Oliver 77 gasser - turbo?

Fatjay

Member
I just bought an oliver 77 with 6 cylinder gas engine. I was looking for ways to add power, it is an industrial with loader and backhoe and gets along ok with 37hp, but lacks breakout force. They have low compression at 6.75:1, so when I saw someone offering a bolt on turbo kit that "doubles" your rated HP, I was curious.

Someone else brought them up a while back but I didn't see anyone's experience. This is hte place offering them: http://keystoneturbollc.com/id72.html

It sort of seems to good to be true, your tractor doulbes in power from a simple bolt on. Not looking to go crazy, just help it when it bogs when digging a bit.
 
A turbo can double the horse power quite easy. However, the engine has to be able to withstand double the cylinder pressure (assuming double the HP at the same RPM) and the cooling system must be capable of rejecting more than double the heat. From your post it sounds like you want instant HP as the governor opens. Turbos are driven by exhaust gas and as such tend to have a lag. For example, the governor calls for power and it takes a second or two for the turbo to spool up to increase intake air/fuel flow rate to supply the power. It is a "boot strap effect", as engine power increases the exhaust gases increase spooling up the turbo to further increase power...etc. Some turbos respond much quicker than others - be sure to ask and go into it informed.

BTW - I had a 1979 Mustang with a turbo charged four cylinder. The early engines had a lot of lag time. That engine never failed to impress - after the lag time passed that is. I used to ride the brake with the accelerator to the floor - once I had full boost I would pull out and make the pass.
 
Are you sure more engine power is really going to help you? If you are lacking break out force, that's a function of hydraulic pressure, not power. In hydraulics, force is equal to pressure times area. Your cylinders have a fixed
area so to get more force you need more pressure and that has to do with system leakage and your relief valve setting. Now if you want more hydraulic flow, you'll need a bigger pump and that could require more engine power. Before you
spend any more time on looking for more engine power, I'd put a gauge on your hydraulic system and see what pressure your running.
 
Bogs down as hyd power is lacking?? Where do you get your hyds from?? Problem with adding something to get more power is a gamble at best because if you add to much to the top you can end up blowing the bottom out of an engine. Upping the compression wit ha turbo can well blow out the lower parts of the engine unless you beef them up first
 
Breakout force is related to hydraulic power. For a given setup, more pressure equals more breakout force. Your engine
has enough power to run the original pump to capacity I would think. If you want more engine power, 77's can be rebuilt
with m&w pistons. I have one that dyno'd at 49 hp and has been used a long time like that. I think you would be better off
overhauling your engine than trying to turbocharge it. It is probably worn some anyway.
Josh
 
Thank you for your input. The engine has an oversized hydro pump out the front, but the engine has trouble keeping up.

I want to clean up the engine and make sure it can handle the abuse of forced induction before considering the route, but it looks like the gas engines were so overbuilt and undertuned, there seems like a lot of potential in them especially being so large.

As for lag, I assumed that was if the rpm's are changing. If I stick it at 1800rpm for digging, wouldn't I be making full power, and when it hits a rough spot, keep going? I'm still learning about hydraulics on this scale, but the cylinders seem to be no different in size than a newer machine and should be able to supply the same force, it's just a matter of pressure from the pump.

I've had a difficult time finding information on this machine, so anything would be great. The 77's are easy enough, but not the industrials. It has a ware front and rear loader, I don't know the models off hand though.
 
The oil pump on the 77 engine is not overly sized, I have always wondered how these kits draw their oil and what that does to engine oil pressure.

Rich
 
I was curious about that too. I'm getting a new oil pressure gauge to hook up and see what it says, just for the sake of curiosity. The kit says 10-14psi at all times is required, I don't know what the pressure is on the system though.
 
The old rule of thumb is it takes 1 horse power for each one gallon of oil pumped at 1500 PSI in a hydraulic system I think you need to check your hydraulic system first. Most likely by now your 77 probably has been overhauled once and it probably has Super 77sleeves and pistons which puts it in the 40 horse power class. 40 horse power would handle a larger hydraulic pump and at more pressure than when the loader was new.
 
This is a picture of the pump, it's clearly not from the factory and it's quite sizable. I haven't been able to get any numbers off it though, so I'm not sure what it's output is.

The makeshift grill is pipe bent and welded onto the frame to protect the extruding pump as it comes a good 10" out the front past where the normal grill would have been.

This will be a working restoration, and getting all new tin. I know it's ugly for now, but it does work.
mvphoto18654.jpg
 
I don't think the GPM of that pump is as large as you think it is. Get yourself a 2000 PSI pressure gauge too and measure the length of the stroke of the cylinders and the bore size and we can do some troubleshooting. How fast do you run the engine when you are doing all this?
 
The machine is coming home monday, I'm just going off what I was able to see when I was test driving. The previous owner had a narrow bucket on it so it could dig better, it didn't have enough power to dig effectively with a 2' bucket.

I'm just trying to learn as much as I can about the machine and it's opperation, maybe I should start a seperate thread for that? I have lots of questions about the 77 in general, plus whatever oddities it received due to being industrial, PLUS whatever was done by the previous two owners. It'll be a working restoration project for me around the yard.
 

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