It appears I'll be replacing the head gasket again. Where to start? A new head at least to get rid of this original 9mm injector bore head. Port and polish, valve springs, o-rings, studs...? Dreading it but I've gotta do it.

 

wow, just starting my first HG job myself. All on a 1991.0 non intercooled motor with less than 90K original. Leaking in the same spot as yours.

How many miles ago was your last HG replacement? did you get the head checked and use ARP studs?
edit: just answered my own questions, read your build thread. Sucks it only lasted 6ish years! How much boost you running?!? Seems like you did it up right last time.

 

Man that sucks.....Hope all goes well with the Re/Re.

 

Yeah, it was done right according to the Shop Manual I have and by recommendations from others along the way. Head was machined, valves and seats were ground to keep recession within Cummins spec., head bolts were torqued per Cummins sequence (at least 125ft. lbs.). At the time, I wasn't working, so I wasn't spending my money and wasn't going to run up an expensive tab that I couldn't pay back in a timely manner. Just did what needed to be done to get it road worthy again. About the only upgrades I made were slightly larger injectors and a piston lift pump. Injectors were done only because 4 of the 6 barely atomized the fuel so they needed a rebuild anyhow. It wasn't much more to upgrade the nozzles.

Since then, the first turbo upgrade from stock was a Super 40/35 hybrid with a 14cm turbine housing. It ran awesome and spooled stupid fast. I then went to a little larger injector which then pushed the turbo a little harder. Shortly after, in 2012, I installed a custom VE pump with enough fuel to make somewhere around 450hp (so long as it could burn it completely and efficiently). Those injectors turned out to be not so great and so I swapped those out for a borrowed set that proved to make a high 400hp (with supporting mods, of course). Those woke things up A LOT! It was enough fuel to spin the Super 40/35 even harder, up to around 45psi at most. That turbo was a champ though. It moved plenty of air for that amount of fuel and I never saw much smoke under acceleration or with my foot in it. The truck became a monster then.

Just last year in March, I put even larger injectors in. Mainly because I needed to return the borrowed set I had been running for a few years. Yet again, the truck was a monster. Making 45psi in a heartbeat and hardly working to do so. A month later came the S362 turbo. It's a great turbo, of course, and only spools slightly slower than the Super 40/35 did. With everything I've done to date, this engine has seen 50psi of boost. Not everyday, though. Rarely would I push it that hard but it's been up there a couple of times and I've never held it at that level. As soon as that gauge wraps around and touch 45psi, my foot is rolling out of it. Anything above 40psi, for that matter.

The custom VE pump has a very broad timing sweep and about 10* worth of dynamic advance alone. I'm sure the motor as is, could only handle so much and I knew it was only a matter of time. Just not knowing when that time would be. Always unexpected, of course.

I've made the decision to pull the motor. I want to get a cam and being able to pull the oil pan will make the job less nerve racking. I may try to locate that groove cutting tool and cut grooves in the block since that's the ideal place for o-rings from what I've gathered. Although, I wouldn't plan on pulling the head again after this so they wouldn't have to be cut again until the head gets pulled and machined.

Lots of thoughts coming to mind. Billet freeze plugs and a rear block-off plate with provisions for a bypass. I've been letting it sit for the last few days. Wondering if I'll be able to see any water/coolant in the oil judging by the dipstick.

 

If you are pulling the pan and cam, might as well put in new rods and mains and swap out the plastic oil squirters with the billet ones, would be a good idea to get rid of the three piece faulty thrust bearing and new rods and mains will take care of that as well.

I'm not surprised your HG blew with that sort of fuel, boost and timing. (no offense)

Mine was running stock injectors and stock VE pump, with just a high drive pressure HE300VG turbo, that never saw more than a blip in the low 30s but mostly in the low to mid 20s. Non intercooled. But also had the integrated exhaust brake. Age might be a factor as well on mine but it only had 85K original miles.

 

No offense taken. I don't beat on this thing much at all. Generally, when driving, the heaviest acceleration I'll put it through will only push around 30psi. Again, it was only a matter of time and a few runs in the 45-50psi range for it to pop. Thanks for the tip on the oil squirters. If the updated ones are billet, I'll certainly opt for those.

You're talking about rolling in new bearings? I'd hope that my crank is still good and I could go with standard bearings. I'll have to get my hands on some PlastiGage and measure it out. I do kind of want to pull a main and rod cap just to get a visual of bearing wear, even though the upper bearing shows more wear from the load of the power stroke. I've never rolled in bearings before. I've only installed them with the crankshaft and rods out of the engine. I'm not planning to fully rebuild this motor to be honest. I don't exactly have all of the tools to handle such a job. Although, a full rebuild kit and special tools can be purchased. The rebuild kit isn't all that expensive.

But, I figure if the bearings check out decent, I'll run it as is. I'd certainly love it if I could park this thing inside a shop with ample spacing and be able to lay everything out and have plenty of room to work around it all. However, I don't have that option at the moment.