Engine explosion

[snipersm7]

I was towing a 6,000lb trailer, transmission would keep downshifting to 2nd and the engine exploded. The man I brought the truck from just put a new 5.7L vortec from summit in the truck. It blew rod caps I believe through the oil pan. Any ideas on the best company to buy a new crate engine. I am looking at putting a 383 in the truck for more power and torque..

 

[stutaeng]

You destroyed a new crate engine the previous owner had just put in? Where you over-revving it? Trying to race up a mountain? Overheat? Did it run low on oil?

 

[snipersm7]

You destroyed a new crate engine the previous owner had just put in? Where you over-revving it? Trying to race up a mountain? Overheat? Did it run low on oil?

New oil/filter low rolling hills running about 60mph, about 3000 to 3500 rm pm's and trans was automatically downshifting kicking rpm's up to 4,000 to 4500 rpm's. Starting losing power, blowing white smoke and then thumping noises. Probably threw a rod, bolts or cap ends. Lost all antifreeze and some in with oil. Probably blew a head gasket or put a rod into water jacket? Has a 1 inch hole just below oil pan rail on passenger side and holes through the oil pan on driver's side toward the rear. Engine was running great, had about 4,000 miles on it before I tried to tow the camp trailer.

 

[snipersm7]

Long story short, The previous owner put in the new engine, had a fire that burned up the engine wiring harness and etc.... I towed truck home, found little oil in the engine, complete mess to work on. Rocker arms were out of adjustment to begin with (so I have no idea of previous owner tried adjusting or came from summit racing that way).

 

[Supercharged111]

Sounds to me like you paid for a truck with a junk motor. I pull heavier than you with my 1500, have done so for a long time. Many many passes over 4000 RPM.

 

[Rob7233]

It's not a 383 but it is all new.. https://www.gmperformancemotor.com/parts/12691673.html

 

[gearheadE30]

The transmission hunting is a problem, but not for the engine. I'd be worried about trans life going back and forth between 2nd and 3rd at WOT.

I'm with Supercharged; something else going on there. I've pulled passes out west plenty of times no problem over 4000 rpm with my 200,000+ mile 5.7...

 

[618 Syndicate]

White smoke indicates water and coolant in combustion chamber to me.

 

[Fast_Z71]

That’s not good at all. I’d be checking into your trans and electronics pretty heavily before you start trying to get a engine.

 

[L31MaxExpress]

The transmission hunting is a problem, but not for the engine. I'd be worried about trans life going back and forth between 2nd and 3rd at WOT.

I'm with Supercharged; something else going on there. I've pulled passes out west plenty of times no problem over 4000 rpm with my 200,000+ mile 5.7...

Definately something wrong. Pulled my 6,000 lbs Jayco up many long grades for miles at a time at about 70 mph at about 4,500 rpm in 2nd gear with my 5.7 Vortec Express van when it still had 3.73 gears. Pulled the 4L85E down to 2nd, flat footed the accelerator and let it eat, letting off the pedal some to hold 70 mph when it could. When I added tow/haul to the 0411 and programmed it properly, shifter in 3rd and it would hold 2nd gear on grades above 1/2 throttle. 2-3 shift set for 80 mph above 1/2 throttle. Gears made a bigger difference for me than the 350 to 383. With the 4L85E I tow in overdrive with a 5.13 gear, 70 mph @ 2,850 rpm. Only kicks down to 3rd and spins 3,700 rpm up long grades now.

That being said a friend of mine recently had a rod let go on a rebuilt L31 cruising about 70 mph at 2,000 rpm. Let go with no warning. No knocking, no loss of power, no overheating, no loss of oil pressure, just a big bang and quit running.