Case open, put distributor drive gear in? Why wait?

[cunning plan]

When you are rebuilding an engine, is there any benefit to waiting for the case to be assembled before you install the distributor drive gear?

I have seen a couple of videos of people building engines where they purposely wait until the case is assembled before awkwardly dropping in the distributor drive gear shims using a long screwdriver and wobbling it around etc.

To me, if you have the case open, it makes logical sense to install the gear before you close it all up. So why do these experienced engine builders wait until it is all assembled? What am I missing?
:sign0009:

 

[chug]

From what I read when I rebuilt mine last year, with the drive gear installed, the crank shouldn't be turned with no distributor fitted. Think it's something to do with the drive gear being able to rise in its bore and possibly damage the brass gear on the crank.

I fitted mine with the case split but made sure it was correctly orientated then fitted the distributor, I also checked the endfloat on the drive gear whilst there.

 

[cunning plan]

Thanks!

I was planning on installing the distributor at the same time to keep the distributor drive-gear in place as the case is being moved about. Plus as you say, you can make certain it is the correct orientation and everything is in place before closing the case.

 

[K@rlos]

You should wait until the case is shit and end float is set

 

[cunning plan]

You should wait until the case is shit and end float is set

Aha! That makes sense!! :rocknroll:

Although, I'm hoping the case isn't too shitty :tongue0013:

 

[mr scoops]

I was led to believe it was easier to pop it in before the case was sealed, you can make sure it is 100% in the correct orientation etc.
Of course if you're a ham-fisted arse like me you intall it 180 degrees out and then wonder for a while why your new engine won't fire up!
Doh!!!!!

 

[K@rlos]

You should wait until the case is shit and end float is set

Aha! That makes sense!! :rocknroll:

Although, I'm hoping the case isn't too shitty :tongue0013:

Shut, case is shut :lol: Stupid autocorrect

 

[atafonso]

I fit it before closing the case, but i install a temporary dizzy to hold the shaft in place and i leave it there until i fit the correct dizzy. If no dizzy is there, the shaft can move out of place and damage the brass gear.
To make sure timing is correct when doing it this way, push the crank against it's seat, then put n1 on TDC. You should be able to see the cam and crank gear marks looking from the pulley side of the engine, if you can see only the crank mark and not the cam, it's 180 out
Abel

 

[cunning plan]

I fit it before closing the case, but i install a temporary dizzy to hold the shaft in place and i leave it there until i fit the correct dizzy. If no dizzy is there, the shaft can move out of place and damage the brass gear.
To make sure timing is correct when doing it this way, push the crank against it's seat, then put n1 on TDC. You should be able to see the cam and crank gear marks looking from the pulley side of the engine, if you can see only the crank mark and not the cam, it's 180 out
Abel

Thanks Abel, good information as always!

I was led to believe it was easier to pop it in before the case was sealed, you can make sure it is 100% in the correct orientation etc.
Of course if you're a ham-fisted arse like me you intall it 180 degrees out and then wonder for a while why your new engine won't fire up!
Doh!!!!!

Yep, this is what I am worried about, I am tempted to put it in while the case is open, I have a spare dizzy to use to hold it in place.

Surely the end float would have a minimal impact on the gear position and not enough to warrant an install after end float is set?

 

[K@rlos]

A good friend of my dads was a vw dealership mechanic on aircooleds during the 60's & 70's. He told me that's the factory way to do it