6v53 vs 8v71

[FordTruckGuy96]

I am looking at getting a different motor for my truck. It is a 1947 that has a flathead v8 in it. I want to replace it with an old two stroke Detroit Diesel. So far I have found an 8v71 and a 6v53. I know both motors are getting up there in years. I was wondering if anyone could tell me good or bad about either of the motors. Also the motors are going in a 2 1/2 ton truck that is getting outfitted with 5 ton rockwells. I don't want to choose the 6v53 only to find out that it under powered for the job, or pick the 8v71 and find out it has problems without end.

 

[155mm]

Both are good motors, same design. The 6-53 was the go to motor in the 60's when the diesels were taking over the over the road market. They are both loud because they are 2 strokes. They will use oil and leak it, slobber it but thats just a 2 stroke. If those are the only 2 choices, just picking the lesser of two evils,i would use the 6-53, reasoning is smaller motor, lighter weight, maybe a wee bit better fuel economy.

 

[155mm]

Oh the over the road trucks didnt call it a 6-53, they called it a 318, or 8-71 was 568. That is the displacement. 6 cylinders 53 cubic inches per cylinder

 

[Gunzy]

I can point you to an 8V92 with 10K on it if you want to go bigger. You may be able to get it for $2500 and it is complete. Former M977 HEMTT power plant. They have the axles, trans and t-case too.

 

[snowtrac nome]

horse power wise the 6v53 is about the same as a commercial cummins 6 b they aren't horse power or torque kings and as stated noisy both tend to live a pretty long life. just have a good tune up done like adjusting the overhead, new injectors and a governor adjustment and it will start quick and run good for you. if I had the room I would opt for the 71 series seems to be a lot more of them out there to scrounge parts off of unless you have il surplus around you seems uncle sam liked the 53

 

[pjwest03]

Weight will be a big factor. 6v53N @ 1485 lbs and 8v71N @ 2306lbs.

6v53 were in all manner of firetrucks, "city" tractors, and boats. No shortage of them around. 8v71N were actually the ones the truckers called 318's. The original naturally aspirated spec was 318 horsepower.

 

[snowtrac nome]

that's good in civilization there are still plenty of 53's. the na 71 seems to be king here they are in loader,s boats, belly scrapers, and haul trucks, along with tractor trailer units. last time I went looking for a 53 blower drive or manifold for a 6v 53 it had to be imported from the lower 48. as a side note the spline on a 671 blower drive is the same as the pre cups on 3306 cat engines a great farm trick to make the tool to remove the pre cups is to cut up a 671 blower drive and weld a big nut to it.

 

[FordTruckGuy96]

At this point it looks like I will be going with the 6v53. The owner shows me that it runs and drives, and is willing to sell me the entire tractor with the motor in it. So I will be able to part the tractor out to lower the cost. The guy who owns the 8v71 told me hes been robbing parts off of it and that the trans doesn't shift gears anymore. The other benefit to the 6v53 is that the owner just had it refurbished and a reman trans put in.

 

[alpine44]

At this point it looks like I will be going with the 6v53. The owner shows me that it runs and drives, and is willing to sell me the entire tractor with the motor in it. So I will be able to part the tractor out to lower the cost. The guy who owns the 8v71 told me hes been robbing parts off of it and that the trans doesn't shift gears anymore. The other benefit to the 6v53 is that the owner just had it refurbished and a reman trans put in.

As an alternative, I have a 6V53 for sale that was built to deliver 400hp with twin turbos and inter-cooler. I built it from the block up with the correct OEM components ([FONT=&quot]cross head-pistons, bypass blower, etc.)[/FONT] for a lobster boat that got destroyed in a storm before I could drop the engine in. If you run it with a single turbo you have essentially the 350hp configuration that was used as a tank engine.

I can deliver to Detroit as I have to head West in a couple of weeks. Please PM if interested.

 

[JDToumanian]

Another advantage of the 6v53 is the higher RPM, usually 2,800-3,000 compared to 2,100 for the 8v71.

Jon

 

[Fredo Corleone]

When you get the motor installed in your truck remember to slam the door on your hand before you drive it

 

[Tracer]

Horsepower for 6V53, 216 normally aspirated, & 320 turbo charged. For 8V71, 318 normally aspirated, & 385 turbo charged. Source Detroit Diesel.