StGeorge said:
Whats wrong with painting? The bolts stood out from the get go.
Can someone increase the microscope magnification and slide another BBSC under there. Lets see what else we can find.
Armando
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BBSC removal and inspection
- Thread starter StGeorge
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Whats wrong with painting? The bolts stood out from the get go.
Can someone increase the microscope magnification and slide another BBSC under there. Lets see what else we can find.
Armando
Yellow Rose
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Careful, Armando.....you are beginning to sound as sarcastic as me.
Govern yourself accordingly.
Govern yourself accordingly.
Yellow Rose
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Friendly Picking On You
Each and every time someone was checking out my engine, one comment or question I would get was "why are those bolts rusted (top surface)?"
Each and every time? In the two years I've had mine, the above comment was not uttered (within my earshot, anyhow) whenever I lift the engine hatch.
All kidding aside.....I am of the opinion that the bolts should be SS from the beginning. StGeorge, take one of the bolts to a hardware store and compare it to what they have, to determine what the thread pitch is. Then do an internet search for the same fastener in SS. Maybe we could do a group buy. See what you started? And now I volunteered you for a group project.
Each and every time someone was checking out my engine, one comment or question I would get was "why are those bolts rusted (top surface)?"
Each and every time? In the two years I've had mine, the above comment was not uttered (within my earshot, anyhow) whenever I lift the engine hatch.
All kidding aside.....I am of the opinion that the bolts should be SS from the beginning. StGeorge, take one of the bolts to a hardware store and compare it to what they have, to determine what the thread pitch is. Then do an internet search for the same fastener in SS. Maybe we could do a group buy. See what you started?
And now I volunteered you for a group project. 
Each and every time? In the two years I've had mine, the above comment was not uttered (within my earshot, anyhow) whenever I lift the engine hatch.
Because those who looked under your hatch were shaking in their boots, fearing should they say something negative about the BBSC that you would publicly embarrass them with a verbal shouting display.
j/k
Because those who looked under your hatch were shaking in their boots, fearing should they say something negative about the BBSC that you would publicly embarrass them with a verbal shouting display.
j/k
AndyVecsey said:Careful, Armando.....you are beginning to sound as sarcastic as me.
Govern yourself accordingly.
That sh*& kinda rubs off ..... better get off PRIME, heading over to RICER.COM
Armando
Hi Andy,
It is my understanding through recent discussions (as in 10 minutes before I posted the info) with MarkB, that the bearing blocks must be "squared up" to insure no misalignment, that can cause the bearings to end up cocked in relation to the shaft. I do not think you will see the bearing on a angle per sa, but it will create preload on the bearings.
Unless I totally misunderstood MB, it does need to be reset in the jig to insure alignment between the shaft and bearings. I know your engineering background enough to know not to take your comments lightly. Please comment.
Thanks,
LarryB
It is my understanding through recent discussions (as in 10 minutes before I posted the info
) with MarkB, that the bearing blocks must be "squared up" to insure no misalignment, that can cause the bearings to end up cocked in relation to the shaft. I do not think you will see the bearing on a angle per sa, but it will create preload on the bearings.Unless I totally misunderstood MB, it does need to be reset in the jig to insure alignment between the shaft and bearings. I know your engineering background enough to know not to take your comments lightly. Please comment.
Thanks,
LarryB
Larry Bastanza said:Hi Andy,
It is my understanding through recent discussions (as in 10 minutes before I posted the info
This is not surprising. Having spent decades with OHC Datsun engines I can tell you that the cam towers are just as finicky. If you unbolt them, then put them right back on and re-torque you are guaranteed to find that the cam no longer turns freely. No matter how tight and positive the locating dowels seem to be there is always enough play to get the towers misaligned. Fortunately it is possible to loosen and tighten the towers while turning the cam by hand until everything lines up, but it tales patience and practice. I've spent as much as a couple hours getting them just right.
I have no idea if something similar can be done with the BBSC shaft but I would hesitate to assume it can simple be bolted back in.
.........it does need t be reset in the jig to insure alignment between the shaft and bearings.
...followed by a string of expletives and FI induced Tourette's Syndrome. Well, just one more reason to call Mark.
Maybe we could do a group buy. See what you started? And now I volunteered you for a group project.
I am on a mission; especially if I have to be committed for above.
Armando, What color paint would you like?
...followed by a string of expletives and FI induced Tourette's Syndrome. Well, just one more reason to call Mark.
Maybe we could do a group buy. See what you started? And now I volunteered you for a group project.
I am on a mission; especially if I have to be committed for above.
Armando, What color paint would you like?
StGeorge said:.........it does need t be reset in the jig to insure alignment between the shaft and bearings.
...followed by a string of expletives and FI induced Tourette's Syndrome. Well, just one more reason to call Mark.
Maybe we could do a group buy. See what you started? And now I volunteered you for a group project.
I am on a mission; especially if I have to be committed for above.
Armando, What color paint would you like?
That would depend on your preference, I would pick the lightest composition, less weight makes you faster.....
Lighten UpArmando
PS: Mine also rusted also but not the whole head of the bolt, only the hex part, dabbed a bit of flat black paint and good as new.... of course its hard to tell at 160 MPH.
as Andy Vecsay ( hows that name spelled?" lol)would say "Govern Yourself Accordingly"
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If MB says the bearings / shaft need to be jigged before bolting them into the long carrier, I'm sure he has a reason for saying so. I am not disputing his insistence on this, rather I am "questioning" the need based on what I saw on my drive unit. It has been three months since I looked at my drive unit when it was off the car for the transmission rebuild, so I could very well be wrong, but here goes.
What I recall seeing is that the tolerance between the bearing block and the inside of the long carrier was a few thousandths of an inch. No, I do not have super-calibrated eyeballs, but I can tell the difference between, say, 0.005" and 0.025". If there was as much "slop" between the bearing block and the long carrier with the latter number, I can see the need to jig. But on my drive unit, if you removed the four bolts from one of the bearing blocks, I bet you couldn't "wiggle" the bearing block back-n-forth angularly so as to induce an artificial misalignment.
But let's say that that some jigging is needed and MB's shop has a long backlog and a BBSCer needs to install the drive unit for an upcoming track event. I think there may be an alternative. Lay the long carrier upside down on the work bench. Lower the shaft / bearings assembly into the long carrier. Get the twelve bolts started by hand, tightening them not even finger-tight. Get a precision machinist's square and ensure (not insure) ensure the bearing block is perpendicular to the shaft to exactly 90° in the vertical and horizontal planes. While holding the machinist's square in place tighten the four bolts, at the same time, making sure nothing shifts.
What I recall seeing is that the tolerance between the bearing block and the inside of the long carrier was a few thousandths of an inch. No, I do not have super-calibrated eyeballs, but I can tell the difference between, say, 0.005" and 0.025". If there was as much "slop" between the bearing block and the long carrier with the latter number, I can see the need to jig. But on my drive unit, if you removed the four bolts from one of the bearing blocks, I bet you couldn't "wiggle" the bearing block back-n-forth angularly so as to induce an artificial misalignment.
But let's say that that some jigging is needed and MB's shop has a long backlog and a BBSCer needs to install the drive unit for an upcoming track event. I think there may be an alternative. Lay the long carrier upside down on the work bench. Lower the shaft / bearings assembly into the long carrier. Get the twelve bolts started by hand, tightening them not even finger-tight. Get a precision machinist's square and ensure (not insure) ensure the bearing block is perpendicular to the shaft to exactly 90° in the vertical and horizontal planes. While holding the machinist's square in place tighten the four bolts, at the same time, making sure nothing shifts.
Another question for the pundits:
I had substantial oil into the SC due to the oil return line. This occured recurrently. The first time was due to too long and too small an oil return line (#6). The second time the #8 line required additional shortening.
This resulted in substantial oil volume delivered to the intake. Enough to affect drivability, and generate a CEL. When I removed my VVIS there was a small pool of oil in the chamber.
My question is could the oil have any damaging affect upon the SC impeller, etc. The oil was also leaking from the bypass valve.
I had substantial oil into the SC due to the oil return line. This occured recurrently. The first time was due to too long and too small an oil return line (#6). The second time the #8 line required additional shortening.
This resulted in substantial oil volume delivered to the intake. Enough to affect drivability, and generate a CEL. When I removed my VVIS there was a small pool of oil in the chamber.
My question is could the oil have any damaging affect upon the SC impeller, etc. The oil was also leaking from the bypass valve.
Yellow Rose
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Oil Mystery
I have heard this happen to one other BBSC’ed NSX. The problem was also with the return oil line. In that situation, the return oil line dropped down from the blower but rose back up before dropping down again into the pan. Eliminating the "dip" in the line such that the line always has a downward slope towards the pan fixed the problem.
An oil film deposited onto the blower impeller will eventually be slung off by centrifugal force, so there shouldn’t be any concern to the rotating element. However, until all of the oil that accumulated in the intake manifold is slowly diluted and burned off, CELs will be present. As long as the O2 sensors are not damaged from excess oil coating, the system should return to normal after the oil is consumed.
The oil pressure will always be greater than blower boost pressure. Because there was "back pressure" (flowing resistance) in the return oil line, the oil seal inside the blower was breeched and oil was ingested by the blower. What I don’t understand is why simply re-rerouting the oil return line prevents continued oil passing through the compromised seal. It is as if the seal magically repaired itself after the back-pressure in the return line was removed. Or is there an internal check valve in the Paxton’s lube oil passages that opens to the blower’s air-side to prevent the seal from being damaged?
I have heard this happen to one other BBSC’ed NSX. The problem was also with the return oil line. In that situation, the return oil line dropped down from the blower but rose back up before dropping down again into the pan. Eliminating the "dip" in the line such that the line always has a downward slope towards the pan fixed the problem.
An oil film deposited onto the blower impeller will eventually be slung off by centrifugal force, so there shouldn’t be any concern to the rotating element. However, until all of the oil that accumulated in the intake manifold is slowly diluted and burned off, CELs will be present. As long as the O2 sensors are not damaged from excess oil coating, the system should return to normal after the oil is consumed.
The oil pressure will always be greater than blower boost pressure. Because there was "back pressure" (flowing resistance) in the return oil line, the oil seal inside the blower was breeched and oil was ingested by the blower. What I don’t understand is why simply re-rerouting the oil return line prevents continued oil passing through the compromised seal. It is as if the seal magically repaired itself after the back-pressure in the return line was removed. Or is there an internal check valve in the Paxton’s lube oil passages that opens to the blower’s air-side to prevent the seal from being damaged?
The problem was also with the return oil line. In that situation, the return oil line dropped down from the blower but rose back up before dropping down again into the pan. Eliminating the "dip" in the line such that the line always has a downward slope towards the pan fixed the problem.
This is the problem, even with the larger #8 line; however, in my case, the dip was extremely subtle and not apparent visually. I emperically removed some additional line and it seems OK (for the moment)
It is as if the seal magically repaired itself after the back-pressure in the return line was removed. Or is there an internal check valve in the Paxton’s lube oil passages that opens to the blower’s air-side to prevent the seal from being damaged?
That also never made any sense to me. You think the seal would be blown; however, it seems to work OK once the line is corrected.
Can the Bypass valve mechanism be compromised by all that oil contamination---in my case, substantial oil was dripping from the valve.
This is the problem, even with the larger #8 line; however, in my case, the dip was extremely subtle and not apparent visually. I emperically removed some additional line and it seems OK (for the moment)
It is as if the seal magically repaired itself after the back-pressure in the return line was removed. Or is there an internal check valve in the Paxton’s lube oil passages that opens to the blower’s air-side to prevent the seal from being damaged?
That also never made any sense to me. You think the seal would be blown; however, it seems to work OK once the line is corrected.
Can the Bypass valve mechanism be compromised by all that oil contamination---in my case, substantial oil was dripping from the valve.
Yellow Rose
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Something else doesn’t make sense to me. The NSX oil pump puts out approximately 50 PSI of pressure. Depending on how much oil flowrate the Paxton requires, this is more than enough pressure to push the oil from the pan, up to the blower. Even if the return line has a "dip" in it, there should still be enough pressure in the supply line to force the oil back down to the pan. On top of that, gravity is working in our favor with the return line. Until we see cross-section drawings of the Paxton, we are speculating.
In regards to the boost divert valve being affected by oil, it really depends on what type of plastic the valve body is made of and what kind of elastomer is used for the internal pressure seal. Even if they aren’t compatible with oil over long-term exposure, perhaps just the brief period of time oil was dribbling though the valve, there shouldn't be any harm done.
In regards to the boost divert valve being affected by oil, it really depends on what type of plastic the valve body is made of and what kind of elastomer is used for the internal pressure seal. Even if they aren’t compatible with oil over long-term exposure, perhaps just the brief period of time oil was dribbling though the valve, there shouldn't be any harm done.
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