Changing existing O&K RH6 LC excavator engine

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BlackCat3
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Changing existing O&K RH6 LC excavator engine

Post #1 by BlackCat3 » Mon Sep 29, 2014 9:37 am

I recently purchased a rather old O&K RH6 LC excavator as a restoration project. Serial Number 80364. It has a Deutz F4L912 fitted to it at the moment which is a bit tired. I would like to know if it is possible to install a F5L912, can anyone advise me on this?


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Re: Changing existing O&K RH6 LC excavator engine

Post #2 by Jeremy Rowland » Mon Sep 29, 2014 10:50 am

BlackCat3 wrote:I recently purchased a rather old O&K RH6 LC excavator as a restoration project. Serial Number 80364. It has a Deutz F4L912 fitted to it at the moment which is a bit tired. I would like to know if it is possible to install a F5L912, can anyone advise me on this?


Hi Joe; the first question you need to ask yourself is there the physical room for an engine with an extra cylinder? Also will the engine mountings marry up okay? Does the five pot lump run at higher revs than the four cylinder engine, would it put too much strain on the hydraulic pumps? Just a few questions that I would be asking if I was considering such a job.

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Re: Changing existing O&K RH6 LC excavator engine

Post #3 by BlackCat3 » Mon Sep 29, 2014 2:27 pm

Hi Jeremy,
Having looked over the RH6 LC operations and parts manuals recently posted in CMN, I find that there are several engines are fitted, including F4L912, F5L912 and F6L912. Most of the later models are fitted with F6L912 engines, therefore one would think it possible to fit F5L912.
One odd thing, is that my present engine shows it to be a 68 hp version of the F4L912 which in many cases show this engine to be 63 hp. I will check my machine's engine mounting's to make sure that it would be possible to install a F5L912 engine.
I take it, as the crankshaft speed being the same and is direct drive to the pumps without any gearbox then, it basically should not effect the hydraulic pumps, as main relief valve are set correctly then there should be no adverse pressure or extra load on the pumps.
I would be grateful if you could let me know your thoughts on this.


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Re: Changing existing O&K RH6 LC excavator engine

Post #4 by Jeremy Rowland » Mon Sep 29, 2014 8:36 pm

Joe you seem more knowledgeable than me on the subject; yes it should not affect the pumps or the output just check the engines power output, direction of rotation, maximum revs etc. If O&K fit all of those different engines into the same machine there should not really be any issues as such, I can't say that I understand why they fitted 3 different engines surely the power output must be virtually the same or thereabouts for all of them, perhaps the torque output of the engines made a difference?

Jeremy


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Re: Changing existing O&K RH6 LC excavator engine

Post #5 by tctractors » Mon Sep 29, 2014 9:30 pm

The R.H 6 excavators I used to work on I thought had 6 pot engines, anyhow I have seen R.H.4's with 3 and 4 pot engines, back to the question asked, the split drive gearbox is in the tank driven via a small prop shaft to the flywheel (No 1 cylinder end) the rear engine mounting would not need to be changed only the front mountings would need possibly swaping around on the plate and possibly spaced some, the engine speed is the same usualy on construction spec with this engine family, the pumps are controlled to max swash by a bolt in the hydraulic tank, so other than things hanging out of the door I cannot see any troubles, thats the door with the air cleaner in.
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Re: Changing existing O&K RH6 LC excavator engine

Post #6 by BlackCat3 » Tue Sep 30, 2014 9:08 am

Gentlemen,
Thanks you for your speedy reply and very useful information. I will make more checks on sizes relating to the overall engine compartment and engine mounting positions. I think I've found an area were it might be a problem and not be possible the any other engine, this being the centre axis position. They appear to be different on both engines.


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Re: Changing existing O&K RH6 LC excavator engine

Post #7 by tctractors » Tue Sep 30, 2014 9:18 pm

Centre axis??? explain.
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Re: Changing existing O&K RH6 LC excavator engine

Post #8 by BlackCat3 » Wed Oct 01, 2014 9:53 am

Hi Tony,
This is the position relating to the center line of the crankshaft / flywheel to the centre of the driveshaft in this case. Depending on the position of the engine mountings and sump clearance it can have an adverse effect on the overall centre line off the drive shaft. However I was on the machine yesterday and have cleared this problem by taking accurate measurement and photos. One set of engine mountings will have to be moved to accommodate a F5L912 engine.
After some research I believe my machine was built around 1974/5. I hope to post some photos of the machine later.


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Re: Changing existing O&K RH6 LC excavator engine

Post #9 by BlackCat3 » Tue Oct 21, 2014 8:13 pm

Having managed to obtain a new engine for my O&K RH6 LC. I find that I'm in need of some good running gear parts for the tracks. Does anyone know if there is suitable O&K parts suppliers or breakers in UK.
One more question, I have a rough idea when the my machine was manufactured. I would however like a more accurate date, my machine serial number is 80364. If anyone knows were I can find some support to authenticate that date of manufacture I would be very grateful.


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