General Supercharger Thread

Damn! LT6 time? What do you even do at this point? Obviously, more boost...

 

Yikes! No wonder no compression.
I forgot about the fuel multiplier since it's basically turned off like you stated.
@Jowett mentioned about the oilers spraying super hot oil under the piston combined with inefficient cooling of the cylinder causing possible failure. Reason I added an engine oil cooler. Plus the added protection of W/M for cylinder cooling. I'll probably move to straight water and ditch the Methanol.
I'll be hopefully installing the lexus 570 windshield washer in the driver's fender this week. It arrives tomorrow.
https://fiinterchillers.com/tech_articles/water-injection-gains-50hp/

 

Let me know how that goes. It’s not high on my list but it’s definitely there.

 

Have you been able to monitor engine temps with your oil cooler installed? Any noticeable difference? It’s been on my back burner list for a while but haven’t mustered the gumption to figure it out yet. Honestly, I wouldn’t expect much of a difference at the gauge except maybe in high load situations like summer towing on grades, but I’m sure it would help even if only behind the scenes.

 

@snivilous
The crank looks normal to me, manufacturing discoloration..
My first thought was squirter plugged. We've had an old supra where one of the squirters fell out and it torched the piston from the bottom side..
Overheating and very hot oil burned the piston? But why not the others?
I assume all the Dots on the top of the piston were facing forward.. I've seen techs put them in backwards and it doesn't end well usually ..
Definitely got hot, all the scratches on the cylinder wall... not a common issue

 

I have a separate oil temp gauge on my sandwich t-stat plate. Oil leaving air cooler is about 180 deg. It probably 200 plus entering.

 

Hopefully it fits. Initial impression is it should. I got a 2 gal intercooler tank coming and needed to switch it up.

 

Built motor lower compression more boost nothing crazy, address the elephant in the room on why this happened. If it was oil squirter plugged how do we prevent? Add an oil cooler as mentioned.

 

No way the oil squirter caused that, oil doesn't have that kind of heat. How would it get plugged? Anything that is big enough to clog the oil squirter would cause bearing damage. That's from running too lean, or severe detonation, or both.

 

Oil comes from the filter to the squirter (oil jet), so shouldn't be any warmer than what's in the pan.

 

But interesting how the top of the piston shows no detonation

 

Probably not detonation, I'm leaning more towards heat from running lean and the piston rings expanding until they lifted the ringlands and broke the piston.

 

This is what sniv and i concluded too but not the lean aspect. I think it happened same time as the trans. Hard day at the dunes in the truck, wet thick sand tons of load and hard runs

 

I forgot who, but was it Matt Smith, having fuel routing supply to front cylinders and exiting the rear for equal fuel distribution. Doing the crossover as 4firemandan did on the regular stock fuel lines before re-doing his AN 8 supply.

 

As I was adding fueling option information to the turbo thread, I realized XAT speaks to additional issues/limitations with the stock fuel rails. I can't recall who is using stock vs upgraded, but given the discussion about possibly running lean, I figured I'd share their link with the details. Choose your poison on which brand you go with if you upgrade, sharing just for the data. https://xatracing.com/XAT-3UR-Fuel-rails.html

 

I think making the modifications to the stock fuel rails to cut/enlarge the barbs and run the feed/return in parallel instead of in series would be sufficient for most builds, but I'm currently running the XAT rails with 8AN lines.

 

I'm still on stock rails. I did remove the bevels on supply/return tube end and it opened the up. I noticed I hit 94% on injector duty cycle with the Five O 750cc injectors. Granted it was it 6-6400rpm. Majority was 85%idc.
6AN supply/return.

 

Viktor G has a video on the stock rails being good for some serious flow. But the old while you're in there motto could be applied

 

If anyone needs some 750cc injectors let me know. Most likely moving up in size

 

Viktor's video is actually included in the Turbo thread since it talked about lines, pumps, injectors, etc.

 

So I'm beginning to do some digging into the piston options. Interesting find is no one offers an off the shelf piston for 9:1-9:5 to 1. Only 10:1 JE is the only option for that as a custom piston starting at $2500.