Windage Tray Failure--Plot Thickens...Crank! |
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Windage Tray Failure--Plot Thickens...Crank! |
wndsrfr |
Nov 11 2012, 07:59 AM
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#1
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Senior Member Group: Members Posts: 1,429 Joined: 30-April 09 From: Rescue, Virginia Member No.: 10,318 Region Association: MidAtlantic Region |
Got in about 20 minutes at Roebling then heard serious knocking from the engine...limped into paddock & shut it down. Towed it home (950 miles round trip for 20 minutes on track (IMG:style_emoticons/default/barf.gif) ) and dopped the engine. Couldn't turn the crank by hand on the fan. So, split the cases. Here's what greeted me as I opened it up--one ear of the windage tray had failed and slid over and was caught under the cam. Check the pics--you can see where the cam was striking the sheet metal piece....nice and shiny there.
It's a "CB" bus case.....anyone seen this before? Anyone with a replacement tray?? Now the plot thickens...see the pics of the crank....think it'll buff out? No wonder it lost power.... (IMG:style_emoticons/default/headbang.gif) Attached image(s) |
914Sixer |
Nov 11 2012, 08:20 AM
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#2
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914 Guru Group: Members Posts: 8,883 Joined: 17-January 05 From: San Angelo Texas Member No.: 3,457 Region Association: Southwest Region |
Was the bolt that holds the tray loose or missing? Second was the tray possibly not slotted correctly in the case? If one side was out it would be bent up in to the cam. Did the tray have the seals on it or did they stay in the case.
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wndsrfr |
Nov 11 2012, 08:28 AM
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#3
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Senior Member Group: Members Posts: 1,429 Joined: 30-April 09 From: Rescue, Virginia Member No.: 10,318 Region Association: MidAtlantic Region |
Was the bolt that holds the tray loose or missing? Second was the tray possibly not slotted correctly in the case? If one side was out it would be bent up in to the cam. Did the tray have the seals on it or did they stay in the case. The cross bolt was in place and tight....it was slotted correctly with the seals glued to it with a dab of weatherstrip adhesive at the ends--you can see a bit of it in the photo. Seals still in place in the case slots--looks like fatigue failure right at the ends of the louvers stamped into the tray ear. |
Matt Romanowski |
Nov 11 2012, 10:09 AM
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#4
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Senior Member Group: Members Posts: 878 Joined: 4-January 04 From: Manchester, NH Member No.: 1,507 |
Was the bolt that holds the tray loose or missing? Second was the tray possibly not slotted correctly in the case? If one side was out it would be bent up in to the cam. Did the tray have the seals on it or did they stay in the case. The cross bolt was in place and tight....it was slotted correctly with the seals glued to it with a dab of weatherstrip adhesive at the ends--you can see a bit of it in the photo. Seals still in place in the case slots--looks like fatigue failure right at the ends of the louvers stamped into the tray ear. I've had them break, but never dislodge from their place. |
wingnut86 |
Nov 11 2012, 10:10 AM
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#5
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...boola la boo boola boo... Group: Members Posts: 1,053 Joined: 22-April 10 From: South Carolina Member No.: 11,645 Region Association: South East States |
This won't help the broken one, but I have read about many racers or at least frequent builders, who create additional slots or holes in the tray to allow for faster oil drainage back to the sump. Not sure that's a great idea with normally aspirated blocks, but if you are running AX or Track, have larger oil demands and have outfitted your block with a stronger oil return system with extended sump and similar, maybe this would diminish this happening in the future?
You need more oil in the twisties, turns and climbs, but not at the loss of oil in other areas without proper volume and pressure to go with it. Just ruminating here... |
wndsrfr |
Nov 11 2012, 11:39 AM
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#6
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Senior Member Group: Members Posts: 1,429 Joined: 30-April 09 From: Rescue, Virginia Member No.: 10,318 Region Association: MidAtlantic Region |
ttt
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NORD |
Nov 11 2012, 12:24 PM
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#7
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Senior Member Group: Members Posts: 1,505 Joined: 14-September 04 From: Lynden Washington Member No.: 2,756 Region Association: Pacific Northwest |
I'm wondering? Did the broken crank break the windage tray or the windage tray break the crank?? Sorry you broke down. |
brant |
Nov 11 2012, 12:30 PM
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#8
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914 Wizard Group: Members Posts: 11,625 Joined: 30-December 02 From: Colorado Member No.: 47 Region Association: Rocky Mountains |
I don't think the tray could do that to the crank...
I'm guessing your crank broke first and then caused the tray as collateral.... |
zambezi |
Nov 11 2012, 03:08 PM
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#9
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Senior Member Group: Members Posts: 711 Joined: 14-April 08 From: Lafayette, LA Member No.: 8,920 Region Association: South East States |
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messix |
Nov 11 2012, 03:27 PM
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#10
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AKA "CLUTCH KILLER"! Group: Members Posts: 6,995 Joined: 14-April 05 From: between shit kickers and pinky lifters/ puget sound wa.north of Seattle south of Canada Member No.: 3,931 Region Association: Pacific Northwest |
who did your crank?
i would have them take a look...... or may be another engine builder. for the crank to break there, there had to be some thing really wrong with the crank before machining or with what they did while maching it! |
Valy |
Nov 11 2012, 04:31 PM
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#11
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Senior Member Group: Members Posts: 1,676 Joined: 6-April 10 From: Sunnyvale, CA Member No.: 11,573 Region Association: Northern California |
Look at the journal of the rod next to the crank. That crack goes to the oiling channel. What size is it? Looks 80mm to me, correct?
This failure is typical for poorly welded and enlarged cranks. The oiling channel is too close to the wall and weakens the crank. For your next crank, make sure the oil channels were correctly relocated. |
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