How would one make a diesel rocket?

[Rocket Scientist]

I remember back in the 70's (well barely) With the Arab oil embargo and the price of gas, General Motors sleeved down some gas engines and made them into diesels. They had a lot of problems with them. I don't even think they were all bad, but I can remember you could hardly give them away.

 

[BigNorm]

That there is a Texas Bike without a doubt.

 

[geneseo1911]

Just the inverse, I'd be shocked if it couldn't withstand it. It's already been proven over 500hp/400lbft or something absurd like that.

It would be a good ideas to destroke or resleeve it for a little smaller displacement though, as insurance.

I'm no expert, but I believe diesel cylinder pressures run about double gas engine pressures. Now the extreme high performance turbocharged Rocket engines in the land speed bike (which do run around 500HP) probably approach diesel pressure levels, but I don't think they'd last very long in Norm's fantasy cruiser. And I'm guessing those engines run better cranks, rods, and pistons than stock.

I bet it could be made to run, but unless it was tuned to be VERY weak, it wouldn't last very long.

 

[BigNorm]

I remember back in the 70's (well barely) With the Arab oil embargo and the price of gas, General Motors sleeved down some gas engines and made them into diesels. They had a lot of problems with them. I don't even think they were all bad, but I can remember you could hardly give them away.

Ahhh so we add a little more material to the cylinder walls for insurance. The draw back is some lost displacement. I wonder how much it would cost to produce a cast iron head. I was thinking that the heads could be machined to put two injectors per cylinder instead of spark plugs. Can injectors handle that kind of heat or should they be installed in the stock location in the plenums? There would be no use for secondaries anymore. Either way I was thinking with two injectors per cylinder a cummins injector pump could probably be made to work and have each injector fire every other cycle. There are a lot more 6 cylinder cummins than there is 3 cylinder turbo diesels. I wonder what gets the injector pump to fire? Or if I went with a 4 cylinder injector pump could it be timed to only work on the first three?

 

[breeze]

I remember back in the 70's (well barely) With the Arab oil embargo and the price of gas, General Motors sleeved down some gas engines and made them into diesels. They had a lot of problems with them. I don't even think they were all bad, but I can remember you could hardly give them away.

if I remember right those were the 5.7 motors you are right they were bad had to get going 90 downhill to make it up the next hill

 

[BigNorm]

I'm no expert, but I believe diesel cylinder pressures run about double gas engine pressures. Now the extreme high performance turbocharged Rocket engines in the land speed bike (which do run around 500HP) probably approach diesel pressure levels, but I don't think they'd last very long in Norm's fantasy cruiser. And I'm guessing those engines run better cranks, rods, and pistons than stock.

I bet it could be made to run, but unless it was tuned to be VERY weak, it wouldn't last very long.

So once again it looks like Rods may be the weak link. Rods can be made stronger. I wonder what the journal sizes and rod lengths are on the Volkswagen TDI motors? Mercedes? Ect.

 

[BigNorm]

if I remember right those were the 5.7 motors you are right they were bad had to get going 90 downhill to make it up the next hill

I remember those being put in Humvees when I was in the army. Turbos change everything.

 

[Fingers]

They were Oldsmobile engines.

 

[rocketjohn]

The GM diesels that were thought to be sleeved gas engines were in fact diesel engines from the get go. They had a superficial resemblance to the Oldsmobile V8, because they used similar bore centers...and it was Olds engineers working on the design. But the block was very much heavier and looks were the only major similarity. The dependability problems were legend, but like everything made at the time, sometimes you'd get a good one, and if taken care of it would soldier on. The rest, were just not quite ready for prime time. They did get exceptional fuel economy though. A four door Cutlass body about seventeen feet long, and weighing near 5000 pounds might get 25 mpg with that diesel. If the engine stayed together it might get 150,000 miles. Not bad for a time when gas engines were often done for at 100,000.

Another problem that plagued these engines that wasn't Oldsmobile's fault, was that at the time, a lot of diesel fuel had water in it, and the Olds engine could not deal with it well at all.

 

[BigNorm]

The GM diesels that were thought to be sleeved gas engines were in fact diesel engines from the get go. They had a superficial resemblance to the Oldsmobile V8, because they used similar bore centers...and it was Olds engineers working on the design. But the block was very much heavier and looks were the only major similarity. The dependability problems were legend, but like everything made at the time, sometimes you'd get a good one, and if taken care of it would soldier on. The rest, were just not quite ready for prime time. They did get exceptional fuel economy though. A four door Cutlass body about seventeen feet long, and weighing near 5000 pounds might get 25 mpg with that diesel. If the engine stayed together it might get 150,000 miles. Not bad for a time when gas engines were often done for at 100,000.

Another problem that plagued these engines that wasn't Oldsmobile's fault, was that at the time, a lot of diesel fuel had water in it, and the Olds engine could not deal with it well at all.

Yeah. Water don't compress too well.