What's new
What's new

Good forum(s) for learning about automotive machine work?

dantm

Plastic
Joined
Jan 30, 2017
I'm trying to rebuild an engine for a car that I am restoring. Based on the leakdown testing, compression testing, etc. I think we need to look at boring the block, oversize pistons + rings, cleaning + polishing crank, new bearings, etc.

I'd like to educate myself such that the local shops doing the work won't be able to push the work beyond what is necessary.

As such can anybody here recommend some online forums where I can post questions, get feedback, etc.?

Thank you!
 
You would have to join Speedtalk where there is a "shop" forum. The general forum would not be too interested in whatever Alfa, Ferarri, or Fiat you have but you might find someone in shop that can steer you. I've done about every import there is in my 42 years in the auto machining biz, what are you working on?
 
I'm trying to rebuild an engine for a car that I am restoring. Based on the leakdown testing, compression testing, etc. I think we need to look at boring the block, oversize pistons + rings, cleaning + polishing crank, new bearings, etc.

First, are you saying you want to have the boring, honing, crank grinding, head work, cam grinding done by a specialized shop and then assemble it yourself? Or do you want a long block you can dress or a turnkey engine?

Next, are you thinking you're going to furnish the parts or have them source the parts. A competent local general engine shop can do all the machining, no problem, but they won't have a clue where to get your parts.

I'd like to educate myself such that the local shops doing the work won't be able to push the work beyond what is necessary.

Thank you![/QUOTE]

Your desire for more knowledge is laudable, but maybe the goal is not. Even an intelligent person who is a quick study is going to be beyond his depth when trying to argue "what is necessary" with a specialist automotive machine shop. You won't have the measuring instruments, the shop manual experience and hands-on experience to debate how many tenths are "necessary" for a reliable Italian exotic rebuild.

The other thing you'll likely find is a shop good enough to do the work will have little patience with a customer who's always questioning their estimates and their work. I've seen more than one too-hands-on customer fired and sent home with his parts in a plastic tub.

As a suggestion, from one who has sixty years in and around this stuff, maybe spend the study time talking with your marque and other Italian exotic owners who've had engine work done. Don't take any single opinion as gospel, but with a wide circle of discussion, patterns of who's good and who's affordable will emerge.

Back to parts, the Italian specialist will most likely have better parts sources than you will and he may not appreciate your help in that area.

If you find a shop with a good reputation but in another part of the country, shipping core engines out and getting rebuilts back is done every day. Today I just picked up a Studebaker V8 at the freight dock; it's in a crate in the back of my truck headed to the shop.

As a freebie, ask your basic questions here and/or PM those who've built a few.

jack vines
 
You would have to join Speedtalk where there is a "shop" forum. The general forum would not be too interested in whatever Alfa, Ferarri, or Fiat you have but you might find someone in shop that can steer you. I've done about every import there is in my 42 years in the auto machining biz, what are you working on?

This is a Lamborghini 4.0 engine as is on a Miura, Countach cca. 1965 - 1979 vintage.

Block is aluminum with cast iron liners. Cylinders have 82 mm bore one or two are slightly out of round. They actually seem to have an inverse taper (bigger inside the block end than at the top surface) but still within 3-5 mils top to bottom.

We're thinking of going oversize +10 mil and getting oversize pistons that are +8 mil (factory lists first oversize for pistons is 82.2 mm which is 8 mil).

Will 1 mil of clearance on each side of the piston (piston to wall) be enough?
 
Go to youtube and look up either Tyrrell's Garage or Harry's garage one of them recently did something. If I remember correctly they had to get custom pistons from a US supplier. Just a side note, when I lived in San Francisco I had some machine work done by Edwards Engineering (?), a small hole in the wall on Ocean Ave. I stopped by one day to bug the owner and he directed me to a corner of the shop where there was Ferrari block waiting. No big deal except that the owner had shipped it from Italy! Said owner was attached to the Italian Consulate and new the shop by reputation as he had been a member of the local Ferrari club.
 
This is a Lamborghini 4.0 engine as is on a Miura, Countach cca. 1965 - 1979 vintage.

Block is aluminum with cast iron liners. Cylinders have 82 mm bore one or two are slightly out of round. They actually seem to have an inverse taper (bigger inside the block end than at the top surface) but still within 3-5 mils top to bottom.

We're thinking of going oversize +10 mil and getting oversize pistons that are +8 mil (factory lists first oversize for pistons is 82.2 mm which is 8 mil).

Will 1 mil of clearance on each side of the piston (piston to wall) be enough?

New liners should be available, make sure you understand the fitting. There is nothing wild or groundbreaking AFAIK in Lambo engine design. Pistons can be bought by the set in any conceivable setup. Same with valves and valve springs and valve seats. Crank grinding is not rocket science.

SO if you are talking about money, you will not save any doing machining yourself.

Sourcing parts is a different story.

The only thing I can think of that you need to buy from a Lambo source is main and rod bearings. Pistons are just diameter wrist pin height valve clearances, the piston companies know what to do. Valves are just head and stem diameter, length and keeper style. Valve seats and guides likewise just diameters etc.

Most find that rather than do a years worth of research they pay the money

But bore 12 liners, fooook that. Pay someone.
 
I've never done one of those but the V12 Ferarri's I've done of that period had .001"-.002" proud flanged dry sleeves, that would drop below the deck so look for that. But you're getting way ahead of yourself on understanding nomenclature and clearances. If indeed an 82.2 piston is available, that means it is meant for an 82.2mm bore, the clearance is built into the piston. And don't talk mils to an automotive machinist, they will immediately pigeon hole you as a rookie who reads too much. Or worse, a millenial. An oversize of that small an increment would be honed to size on a good hone, and a deck plate should be used also. I've made deck plates for dozens of special app aluminum blocks. A competent shop could make one if they have a CNC.

Karl mentions Edwards Engineering, John Edwards now deceased. Thought by many to be a guru, with many Youtube videos wowing his fans. But talk to his customers, another story. Not to disparage the dead, but all you need to do is watch his video of installing sleeves in a V12 BMW. Beating the daylights out of them with a sledge, still mounted on the table of his "super high tech" ProtoTrac mill. Each whack gains maybe 1/4". These are alusil blocks, very brittle. There's no way that block is not cracked between cylinders. I've done a dozen of those and install all sleeves with liquid nitrogen. After eyerolling most of his videos, this one was over the top. Amazed he did them this way and more amazed that he showed it!
 
Talk with some of the local racers and restorers, find out what shop they use. To the best of my knowledge there are no forums dedicated to automotive machining, no idea why.

I think there are a fraction of automotive machine shops that do custom work compared to what there used to be. I think affordable crate motors and large scale re-builders put a lot of them out of business. Combine that with the video game craze, where I doubt you have many groups of High School buddies spending a weekend helping a friend drop an engine in a car these days.

I even wonder how many shops turn rotors or brake drums anymore.
 
I think there are a fraction of automotive machine shops that do custom work compared to what there used to be. I think affordable crate motors and large scale re-builders put a lot of them out of business. Combine that with the video game craze, where I doubt you have many groups of High School buddies spending a weekend helping a friend drop an engine in a car these days.

I even wonder how many shops turn rotors or brake drums anymore.

my kwik way drum rotor machine sees little work these days
 
That's a motor you take to place with a reputation for performing that type of work flawlessly... thats also not a job you save money on lol. I would get a recommendation from Ross on where to take that motor and write the checque.
 
Exactly right....if the shop dont have experience with that specific motor......they will learn on yours,and the result may not be pretty.....Also ,the piston maker normally specifies the clearance required....and you would need a lot of experience to ignore the recommendation.......grinding the crank may also be a trap....some of the special hardening methods used will need to be known by the grinder.........your crank will endup covered in blue spots,that are heat checks......the grinder will of course hide these with linishing,but the microcracks are still there......The crank may also need to be nitrided,fillet rolled,shot peened ,or whatever .....Lots of grinders dont get the correct fillet radius,because they dont like dressing diameter off the wheel for a one off job.
 
Money should be no object to those who buy expensive Euro trash. Just open the wallet and pay what ever Tony wants.
 
my kwik way drum rotor machine sees little work these days

A long time ago in a land far away I lived in a town that had two crank grinders in it, that was all they did and they were always busy. Pretty much every mom and pop auto parts store had a full time machinist in the back doing head and block work along with brake turning. I used to try to go Nascar fast in High School and College so I blew more engines that I care to count, also increasing the horse power on every rebuild. I had a 1970 Chevelle SS and I kept a bone stock 396cu in that had a measly 325hp as my back up engine to use when my real engine had it's parts spending time in machine shops. The crank grinders always had exchanges available, but I had a high end forged steel crank that no way I would swap for a cast iron one. Every time I would tear a blown motor down I would pray the crank survived, my prayers were never answered. Usually a spun rod bearing.

Part of that cars life was during the odd/even gas rationing of 1979. Fortunately I had a buddy that worked at a salvage yard and there and then they destroyed the plates. I would drive with the wrong plate as little as possible.
 
I remember seeing a video of a guy grinding a Duesenberg crank with the owner standing over him...poor guy had sweat pouring off him .....they said the genuine crank cost $2 million......but I imagine one of the shops that machine cranks out of bar could have done it considerably cheaper than that......I once cut a crank blank for an Ace motorbike from plate freehand with an oxytorch.....the original was supposedly carburized to a thickness of 1/16".....I just left it soft ,and its still running ,as far as I know.Soft leaded babbit bearings.
 
JAPANISCHES DREHZAHLSCHWEIN ! Kriegen wir das ding standfest? | Honda S2000 | Subi-Series - YouTube

This guys channel is really good - Builds and rebuilds a lot of Subaru sports engines and others,

I've learnt a "Lot" / some from his channel to get a handle on some more Automotive custom engine processes. [That's not my wheelhouse but great vids and techniques including honing machines + how he fits everything + mistakes :-) ].

Does kinda give you an idea that a lot can (with skill ) be done with HAAS machines.

Even if you don't speak German , if you know machining / engines / whatever, you can get a lot out of his channel.

Subi-Performance - YouTube

^^^ Channel root.

Really explains and shows a lot of what he does. Skillful guy and business owner.
 








 
Back
Top