Kubota KH8 engine transplant D600 replacing d850

[Kh8]

Hi all

I'm writing this on my iphone before I get in so apologies for a small explanation.

I bought a kh8 mini digger which has just thrown a Conrod though the bottom of the engine block....

I have an old d600 engine in a jacobsen mower here, I want to know if it is a straightforward transplant to
Put the d600 engine in the kh8 excavator?


I don't like to come to a forum just seeking advice but I have been reading threads on this site for years and
There seems to be some very knowledgable guys on here.


Any advice would be greatly appreciated before I start ripping it apart!


Thank you in advance

 

[Kh8]

Anyone got any ideas?

Thanks again

 

[wmonroe]

I don't really know anything specific about the two engines but if they are close to the same size I sure they could be interchanged with a little fab work. My only concern is it sounds like you are wanting to swap in a lower hp engine, will it have enough grunt for the machine?

Welcome to TBN.

 

[Kh8]

Well I'm hoping no fabrication work as I can't weld, I think the block is the same just a longer stroke and wider bore in the d850, according to tractor data the d600 is rating 14hp at 3500 odd rpm but is only 600cc. The d850 is supposed to be 15hp at 2800rpm..

I'm thinking i may get away with it.

The housing for the d600 looks the same as the housing for the hydraulic pump on the d850, I can't weld although can get it done if necessary.

I'm hoping that as the block is the same size I should be able to change all the bits off the d850 to suit

Thanks for the reply and any advice would be greatly appreciated

 

[PHILIP8N]

So the KH8 D850 engine makes 15hp at 2800rpm. I assume when the KH8 is in operation, it should be run at 2800rpm, as this is where the hydraulic pumps and other engine driven equipment are designed to operate. The D600 makes 14hp at 3500rpm. Big difference in rpm. How much power does the D600 make at 2800rpm? If this install goes well for you, I would operate the D600 at 2800rpm. You will have less power and less hydraulic flow, but if you can live with it, and if everything fits, good for you. Philip.

 

[wmonroe]

Like Philip said, you are not going to want to spin 700 rpm faster than what the machine was designed for. I'd set the governor on the 600 to limit it to 2800-3000 rpm's.

 

[Kh8]

Do you not think the hydraulic pump would be up to the extra rpm?

 

[wmonroe]

It might work but I would find out for sure first.

 

[PHILIP8N]

Do you not think the hydraulic pump would be up to the extra rpm?

If the pump is rated for the higher speed, it will take more horsepower at the higher speed. Philip.

 

[Kh8]

If the pump is rated for the higher speed, it will take more horsepower at the higher speed. Philip.

Hi how would I check the rating?

Oliver

 

[aczlan]

Hi how would I check the rating?
Oliver

Post the make and model numbers off of the pump and we can look for them, or you can look yourself to see what the manufacturer has listed.
You might get lucky and find that the pumps have that info on the tag.

Aaron Z

 

[Kh8]

Fantastic thank you, I'm going to finish getting the lump out of the old mower now. The block looks almost identical so I think it should be a straight swap...

 

[PHILIP8N]

Research. Engine power curves. Pump power curves.

 

[Kh8]

Ok, have got the motor out and trying to get it running on the bench/floor.. I am an amateur mechanic at the best (with a tractor as a winch) and the starter seems to be slipping when spinning upp

 

[Kh8]

Engine is seized almost solid...

 

[wmonroe]

The replacement engine is seized?

 

[Kh8]

Yes seems to be, it's been stood for years..

 

[valkyrie9901]

Old trick is to put water into a seized engine and let it set for a few days. Then put a breaker bar on it and slowly put pressure on it. Should free up......Rust is dried up water.

 

[wmonroe]

Old trick is to put water into a seized engine and let it set for a few days. Then put a breaker bar on it and slowly put pressure on it. Should free up......Rust is dried up water.

I've heard of using auto tranny fluid but not water. Anything is worth a try at this point.

 

[valkyrie9901]

Rust will dissolve and soften the rust and dissolve
where as oils will not....