View Full Version : Toro 580D engine swap?

05-11-2007, 11:08 AM
I was hoping to get some insight from some of the mechanics out there.
I have a '97 Toro 580D that, long story short, the engine block is scrap metal. It dropped a valve into the cylinder, which went right through the side and snapped off the connecting rod, etc, etc. I now have 135 acres of grass growing by the minute, so I need to get this mower up and going fast and possibly at a human price.

This was the last year that they used the Mitsubishi S4F engine. I can't find a rebuilt one or even a new one, I don't think they make it anymore. A new short block from Toro (crooks) is $9800.00. I can get ahold of an old one that would need a complete overhaul, this is a possibility.

'98+ 580Ds use the Mitsu S4S/DT engine. I can get one of these NEW for about $4500.00. I could swallow this if it meant making the machine reliable everyday. My big question is does anyone know what all is involved in swapping to the new style engine. So far I know it uses different engine mounts and you have to do a little wiring, thats no big deal. But will the flywheel that connects to the hydro pump bolt from the old to the new engine, etc.

I've also talked with and read about people swapping in a Cummins B Series into these mowers. I can get ahold of multiple cummins really cheap. However I'm pretty sure this involves custom machining adapter plates and other parts. Nothing available off the shelf? Not a quick process and by the time you custom make parts you could quickly offset the cheap engine price.
My goal is to have this up and running in about a week.
Thanks in advance for any help and sorry to be so long winded, I just wanted to put all the info out there.


05-11-2007, 12:40 PM
It sounds like you said the valve went through the side? Did you mean the rod? Maybe the cylinder can be sleeved? If your rod went through the crank case it possibly could be welded. There is a welding shop here that welds blocks and heads everyday.

05-11-2007, 01:02 PM
You're right, the valve didn't actually go through the cylinder. The valve broke off and fused to the top of the piston, which beat up the head. The two large holes in the cylinder wall were just part of the carnage. Also a piece of metal wedged itself between the piston and the cylinder wall which put a really deep gouge out of it. The piston isn't even round anymore. I know i could possibly have it welded and sleeved, but everywhere I've talked to would be a few weeks out to do it. I can't afford the downtime. Plus it would probably end up costing as much as the used block.
I would idealy like to drop the new engine in, I just want to make sure I know exactly what's involved before I drop the $$ on one.
Thanks, that still is a good option if I can find somewhere to do it quickly.
Maybe these pics will tell you more.

05-24-2007, 07:54 PM
Have you talked to Nelson Eberly out in Ohio about engines for a 580? He has put in a cummines engine in one I think, so he might be able to talk you throught it.

05-24-2007, 10:56 PM
May I ask how many hours you have on your machine? Do you know what may have caused it?

I am having similar trouble with a Jacobsen HR9016 that I just bought (used) and mowed with it for 1 hour, at best, and now I'm putting in a NEW Detroit Diesel this weekend. Jacobsen switched to Kubota engines a few years ago and the "swap" kit (includes engine) is $11400! and they say it calls for 32 hrs labor on top at $90/hr!! So, I stuck with the Detroit and will do the swap myself.

I also have a 580D with the older Mitsu engine and hope that I get many more hours out of it before having anything close to what you have going on.

Isn't it sad that a motor is about the same price as a used (complete) machine?

05-24-2007, 11:21 PM
they say it calls for 32 hrs labor

What were they going to do give it to a one armed three fingered guy to work on ? :dizzy:

05-24-2007, 11:25 PM
Yeah, I couldn't figure out that many hours either. I think it was the conversion kit to go from Detroit to Kubota and there may have been some fabricating, rewiring, etc. But still, 4 days...that seems crazy (along with the price). I found the Kubota motor for $4200 but they wouldn't break it out of the "conversion" kit...$11400 or nothing...go figure. I'm sure if I tried to buy the individual parts without the motor, I would have been back up to the 11400...:rolleyes:

05-24-2007, 11:37 PM
I still think you should take it to a machine shop to see if they can sleeve that cylinder. There's nothing to loose...

05-25-2007, 11:05 AM
Hey there, I just noticed all the replies, I didn't get notified in my email so I thought no one had answered.

Crawford - I bought the machine from Nelson. He was one of the first people I talked to. He says his son has done the cummins swap but he knows nothing about it other than it took a long time and he had to have custom parts machined. He did have a few used blocks that I could rebuild.

desii - Macine has about 4100 hours.

khouse - I've talked to machine shops about sleeving it and rebuilding it. Even tri-states in Iowa that specializes in toro macines. Everywhere would take about 4 weeks and cost around $4500.

After doing a lot of research and talking with a few service managers at Toro dealers we determined what parts were required to convert it to the newer s4s-dt engine. So I drove down to Richmond, Virginia last Friday to pick one up for $4300, brand new, complete fan to flywheel. I know thats crazy but everywhere locally would take two weeks to get it here and were about $500 more plus shipping. I ordered all the conversion parts from Toro and I'm putting it in this weekend.

05-25-2007, 11:13 AM
I also need an opinion. The new fan and elaborate pulleyand bracket system I got from Toro cost about $1200. I figured I could put on two high performance electric fans for about $250. A pusher on one side and a puller on the other. This would save me almost a grand and actually be easier to install.
Question is, do you think two electrics would move enough air. 16" ones are rated at about 2000 cfm each. I'm not sure how much cfm the stock mechanical fan moves. I can't find that info anywhere.

Any opinions?

05-25-2007, 11:18 AM
You bet electric would work. I would use them as a pusher OR puller but not both.

05-25-2007, 12:37 PM
Why not both?

desii - we haven't determined what exactly caused the valve to break in the first place. Also if you happen to need any parts for the older engine on your machine let me know. I'm probably just going to part it out since the new one is complete and most of the parts aren't interchangeable. Still has a good turbo, manifolds, injection pump, fuel solinoid, water pump, etc. Stuff thats super expensive new.

05-25-2007, 01:12 PM
I installed a 16" puller (Mounted to the inside) on my small block Chevy truck and it cools just fine, I see no reason why one wouldn't work on a mower. It may be even better than the stock fan.

05-29-2009, 04:09 PM
how did that sts-dt conversion go ? any big problems

04-08-2013, 12:44 PM
do you have the head off the old motor you switched out still?

piston slapper
04-08-2013, 07:49 PM
This thread is only 6 years old....
Think I saw the part you were looking for on RestroRobs bench...
Check the Messy Bench thread....

04-17-2013, 12:01 AM
If your looking for the head off of the Detroit Diesel, I think I still have it (complete engine possibly). I'll have to check, I think I switched out the 580 Mitsu too, so I'm not sure which engine is here. Let me know which one your looking for and I'll take a look in the next day or so to see what I have.

04-17-2013, 11:37 AM
I am looking for the Mitsubishi head, older engine model 1996.

04-25-2013, 10:53 PM
looking for 1997 toro 580d parts

04-28-2013, 09:10 PM
I am looking for the Mitsubishi head, older engine model 1996.

I do have the head from the Mitsubishi engine. Actually it's still on the engine. However,as you can see from the attached pic, the valve cover has a pretty size able hole in it. Let me know if you need anything else, i.e. model or serial number.

04-28-2013, 09:50 PM
I do have some parts available. 3 or 4 of the skid plates, a few filters, a bearing and spacer kit and some deck belts.

Filters are (1 each) (first two still in shrink wrap) #69-1720; 108-3835; 108-3818;

Bearing and spacer kit 71-2530;

Belts: 93-8457 (Stens 265-900); I think these were for the 580 also - Hi-power C105 and (2) Hi-power B100's.

I hope it's ok to post these here.