Cat 920 that has been sitting

[kshansen]

numbers:

Yes, I forgot that you had posted that picture!

The part numbers I posted are the correct ones for that 7N1515 according to SIS as of today.

The original ring group was a 7S9404 but back in 1983 they changed the top ring material and the new ring group is the 9S3068 number.

There appear to have been several other versions of the piston part number but the 8N3180 is the latest that they list. They do show the 2506563 as the Yellowmark part number which I guess is a different form of the "Cat Classic" line of parts.

Just for fun I checked Milton's price on the two piston numbers:
8N3180---$198.94
2506563---$78.45
Or at least that is the price I'm seeing on SIS

 

[Joel59]

Great info. Thank you. Are you comfortable with the quality of the kits listed on ebay? In frame kits are in the $600-800 dollar range. I appreciate the prices from Cat. I think I'll be purchasing a kit rather than just the individual parts if that makes sense.

 

[Nige]

I'm sorry but TBH I wouldn't trust anything I could find on eBay as far as I could throw it....... YMMV.
Have you tried talking to the good folks at Offroad Equipment..? www.offroadeq.com
Lots of posters here swear by Offroad prices & service. If you do speak to them don't forget to tell them that you were sent to them by HEF.

 

[Bluox]

Great info. Thank you. Are you comfortable with the quality of the kits listed on ebay? In frame kits are in the $600-800 dollar range. I appreciate the prices from Cat. I think I'll be purchasing a kit rather than just the individual parts if that makes sense.

You will have to know which bearings you have before you order .Call Cat and price their classic kit ,bear in mind Cat has the same warranty on all their parts and you will need parts not in the kit .Consider with local company ,Cat or otherwise they will want to help you with your problems and likely have people who have actually seen one of these engines.
Good luck
Bob

 

[Joel59]

Ok. Thanks for the insight, guys. Your experienced opinions definitely help the inexperienced such as me! I have gotten a price from offroadeq. Right now I'm looking at a CTP (costex) premium kit with rods and ready to drop in sleeves for around $900. Thoughts on this kit??

 

[kshansen]

I have no knowledge of this kit but one thing you do need to check no matter what parts you use in the liner projection and condition of the counter bore in block for the liner flange. Not sure how much of that is in the manual you have. I attached some of the information below.

Note they refer to the "cat official tools" but there are other ways to measure this it just takes a bit of imagination.
One easy to use option is:
https://www.amazon.com/Central-Tools-6434-Sleeve-Counter/dp/B000OQHR9W
Which is in my opinion better than the Cat tool.

 

[Joel59]

Well, guys, I am pretty disheartened to report this (and quite embarrassed as well) but I really messed up on this one. While pulling the oil pan, I quickly realized the real reason this machine was put out of service. Somehow I completely missed the rod poking out of the block on the cylinder closest to the cab (#1 or #4?) I really don't know if the widow that I bought it from intentionally misled me, or had no knowledge of this problem, but it really doesn't matter anyway. I inspected it, and just totally missed it. I know the picture isn't the best, but I think you get the idea. There is nearly a perfect circle poked out of the block. I believe the area is non-structural and could be plated. Is it crazy to think this? What are the odds that the crankshaft is salvageable? Does anyone have a lead on 3304 short block for this without spending a fortune? Are different serial numbers/arrangement numbers/part numbers critical for finding a used block since I will be using all of my bolt ons? Thanks for the help...and go easy on me!

 

[Joel59]

Here is the pic.

 

[bam1968]

Ouch!!! I feel your pain. It looks as though it had the engine side panels on it and it can be difficult to see behind them so I can see how you could have missed that. Hopefully you will be able to find another block for a reasonable price. I have heard of guys patching them up but have never tried it myself.

 

[Joel59]

Yes the engine side panels were in the way. That's what I'm going with anyway lol!

 

[kshansen]

Being you are in Western NY I might give this outfit a call:
https://www.hrparts.com/

Or this place near Syracuse:
http://businessfinder.syracuse.com/s-s-tractor-parts-inc-marcellus-ny.html

 

[Joel59]

Ok. I'll give them a call. Thanks. My block part number seems to be 2P8774. The commonly advertised one is 1N3754. Do these interchange, or is this 1N3754 for a spacer plate engine?

 

[kshansen]

Ok. I'll give them a call. Thanks. My block part number seems to be 2P8774. The commonly advertised one is 1N3754. Do these interchange, or is this 1N3754 for a spacer plate engine?

Okay here is what I find:

 

[Joel59]

Wow. You are a great help! Thanks for the information. That will make shopping much easier. It sounds like there is no sense in buying the updated block unless it comes with the head, rocker assembly, thrust washers, etc.

 

[kshansen]

Wow. You are a great help! Thanks for the information. That will make shopping much easier. It sounds like there is no sense in buying the updated block unless it comes with the head, rocker assembly, thrust washers, etc.

Yes! that's why I felt it was best to just post the full service bulletin instead of just saying it was the spacer plate replacement block.

 

[old-iron-habit]

You might drill it with a hole saw. and tap it for a big pipe plug or use a cleanout plug with the recessed square hole. We fixed a 4-53 block this way once with a 2-1/2 inch pipe plug. It was behind the starter where a rod came out when a sleeve broke at the intake ports. Just threaded it and gooped it up with JB weld when we screwed it in. No big loss if it does not work. You may need a metric hole saw to get the size close enough to tap. A little sloppy thread is OK if you use the JB weld to seal it.

 

[kshansen]

Another idea I have seen used to patch a hole in a block where it was not really a critical structural area. Just take a piece of say 1/8 inch aluminum a bit bigger than the hole and form it to fit the contour of the outside of the block then start with one hole drilled and tapped into the block and fasten it on and drill another hole about one inch away and tap and fasten that and keep going around the hole. This way you keep everything lined up.

Then remove plate and clean area real good and use JG Weld or sealer of your choose and reinstall plate. It may not look pretty but if only a limited use machine could save a few thousand a replacement block would cost.

 

[Joel59]

Great ideas guys. I really hope they can help someone, and I'll definitely tuck those methods into my "bag of tricks". However, this block is definitely a goner, unfortunately. I got it apart last night. There is a crack going up from the hole, and the rod hit one of the balancer shafts which cracked and broke the corner off the block as well. This one is a boat anchor. Is there any reason this one won't work?
https://www.ebay.com/itm/Caterpilla...rentrq:6e5cc2361630aad71666485dfffebc94|iid:1

 

[kshansen]

Just looking at that one in the pictures it looks like it has been stored outside in the weather. Looks like rust on every surface.

Also it may be just old gasket and cracks in the paint but the area circled in red below has me worried:


I would want to get a very close look at it before deciding to go for it. The amount of rust on what I see really would be a turn off. Top of block and counter bore areas as well as the bores for the main and balancers looks very rusty.

 

[Joel59]

Well, I got a good deal on a remanufactured CAT block with the correct casting number on it. It is on its way. I have my crankshaft at the machine shop getting cleaned up. I'm sure I will have many more questions coming soon, such as how to properly time everything from scratch. Thanks for the help.