A few of you expressed a desire to see photos of the engine I am building, step by step, as I put it together. After about two years I have accumulated the parts and pieces to get started on it.

I'm going to try to explain what I'm doing and the logic (?) behind it. I'm not the last word in Caterpillar mechanics, so I'm inviting comment on any or all of this. (For goodness sake, tell me if I'm about to mess up an engine!) I know a lot of the folks that follow ACMOC own 5U D2's, so I hope I can offer something that will be of some use to you.

First off, I got an engine with a good rebuilt head. The bad part was the block had been frozen (reason for the head) and had been welded. It looked like a reasonably good repair until I got it stripped. I have never seen a D2 engine split in this place (I havn't seen them all.) and the old hand that's been finding parts for me hadn't either. ATTENTION: IF YOU'RE BUYING AN ENGINE THAT'S BEEN FROZEN, PULL OUT THE TAPPETS AND LOOK AT THE BLOCK BEHIND THEM. pics 1 & 2.

Last picture: The solution. I found another block that seems to be souond, am removing the assessory drive, pump and governor as a unit with the timing case to be put on my good block. I found this to be an easy way to do it without disturbing parts that showed no sign of deterioration or unsoundness.

I'm going to have to attach the pictures with another post to follow directly, I hope. Running this computor just reminds me how much I appreciate good, honest control levers operating good, solid machinery.

Next installment, we're going to talk about valves.

Here goes one more time:

OK, seems I sorta went nuts posting pictures and the site said "Enough, already!" I think I got it working again now, though.

It was a pretty day yesterday here. I added one of the orchard just past full bloom with the mandatory Cat in foreground, of course.

Your shop is too clean!

Hi Jack,

That Washington State backdrop behind the orchard sure looks nice. I'm really feeling the pull to visit the area again. Cudos on the rebuild. Hope all is well otherwise.

Alan

Drujinin, you havn't seen my shop:eek: , just the little bit that shows around the edges in my ultra close pictures. That's why I use ultra close pictures...

Hi Al, Always good to hear from you. Going to the Steamup in Brooks this year? If you're in the neighborhood give me a call. That offer for breakfast at the Pancake House is still open.

I said I was going to talk about valves, so here goes. As I said, I got lucky and got a good head with a recent valve job mostly intact. However, the end of #4 intake guide bushing had split off, I couldn't find a reason. There was slight water damage on one valve and it's seat, and whoever assembled it had swapped an intake valve into an exhaust port. That valve got some serious heat treating.

So we need one new guide bushing, and need to grind the seat to line up with it, not much of a grind a actually. I found a good used intake valve and had to have it surfaced. The misplaced exhaust valve went back into an exhaust port. In all, I had to grind the one "new" valve and the rusty one, and one rusty seat and the seat over the new guide. Not a bad expense.

Then, just on suspicion, I decided to lap in the valves. They seated pretty good mostly, but I found one seat that didn't line up on the valve. I had to have one more seat ground true. I also found one of the valves that had just been ground didn't touch on two oposite sides.

OK, now I am making a case for hand lapping valves. I would not have found the eccentric seat if I hadn't done it, and it was bad enough to probably cause trouble.

The water damage didn't really show up until I did the lapping; then it showed up. I had missed it.

The newly ground valve was faced in a state-of-the-art Sunnen centerless grinder and still had two flat sides, though not by much. The best grinder in the world can only line the poppet up with the stem as it finds it.

All of the seats had been left with a rather rough finish as if done with a pretty coarse stone. They looked a lot better after lapping.

I know the prevailing wisdom is that you don't have to lap if you do a fresh grind, and I've done several without lapping. This case made a believer out of me though. These large valves will run well within accepted wear limits and still have enough stem wear to cause them to run out of true in the grinder. If you lap them in you can see where they connect and have no doubts. I like no doubts.

Pic #1 The flats don't show well in the picture, but the lapping was barely touching after about five minutes grind. I did succeed in getting a good full contact without all that much lapping.

Pic #4,3 & 2 in that order. Keep the valves in order in a stick as far as possible and figure on refacing ones that have to be swapped around. On a D2 head you can just oil them, stuff them in the holes and lay the head on a padded table top to finish up. Pic #2 is a handy little spring compressor that I built and I like it better than anything else I've used. It just runs down the stud with a rocker nut and holds steady while you juggle the three little wedges into possition. To use it on the other valve I just turn it upside down; it's machined on both sides.

No doubt I've missed something. Feel free to comment.

Jack

Hi Jack,
Great topic and start:D
I'd be willing to bet the valve guide got damaged when the installer hammered them in rather then pressing.
Valve grinding is a science on to itself. I would advise following the Cat specs for valve seat contact dimensions, depth of seat grinding and amount of valve recession. Cat doesn't give any specs on installed valve spring height so these specs are what you have to work with.
Valve seating can also be checked with bluing but usually the lapping is and excellent indicator.

Glad to see your making progress. I finally got all of my main and rod bearings. I just got my crank back from grinding and I iching to get started on the build up of my D2 5U engine as well. Valves look good. I did mine the same way, resurfaced them on a valve grinder, regound the seets, then lapped in. Thats the way my Dad taught me. When I get started on assembly I'll try to post pics as well. Good luck

I guess I have not been around rebuilding for quite some time or maybe my dad was just more demanding in his work but whenever I had ground valves and seats I always had to hand lap to assure the contact was not too large and in teh center of the face of the valve and seat. Huh maybe teh standard of not requiring the lapping has been around for a long time and I just believe if I am doing that much work internaly I want it right and to last. The last thing I want is to pull the head again.

D2 Darwin, you nailed it--my reasoning exactly.

So now we have the head assembled and have aquired a block that appears to be sound. I'm going to get into my reasoning here: You do the head first, then the pistons and sleeves and get the block prepared, all of this before you start installing the crankshaft.

There's a sound reason for all this. You can put a piston/sleeve unit down through the top of the block. You cannot put a rod big end down through a sleeve. So by setting up the rod/piston/ring assemblies and installing them in their respective sleeves, you get a unit that can be dropped in from the top and you have a handle in the rod by which to steer the whole thing into place. I like to put a thin smear of KW Copper Coat on the top sleeve seal copper ring and I like to pull the whole thing down tight before the Copper coat starts to set up, thus the complete ready-to-bolt-down head assembly. More on this to come.

Notice I check the end gap on every ring in the bottom of the cylinder in which it will run. Most rings come pre-gapped now, but check them anyway. (I just did a Briggs and Stratton where two rings were gapped and one was not!) It's sort of a shame that manufacturers have gone to pre-gapped. In a cylinder with wear well within acceptable limits, the pre-gapped rings will be gapped a little excessive, roughly pi x the amount of bore wear, so an acceptable 0.002" of wear gives you an extra 0.006" of extra gap and there's not a damned thing you can do about it except resleeve or live with it.

Notice I paint a reference mark and number on my sleeves. I use soap stone when I remove them and mark the front side full length. I remark them any time I rub off some of the mark until I'm through cleaning them, then paint the marks on so they will stand the wet honing at the grind shop. There is no place on a sleeve to put a punch mark without damaging a gasket surface or starting a point for cavitation damage. Cat does not specify numbering or register marking but John Deere does. I choose to err on the side of extra caution as far as possible, take every possible advantage.

The correct rotation for a pin keeper. In a heavy engine running at 1600 RPM or less in this case, I can't believe there will ever be enough of an inertia load in that ring to spring it out. Still, put the split on the bottom.

Rods/pistons are assembled with rod numbers facing the crankcase inspection doors. This is the side under the governor/injection pump. The injectors are over the pump, thus the firing cavity in the piston is on the door/rod number/pump (left) side of the engine and the valve reliefs are on the other (right) side.

Piston rings are marked with a "top" or "up" or such term, top meaning the firing chamber. If you tangle with an inverted engine, top is on the bottom, etc. Other times there will be an instruction sheet that explains how a step or bevel is to be possitioned. There is nearly always a difference between the top ring and lower compression rings. With modern ring sets you can bet on it. Ancient sets and steam engines, maybe not. Be a believer. If you expect the rings to function as intended, you'd darn well better have them installed as they were designed to run.

Right now I'm looking for sleeve soap. I used to get it from John Deere. Now they look at me funny down there when I ask for it. What are we using now? A little advice, please?

I'll be back with piston/sleeve assembly and insertion into the block when I find some sleeve soap.

Jack

Hi Jack,
The heavy tire mounting soap works good for installing liners or you can go the fancy silicone "O" ring lube.