1931 Nash engine help!

[31nash880]

Will try to keep this short. Have thread in restoration if you need more info.

Trying hard to save this engine on a reasonable budget. 

31 nash straight 8 twin inginition. 

Top end done last year. New timing chain this winter. Major clean and lubing after 20+ year sit.

Test drove Monday and blew apart a babbit bearing. Pics in resto thread.

Questions:

Will pistons come out from under car?

Pic shows manual I have, will at least need torque specs for head and bottom end.

Can rings be reused?  Compression results are

 1=60

 2=50

 3=40

 4=60 oily

 5=45 very oily

 6=40 oily

 7= 50 oily

 8=70 oily

Does have an upper oiler that I was running mmo in to lube things.

Pics show things I think are odd and/or poor repairs in past.

 

Thanks to all here helping me through this!

[F&J]

You have more issues besides the Number 1 babbit failure.   I was looking closely at a lot of things in the two crankcase pics.  PIC 1.... Look at the Number 2 rod where the rod bearing babbit should be.....The thrust surfaces are totally gone, so I would think the babbit is all gone on that rod too.

 

Number 3, you can see the thrust surfaces still there.

 

ok, next pic number 2 of crankcase pics:   The big diameter oil feed pipe U bend...at the left side of the U, looks like the tube is crushed, or kinked or perhaps split?  I can't tell, but that's not looking right.   Also look at the rod bearing thrust on the rod on the left.  Look up top of thrust surface on the right side of that rod.  The thrust looks deformed up at very top, like it's squeezed out?    Or it could be an optical illusion.

 

 

Before anyone can help you plan any path of repairs, you must measure any of the rod journals on the crank where the babbit is now gone.  Measure all the way around to tell if the journal are out of round.

 

We, and you, need to figure out why this babbit went bad so quickly on your test run.   Did this engine always have some knocks down low since the first time you ever ran it?   I ask, because if it did, then maybe a prior owner ran it out of oil but then shut it off before the babbit fell out, then added oil only to hear knocks, and then parked it for good?

 

If it was not knocking at all before this last run, that will take more ideas on what could have happened to have lost oil pressure...like a bad pump drive or whatever.

 

one odd thing i see is that the undersides of pistons look way cleaner than they should be by looking at sludge build-up on the crank, etc.  Maybe it had new pistons a long time ago?  

 

 

 

 

 

[Rusty_OToole]

Normally piston and rod come out the top of the engine. You will need to measure cylinder wear or taper to determine if rings will fix it, if there is less than .007 wear it is usually ok to hone and put in new rings.

 

The bearings will be the big problem. An engine of that age will have poured babbitt bearings and they are expensive to replace, and it is difficult to find someone who can do the work.

 

Under the circumstances the engine should come out and be completely torn down so everything can be measured and evaluated. If you are not prepared for a complete rebuild and a large expense best STOP right now and sell the car to someone who is prepared to do it right.

[31nash880]

Knock was there when bought. Had sat for years and owner tried to start it with minor success. May have been when damage started.

I appreciate what you are saying Rusty_Otoole but not many buyers would restore this car. Just hot rod it. So doing what I can, best I can.

I do have a contact for babbit pouring and yes expensive but within budget.

Question now is, can insert bearing rods be used in there place? Would new pistons be required?

[31nash880]

Knock was there when bought. Had sat for years and owner tried to start it with minor success. May have been when damage started.

I appreciate what you are saying Rusty_Otoole but not many buyers would restore this car. Just hot rod it. So doing what I can, best I can.

I do have a contact for babbit pouring and yes expensive but within budget.

Question now is, can insert bearing rods be used in there place? Would new pistons be required?

 

New issue?

Pic from underside of piston

Should there be a crack? All pistons seem to have in same place.

[ArticiferTom]

Yes if uniform , maybe be expansion slot . Your Book of Information should give all .

[Oldtech]

Yes. Split skirt pistons. 

If it was mine - and I'm a sucker for old engines, I'd take it apart and if the pistons and cylinder's are as good as they look,  get the crank done and bearings re babbited, a set of new rings and a valve grind. will outlast whatever normal old car duties you give it.  just my  $.02 worth.

 

[Rusty_OToole]

Some engines with poured babbitt bearings can be converted to insert bearings. You can usually find suitable bearings, they come in all sizes. The trick is fitting them to your rods. Perhaps someone who has done this, can give the particulars. It should not be necessary to change pistons.

 

In the old days they would overhaul a motor with more than .007 cylinder wear using "10 UP" or "Cord" rings, piston skirt expanders, knurled pistons and other tricks. The old tricks still work, especially on a motor that will see limited use.

[31nash880]

This is a learning curve. Keeps the brain going!

Sat and looked at this thing and decided at least get it apart. Pics below. Have not found an issue yet but does look like low oil pressure. Overall clean. Appears questionable repairs in past to oil tubing. Hope to get head off tomorrow and get piston out.

Do wonder if wrappings on rocker shaft are factory.

[F&J]

9 minutes ago, 31nash880 said:

Have not found an issue yet but does look like low oil pressure.

You said that the engine had a knock since you first got it to run.  I said in a post that if it  knocked when you bought it, it is likely that it was run out of oil by a prior owner and he stopped using it after adding oil and it was then still knocking (because he ruined the babbit).   Look at the earlier pics in the crankcase...there is a heavy drip of oil hanging on each cam lobe.  That means the pump was still supplying "some" oil to the crankshaft during your test drive. The crank throws oil up to the lobes and cylinders by design.

 

 The babbit was badly damaged before you bought the car because you said it knocked when you first ran it.  Yes, due to loose fitting babbit bearings on at least two rods, the oil pressure would definitely be lower due to major oil pressure/oil flow losses leaking past those sloppy bearings, but the pump was still making flow to the crankshaft by looking at all the pics.

 

as far as using modern rod bearings on those rods,....you cannot.  Modern rod bearings don't have thrust surfaces.  The babbit bearings had thrust surfaces on each side of the rod which makes the rod wider, and with those thrust surfaces missing, you now have a rod that is far too narrow for the crank journal.  Like 3/16" of slop.  Look at the number 2 cylinder rod that has missing babbit thrust surfaces, you can easily see the big gap between rod and crank thrust surfaces.

 

Don't forget to mark each piston top with an arrow to know what side of piston faces front.  If you ever take a piston off of the rod, then mark the front of the rod as well as the piston.  Mark the front of each rod cap as well as numbering each one of them.

 

Looking forward to seeing this engine and car get saved.  The hobby is aging out and there are fewer people around that are willing to save a broken engine on an obscure brand of early car, knowing that rebuilt parts are not being reproduced.

 

.

[31nash880]

Will soaking the pistons in a ultrasonic cleaner save the rings? That is if all looks good when removed.

[Bloo]

You should not re-use them. That said, I would do everything in my power not to damage them just in case there is no reasonable alternative for replacement rings.

[Bloo]

1 hour ago, 31nash880 said:

Do wonder if wrappings on rocker shaft are factory.

I was wondering about that too. It wouldn't surprise me. I seem to recall the 1950s Ambassador Six used some sort of oil wicks in the rocker arm system.

[Dandy Dave]

Agree with what others have said. Take the engine out of the car. Have an engine stand handy. Disassemble it. Clean and measure everything so you know what you have. Agree that all of the Babbitt should be done. Check those feed lines thoroughly for cracks. Some of the solder looks iffy. Mike the crank to see if it needs to be turned. And yes, a valve job while your at it. You will not be sorry in the long run to go though it with a fine tooth comb. Get everything right and it will be reliable and enjoyable to drive. Dandy Dave! 

Edited April 15, 2023 by Dandy Dave (see edit history)

[trimacar]

12 hours ago, F&J said:

as far as using modern rod bearings on those rods,....you cannot.  Modern rod bearings don't have thrust surfaces.

It can be done, one just has to account for the thrust surfaces when installing modern inserts on rods.

 

One way, build up the side of the rods and machine to correct width.

 

Second way, which I've used successfully, put braze three mounds on each side of the rod equidistant from each other, machine to correct width.

 

Both methods require a jig to assure machining work is true.

 

And yes, oil pressure is fine even with the brazing method.  I have thousands of miles on that engine, a Packard Super Eight.

[bradsan]

Glad you are trying to keep the original motor in it .

Just a reminder, to add to the list,it would also be a good time to get the crack in the block properly fixed 😁. Search for Frank Casey on this forum.

Interesting thought on insert bearing conversions, if you go that route, make sure that you don't pick an obscure size of insert .

I fear that the availability of ICE parts is going to drop rapidly in the near future. Babbitt will always be a rebuild option!

(And now I can hear my Dad saying how far do you think this vehicle is going to go after it is rebuilt!)

 

New pistons are available from the custom manufacturers like Ross and Arias. They can usually supply rings too. Hopefully , you don't need them. Not sure of the current pricing . Probably $1500?

[edinmass]

Insert bearings are not worth the effort 95 percent of the time………I won’t go into details. It’s more expensive than going the original way.

[31nash880]

Everything unbolted just no time today to get head off. Will be back soon.

[Dandy Dave]

16 hours ago, edinmass said:

Insert bearings are not worth the effort 95 percent of the time………I won’t go into details. It’s more expensive than going the original way.

Ed, you took the words right out of my mouth. You and I could chat for hours and still come back to "pour babbitt" most of the time.

 

For those that don't know, modern insert bearings have a steel shell, copper undercoating, and then a thin film of guess what? Good old fashion Babbitt.

 

 

Edited April 16, 2023 by Dandy Dave (see edit history)

[Dandy Dave]

9 hours ago, 31nash880 said:

Everything unbolted just no time today to get head off. Will be back soon.

Nice, That Nash engine is singing to you. Love it enough not to throw it to the wolfs. 😉🙃

 

 

[31nash880]

Singing a sad song. " sitting by the dock of the bay"

[31nash880]

Will continue this thread just a bit longer.

The fun continues:

Got head off. 

Gasket has funny marks like it was blocking off water passages. Mechanic that did head last year still has old gasket so will get it back and compare.

 

Pushed piston up to remove. Guess what, comes out bottom. Rod end is to large to fit hole.

 

Last pic is of piston tops. What makes the one so carboned then the others?

[ramair]

Gosh, from the angle that the photo is at I can’t see for sure but is that head gasket blocking all the cooling passage ways to the head?

[31nash880]

All on passenger side. 

[EmTee]

4 hours ago, 31nash880 said:

What makes the one so carboned then the others?

I would ask the opposite: "Why are those three pistons so clean?"  Almost as if they were 'steam cleaned'...

[Bloo]

5 hours ago, 31nash880 said:

Gasket has funny marks like it was blocking off water passages.

Worth looking into for sure, but probably normal. You have to cool the back of the engine as well as the front. Left to it's own devices the water would flow through the front of the engine and leave the back to boil.

 

How the engineers controlled the flow varies by make and model, but not every casting hole is necessarily a water passage, and some casting holes that are water passages might have holes in the gasket that are smaller to control flow.

 

[Ben Bruce aka First Born]

9 minutes ago, Bloo said:

Worth looking into for sure, but probably normal. You have to cool the back of the engine as well as the front. Left to it's own devices the water would flow through the front of the engine and leave the back to boil.

 

How the engineers controlled the flow varies by make and model, but not every casting hole is necessarily a water passage, and some casting holes that are water passages might have holes in the gasket that are smaller to control flow.

 

 And if like Buick, gasket is used for several years and changes were made.

 

  Ben

[Oldtech]

Rods likely come out the bottom. Common on old engines.

[Rusty_OToole]

On some old engines you need to push the piston up until the wrist pin clears the block, remove the wrist pin and piston, then take the rod out the bottom of the engine.

[Dandy Dave]

Time to get the radiator out of the way and start unbolting the engine mounts, and other stuff holding it in, and pull it out. It will be a lot easier to work on in an engine stand. It needs to come out to do a thorough job anyway. In an engine stand it will be a lot easier to inspect and clean things. Do it once. Do it right.

[edinmass]

 

 

Sure looks like blocked off coolant passages, and the pistons look like the head gasket was leaking.............from what you have posted, it's time to pull the engine and get it on a stand........that is not a canadiate for an in place partial engine overhaul. 

[Dandy Dave]

4 hours ago, edinmass said:

 

 

Sure looks like blocked off coolant passages, and the pistons look like the head gasket was leaking.............from what you have posted, it's time to pull the engine and get it on a stand........that is not a candidate for an in place partial engine overhaul. 

Looks like you and I were thinking the same thing at the same time. 🙂 I've seen "steam cleaned" pistons in the past myself from a leaky head gasket.

[stakeside]

I had my 29 DODGE BROS engine rebuild. Most important is verify you have a rebuildable engine. Have your block inspected and mag-fluxed before further expenses.

[31nash880]

Disheartened at this point. Got piston out from bottom. Broke a ring in process. Looks to put in, put rod up from bottom then put piston on from top then insert. What a pain. Approximately $1450 plus shipping to rebabbet rods.

Going to go cry in a beer.

[EmTee]

17 hours ago, 31nash880 said:

Going to go cry in a beer.

No, that's what the pretzels are for... 

[Rusty_OToole]

20 hours ago, 31nash880 said:

Disheartened at this point. Got piston out from bottom. Broke a ring in process. Looks to put in, put rod up from bottom then put piston on from top then insert. What a pain. Approximately $1450 plus shipping to rebabbet rods.

Going to go cry in a beer.

Welcome to the old car restoration hobby. You probably thought we were having fun all this time.

 

To avoid breaking rings and possibly damaging the cylinder or piston you need a ridge remover to cut the ridge away at the top of the cylinder. This ridge gives you a clue as to the amount of cylinder wear but at some point you will need to mike the cylinder top and bottom.

[31nash880]

Thanks everyone for your thoughts. Went to local chapter meeting last night. Found quite a bit of help from fellow members.

Looks like any way this goes I need the motor out. Best to pull transmission with it? Where do I get an engine stand to hold something this big and heavy?

 

This will take some time. Looks like I will need tech. data in future if available. 

 

Will continue updates under "restorations " thread.

 

Thanks,

Mark Kling

[Rusty_OToole]

Friend of mine had a similar problem. He bought a cheap engine stand, welded extensions onto the legs and added braces between the legs and upright. It worked fine.

[Ben Bruce aka First Born]

Mark,  I use a 2 ton unit from Harbor Freight. For my Buick.  A little difficult to rotate, otherwise does ok.

 

  Good luck

 

  Ben

[chistech]

On 4/17/2023 at 3:53 PM, 31nash880 said:

Disheartened at this point. Got piston out from bottom. Broke a ring in process. Looks to put in, put rod up from bottom then put piston on from top then insert. What a pain. Approximately $1450 plus shipping to rebabbet rods.

Going to go cry in a beer.

Did you call Paul’s Rod and bearing? Talk with Russ. He’s done probably my last 6-8 engine rods. Last year he was $75 a rod I believe.