BIB5566

[knapmann]

Regarding the MFI cut out. You can get the CDI+ to perform the speed switch function. Programmable on and off RPM too!

Can you now... sounds much more reliable than a 50y/o circuit board! How do you do this? I cannot see it mentioned in the install manual or am I over looking this? Surely it would need a seperate wire from the CDI which it doesnt have the facility for?

[knapmann]

Very much 1 step forward 2 steps back with this car at the moment. Investigated my oil leak further today. Took the pulley off, and cleaned up the oil seal and #8 bearing area. Ran the engine without the fan for a few mins to see if I could see where the leak was coming from and yes its the dreaded #8 bearing leak. Its not just leaking a bit, its leaking a LOT. I reckon I get about 3 drips of oil a minute from it, so 5 mins of idling in one place and you have quite a patch of oil on the floor. I dont think this has been sealed up correctly when the engine has been split and put back together in the past but its impossible to know now.

Theres no way I can simply live with it, im going to have to deal with it somehow. From what I have read, even minor leaks from here are very difficult to fix so im going to have quite the mission to try and fix this. Its engine-out in any case. Im going to have to attempt the clamp ring method and hope I finally get a bit of luck for once! If that doesnt work, Ill really be up shite creek

Has anyone had any joy dealing with a #8 bearing leak?



Oil running down the block from the base of the #8 bearing over the intermediate shaft cover

[911hillclimber]

Not sure I would call that "one step back".
I am not aware of any quick fix for a leak there other than full strip and start again.
I wish you good luck as you are so very close.

[rhd racer]

I know there is a kit you can get from the US to repair in situ, but have never tried it I’m afraid. Plenty seem to have had success with it

[Nine One One]

http://forums.pelicanparts.com/porsche- ... d-how.html

http://forums.pelicanparts.com/porsche- ... k-fix.html

http://forums.pelicanparts.com/911-engi ... -seal.html


https://www.mobileworkswest.com/for-sale-911/

[DarthMJH]

Looks like it’s this TAS-Nose Bearing Seal sleeve https://www.mobileworkswest.com/for-sale-911/ $129

[sladey]

I've never heard of those fixes - got to be worth a try.

If they don't work I was going to suggest that you get a tray to put under the car and live with it. My car used to pi55 oil - as people who followed me on road trips will attest. However it drove brilliantly and I had some fantastic fun with it before my big rebuild. I would say if you are looking to do a full rebuild to solve it then perhaps you should live with what you've got for a while - sort some of the other stuff out and enjoy driving the car - then maybe take it off the road in a year or two. Just my 2 pence worth.

However those fixes on the pelican forum look to be worth a try - if they solve it then looks like happy days for not too much work.

[hot66]

Agree with Sladey .... full engine rebuilds is usually opening a can or worms plus the ‘whilst I’m in here’ syndrome. I’d encourage you to get the car fully built and get some miles under it during 2021 ... then maybe if you can’t live with the oil leak plan on a winter build

We had one Ddker who used to top up with oil almost as often as we all filled with petrol ... didn’t stop him driving it and having fun

[neilbardsley]

Wise advice above. Dripping oil means you change more oil and have a cleaner engine

Sent from my Redmi 7 using Tapatalk

[knapmann]

Hello all, thanks for all the advice. I certainly dont want to be splitting the case on this motor. Im going to try the clamp ring method to seal it. Hopefully I can get a permanent seal or at the very least reduce the leak significantly. I have a friend with a lathe so going to make our own interference fit ring and see how it goes.

I think the hardest part about the fix will be evening out the case faces. The two halfs are not level, there is a 1mm step from one half to the other, no ring will seal against that. So going to have to figure out away to get them more level.

Just my luck eh!

[Jonny Hart]

Regarding the MFI cut out. You can get the CDI+ to perform the speed switch function. Programmable on and off RPM too!

Can you now... sounds much more reliable than a 50y/o circuit board! How do you do this? I cannot see it mentioned in the install manual or am I over looking this? Surely it would need a seperate wire from the CDI which it doesnt have the facility for?

It uses the red wire flying lead to switch a standard automotive relay. The manual is a little out of date but Richard wrote it up on his site here:

https://www.safetycolours.com/porsche-9 ... l-from-cdi

[knapmann]

Regarding the MFI cut out. You can get the CDI+ to perform the speed switch function. Programmable on and off RPM too!

Can you now... sounds much more reliable than a 50y/o circuit board! How do you do this? I cannot see it mentioned in the install manual or am I over looking this? Surely it would need a seperate wire from the CDI which it doesnt have the facility for?

It uses the red wire flying lead to switch a standard automotive relay. The manual is a little out of date but Richard wrote it up on his site here:

https://www.safetycolours.com/porsche-9 ... l-from-cdi

Good to know. I forgot about those additional wires! Im going to try and fix my original but if I cant I'll go with this I think! Thanks Jonny

[knapmann]

So Ive tackled my No.8 bearing leak this weekend.

Firstly I did a partial engine drop to access the bearing, removed the silencer, and rear engine mount and tinware, and the crank pulley.



The next issue is that the face of the two case halves are not level around the No.8 bearing. Ideally you would want to machine these level but obviously thats impossible. I had to file and grind very carefully by hand the side that was proud to level it out as best as possible. Then I cleaned the area with every degreaser I had available.




With the area ready I collected my repair parts, a 60mm Nitrile gasket, a tube of Dow Corning 730FS, a sturdy metal plate drilled to fit the crank bolt through and 2x aluminium rings I had my friend make who has a lathe. One ring is an interference fit made at 60.00mm ID (the no8 bearing on my car measured at 60.05mm), the other is a loose fit at 60.50mm.

Plaster the area with the DC730, put on the nitrile gasket, them more DC730. Now you have to work fast... slip over your oven heated interference ring (it expanded to 60.20mm when hot) Then put on the loose fit ring which finishes proud of the end of the crank face. Finally use the metal plate and the crank nut to press in the interference ring while still hot, and compress the whole thing together.





Put it all back together



Ill leave it for a week to set. take the plate and the loose fit ring off and hopefully it will seal... we shall have to see!

Whilst I was in there I noticed my silencer had some cracked welds on the top of the two inlet pipes. Not sure if this is common but I fixed them as they had clearly been blowing somewhat.



I got some sway-away rear spring plates for cheap as one of them had failed on the weld. I dont think this is very common, ive not heard of this issue before. Anyway Im happy to make do and mend so I fixed the broken side and installed them. No more messing around trying to get the ride height right I hope!






Hopefully all of these finishing niggles will soon be done with and I can take the car for a proper drive more than 10 mins from my house. I still need to have another crack at fixing my speed switch next.



.

[911hillclimber]

Interesting repair, new to me.
Looks like if everything was surgically clean it will work a treat. Await with interest!

[knapmann]

Interesting repair, new to me.
Looks like if everything was surgically clean it will work a treat. Await with interest!

As do I!

Im going to leave it a full week to set. I really want this to work