 threads. These little tubes are doomed on all Fs if they're left on the car -- I used Classic Tube in N.Y. to make some matching replacements for my TR using the old fittings (and I provided the old tube bits), but it was not an easy project (took some prodding). |
'75 308 GT4 (Peter)
Intermediate Member
Username: Peter
Post Number: 1933
Registered: 12-2000
| | Posted on Saturday, August 10, 2002 - 12:26 am: | |
No engine removal necessary. You can pull the header out from the passenger's side wheel-well (most probably you need to remove that side's fuel tank for clearance).
I didn't follow any of the original sizes as it would be too difficult trying to find the correct-size threaded fittings (and next to impossible to try to remove the remains of the old fitting...).
I drilled out and tapped to 1/4"NPT (there's enough meat left on the bung to do this) and used commonly-avaliable Stainless compression fittings and using 1/4" O.D. Stainless tubing for the CO analyser tubes. Done deal with no leaks. |
magoo (Magoo)
Advanced Member
Username: Magoo
Post Number: 2973
Registered: 2-2001
| | Posted on Friday, August 09, 2002 - 11:39 pm: | |
Terry, There should still be threads in there. I think the person who installed the bolts just used the "whatever" substance because he didn't have the correct thread on the bolt. Some of these guys on the site have done this and they have the right thread count and what to use. I don't think you will have to pull the engine as long as the old threads are not stripped out. |
Terry Springer (Tspringer)
Junior Member
Username: Tspringer
Post Number: 193
Registered: 4-2002
| | Posted on Friday, August 09, 2002 - 9:21 pm: | |
Standing over my 308 trying to set the timing is getting very hard due to eye watering and dizzy feelings! I have exhaust leaks!
After bolting on the cam covers and generally re-assembling things in the engine bay during my detailing and distributor upgrade project, the car appears to be leaking exhaust much worse.
It seems this is coming from the CO tubes where they screw into the exhaust manifold. With this theory in mind, I put a wrench to the ones on the rear bank. Not the tubes mind you, they have been removed prior to my ownership and in place some bolts appeared to be screwed into the manifold. Wrong... Only bolt heads and they were "screwed" into what appears to be JB Weld. Of coarse when I applied some torque to them, they came loose and can now be lifted out.
The front bank appears to be leaking from the 2 CO tubes on the drivers side. Early in my project I had contemplated removing these and plugging the holes but after determining that this would be an engine out procedure, I begged off. This was due to the fact that when I applied a wrench to the 2 drivers side attachment nuts, they appeared to be stripped or broken off. I attempted to unscew them, but they quickly and easily seemed to break free and just spin. Now I wonder if they too were not really screwing into some JB Weld or other such repair.
Now I have something of a quandry. How do I fix these leaks. I reckon I could remove the engine, take tons of stuff apart, have some proper plugs made by a machine shop, drill / tap and them plug all of the holes. Maybe my car will be back on the road in 6 to 12 months. Grrrrrrrrrrrr
Is there any way to seal these leaks? Should I attempt to fix it the same way it was before, with JB Weld or some other exhaust resistant substance? I really dont want this to degenerate into some kind of major engine project. I expect to have the engine out in a couple of years when its time for a major service (and when the Porsche is finished) and I can do more permanent repairs then. What kind of shorter term solution is a good idea? |