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Any machinists want to tackle the forged crank into the cast crank block?
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Author:  hyper_pak [ Fri Mar 01, 2024 7:47 am ]
Post subject:  Re: Any machinists want to tackle the forged crank into the cast crank block?

All good points.
I want a solution to installing the forged crank.

Author:  Killer6 [ Fri Mar 01, 2024 10:02 am ]
Post subject:  Re: Any machinists want to tackle the forged crank into the cast crank block?

Right, chosing a cast crank leaves You figuring out what You're going to do for con rods..

Author:  Rick Covalt [ Fri Mar 01, 2024 1:00 pm ]
Post subject:  Re: Any machinists want to tackle the forged crank into the cast crank block?

Quote:
leaves You figuring out what You're going to do for con rods..
I bet you a donut he already has all that figured out! :D :D

Author:  Killer6 [ Fri Mar 01, 2024 9:11 pm ]
Post subject:  Re: Any machinists want to tackle the forged crank into the cast crank block?

Mmmmmm, Dohhhhnuuuts....

Author:  slantzilla [ Fri Mar 01, 2024 9:31 pm ]
Post subject:  Re: Any machinists want to tackle the forged crank into the cast crank block?

I understand why they did it, but I still think it's a weird idea when a forged block is easier to find than the spacers.

FYI, Mike made real close to 500 horse on spray with a light cast crank.

Author:  Dart270 [ Sat Mar 02, 2024 3:54 am ]
Post subject:  Re: Any machinists want to tackle the forged crank into the cast crank block?

I am now thinking I should build an aluminum engine with the late/light cast crank. Doug did this for his "twiggy" build way back when. This would make an engine (shortblock) that is more than 100 lb lighter than a standard iron forged crank engine. I guess you just cut the #3 main bearing saddle, and both halves are easily removed from the Al block. It's fun to daydream...

Lou

Author:  Team Green [ Sat Mar 02, 2024 4:55 am ]
Post subject:  Re: Any machinists want to tackle the forged crank into the cast crank block?

Didn’t gramps lose a lot of parts out of a cast crank engine at the starting line at St. Louis one year? I can’t remember if it was a crankshaft or rod or something else let go. It sure tore up a bunch of stuff.

Jr.

Author:  hyper_pak [ Sat Mar 02, 2024 6:39 am ]
Post subject:  Re: Any machinists want to tackle the forged crank into the cast crank block?

Still looking for a competent machinist.

Author:  Dart270 [ Sat Mar 02, 2024 7:08 am ]
Post subject:  Re: Any machinists want to tackle the forged crank into the cast crank block?

Depending on years, the cast crank can be the same (70s versions) or 14-18 lbs lighter (mid-late 80s) than the typical "smaller" forged cranks.

Lou

Author:  Greg Ondayko [ Sat Mar 02, 2024 7:46 am ]
Post subject:  Re: Any machinists want to tackle the forged crank into the cast crank block?

Quote:
Still looking for a competent machinist.

I am pretty sure procycle could make what you need if you had all the measurements and a good drawing(s) for him.

I am in no means volunteering his service, and he may not have time or interest in your project. I am sure he could make them.

There is a local machine shop here that likes when I come in with my "little side jobs for the slant 6". They have a file folder for me in stock :-o

Author:  ProCycle [ Sat Mar 02, 2024 8:58 am ]
Post subject:  Re: Any machinists want to tackle the forged crank into the cast crank block?

Quote:
Quote:
Still looking for a competent machinist.

I am pretty sure procycle could make what you need if you had all the measurements and a good drawing(s) for him.

I am in no means volunteering his service, and he may not have time or interest in your project. I am sure he could make them.

There is a local machine shop here that likes when I come in with my "little side jobs for the slant 6". They have a file folder for me in stock :-o
I could. I don't have a surface grinder but no doubt some local shop has one.

How I would go about it is to hunt up some steel pipe or tube that has I.D. and O.D. somewhat close to the necessary dimensions. Then turn that on the lathe to the correct dimensions and cut off a couple of rings that are several thousandths too thick. Those rings would be cut in half and all the pieces go to a magnetic base surface grinder. First they would be faced on one side for flatness then flipped over and ground to the precise thickness. If a piece of appropriately sized pipe was not available some solid round stock would work fine it would just take a little more material removal.

Any machine shop or hobby machinist with a medium to large lathe and a surface grinder could do this easily. It probably would only take an hour or so of shop time.

@hyper_pak - You're in the Dallas area? There must be dozens of machine/fabrication shops nearby who could whip these out.

Author:  kesteb [ Sat Mar 02, 2024 11:08 am ]
Post subject:  Re: Any machinists want to tackle the forged crank into the cast crank block?

Quote:
The Engine Power program used either a turbo or blower, don't remember right now.
So their reason was they wanted the strength of the forged crank for the higher power levels.
So there is one possible answer.
My take on their reason, was "we have this nicely machined free engine block, and we have this nicely machined free crank and we didn't know they wouldn't bolt together, so we cobbled something up".

They also used a turbo at 11psi to produce the power numbers. Nice build, I am sure the advertisers were happy with the results.

Author:  ceej [ Sat Mar 02, 2024 12:23 pm ]
Post subject:  Re: Any machinists want to tackle the forged crank into the cast crank block?

Is there anyplace making custom bearings these days? Cheater bearings for smaller diameter mains to a larger diameter bearing cap for instance. That used to be a thing when making home-spun 302 Chevies from early 327's.

I haven't been able to find undersized bearings for any OEM applications with over-length thrusts. That used to be a thing for cranks that had to have the thrust surface machined following damage. (Common in SB fords of a previous generation.)

One used to be able to order a .010" dia. under, .010" over length bearing. Nobody seems to do that anymore. Or am I wrong?

CJ

Author:  CNC-Dude [ Sat Mar 02, 2024 12:37 pm ]
Post subject:  Re: Any machinists want to tackle the forged crank into the cast crank block?

King Bearings used to make a variety of oversized thrust bearings. Not sure if they still do though. There were also a number of specialty companies that made main bearing spacers as well. They were a rave years ago and might have faded away by now, but there could be some that do them on a custom order basis...

While making them in a lathe might seem to be the best plan of attack, spacer bearings actually have preload made into them and a tang to prevent spinning in the bore just like the rod or main bearings do.....I have seen custom ones used in a few Ford Winston Cup blocks that were attached to the main webbing with small hex head screws. They initially require line boring and align honing to install them....

Author:  slantzilla [ Sat Mar 02, 2024 12:47 pm ]
Post subject:  Re: Any machinists want to tackle the forged crank into the cast crank block?

Quote:
Didn’t gramps lose a lot of parts out of a cast crank engine at the starting line at St. Louis one year? I can’t remember if it was a crankshaft or rod or something else let go. It sure tore up a bunch of stuff.

Jr.
At one time that block was laying at my shop. Pretty sure a small end broke off a rod. It made a big hole.

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