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I've just received a partially dismantled engine which suffered two pistons which lost bits of their skirts, together with a rebuilt block and my task is to put it together. The phoenix crank was still in the crankcase so it got a good cleaning which revealed the rear main was spinning on the shaft so that came out which revealed the rollers were damaged. Then I spied that there has been light contact between the center of the crank and the camshaft center bearing housing. Is there a clearance issue with 15/16" two bearing jet fed phoenix cranks?
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Yes - I have needed to remove material to get adequate clearance on some.
Can you tell me more about the rear main spinning please?
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11-10-2020, 09:05 PM
(This post was last modified: 11-10-2020, 09:06 PM by Steve Jones.)
There can be, Dave, but it's more an issue with the outer dimensions of the centre camshaft bearing housing casting than the crank itself. It's always something worth checking when fitting a Phoenix crank or, indeed, any crank. I think I've had to take a touch off the casting once. In the case that you refer to could it be that the issues with the rear main have caused the crank to run out of line slightly? If so, might also explain the piston damage?
Steve
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Roller damage other than rusting is unusual, unless something has wedged, which could cause spinning. If the cranks are not ground after nitriding the diameter could be out of tolerance. It is vital to avoid high heating and to retain the fatigue protecting thin nitride layer intact.
For those with patience I cannot see why the crank cannot be sleeved and the housing bored to take an inexpensive metric bearing.
Fully split skirt pistons had limited life on many makes. And most rapidly developed clearance to rival solid ones.
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While turning the crank and spraying lots of cleaning fluid everywhere particularly through the bearings I spotted that the crank was turning inside the rear roller inner race, so it was removed with the intention of refitting it with Loctite bearing fit. However on removal it was noted that the bearing had seen better days, so a new one will be fitted. The rear journal had a noticeable step where the bearing inner race had been spinning which didn't surprise me until the owner said it was a phoenix crank which had run only a couple of thousand miles. I was very surprised.
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Are you sure it’s a phoenix crank, they are nitrided and unlikely to wear quickly.Also unlikely to be undersize on the rear main on initial assembly.
Can you post a photo.
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Dave,
are you able to see if it has been hardened properly please?
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The moral of the story is don't believe all that you are told. Looking into the crankcase with a torch to see just how much clearance there was between the crank and center camshaft bearing housing ( at least 1 mm) I spotted a plug in the crank, knowing the phoenix cranks don't have plugs I did a check and found 4 plugs and an engine number (the same as the crankcase) so it's not a phoenix crank and a not happy owner.
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Oh dear - a good news/bad news story...
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Car type: 1929 Chummy, 1930 Chummy, 1930 Ulster Replica, 1934 Ruby
...but it's now a fashionable matching-numbers engine - and its value has skyrocketed. Until the crank breaks, of course. Does it sounds as though saleman of the pork-pie-hat-wearing variety has been telling porkies?
