rebuilding a v12

[Roger H]

Hello everyone
I am starting to rebuild my v12 and could use some advice on repair order sequence.  From my reading and pondering I have come up with this order.
here is the condition :  the engine is dissassembled, needs pistons and bearings. the cyls will need to be bored,  crank turned.  Cam is good,

Here is the order I have come up with

1 Have crank turned   ( any reccomendations on Machine shop?)
2  send  mains and rods to be re babboted ( pauls rod and bearing is who I have seen reccomended)  and  give Pauls dimensions of  newly turned crank
3 install mains and have  block line bored
4.  have cylinders bored
5 have pistons and rings made to fit new cylinder dimensions ( have found a place to do this already)

I would greatly appreciate any advice or reccomendations of machine shops.  I live in the  Seattle area

Thanks

Roger

[Otto Skorzeny]

I take it from your questions that you are rebuilding the engine yourself. By that I mean that you are reassembling all the components yourself.

Just speaking from experience:

If you can find a top notch rebuilder who comes highly recommended and who has done engines like yours in the past, I would pay to have it done by a professional. This way the entire engine stays in one place and you will get a guarantee that everything works together, that it's balanced properly, etc. etc.

I understand the desire to do it yourself - I'm the same way - I usually think I can do it better than anyone else. The problem comes from sending many different parts to many different shops for assorted machine work.

You are dealing with an extremely rare and valuable engine. If parts are lost, damaged, incorrectly machined, etc. you will be in big trouble. If there is a problem after reassembly, no one will guarantee anything. The crank guy will blame the bearings, the cam guy will blame the lifters, everybody will blame incorrect tolerences  of assembly.

If you can control every single aspect of the rebuild - and either do the machining yourself or have it done locally by someone you trust - then do it yourself. If not, find one single place to have all the work done there. Believe me, you do not want the block sent to one place, the crank to another, the heads to a third, etc. The risk of loss, damage or misunderstanding is too great.

[Bill Gauch #23121]

Sounds like you are in the same situation I am in. I am starting the rebuild process on my V-8, having never rebuilt an engine ever before. I agree that paying a quality shop, with experience rebuilding old engines (preferably Cadillac V-12s), is the "best" way to go. You may save a bunch of money doing it yourself, but how much will you save if you do something wrong and have to redo it?

That said, I am going to rebuild my engine solely for the experience of it. Coming from my "newbie" perspective, I have had to read lots of articles and books, plus ask questions here and on other boards, plus call a machine shop and ask them questions. I'm sure others with more experience can provide a much more thorough list of details, but here is my best effort.

1. The block can have cracks that need repair. Some cracks are unrepairable. The first task is cleaning, pressure testing and/or magnafluxing the block. It used to be that every corner machine shop had a hot-tank where they could dip your block and chemically remove everything and anything. Now, it seems like most have gone to ultrasonic cleaning or thermal cleaning, followed by shot-peening. That is typically followed by magnafluxing, followed by crack repair or sourcing of a new block. Any head bolts that broke off are removed. The deck is milled to ensure a perfectly straight and flat surface exists for mounting the heads. The cylinders are bored out to the next available size. If the bore would exceed tolerance, the cylinder can be sleeved and overbored to match the rest of the cylinders. After boring, the cylinders are honed to leave a nice crosshatch for ring seating.
2. The crank must be straight. It can be minimally straightened, but long term storage on its side without support or dropping it or whatnot can effectively destroy it.
3. The heads get a similar treatment to the block. I don't really know the V-12, but I would assume it is an OHV. There is certainly additional machine work that can/should be done. I just don't know what it is.
4. You need to source new parts for anything that needs replacement. This is kind of vague, but I haven't gotten to that yet on my engine.
4. The individual components need to be balanced for weight.
5. The rotating assembly needs to be rotationally balanced as well.
6. New babit bearings can be poured, but inserts may be available.

If it were me, I would do the block first if it is fully disassembled. Why bother with everything else if you don't know if the block is good? It's unfortunate, though, because you need to transport this massive hunk of cast iron to a machine shop just to find out if it's even usable. I've been asking friends/family if they have ever pulled an engine before because it would be nice to have some street smarts rather than just book smarts. Of course, no one works on their own cars anymore.

[homeonprunehill]

03-16-09
ROGER, since you live in the Seattle area. There must be  some NAPA Stores  in the  area that has a machine shop. Let them do 
the machine and assemible work,(if they willl grantee their work). You may have TO TELL them where to order parts. It is always
better to have a buffer between you and whatever can go wrong.  Let  the machine shop operator tell you what needs to be done.
nuff said Good Luck,Jim

[Jeff Hansen]

Roger,

Get in touch with the folks in the Pacific Northwest Region of the CLC.  They'll know which shops in your area work on vintage Cadillac engines.

HTH,
Jeff

[Chris Conklin]

And check this months Hemmings Classic for a brief history of the V12.

[Roger H]

Thanks for all the great advice.  I have talked with Paul's rod and bearing this morning and they can do the crank, line bore, pour the rods and mains all at their shop ( they send the crank to be ground locally) they will fit the crank after line boring to make sure it is good.  This should take care of most assembly issues surrounding the crankshaft  and prevent the need of sending the block to another place.  I had called to find a shop to rebuild the entire engine and the price was over $10,000, I should be able to do it myself for about $5,000.  I have rebuilt several engines in the past just not a v12.  Thanks again for the input I will continue reading as suggested.

Roger

[Chris Conklin]

Best of luck to you Roger! Keep us posted with progress on the forum (when you have the chance).