blown engine
#556
^Thanks! You said "...replaced the whole engine with an IMSB "fix" but don't know from where..."
I think the first step is find out as much about the engine and IMSB "fix" as possible. Without knowing both, it's hard to say anything about them. There are may sources of engines. Could be a crate engine from Porsche, a used one, or a "rebuilt" one. The same goes for IMSB "fixes".
I think you have a '99 from your earlier posts and as you know '99 has its own problems like cracked head (cyl #1) so there's really no guarantee.
No one knows the true % of IMS failure. The best you can do is do all PM and as much corrective mods you could to minimize the risks. Mag drain plug and spin-on filters are always good. Also oil and filter change every 5k miles/6 months with good oil is good too.
The car (sans the engine) is in great shape and it only needs a few minor things...will see once I can drive it
I think the first step is find out as much about the engine and IMSB "fix" as possible. Without knowing both, it's hard to say anything about them. There are may sources of engines. Could be a crate engine from Porsche, a used one, or a "rebuilt" one. The same goes for IMSB "fixes".
I think you have a '99 from your earlier posts and as you know '99 has its own problems like cracked head (cyl #1) so there's really no guarantee.
No one knows the true % of IMS failure. The best you can do is do all PM and as much corrective mods you could to minimize the risks. Mag drain plug and spin-on filters are always good. Also oil and filter change every 5k miles/6 months with good oil is good too.
The car (sans the engine) is in great shape and it only needs a few minor things...will see once I can drive it
#557
The flange is the wear surface, for longitudinal and rotational loads. Using DLC on these components is done primarily for cold start wear.
After 5,200 start cycles, a DLC coated flange had zero measurable or visual wear.
DLC adds a ton of cost to these products, but it's worth it. I did all the development and I know what changes it made.
All DLC is not the same, we tried 3 companies and 6 different profiles before deciding which to utilize. It's overkill, and overkill is just right.
After 5,200 start cycles, a DLC coated flange had zero measurable or visual wear.
DLC adds a ton of cost to these products, but it's worth it. I did all the development and I know what changes it made.
All DLC is not the same, we tried 3 companies and 6 different profiles before deciding which to utilize. It's overkill, and overkill is just right.
Also did you ever test the Solution without oil until it failed? I don't know if you've ever mentioned that before.
#558
Yes, I did run the IMS Solution with no pressure fed oil. I'll share the pics and video later today. The unit never did fail, and the wear was not significant at all considering that it ran 1-7K RPM for 20 miles and a dyno session.
#560
I do remember this but I just wasn't sure if you kept running it til failure.
#561
Here's the pics of the IMS Solution that I punished with no oil feed line fitted. Its been in 5 engines so far. This was 7,000 RPM over and over again, as well as lots of idle time, and 20 miles of street driving.
The wear on the flange is nil, the scratches are not measurable, nor can they be felt with your finger. The bushing also looks worse than it is, after it was cleaned up, and measured it had only .002" of wear in the worst spot. Again, this did NOT FAIL and can be cited to another engine right now, if I wanted.
#562
That's pretty impressive. It's almost like the splash lubrication is "almost" enough to satisfy the conditions, with the oil line being there to pickup the slack as a backup. I know this isn't the case though but it seems like the oil line isn't as crucial as I originally thought in keeping this thing alive.
#563
That's pretty impressive. It's almost like the splash lubrication is "almost" enough to satisfy the conditions, with the oil line being there to pickup the slack as a backup. I know this isn't the case though but it seems like the oil line isn't as crucial as I originally thought in keeping this thing alive.
People like him are lost, people that listen to him are even more lost.
#564
Wrist pin offset and bore scoring
Jake mentioned in a 997 thread that a wrong pin offset can contribute to bore scoring. Naturally I was curious so I measured the wrist pin offset and see how much are we talking about here.
See post #107 here https://rennlist.com/forums/997-foru...-engine-8.html
I found that the offset is toward (closer to) the exhaust side for 0.5mm ((59.54 - 58.53)/2). Since the offset should be toward the thrust side and the same piston is used for all of our cylinders, bank 1 has the correct pin offset while bank 2 has the unfavorable pin offset...just like Jake explained.
Seems this has been a problem with older VWs and 911.
http://forums.pelicanparts.com/911-e...in-offset.html
http://www.thesamba.com/vw/forum/viewtopic.php?t=346211
So how do Nickies and JE pistons solve this? JE pistons have no offset and their skirts are coated. Also, the cylinder to piston clearance was chosen such that it doesn't cause issues in cold weather.
See post #107 here https://rennlist.com/forums/997-foru...-engine-8.html
I found that the offset is toward (closer to) the exhaust side for 0.5mm ((59.54 - 58.53)/2). Since the offset should be toward the thrust side and the same piston is used for all of our cylinders, bank 1 has the correct pin offset while bank 2 has the unfavorable pin offset...just like Jake explained.
Seems this has been a problem with older VWs and 911.
http://forums.pelicanparts.com/911-e...in-offset.html
http://www.thesamba.com/vw/forum/viewtopic.php?t=346211
So how do Nickies and JE pistons solve this? JE pistons have no offset and their skirts are coated. Also, the cylinder to piston clearance was chosen such that it doesn't cause issues in cold weather.
#565
Jake mentioned in a 997 thread that a wrong pin offset can contribute to bore scoring. Naturally I was curious so I measured the wrist pin offset and see how much are we talking about here.
See post #107 here https://rennlist.com/forums/997-foru...-engine-8.html
I found that the offset is toward (closer to) the exhaust side for 0.5mm ((59.54 - 58.53)/2). Since the offset should be toward the thrust side and the same piston is used for all of our cylinders, bank 1 has the correct pin offset while bank 2 has the unfavorable pin offset...just like Jake explained.
Seems this has been a problem with older VWs and 911.
http://forums.pelicanparts.com/911-e...in-offset.html
http://www.thesamba.com/vw/forum/viewtopic.php?t=346211
So how do Nickies and JE pistons solve this? JE pistons have no offset and their skirts are coated. Also, the cylinder to piston clearance was chosen such that it doesn't cause issues in cold weather.
See post #107 here https://rennlist.com/forums/997-foru...-engine-8.html
I found that the offset is toward (closer to) the exhaust side for 0.5mm ((59.54 - 58.53)/2). Since the offset should be toward the thrust side and the same piston is used for all of our cylinders, bank 1 has the correct pin offset while bank 2 has the unfavorable pin offset...just like Jake explained.
Seems this has been a problem with older VWs and 911.
http://forums.pelicanparts.com/911-e...in-offset.html
http://www.thesamba.com/vw/forum/viewtopic.php?t=346211
So how do Nickies and JE pistons solve this? JE pistons have no offset and their skirts are coated. Also, the cylinder to piston clearance was chosen such that it doesn't cause issues in cold weather.
Told ya so... This offset only makes sense to a corporate accounting team.
Having an offset only helps if both banks have an offset that lends it's self to positive results. In this scenario we have an offset that have a correct offset on bank 1, and an *** backwards offset on bank 2.
Note how much offset we are talking here, that's a huge offset!
Couple that to an 82.8mm stroke, and the shorter rod coupled to that crankshaft, and you have accentuated mid bore wear by design, due to the steeper rod angle.
Never read about that before, huh? Never heard of that before, huh?
#566
"What, you didn't believe me? Lol!
Told ya so... This offset only makes sense to a corporate accounting team.
Having an offset only helps if both banks have an offset that lends it's self to positive results. In this scenario we have an offset that have a correct offset on bank 1, and an *** backwards offset on bank 2.
Note how much offset we are talking here, that's a huge offset!
Couple that to an 82.8mm stroke, and the shorter rod coupled to that crankshaft, and you have accentuated mid bore wear by design, due to the steeper rod angle.
Never read about that before, huh? Never heard of that before, huh?
Sounds like Porsche engineered in certain failure - hopefully past the warrantee period...
Told ya so... This offset only makes sense to a corporate accounting team.
Having an offset only helps if both banks have an offset that lends it's self to positive results. In this scenario we have an offset that have a correct offset on bank 1, and an *** backwards offset on bank 2.
Note how much offset we are talking here, that's a huge offset!
Couple that to an 82.8mm stroke, and the shorter rod coupled to that crankshaft, and you have accentuated mid bore wear by design, due to the steeper rod angle.
Never read about that before, huh? Never heard of that before, huh?
Sounds like Porsche engineered in certain failure - hopefully past the warrantee period...
#567
Lol, I believe you but a pic is worth a thousand words. I've heard of it before from yourself and Charles but for some reason after the engine rebuild class my impression was there's either no or insignificant offset. Your recent posts just made me revisit this issue. I already have a clean piston lying on my bench so why not just measure it.
So obviously this is another money-saving decision. Do the Mezger engines use different pistons between the banks and have the correct offset?
So obviously this is another money-saving decision. Do the Mezger engines use different pistons between the banks and have the correct offset?
What, you didn't believe me? Lol!
Told ya so... This offset only makes sense to a corporate accounting team.
Having an offset only helps if both banks have an offset that lends it's self to positive results. In this scenario we have an offset that have a correct offset on bank 1, and an *** backwards offset on bank 2.
Note how much offset we are talking here, that's a huge offset!
Couple that to an 82.8mm stroke, and the shorter rod coupled to that crankshaft, and you have accentuated mid bore wear by design, due to the steeper rod angle.
Never read about that before, huh? Never heard of that before, huh?
Told ya so... This offset only makes sense to a corporate accounting team.
Having an offset only helps if both banks have an offset that lends it's self to positive results. In this scenario we have an offset that have a correct offset on bank 1, and an *** backwards offset on bank 2.
Note how much offset we are talking here, that's a huge offset!
Couple that to an 82.8mm stroke, and the shorter rod coupled to that crankshaft, and you have accentuated mid bore wear by design, due to the steeper rod angle.
Never read about that before, huh? Never heard of that before, huh?
#568
That's why I love your posts Ashai. I don't discount or don't believe what Jake has to say but he hardly ever posts the pudding ( don't take that the wrong way, Jake)
you do and that is what will convince most people of the truth on these motors.
you do and that is what will convince most people of the truth on these motors.
#569
Don't think Jake will bother but I'm looking forward to a video of him leaving an opened engine block and piston in the snow overnight. Then the next morning swing a 3lb hammer at it to knock the seized piston out of the block
#570
Engine heads are back from Len Hoffman Automotive Machine!
Amazing machine work! New valve guides, seals, springs, and intake seats, stage I port work. All cleaned, pressure tested, cc'ed and decked.
Clean and shiny
Beautifully finished deck.
So clean!
Shiny exhaust ports.
Beautiful port work and new valve guides.
You can see the new springs and seals.
With the lifter cradle.
Amazing cleaning process.
This is a BEFORE photo, already after soda blasted. Compare this with the last photo.
This is a BEFORE photo.
Clean and shiny
Beautifully finished deck.
So clean!
Shiny exhaust ports.
Beautiful port work and new valve guides.
You can see the new springs and seals.
With the lifter cradle.
Amazing cleaning process.
This is a BEFORE photo, already after soda blasted. Compare this with the last photo.
This is a BEFORE photo.