Quote Originally Posted by More Power View Post
"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.
“Everyone I’ve talked to” means just that. Not every hx35w 6.5 owner out there. Simply everyone I have talked to. I have not personally yet to find anyone that has driven their 6.5 with an hx35w that has not had problems while daily driving. If you go on YouTube, and search 6.5 hx35w swap and ask the poster years later if they still have it, their usual reply is they sold it because of too many problems or it blew up. Many individuals that I bought 6.2 and 6.5 parts off of, claimed the same thing about the hx35w.

I am not saying your information here on the diesel page is incorrect or misleading. The people I have talked to could have not had the proper upgrades to handle the hx35w and did things half assed. Currently, I am very happy with my GM1 turbo. It serves its purpose for my off road driving conditions and habits. I have most of the diesel page books and have used a lot of its advice which has helped a lot!