General Supercharger Thread

Yessir

I will ask Monday what they gapped it at.

The procedure was uneventful, only thing there is in about a year, they will need to do reconstruction, taking skin from somewhere (back, most likely) to "create" the breast, as after irradiation, the skin can't be stretched anymore.

So that's going to be fun.

Thanks

 

Hopefully he didn't fuel up in Tonopah or Goldfield...

 

Crap man, sorry you are both going through that...

I wish you guys the best in dealing w/that and her finding some comfort and peace!

 

Tonopah is one of my planned routes on dirt and goldfield on dirt also for a few hundred miles

 

Same/similar windowed piston failure on a Honda w/ boost.

https://www.k20a.org/threads/turbo-k24-failure-help-me-diagnose.228857/page-3#replies

 

Forged Mahle from the BMW.

 

Interesting info there

 

Good read! Thanks

 

FedEx decided they could find my house today - woohoo! I opened up the box and found something interesting. The blower appeared to sit much further forward on the intake, so I checked my pictures of the Gen4 all crated up and sure enough, there's a significant difference.







That also means Gen6 pulleys are much different than Gen 4 pulleys, and not compatible. New pulleys have quite the positive offset, are five bolt and have a hub bore of ~52mm vs 42mm of the Gen4. The base pulley is also larger (3.75") compared to the Gen4 base pulley (3.625").

 

Looks like the smaller pulleys would be an issues sooner than the gen4 since they sit further back in the snout. Granted at that point it’d be better to move to a larger lower and larger upper combo for better belt grip than a smaller upper with slip.

 

Possibly. Whipple sells a 3.0" pulley in the 5 bolt, 8 rib variety; I think that's the smallest off-the-shelf pulley they sell for the 4 bolt 8 rib as well. Now I'm curious about clearance, but I don't think I'd ever go that small on the pulley. Well, not in the foreseeable future... But you are right - I think moving to a larger lower would be the better move there. I'm debating between possibly a 3.375" and 3.5". Or I just leave it be a for a while. Or not..

 

Was there a clearance issue with the firewall or? Wonder why the change especially since they are not going forward with further development on the Tundra.
At least we got ASP, XAT and Prospeed 7 inch crank pulleys to choose from. ASP quoted $250 for the 7in crank pulley and will make whatever workable size you want. I thought of the 7 but it's only a 4.23 percent increase from what I got.

 

My guess is for increased bearing support and/or to standardize with the 5 bolt pulley. I don’t know what other vehicles use the 5 bolt 8 rib pulley (if any) so that point may not be valid. But the much larger hub bore makes room for a much larger input drive shaft (not sure of the technical term), which hopefully makes room for larger support bearings.

But I’d wager the biggest reason is for the fact that the pulley centerline is now behind the hub face instead of in front of it like the Gen4, decreasing the cantilever forces dramatically between the support bearings. I will try to figure out how to post a video, but my blower pulley had 1/4” of play in all directions and about 15 degrees of rotational play. I didn’t have to guess that I heard I noise or thought there was excessive play - it was very obvious. Hopefully this fixes that propensity for bearing failure.

 

Nope no clearance issue on the gen 4. I think it’s just as Blenton said. Updating the product line to the newest gen etc

 

My wife went thru the same thing...19 years ago.

 

@snivilous examination of @reywcms engine gives us the clue I suspect we desperately needed, all the piston failed in the same spot. Now, This is bit of a guess at this point, but a good chunk of my morning was spent staring at torn down UR Series engines and their various systems. Then it hit me… but before the possible problem and solution is shared, let’s have some fun with this and see if anyone else can spot it. It’s right there in Toby’s photo.

 

This is one of the pistons out of the engine, I got my SC from..
Looks familiar... And 2 of the injectors were plugged solid as per SOL

 

Swollen metal, torn up ring lands, heat deformation, and dirty fingernails...detonation for sure, but it looks like from the underside

 

Are you looking at the casting/machining ridges in the piston side?

 

Good guesses, but looking in the wrong places…. I looked there, too.

 

I was thinking heat from running lean under boost, probably from clogged injectors after seeing Rey's fuel. @reywcms , do you have a fuel filter added anywhere?

 

Well, the right is fused together on top...the middle and oil ring have GREAT clearance, now, tho...a prying mark or contact point on the bottom edge of the piston, too

 

I know the pistons are not custom fit and its a one size fits all deal. Maybe knock induced heat causing the ring faces to expand into liner followed by severe blow by melting the piston?

 

Clue… It’s not the piston or rings, but it is in the photo.

 

Years back talk of weak wrist pins inducing knock? Or something like that...?

 

Can't quite put my THUMB on it, but there's a thumb in the photo...

Me wildly speculating... I think it's interesting that the land failure happened under the thicker part of the piston where the material is built up on the top of the piston. I would think a bad knock event would find the the thinner edge of the piston to squeeze past and blow out the rings to the left or right of that hump in the material just like @mustang67408 picture. This makes me think that there is either a heat build up in that area - the piston skirt appears to be worn more but I don't know if that's from after the chaos or before, but if before, it could lead to a hotspot. Or perhaps the piston is holding too much heat from the block since there is more surface area there. So cooling the oil with an external cooler would pull more heat away from the block, and in turn, more heat from that side of the piston?

Or alternately, the oil is crudded up in the piston rings, restricting movement, causing them to bind. I think that's called oil coking and one of the selling points for products like Valvoline Restore and Protect. Again, the simple solution would be better oil cooling...

 

The plastic water jacket thingy?

 

Winner.

 

Praytell..

I mean, please explain for why the water jacket thingy is the culprit. I think I have an idea, but I'm just guessing..

 

Yeah, the wrist pin is showing heat coloration on the right side of the photo...