Originally Posted by
More Power
"Everyone"? "Killed their motor with an HX35 while daily driving"? "Pulled the studs"? My BS detector is flashing...
Combustion pressure can be up to 3500-psi at full power. If the exhaust is clean, how can going from the stock 7-psi boost pressure produced by a GM turbo to an efficient 15-psi from an HX35 or even an efficient 20 from an HX40 hurt a 21.3 CR engine? By the way, I only advocate for 7-10-psi from the GM series of turbos, 15-psi from the HX35 - 20-psi from the HX40, all because of efficiency - cool boost and low backpressure. In gradation, anything over 7-psi boost pressure requires an intercooler and a performance exhaust system.
I'm putting a 1994 6.5TD Blazer back together right now that was a victim of too heavy a right foot while towing and an inefficient turbocharger for how this Blazer was being used - i.e. high EGTs due to a turbocharger with a too restrictive turbine/compressor (GM-4). The prior owner was also running a Turbomaster and a performance chip, and wasn't paying attention to the EGT/Boost gauges as the pistons melted around him.
Also, by the way... 18:1 pistons are only recommended for those who tow a lot or are running a boat. Not for daily drivers. 18:1 pistons allow people to add fuel and boost to make more power (build more combustion pressure), while giving the engine more heat rejection capability. The Diesel Page has discussed all this to exhaustion in years past. In the tens of thousands of 6.5 owners I've communicated with over the past 25 years, I've only heard of maybe 1 -2 examples of pulled threads in the block deck, and this was due to a rotten block or damaged threads, and it happened during a head installation - not from turbocharging.
Final by the way... Some years ago I attended a local diesel dyno event where Heath's 6.5 shop truck was there to spin the rollers. That 6.5TD powered 1995 truck was running (or so they said) 21.3 Cr pistons, a Turbomaster on a GM turbo, his custom programming, propane injection, nitrous injection, water/meth injection and the kitchen sink.... I've heard thousands of diesel pickups run at dyno events - from lots of stock trucks to 1000-horsepower super trucks. That 6.5 sounded way-way different - raspy and scary - I stepped way back..., but it made 300 rear wheel horsepower for the 1-2 seconds it had to. Then, they drove it back to Washington state after the event, or at least that's what they said they were going to do as they left the event. I reported all this right here in The Diesel Page at the time. That engine didn't pull the head studs or bolts, or whatever the engine was equipped with. That was certainly no daily driver, and I sure wouldn't want to tow a 10K trailer out of the Columbia river gorge on I-90 with it - with all that stuff switched on.