Restoration of a 1969 911S 2,0L engine.

[Hebster52]

Started the restoration of my 911 engine (case 901/03) today. Opened the case to find this sight.. Appears that one of the mainbearings have run hot? Is it possible to replace the mainbearings if the case is OK and the crankshaft is straight?

What might be the reason for this? You can see that one is brown and appears to have shrunk so it is too loose in the case...






I will update this thread at every progress.

Edit: Sorry, could some moderator correct the header? Should read 911T..

[304065]

Hebster, I was just going to mention that someone played the old switcheroo with your crankshaft, that is a non-counterweighted crank from a 911T.

Anyway, over on the Engine Rebuilding Forum you will find many tips and suggestions for the restoration of early 2,0 engines. Good luck!

[Hebster52]

Yes, I constantly mix up the S and T's... LOL

Hmm. Engine rebuilding Forums. Maybe I even posted in the wrong forum...?

Have to check some more there.

[Flieger]

This is a suitable forum- I find this project intriguing. There are more engine rebuilding experts in the engine forum, though. I just watch and learn from people like you.

[Shoepop]

T indeed, a 69 S case will be type 901/10.

[Hebster52]

Yes, it was a unfortunate typo as I wrote it in the thread header... I knew that it was a T too..

As my guidance I have the book How to rebuild and modify the 911 engine by Wayne R. Dempsey.

So, we'll see how it goes.

[Hebster52]

Got the crank bearing necks measured yesterday. They were all in good condition and at stock measurements. The crank isn't bent either so I'll replace the bearings and also replace the pistonpin bushings before I assemble the crank and case again.

[vreference]

Seems like it would be prudent to check the rod bearings in the vicinity of that main?

[911pcars]

Among other numerous inspection steps, take the crankcase to a specialist where they can check the alignment of the main bearing saddles, especially no. 4. No. 4 main journal appears to have some score marks.

Sherwood

[Hebster52]

While I'm waiting for the main bearings etc. to arrive I decided to start cleaning the carbs.

When I look at the "floats" inside it seems like they are different. Could it be that one of them have been distorted somehow?




An other question too. Were the carb housing all grey as new ore were they yellowish as new too? Or is the yellowish 40 years of patina?

[Hebster52]

I guess this finish will do for now..

[Hebster52]

Not done much on this the past months. While disassembling the rest of the carb I managed to brake one of the Idle Mixture Control screws..



I'm now leaving the carb body to a friend who have the machinery so he can remove the snapped end of the screw without destroying the threads in the housing.

My brother also made me a pair of new needles..

[911pcars]

Notice the difference between the mixture screw sample, the machined dupe and the original mixture screws as seen with the broken mixture screw.

I suspect the carbs are type 40IDTP3CI. These were used in the early emission days and featured a mixture screw profile that was more needle-like than cone-shaped. I think they did this to narrow the range of A/F mixture adjustment.

Nice job on the machining.

Sherwood

[Hebster52]

Thanks.
The carbs are Zenith 40 TIN's

[t6dpilot]

Sub'd

[Hebster52]

I got this kind of replacement bushings for the connecting rods for my 2,0L T engine. (The one to the left)

Where is the "joint" supposed to be when installed into the rod?

[Hebster52]

Okay... Guess this thread needs some refresching...

Not that much have happened due to a lot of other projects too but some anyways...

The carb issue was the biggest problem that took the air out of the inspiration.
But I finally got the first carb done this fall when I fixed the lost threads for the idle mixture screw with some JB-Weld.

First one done here and second now torn down.



I also have washed the crankcase and pantstripped it from the flaking silvermetallic.



Trying to decide what to do with the case. Thinking of painting it flatblack.

Pushrods upper end bushing ready for machining in the background in this picture.
(The head in front is also a Porsche part...)



The past few days I've made up some mad ideas.... All the from the beginning I've had fuelinjection fantasies...

Now, been searching and found some intersting stuff about making my own EFI with separate throttlebodies from superbikes.

For some reason I liked the ones in Triumph Daytona 675's... And guess if I was surprised when I found a link to a thread over here when I Googled them...

Not just sure if the 43mm throttle bodies are overkill on a 2,0 litre engine???

[RWebb]

check all the oil passages carefully and verify they are not clogged

Good Luck!

[Hebster52]

Thanks!

Bought a pair of Triumph Speed Triple throttle bodies during the Christmas holidays for the future fuelinjection project of this engine. The ITB's are on the way from UK at the moment.

While sitting here waiting for them from UK I have to do something fun when I cant go to the garage so I now started reassemble the second Zenith.

Here it is as it was yesterday still exploded...



This morning when I started assembling.



And a bit later when I got the main parts back together.



Still got the US spec. auxillary unit undone. Will probably later be plumbed but still have to restore them to original spec first...

[Hebster52]

Today the Triumph ITB's arrived from UK!
Nice set on our kitchen table...