Author Topic: Bottom cases dowel pins in when already put together?  (Read 1120 times)

Offline alexdecker

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Bottom cases dowel pins in when already put together?
« on: July 10, 2022, 01:34:28 PM »
Hey all

Made a blunder and forgot the dowels for the bottom cases when putting it together. I have assembled the entire engine now. Is it feasible to put them in now with a hammer?

Offline Nurse Julie

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Re: Bottom cases dowel pins in when already put together?
« Reply #1 on: July 10, 2022, 01:53:12 PM »
Do you mean crank case dowels or dowels elsewhere?
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Offline alexdecker

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Re: Bottom cases dowel pins in when already put together?
« Reply #2 on: July 10, 2022, 01:57:16 PM »
Crank case dowels. One in front and one in back in that extra little loop that protrudes from the crank cases…

Offline Oddjob

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Re: Bottom cases dowel pins in when already put together?
« Reply #3 on: July 10, 2022, 05:43:45 PM »
Think the outside edge is thinner than the inside edge so the dowel doesn't go all the way through.
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Offline alexdecker

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Re: Bottom cases dowel pins in when already put together?
« Reply #4 on: July 10, 2022, 05:45:52 PM »
Damn it. How big a problem is this?

Offline robvangulik

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Re: Bottom cases dowel pins in when already put together?
« Reply #5 on: July 10, 2022, 06:30:27 PM »
Those dowels are there to make sure the top and bottom cases are perfectly lined up, because especially the crank bearings are measured with thousands of an inch (or mm), so what do you think happens when you screw those cases together without dowels?

Offline McCabe-Thiele (Ted)

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Re: Bottom cases dowel pins in when already put together?
« Reply #6 on: July 10, 2022, 07:22:10 PM »
I hate to say it but you need to split the crankcase and fit them before you tighten up the crankcase bolts.
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Offline alexdecker

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Re: Bottom cases dowel pins in when already put together?
« Reply #7 on: July 10, 2022, 07:25:03 PM »
That's what I feared. I am a little in doubt though, as I seem to remember when putting it together, that there were dowel pins holding it together. I am a little uncertain as to how many dowel pins are actually in the crank cases. The holes in the crank cases I noticed are in the front and in the back (circled in the picture), and I assume it's part 16 (also circled) that are going in the holes. But are these the only dowels holding the crank cases aligned?


Offline alexdecker

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Re: Bottom cases dowel pins in when already put together?
« Reply #8 on: July 10, 2022, 07:29:52 PM »
Only asking as I just put the valve cover on, and the holes for the dowel pins on that one looks a lot like the holes I circled in the crank case part diagram.

Offline Pangloss

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Re: Bottom cases dowel pins in when already put together?
« Reply #9 on: July 10, 2022, 09:55:47 PM »
Those dowel holes are External and NOT used.!  They are used in the case manufacturing process only .

Offline alexdecker

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Re: Bottom cases dowel pins in when already put together?
« Reply #10 on: July 11, 2022, 07:14:11 AM »
Those dowel holes are External and NOT used.!  They are used in the case manufacturing process only .

Oh thank god. That is good news! Those holes just look exactly like the dowel holes in the cylinder head, so all of a sudden I though I missed something. Glad that isn't the case!

I saw some pictures on the internet where people have put bolts through those holes in the crank case. Is that normal prodecure, or do you guys just leave them empty?

Offline McCabe-Thiele (Ted)

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Re: Bottom cases dowel pins in when already put together?
« Reply #11 on: July 11, 2022, 12:42:25 PM »
I'm slightly confused in that I thought you had found the dowels left over after assembly rather than thinking the other holes should have dowels in them.

That must be a relief after the issues with the rear swing arm bearings.
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Offline alexdecker

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Re: Bottom cases dowel pins in when already put together?
« Reply #12 on: July 11, 2022, 03:37:13 PM »
I'm slightly confused in that I thought you had found the dowels left over after assembly rather than thinking the other holes should have dowels in them.

That must be a relief after the issues with the rear swing arm bearings.

No, I just noticed the holes all of a sudden, and fear struck that I might have forgotten something! Glad it wasn't the case! This project is not good for my poor nerves 😂

Offline McCabe-Thiele (Ted)

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Re: Bottom cases dowel pins in when already put together?
« Reply #13 on: July 12, 2022, 12:27:15 PM »

No, I just noticed the holes all of a sudden, and fear struck that I might have forgotten something! Glad it wasn't the case! This project is not good for my poor nerves 😂

Nice Pun btw.

I know that feeling too well. I think a lot of us have had sleepless nights during rebuilds for both real & imagined errors.
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