Gotta love engine compresion in the crankcase

[BillBallinger Sr]

Re: Gotta love engine compresion in the crankcase

The DT-466 is probably the gold standard light to medium duty engine out there. That said a DI Powerstroke had very few flaws, really o-rings for the injectors were about the only major maintenance item that determined life or death. If they started passing oil, death was on its way from excessive pressures in the cylinders. The IDI motors were about as low maintenance as you can get for a diesel, less mileage and power, but man those things lived forever. Scott's comment on the Cummins is a good one, back when I spun wrenches I could service the injectors bleed and time the pump while you are still getting the valvetrain off a 7.3.

GMs smartest move was ditching the 6.5 and going to the Isuzu. Good architecture for its application and people are putting unholy amounts of boost to them. I am still a 2-stroke Detroit diesel fan even though they are really obsolete and dirty. A turbocharged 3-71 in a 3/4 ton 4X4 pickup comes to mind as pretty sweet. ;D

A 371 turbo is sweet a little low on power for that app.

If you had to choose would you go for a 4-71T or a 6V-53T? Weight wise I would think the 6V would be better because you can set them back more, lower down . My truck has the mid mount bell and an NP-435 with a divorced case and a front mount plate on the engine. Plenty of room for either. If I pull the FE out I am going to a diesel, and a 2-stroke Detroit has always been my favorite. I'm like Dan, firetrucks hell yeah, they do sound good!

[Brian Lohnes]

Re: Gotta love engine compresion in the crankcase

2 stroke Detroit's are very neat.

Here's a 6V-53's at work in a unique application:

http://www.youtube.com/watch?v=Rve2Z3xZ02A

The guy who owns that car used to have the motor in a tube chassis Chevy truck.

You can see photos @ www.teamdiesel.com (hit the photo link)

Can't beat the sound, that's for sure.

Brian

[DanStokes]

Re: Gotta love engine compresion in the crankcase

Most that I am familiar with have a flat deck, but I suppose that there could be one somewhere that doesn't. The DT466 that I messed with for a couple of years (we were trying to get it to run on pure (neat) methanol) was a flat deck with 4 valves/cylinder, as is the ISB. I think that's pretty standard for Diesels.

I don't remember the configuration for the 2 strokers, as it's been MANY YEARS since I've messed with one. Bill can chime in here. But they run exhaust valves with intake ports that are exposed when the piston slides down a way. That's why the HAVE to be blown - they have to have the air forced in (which forces the exhaust out) or they don't have enough O2 to light the mixture when the fuel is squirted in. Bill - did I remember this correctly?

Dan

Dan, I'd been wondering why the top of the piston looked that way. Thanks for clearing that up. Do these diesels have the valves just sitting on a flat section of cylinder head?

[dieselgeek]

Re: Gotta love engine compresion in the crankcase

Matt, do you have a copy of the Bosch Automotive Handbook handy? It has a TON of good info on the history of diesel engines and combustion chamber designs, fuel pump setups, injectors, etc.

[Wally]

Re: Gotta love engine compresion in the crankcase

When I started driving for the bus company we still had a few two stroke Detriots left. Being new and working late at night I almost always got one. The sound great echoing off apartment buildings when everythingf else is quiet.

[BillBallinger Sr]

Re: Gotta love engine compresion in the crankcase

Most that I am familiar with have a flat deck, but I suppose that there could be one somewhere that doesn't. The DT466 that I messed with for a couple of years (we were trying to get it to run on pure (neat) methanol) was a flat deck with 4 valves/cylinder, as is the ISB. I think that's pretty standard for Diesels.

I don't remember the configuration for the 2 strokers, as it's been MANY YEARS since I've messed with one. Bill can chime in here. But they run exhaust valves with intake ports that are exposed when the piston slides down a way. That's why the HAVE to be blown - they have to have the air forced in (which forces the exhaust out) or they don't have enough O2 to light the mixture when the fuel is squirted in. Bill - did I remember this correctly?

Dan

Dan, I'd been wondering why the top of the piston looked that way. Thanks for clearing that up. Do these diesels have the valves just sitting on a flat section of cylinder head?

The main principle of 2-stroke diesel is that pressurized air is all that is dispensed into the cylinder and pushes the burned exhaust out through the valves. In a Detroit you have air ports under positive displacement (supercharged) that are uncovered by the piston on the downstroke. The valves open (all of them are exhaust and most were 4 valve per cylinder) and the piston and pressurized air clear the cylinder very quickly. The valves close, pressure builds and right at TDC the injector hits pushing the piston down for power. Emissions wise they are cleaner than a two stroke gas engine because the mixture is timed so tightly and the fuel is pretty much completely consumed. Here is an article that might make it clearer, and they do have to have a supercharger to run. The air ports in the diagram go all the way around the perimeter of the cylinder, there is an air chamber in the block that the blower feeds. Keep in mind it is air only, no fuel or oil, the lubrication is crankcase just like a 4-stroke motor

http://auto.howstuffworks.com/diesel-two-stroke1.htm

[Screaming Detroit]

Re: Gotta love engine compresion in the crankcase

The DT-466 is probably the gold standard light to medium duty engine out there. That said a DI Powerstroke had very few flaws, really o-rings for the injectors were about the only major maintenance item that determined life or death. If they started passing oil, death was on its way from excessive pressures in the cylinders. The IDI motors were about as low maintenance as you can get for a diesel, less mileage and power, but man those things lived forever. Scott's comment on the Cummins is a good one, back when I spun wrenches I could service the injectors bleed and time the pump while you are still getting the valvetrain off a 7.3.

GMs smartest move was ditching the 6.5 and going to the Isuzu. Good architecture for its application and people are putting unholy amounts of boost to them. I am still a 2-stroke Detroit diesel fan even though they are really obsolete and dirty. A turbocharged 3-71 in a 3/4 ton 4X4 pickup comes to mind as pretty sweet. ;D

A 371 turbo is sweet a little low on power for that app.

If you had to choose would you go for a 4-71T or a 6V-53T? Weight wise I would think the 6V would be better because you can set them back more, lower down . My truck has the mid mount bell and an NP-435 with a divorced case and a front mount plate on the engine. Plenty of room for either. If I pull the FE out I am going to a diesel, and a 2-stroke Detroit has always been my favorite. I'm like Dan, firetrucks hell yeah, they do sound good!

I would defently go for the 6v53 or the 6v 71 I'd have to find it, a guy put one in a 79 f350 on youtube it fit in good and seemed to work ok then you would have decent power for cruising, and sound awesome

[1FastMopar]

Re: Gotta love engine compresion in the crankcase

I know little of the various diesels out there, but since someone mentioned the 6.5L GM... ;D


I am rebuilding a 6.5L for my 99' Suburban, I have done some things to have it live. One problem they had was the main support is weak, well, I fixed that as good as I could, went to ARP 12mm studs for the inboards, also machined and installed 1/2" studs to the outboard, they had little 100mm bolts, so that should tighten things up a bit. ;) I picked up a set of brand new castings and will be porting them a bit, so we will see how things work out.. I also have a brand new GM crank, as they are cast and a little weak and didn't want to use the one I had that was beat up a bit and reground.. I NEED to speak with someone knowledgeable on the 6.5 to get some pointers. Anyone out there that can help me along with this one would be nice.. Maybe a phone call. ;D

I am gonna run the thing on straight used veggie oil.

[BillBallinger Sr]

Re: Gotta love engine compresion in the crankcase

I know little of the various diesels out there, but since someone mentioned the 6.5L GM... ;D


I am rebuilding a 6.5L for my 99' Suburban, I have done some things to have it live. One problem they had was the main support is weak, well, I fixed that as good as I could, went to ARP 12mm studs for the inboards, also machined and installed 1/2" studs to the outboard, they had little 100mm bolts, so that should tighten things up a bit. ;) I picked up a set of brand new castings and will be porting them a bit, so we will see how things work out.. I also have a brand new GM crank, as they are cast and a little weak and didn't want to use the one I had that was beat up a bit and reground.. I NEED to speak with someone knowledgeable on the 6.5 to get some pointers. Anyone out there that can help me along with this one would be nice.. Maybe a phone call. ;D

I am gonna run the thing on straight used veggie oil.

The passenger side head gets really hot from the turbo, so go easy on the porting and check it for discoloring or cracks in a few thousand miles. The valve springs weaken too, practically turn to jelly. Some aftermarket stuff would help on the valvetrain along with watching those springs. Gale Banks has some things that will help. I have not been a big fan of this engine, but as with anything you can get good service out of them with the right upgrades. A pyrometer gauge is very important, when you see it get out of the normal range it runs in, you have a problem that needs to be addressed ASAP.