Damaged bolt hole on block question

[kiato4]

Hi all:

In looking at the 3.2 engine about to go into my 1975 911, I noticed that one of the bolt holes on the block was cracked and elongated. A closer look showed that there was a crack on the side of the bolt hole which caused the hole to elongate. There are two bolt holes just under the distributor lock down bolt, both of which face outward from the block rather than upwards like the distributor lock down bolt, and the bolt hole in question is the one on the left. As the engine is still out of the car, can someone tell me what this is used for? The engine will run PMO carbs and nothing more (no AC, no heater, etc), so what are my options here? Do I need the bolt hole for anything, and if no, can I just weld it up?

Thanks in advance.

[kiato4]

Bolt hole in question is circled in red (pic is not my engine, from another project I found on the web).

[Henry Schmidt]

That hole is used by the late engine cradle. If a 911SC cradle is used the hole in question will have no meaning.
The earlier cradle will work because your engine has a non Carrera crank pulley.

[kiato4]

Thanks for the help Henry, much appreciated. Unfortunately, this is not my engine, on my engine I will be running a different crank pulley(a Clewett unit I believe, was on there when I got the engine, but engine will be run with carbs). The engine was a 1986 and I only have the 1986 Carrera mounts...should I just go and buy a SC cradle and mount?
Also, should I have the hole welded up so it doesn't crack more or should I just leave it?

[gtu935]

The 3.2 cradle does not use the hole/stud in question.

[Henry Schmidt]

Originally Posted by kiato4

Thanks for the help Henry, much appreciated. Unfortunately, this is not my engine, on my engine I will be running a different crank pulley(a Clewett unit I believe, was on there when I got the engine, but engine will be run with carbs). The engine was a 1986 and I only have the 1986 Carrera mounts...should I just go and buy a SC cradle and mount?
Also, should I have the hole welded up so it doesn't crack more or should I just leave it?

Talk to Richard and find out if the pulley he makes will fit inside a 3.0 cradle.
If so, buy a 3.0 cradle and you're good to go. I think he makes a small pulley with a trigger wheel attached. The small pulley will offer a better fan speed for most applications.
I wouldn't bother with the crack if you are not using the later mount.
Cheers.

Originally Posted by gtu935

The 3.2 cradle does not use the hole/stud in question.

Well gtu935, although you may be an expert at some things, identifying case attachments apparently is not one of them.
As shown in the illustration, the case stud hole in question absolutely supports the 3.2 Carrera engine mounting cradle.

[gtu935]

oh boy, I was wrong.

so sorry. I have which I thought was a 3.2 cradle on my engine and the outside hole is not used. Photo to come