I need some input from Detroit experts. A customer brought me a 471 Detroit today, it came off a water pump from the local water works and only has 138 hours on it, I assume it is from the 70's. I purchased a jensales manual that is a exact copy of the Detroit service manual. The question is we need to reverse the direction according to the Detroit book it is now in the RB configuration. I need to get it to the LB configuration the book explains the timing and I know I need to move the idler gear to the other side and will have to change the plumbing on the oil pump (IE switch the pick up and pressure to opposite sides of the oil pump) But the book does not cover how to change directions and what parts you need. Will I need a different cam? will the fuel pump work? do I need to put the blower on the other side of the engine? Any help would be greatly appreciated
Its been a long time ago but i am pretty sure the blower is on the other side. The place i worked had both siting side by side and they had alot of things diffrent. It had me thinking that it was a big job to change around.
I have been told that some oil rigs had two inline 6-71's (238) side by side. They ran opposite directions. Blowers were on opposite sides as well. My guess is this is going to be an expensive problem.
I have built a couple of detroits but I am not an expert, but I believe it is simply how they are assembled . You will have to have left hand fuel pump also. I have heard tale of them being build backwards by accident.
The blower can be on either side with either rotation. There's no such thing as a left hand fuel pump since it is just a lift pump, injection pressure and timing is created in the injector on a -71. I don't think there is a difference in cams either. They will start and run backwards, blowing smoke out the air filter, but without reversed oil plumbing they won't do it long. A mechanical L10 Cummins with the PT pump will run backwards, too.
I believe you will find there is a different cam for the right hand rotation from the left. And also I think you will need to change the idler and crankshaft gears. If you have the cam out of the engine there should be a number stamped in it Left hand engine cam is marked #5102666 right hand cam is #5102663 The RB engine should have a 5113817 idler gear, the LB would have a 5113818 idler gear. The RB engine would have a 5113814 crank gear, the LB would have a 5113815 crank gear. Once the correct gears and cam are installed the blower and fuel pump and governor can stay right where they are, blower runs off the cam and no matter the rotation of the crank the cams still turn in the same direction for both crankshaft rotations, that's why the idler has to move. Note gears should be the same for 3-71 through 6-71 so if you can find a donor from any one of them you would only need to find the proper cam. Note: number stamped on cam is not the same as the part number, if you need the part number let me know. EDIT: I think you also must know that the starter will have to be changed as well. As cam turns the same direction on either engine the generator if it has one will not need to change,alternators don't care about rotation.
Thank you Kshansen that is the kind of info I was looking for, I have both starters, I will check the numbers on the cam and crank on Monday. Not that it makes any difference I was wrong about the current configuration of the engine it is set up as RC now and needs to be LC ( exhaust on left side blower on right side)
Picture Here is the Pic out of the service manual
Better picture I circled the config I have and the one under it is what it needs to be
When ordering fuel pumps in the past i had to specify right had or left rotation. I also looked it up and right hand and left hand pumps are listed.
What about the water pump?
water pump is driven off the blower so it does not need changed, because the blower does not change directions
Okay, thanks. I was remembering belt driven, must have been an old CAT I was dreaming about or something, lol.
You may be thinking about a 53 series, they had a belt drive water pump.
If he is changing from RC to LC configuration the only thing that will be changing rotation direction will be the crank so even though there are right and left hand fuel pumps that should not be an issue for this engine. As I said the thing that has me concerned is the oil pump and lines. Is there an original engine that this new one is replacing? That would make it a very simple project. Just pull the cam and idler gear and oil pump and pipes off the old engine. Head will have to come off to remove the cam.
Unfortunately this motor is not replacing another one. The whole thing is really pretty silly in my mind. My customer bought this motor for less than scrap price and has bought a Allison transmission and has plans of putting it in a 3/4 ton dodge pickup. I know it is to heavy but not to worry I was hired to reverse the engine not install it.
Just flip the rear axle and call it good enough
I already thought about that but the Allison automatic won't like turning the opposite direction. If it were a manual I think I could convince him.
Check out 4bt swaps fourm. Ther is a section on detroits that has every thing you wanted to know about puting a screaming jimmy in a pick up. I have a 453t that is on my list of projects.
Did some research. This engine is reversible with nothing more than a gasket kit and starter. You have to swap the cam and balance shaft but not the gears they remain in their position, the idler gear has to be moved. The oil pump can be assembled to work either direction as well. All other acces can be mounted either way. There should be timing marks already on the gear for left or right hand rotation. Go to whaleboat.us , this is where I found the Detroit Manuel that I got this info from. I think this is what you are looking for as it explains how to set the engine up for the desired rotation.
Any better info on where to see this info at that site, I tried searching with no luck.
Select library on home page then select detroit diesel maintainance manual .
Not to muddy up this topic but are we sure we are going at this the right way? Is the engine as it sets right now in the RC configuration? Unless I'm way off kilter that would be the correct rotation for a Allison transmission. Looking at the flywheel it would be going counter clockwise so looking at the front of the Allison it would be turning clockwise, just like the crank pulley on the front of the RC configured engine when looking at it from the front. Refer to Post #9 for picture showing RC Rotation.
Keep us updated on this build!
I hope I didn't upset the original poster with my last comment.
I don't think so. But maybe...if he is very sensitive.
Sorry guys been busy all week with C7 cat and tile plow final drive haven't spent much time on the Detroit, I did some more looking and I think that Kshansen is correct it is in the R configuration and that is the direction it needs to turn, I called the owner and he said he thought all stationary engines turned the wrong direction then he said the fan blows forward so he thought it was turring the wrong way, He brought me the tranny and I need to adapt the flywheel flexplate and torque converter to mount up. I will get it running this week and connect the tranny then start it and check thet the output shaft turns the correct way but I am 100% sure that it does not need reversed, just a different fan. Thanks for all the input there is a welth of knowledge here.
I just happened to take a second look at the service manual and had to check back through the posts to see what you had and what you were told needed doing. Yes some stationary fave fans that push through radiator and some that pull you may even find some with fans that have reversible blades, I know many old Cat machines could come that way. Blow out in hot weather and in the cold reverse them to suck heat back in to keep things warm. I would believe most stationary engines would be "standard rotation" most common use for the "left hand" engines is in boats where they like to have them in pairs turning opposite so the torque of one engine counteracts the other. Way OT but wonder if they do the same with multi-engine air planes?
That's affirmative Kshansen. Props turn opposite. Tandem helos too...
Marine contractor I worked for many years ago had a big water pump that was powered by a pair of 6-71s running thru clutches and hard coupled into a common gearbox. They sat side by side on the skid and one turned left and one turned right. I loved to hear them snort under load. One always started hard so we would start the good one and then crank the other one thru the clutches to spin it faster.
did one a couple years ago on a grader what i can remember , swap bellancer and cam shaft and bell housing cause starter has to be on opposite side to make engine turn opposite direction .