IMS bearing alternate fix
03-02-2018, 02:58 PM
#46
Originally Posted by rocketbob
Thanks for pointing out this solution as I was not aware of it. If I were not so set in my DIY ways I would likely go with their solution since it uses pressure fed roller bearings. SKF has some bearing calculators online to determine the expected life of a bearing based on type of lubrication and contamination factors. It would be interesting to compare the two (roller vs. ball) to see which one in theory would have more life given expected contamination values one would see with normal engine oil contamination.Thank you. I have an IA (inspection authorization) from the FAA so I have a bit of a keen eye for doing modifications in the airplane world. I've had to deal with analyzing ball bearing failures in some Lycoming engines that have a ball bearing support for magnetos so I'm aware of how they fail in bathed applications. In that case the bearings are fed with splash oil and I believe underutilization is a contributing problem. Water and acid gasses are byproducts of combustion which end up in the oil. If the engines sit for long periods of time then these contaminates cause corrosion on steel parts which is obviously hard on contact bearings.Sure, just don't know the extent of damage yet, if any. Will get the car up on the lift this weekend and start poking around. Dropping the motor and transmission is something I was planning on doing anyway to do the IMS bearing fix. I know I don't have to do that but I want to do some other maintenance as well and its just easier if everything's out in the open.
Good luck bob!!
Keep posting updates!
03-02-2018, 05:19 PM
#47
Race Director
I've been charging that windmill since people started trying to use the class-action data as The Definitive Guide to How Long Your Bearing Will Last(tm). It's maddening.
03-04-2018, 06:24 PM
#48
Track Day
Thread Starter
Mystery deepens on the cam timing. Drained the oil, cut apart and inspected the oil filter. I noticed small particles of what appear to be bronze bushing material but a relatively insignificant amount. Ok, cool, no evidence of major carnage. I then proceeded to pull the cam plugs to have a look at the notches. When turning the engine over by hand, the exhaust cam rotates but the intake cam does not. Huh? This is a three chain engine. Perplexed by this, a friend advised me to pull the scavenge pump cover to have a look. I was able to pull it out far enough to see a perfectly normal chain. The chain, exhaust cam gear, AND the intake cam gear turn properly with crank rotation. So, at this point, the intake cam gear must have a key that's sheared or the cam has broken (highly unlikely I think.) The notch side is not moving, but the gear is turning.
03-04-2018, 08:32 PM
#49
Rennlist Member
Mystery deepens on the cam timing. Drained the oil, cut apart and inspected the oil filter. I noticed small particles of what appear to be bronze bushing material but a relatively insignificant amount. Ok, cool, no evidence of major carnage. I then proceeded to pull the cam plugs to have a look at the notches. When turning the engine over by hand, the exhaust cam rotates but the intake cam does not. Huh? This is a three chain engine. Perplexed by this, a friend advised me to pull the scavenge pump cover to have a look. I was able to pull it out far enough to see a perfectly normal chain. The chain, exhaust cam gear, AND the intake cam gear turn properly with crank rotation. So, at this point, the intake cam gear must have a key that's sheared or the cam has broken (highly unlikely I think.) The notch side is not moving, but the gear is turning.
03-04-2018, 09:16 PM
#50
Track Day
Thread Starter
Interesting. Why would they do this rather than the tried and true ways of putting in keys or using a taper?
03-04-2018, 09:27 PM
#51
Rennlist Member
03-04-2018, 09:59 PM
#52
There is a big bolt that bolts down the intake variocam+ sprocket to the intake cam. My guess is that bolt is loose. So I assume the engine doesn't run at all?
What's the history of the engine?
What's the history of the engine?
03-05-2018, 01:37 AM
#53
Track Day
Thread Starter
The engine runs, actually not too badly not firing on bank 1.
No metallic noises.
Long story short, car was brought into a dealership for the problem and basically abandoned due to sticker shock...dealer told owner he needed a new engine. 44K miles. Sat in storage for several years.
No metallic noises.
Long story short, car was brought into a dealership for the problem and basically abandoned due to sticker shock...dealer told owner he needed a new engine. 44K miles. Sat in storage for several years.
