Main and rod bearings

[jclary]

My take on lapping compound is that, like many other tools, there is a time and place for it. In addition, as in most things touched by human hands...there is a degree of ART and SKILL in its application. Hand-lapping on a small engine can work well to merely resurface and match a valve to its seat. In the hands of a skilled practitioner, a valve and its companion seat can be fine-tuned. For someone with little dexterity, inattention to detail, and no patience, the match, and angles could be made worse.

I have used lapping compound to match spray gun needles and nozzles. I understand Jack's concern regarding introducing a grinding compound into an engine. However, all machining processes involve either cutting, grinding, and polishing. All of these processes require thorough cleaning and then keeping the entire workspace free of dirt, debris, and any abrasive contaminant while assembling. What good would it be to place any critical machined or bearing surface where a breeze could blow fine sand onto it while awaiting assembly? It is a matter of attention to detail and good housekeeping.

I have not been around a valve grinding machine in years, so I'm not up on the latest technology, but it seems to me that even the latest and greatest would still require a thorough cleaning of the block once the process was completed.

[PackardV8]

My take on lapping compound is that, like many other tools, there is a time and place for it. In addition, as in most things touched by human hands...there is a degree of ART and SKILL in its application. Hand-lapping on a small engine can work well to merely resurface and match a valve to its seat. In the hands of a skilled practitioner, a valve and its companion seat can be fine-tuned. For someone with little dexterity, inattention to detail, and no patience, the match, and angles could be made worse.

I have used lapping compound to match spray gun needles and nozzles. I understand Jack's concern regarding introducing a grinding compound into an engine. However, all machining processes involve either cutting, grinding, and polishing. All of these processes require thorough cleaning and then keeping the entire workspace free of dirt, debris, and any abrasive contaminant while assembling. What good would it be to place any critical machined or bearing surface where a breeze could blow fine sand onto it while awaiting assembly? It is a matter of attention to detail and good housekeeping.

I have not been around a valve grinding machine in years, so I'm not up on the latest technology, but it seems to me that even the latest and greatest would still require a thorough cleaning of the block once the process was completed.

Yes, machining creates grit and iron debris. The blocks have the mains line honed, cylinders bored and honed and the block surfaced. The guides are honed, the seats cut and the head surfaced. Typically, we run heads and block through a professional spray wash cabinet at least three times before assembly. It has 185-degree water and industrial detergent being sprayed 360-degrees while the parts are on a rotating turntable.

jack vines

[Ron Dame]

OK, guys, I'll not lap!. I've not removed the valves yet, so maybe they are fine as-is. I thought maybe that would be OK for a light touch-up, but I guess not.

In other news, I pulled the very new looking core plugs, and though they are new, no one bothered to clean the cooling passages. And in looking at the head gaskets and mating surfaces on the block and heads, this thing was loaded with stop-leak. I am already having the radiator re-cored since it looked pretty weak.

Now what was John Polous's saying?

[jclary]

OK, guys, I'll not lap!. I've not removed the valves yet, so maybe they are fine as-is. I thought maybe that would be OK for a light touch-up, but I guess not.

In other news, I pulled the very new looking core plugs, and though they are new, no one bothered to clean the cooling passages. And in looking at the head gaskets and mating surfaces on the block and heads, this thing was loaded with stop-leak. I am already having the radiator re-cored since it looked pretty weak.

Now what was John Polous's saying?

Have you found a local old-school radiator repair shop? Most of the ones around here seem to have either died off or the throw away types have obsoleted their business. If you have, I'd like to visit and perhaps have them to evaluate one or two of my Studebaker radiators.

[TWChamp]

I agree. If the radiator doesn't have an aluminum core and plastic tanks, most of the shops around here don't know what to do with the radiator.

[PackardV8]

OK, guys, I'll not lap!. I've not removed the valves yet, so maybe they are fine as-is. I thought maybe that would be OK for a light touch-up, but I guess not.

In other news, I pulled the very new looking core plugs, and though they are new, no one bothered to clean the cooling passages. And in looking at the head gaskets and mating surfaces on the block and heads, this thing was loaded with stop-leak. I am already having the radiator re-cored since it looked pretty weak.

Now what was John Polous's saying?

Yep, nothing so expensive as thinking it will just be a CASO look-in-and-reseal. With all that crud in the cooling passages, it's decision time. We spend a full day disassembling and cleaning crusty, rusty old cores. The latest took three trips through the pressure washer to get it clean enough to begin machine work; with flushing and rodding out between each wash.

The two screw-in plugs in the back of the block must be removed to clean the oil passages. Heating the plugs with a torch is often required to loosen them.

FWIW, get on the same price point page with your machine shop before any work begins. We recently had to give up on one CASO. We disassembled his engine and showed him what needed done. He argued with every step of the process. He wanted to regrind worn valves and knurl worn guides. He didn't want to pay to have the rocker system reground and cleaned. I opened one end of one rocker shaft and showed him it was plugged with crud. He didn't want to pay to have the block cleaned. I ran a brush down one oil passage and pulled it out solid with crud. The last straw was wanting to save the cam bearings; we won't try to clean the block with cam bearings in place and they were so worn it would have affected the oil pressure. Finally, we loosely reassembled his engine, loaded it back on his truck and had to eat the day's wasted effort. He called back a few days later and said he now wanted it all done right. We told him we were booked up for the next six months; find someone else.

jack vines

[(S)]

Wow! Save the cam bearings? Of the last 4 or 5 we have done, the cam bearings were 'acid etched' from old oil sitting in there. It only takes a little time to do it right, and a lot more time to do it twice. At the first sign of low oil pressure on a V8, its the bearings.....

[TWChamp]

It's amazing how tight some people are. About 20 years ago a body shop painted a 1928 Model A Special Coupe, then wanted me to install the engine. Of course we know the engine should have gone in before the body was painted, but I agreed to do it. This was an old as is engine that sat in a shed for many years, and the shop told me to install it as is. I told them I won't do it without at least removing the manifolds to check for mouse crap. Well, when I removed the manifolds all the ports and pipes were filled with mouse turds, grain seeds and dirt. I clean it as well as I could, then oiled the stems and poured some oil down the cylinders. Surprisingly it finally did run OK, but sure would have been a mess if I hadn't removed all the crap.

After installing the engine, the hood gap changed, and got wider at the bottom due to frame flex. The fool shop owner tried to blame me for that, but I told him the cause and how to fix it. I never helped out that fly-by-night body shop again.

Trying to save too much money usually costs more in the end, than if the job was done right to begin with.

[Ron Dame]

Rest assured, I want it built correctly. I want to do as much as I competently can. The machinist I found a couple of years ago in an adjoining town prefers old engines and is meticulous, but I don't know if he has done a Stude V8 before. I will copy the appropriate pages of the shop manual for him.

At present, I've borrowed a bore gauge and have about 0.0010" -0.0015 taper on some bores. Fortunately and opposite of what I first thought, only one bore has scores that I question if they will clean up with honing. Even though the last build was not good and contributed to it's failure, it appears it was balanced, so I hope I don't have to bore and replace pistons, because then I'll need to balance it again.

[PackardV8]

Rest assured, I want it built correctly. I want to do as much as I competently can. . . . it appears it was balanced, so I hope I don't have to bore and replace pistons, because then I'll need to balance it again.

Yes, in theory.

No, in practice, here's one area a CASO can get by. Since the bob weights used to balance the crankshaft are based upon an arbitrary formula averaged across the entire RPM range, new pistons if they're slightly more or less weight, will not affect the smoothness enough to notice.

The new pistons all should weigh the same within two grams and most times they do right out of the box; if not, easy to make it so at home. A gram scale can be borrowed if one asks around.

jack vines

[Ron Dame]

Good to know. Now my reason for why I think it was balanced, all of the rod caps have been ground upon, the counterweights on the crank have been ground on the circumference and the.. (Sides?), and two holes have been bored into one counterweight. OTOH, the number 444 is stamped into one throw...what does that mean?

Today, I gasket matched the intake side of the heads and will do the same on the exhaust manifolds. Valve faces look good, and the guides are tight and not knurled.

[PackardV8]

OTOH, the number 444 is stamped into one throw...what does that mean?

That's most likely a late long-snout 289" forging number.

jack vines

[Ron Dame]

New bad news. The machinist thinks I am better off replacing all of the valves rather than grinding, but I don't think he knows how much they are ($15.50 each). I'll ask tomorrow. But I remember there is some conversion to maybe a Chevy? that might be better and/or cheaper if these valves are beyond hope.
I've not had luck in the searches for this.

[DEEPNHOCK]

Couple of weeks ago I was at an event and was talking to an engine builder, and there was a conversation about some
offshore boat racers and their 900+cid race engines...and valve leakage.
He told them to ignore the minute fuel leakage at the valve seat, as it did not hurt horsepower and trying to fix it caused more problems than it solved.
Jon Kaase has a little bit of experience in that area..

Your engine, your decision, but FWIW, hand lapping valves is way old school CASO. <snip>
jack vines

[PackardV8]

New bad news. The machinist thinks I am better off replacing all of the valves rather than grinding, but I don't think he knows how much they are ($15.50 each). I'll ask tomorrow. But I remember there is some conversion to maybe a Chevy? that might be better and/or cheaper if these valves are beyond hope.
I've not had luck in the searches for this.

The Chevy valve conversion is old school CASO performance dating back to Dave Lavesque, Tom Covington and Dick Datson. It's easy to do until you get to the part about needing to mill .250" off the rocker stands and make or buy shorter pushrods. We do these regularly for about the same cost as new Stude valves and springs. Bottom line is better valves and springs for the same cost.

Get a quote from your machinist and then PM me.

jack vines