Author Topic: 15cc Seal Help  (Read 9241 times)

Online Vixen

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Re: 15cc Seal Help
« Reply #30 on: March 06, 2020, 09:12:28 AM »
Hi Mark.

Good find  :ThumbsUp: where did you get your .375 X .563 X .0935 seals from? Do you have a part number or the address of a supplier?

Will you have a splash lubrication problem at the front of the engine if the Seal engine is tilted at an angle.

Michaels arrangement looks neat.

Mike
« Last Edit: March 06, 2020, 12:00:20 PM by Vixen »
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Offline gadabout

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Re: 15cc Seal Help
« Reply #31 on: March 06, 2020, 08:46:07 PM »
Mike,
I have ordered the seals from my local bearing supplier, the part number I gave him was CR 3621 (SKF)and he cross referenced it with another number.
Yes I have some concerns with the splash lube with engine at an angle as most of the oil will be towards the rear and the front might get starved. Was thinking I might have to run a higher oil level in the sump which might make cylinders 3 and 4 smoke a bit.
Regards
Mark

Online Vixen

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Re: 15cc Seal Help
« Reply #32 on: March 06, 2020, 09:06:09 PM »
Mark,

I have been searching around and have found a UK supplier. 'M Barnwell Services Ltd', who can offer two useful sizes of shaft seal for the rear bearing. They offer a 0.375 x 0.563 x 0.13  and also a slightly larger 0.375 x 0.625 x 0.125 shaft seal. Both will fit easily into a redesigned rear main bearing housing within the flywheel recess. I think I will chose the slightly larger diameter shaft seal as it should have a little more compliance.

I've little experience with splash lubrication. Perhaps the rear cylinders will kick up enough splash to reach the front, without the need to overfill the sump.

Mike

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Offline gadabout

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Re: 15cc Seal Help
« Reply #33 on: March 06, 2020, 09:13:12 PM »
Mike,
Those seals should be good!
Think I might do a cad drawing to see how the angle will affect the level in the sump, so I can tell on the dipstick where it needs to be filled too .
Mark

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Re: 15cc Seal Help
« Reply #34 on: March 06, 2020, 09:15:48 PM »
Mike,
While I am thinking about the engine I remembered the the rear camshaft bush interferes with the crankshaft  bearing housing flange and I had to machine a scallop out of the camshaft bush flange.
Mark

Online Vixen

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Re: 15cc Seal Help
« Reply #35 on: March 06, 2020, 09:21:22 PM »
I guess there will be a few of those 'make it fit' jobs.

Another shaft seal part number to cross reference is 'Timken 340827'

Mike
« Last Edit: March 07, 2020, 10:49:35 AM by Vixen »
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Offline gadabout

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Re: 15cc Seal Help
« Reply #36 on: March 07, 2020, 02:00:55 AM »
I have looked for that Timken number and can't find it  :thinking:

Online Vixen

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Re: 15cc Seal Help
« Reply #37 on: March 07, 2020, 10:50:29 AM »
Try the corrected Timken part number  :killcomputer:
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Offline gadabout

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Re: 15cc Seal Help
« Reply #38 on: March 07, 2020, 08:52:17 PM »
Mike,
Found it now! That looks good too , I will see what the ones I ordered are like and if I m happy with them I will use them , if not I will get some Timken 340827's
Mark

Online Vixen

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Re: 15cc Seal Help
« Reply #39 on: March 07, 2020, 09:20:58 PM »
Mark
Can you recall how much surplus material there was on the top face of the crankcase casting? It may be easier to increase the height of the block rather than shorten the Conrods
Mike
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Re: 15cc Seal Help
« Reply #40 on: March 08, 2020, 02:27:27 AM »
Mike,
From memory the block was grossly oversize everywhere, there was certainly enough to make the crankshaft centre to deck height greater. I would also only just clean up the face where the manifold bolts on and the same with the manifold, I didn't take mine to drawings but did still have to put a 1/8 spacer between them to get the carb to clear the block. Also the cavity where the valve springs and adjusting nuts goes needs to be squared up as much as possible in the corners as I machined mine with a 3/8" slot drill that left a radius in the corners and made it very hard to adjust the valve clearance on number 1 & 4 exhaust valves.
Mark

Online Vixen

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Re: 15cc Seal Help
« Reply #41 on: March 08, 2020, 11:54:21 AM »
Thanks for the reassurance about the crankcase casting wall thickness. I am still awaiting delivery from Hemingway's; another two weeks (or longer).

I was aware of the lack of clearance between the carb and the crankcase block. You used a spacer, while Jo angled the manifold/ carb flange, so her carb is now at an angle.

I've been doing some more CAD work while I wait. There looks to be a potential clash between the cast conrod and the base of the cylinder liners on the inner side. Has anyone had an issue here? looks like a few strokes with a file on the cylinder liner may be needed. Jo, did you get as far as fitting the crankshaft and conrods into the 15cc Seal?

Mike
« Last Edit: March 08, 2020, 03:29:00 PM by Vixen »
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Offline Jasonb

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Re: 15cc Seal Help
« Reply #42 on: March 08, 2020, 04:13:32 PM »
If the block is oversize externally what is it like internally eg can you still end up with 5/32" thickness at the ends by the time you have removed the excess?

Online Vixen

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Re: 15cc Seal Help
« Reply #43 on: March 08, 2020, 04:25:46 PM »
Hello Jason,

That's the $64 question. I will have to wait until Kirk sends the casting before I know for sure. Fortunately nobody else has mentioned it as a problem

Mike
« Last Edit: March 08, 2020, 05:25:30 PM by Vixen »
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Offline gadabout

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Re: 15cc Seal Help
« Reply #44 on: March 08, 2020, 09:03:29 PM »
Mike,
Yes I still ended up with correct wall thickness ok.
In the original build log in ME it says to notch the bottom of the cylinder liners. The build log is downloadable in two parts if you don't already have it.
Mark

 

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