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Low Compression 6.2

Got a weird problem,the engine surges on hills only,like turning the key off and on. It gets worse with more throttle. Charge psi stays constant,no lift pump gauge at the moment. Don't matter how full the fuel tank is.
 
6.2 turbo said:
Well that didn't last long. Spun the mains bearings. Rods are still nice and straight.
Click to expand...

Likely you overspead the engine when the trans shaft snapped under load. Had a V6 loose the mains after a trans started slipping bad. The metal from this main failure could have plugged the oil cooler.
 
I flushed the cooler,but it still restricted oil psi. If I was running the stock bypass,some oil would have gone through that instead. Simply connecting the cooler lines together= 20 psi more. Just running with the filter on the motor = 30 psi more.

I checked my fuel volume right before the ip,a little over 1 gal per minute free flow. No air bubbles.
 
Well I upgraded to 1/2 inch hose ,and a bulkhead fitting in the bottom of the fuel tank. Also removed the lift pump screen,and set psi to 20. Surging problem stayed the same. I decided it's the torque converter,or tranny. Gets driven everyday and boosted to 30 psi,on a GM-4 :eek:
 
There went the converter,sounds like a supercharger,and slips constantly. I think it's time to upgrade to a NV 3500.
 
I have a few NV 3500's complete and ready to install. I only have one spare 4500 very incomplete,and a two wheel drive. Too make my 4l80-e survive it needs a billit input shaft,and a twin disc converter.
 
Got the 5spd installed. Didn't drive it yet, still need to find a longer rear drive shaft. Got the peddle,slave and master cyl all done and bled. I used a Hays steel flywheel from a small block Chevy. The clutch is a used 12 inch Hays kevlar. No doubt the clutch will need to be upgraded fairly soon,but should be fine to start with.
 
I welded on a weight from a flex plate. I ran this flywheel before so it should be fine.
 
Finally got it all done . I like it better than the 4l80-e. The Tahoe feels lighter and quicker:)
 
Well I got around 3500 miles on this motor. Was getting lots of compression in the water. I pulled the left head,gasket looks fair. All the pistons on that side protrude past the deck surface. Now if only I new what I did that kept the rods straight this time. I was running 30 psi boost every day with a GM-4. Smaller turbo,a governor,and diamond precups ,compared to HX52,no governor,and T precups.
 
Gaskets blown at #2 cyl. The fire ring and oring held,but the graphite pushed out. I didn't oring the center cyl's,and they are fine. All 8 pistons stick above the deck,rods are probably ok.
 
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