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I would like some photos of the link for the crankshafts.
A good explanation etc. Does the rear engine have an upgraded crankshaft to take the extra torque?
Thanks ahead of time.
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Question for Catserveng
- Thread starter dicer
- Start date
MiketheEngineer
Structural
Which is the rear one??? and which drives which. Good God - that is one heck of an engine. I count 24 cylinders. I do know some WWII engines had 18 but all on the same crank.
And I think Craig Breedlove put four V-8's together to try some land speed record. I understand it was a nightmare.
Call CAT and ask them
And I think Craig Breedlove put four V-8's together to try some land speed record. I understand it was a nightmare.
Call CAT and ask them
MikeHalloran
Mechanical
Mickey Thompson's Challenger I had four NA Pontiacs, coupled crank to crank and ring gear to ring gear.
Craig Breedlove mostly used jet engines.
Mike Halloran
Pembroke Pines, FL, USA
Craig Breedlove mostly used jet engines.
Mike Halloran
Pembroke Pines, FL, USA
catserveng
Electrical
The 3524HD is two 3512HD (High Displacement) engines coupled with a torsional coupling. It is a specific application for the 797 mining truck, it is not offered for any other use.
As far as I know (I'm not from the dirt side of the business)the front and rear engines are the same. The torque was limited by the electroninc controls to prevent failure, although some did occur early on, and pretty spectacular from what I've been told. The truck pulls a 6% grade with a full bowl at about 22MPH.
The C175 is the current replacement (a 16 cylinder C175 replaced the 3524HD), and is slated to replace the entire 3500 series family eventually in all applications.
I'll see if I can get some pictures or cutaways, I don't work for a dealer anymore and only do limited contract work on the oil and gas and power side, so I don't have all the access I used to.
We also did G3516 tandem units, there are four running on landfill gas here in San Diego for about 11 years.
Mike L.
As far as I know (I'm not from the dirt side of the business)the front and rear engines are the same. The torque was limited by the electroninc controls to prevent failure, although some did occur early on, and pretty spectacular from what I've been told. The truck pulls a 6% grade with a full bowl at about 22MPH.
The C175 is the current replacement (a 16 cylinder C175 replaced the 3524HD), and is slated to replace the entire 3500 series family eventually in all applications.
I'll see if I can get some pictures or cutaways, I don't work for a dealer anymore and only do limited contract work on the oil and gas and power side, so I don't have all the access I used to.
We also did G3516 tandem units, there are four running on landfill gas here in San Diego for about 11 years.
Mike L.
MikeHalloran
Mechanical
I worked on one boat that had a pair of Detroit Diesel V16 (2xV8) engines. One engine acted like it was losing exhaust valves, which had the owner considerably miffed because both had just had a valve job, at considerable expense. They were 'mechanical' engines, and nobody could figure out which cylinders were misbehaving. ... and nobody wanted to front the cost of doing an exploratory teardown. (My then employer had made the exhaust system, and fingers were pointed at us because the pipes wobbled whenever the engine misfired. Cause and effect confused; duh.)
I worked on another boat that had had a pair of DD V24 (2xV12) engines, which had been removed under warranty and replaced with something simpler because they were troublesome. Nobody mentioned trouble with the inter-crank couplings, but apparently everything _else_ broke pretty regularly. (The newer engines should have received smaller mufflers, but the original monsters were left in place to save a little money. The mufflers shook the entire boat because the engines couldn't always blow the water out of the lift tubes. That was the only boat out of 450+ I worked on that had an exhaust component that was too big.)
I remember seeing such 'doubles', even 2xV6, in Detroit Diesel literature when I was a kid, but in real life, they are not common.
On the few engines I've had occasion to check, the usual 'crank nose' drives the accessory belts and the damper with a press fit and a single key, and couldn't be expected to carry the torque of another entire engine, so torque limiting and/or special 'rear' cranks would be required. Add to that the difficulty of servicing the camshaft or its drive on the 'rear' engine, and you wouldn't buy one either.
Mike Halloran
Pembroke Pines, FL, USA
I worked on another boat that had had a pair of DD V24 (2xV12) engines, which had been removed under warranty and replaced with something simpler because they were troublesome. Nobody mentioned trouble with the inter-crank couplings, but apparently everything _else_ broke pretty regularly. (The newer engines should have received smaller mufflers, but the original monsters were left in place to save a little money. The mufflers shook the entire boat because the engines couldn't always blow the water out of the lift tubes. That was the only boat out of 450+ I worked on that had an exhaust component that was too big.)
I remember seeing such 'doubles', even 2xV6, in Detroit Diesel literature when I was a kid, but in real life, they are not common.
On the few engines I've had occasion to check, the usual 'crank nose' drives the accessory belts and the damper with a press fit and a single key, and couldn't be expected to carry the torque of another entire engine, so torque limiting and/or special 'rear' cranks would be required. Add to that the difficulty of servicing the camshaft or its drive on the 'rear' engine, and you wouldn't buy one either.
Mike Halloran
Pembroke Pines, FL, USA
- Thread starter
- #8
I would really like to see more info on the couplers. Are they Spring? Solid? Rubber isolator?
I like Mike remember the doubles in the detroit literature.
Always wondered what the rear engine crank snout was like. Is it a flange like the flywheel flange?
Where any of these a solid link? Would be similar to a built up crankshaft in large engines.
I like Mike remember the doubles in the detroit literature.
Always wondered what the rear engine crank snout was like. Is it a flange like the flywheel flange?
Where any of these a solid link? Would be similar to a built up crankshaft in large engines.
TheBlacksmith
Mechanical
The Knox Class (FF1052) Navy Frigates had an emergency generator with 48 cylinders, (as I remember it was a GM/Detroit Diesel 71 series), 2 V8's tied together on each end of the generator. If one engine was out of commission, it could be unclutched and the generator run at half its rating.
catserveng
Electrical
The couplings are a rubber hub in a cast steel drive ring bolted to the flywheel, it is similar to the intermediate and generator coupling used in the tandem generators but as I remember a significantly stiffer rubber element.
The crankshafts on a 3500 series engine is flanged at both ends, can be flipped end to end for reverse rotation engines, the engines are rated to be able in most applications to deliver full power from the front with the right front housing adaptor, not common but have been applications like drdge engines with a pump on one end, a generator or gerbox for propusion on the other.
The first couplings were supplied by Vulcan, currently I think they are using APEX (at least on the tandems they are).
My son works on the dirt side as a mechanic, he's going to a class at Tinaja Hills Training Center next month, he'll see if he can get any 3524 info or pictures of the cutaway if it's still there.
Mike L.
The crankshafts on a 3500 series engine is flanged at both ends, can be flipped end to end for reverse rotation engines, the engines are rated to be able in most applications to deliver full power from the front with the right front housing adaptor, not common but have been applications like drdge engines with a pump on one end, a generator or gerbox for propusion on the other.
The first couplings were supplied by Vulcan, currently I think they are using APEX (at least on the tandems they are).
My son works on the dirt side as a mechanic, he's going to a class at Tinaja Hills Training Center next month, he'll see if he can get any 3524 info or pictures of the cutaway if it's still there.
Mike L.
- Thread starter
- #11
catserveng
So I'm guessing the way the couplings are attached is:
There must be at least 3 items.
A steel spider of sorts that attaches to each of the crankshaft flanges, then the rubber absorber that will be put in one, then engine number 2 is slid into postion and the spider engages the rubber??? I figured it would have to be some sort of isolator to
absorb torsional vibrations and shock.
There isn't much information about marrying 2 or more recip engines. The coupling needs to be somewhat forgiving of missalinement too.
So I'm guessing the way the couplings are attached is:
There must be at least 3 items.
A steel spider of sorts that attaches to each of the crankshaft flanges, then the rubber absorber that will be put in one, then engine number 2 is slid into postion and the spider engages the rubber??? I figured it would have to be some sort of isolator to
absorb torsional vibrations and shock.
There isn't much information about marrying 2 or more recip engines. The coupling needs to be somewhat forgiving of missalinement too.
catserveng
Electrical
Here is a link to one of the coupling styles used,
Sorry, I don't know exact model being used.
Our spec for alignment using a laser tool is +/- 0.008" vertical offset and +/- 0.004" horizontal offset, angularity is 1 mil/inch in both axis. The rear engine is clocked 30 degrees behind the front engine, both engines on TDC #1 compression stroke. This info is from our tandem gas engines. On the 3524 there are two close coupled housings, flywheel housing on front engine to front adaptor housing on rear engine. Early on there were tolerence stack up problems that exceeded the couplings ability to compensate for the misalignment, closer attention to the mating faces improved performance and coupling life. Compared to the tandem gas engines the coupling life is short, 8-10k hours on the 3524 compared to 40-50k on the G3516 tandems, of course not nearly the abuse on the gensets the rock trucks see.
Hope that answers the questions, Mike L.
Sorry, I don't know exact model being used.
Our spec for alignment using a laser tool is +/- 0.008" vertical offset and +/- 0.004" horizontal offset, angularity is 1 mil/inch in both axis. The rear engine is clocked 30 degrees behind the front engine, both engines on TDC #1 compression stroke. This info is from our tandem gas engines. On the 3524 there are two close coupled housings, flywheel housing on front engine to front adaptor housing on rear engine. Early on there were tolerence stack up problems that exceeded the couplings ability to compensate for the misalignment, closer attention to the mating faces improved performance and coupling life. Compared to the tandem gas engines the coupling life is short, 8-10k hours on the 3524 compared to 40-50k on the G3516 tandems, of course not nearly the abuse on the gensets the rock trucks see.
Hope that answers the questions, Mike L.
- Thread starter
- #13
It looks like the rubber is all that connects them? Appears to be a rubber disk in shear? Not what I thought it would be. Thanks for the info.
V12, so do they have a 120 degree crankshaft like a 6 cylinder?
I would have thought a 60 degree clocking.
V12, so do they have a 120 degree crankshaft like a 6 cylinder?
I would have thought a 60 degree clocking.
here we have 2 kvr-616 ir integrals which are 2 v12 engines coupled together and every other cylinder removed for compressor throws out the side of the block, they are 5500hp at 330rpm. big as a house but burn a tremendous amount of natural gas, in continuous use since 1964 and still goin. coupling between cranks on these is a 6 roller chain of large demension
- Thread starter
- #15
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