Lincoln V12 engine needs a car build around it

That make sense to me. Optimize the replacement parts to take advantage of lessons learned over the intervening years.
Lighter weight, strength as needed.
Very few would build a 1940 Ford flathead with cast iron pistons just to be correct.
https://www.jalopyjournal.com/forum/threads/steel-pistons-in-a-32-45-ford-flathead-v8.1011464/
Setting your own compression height, skirt length, pin height, pin size and retaining method, rod length and weights if you are going custom made is just getting your money's worth.
Check into balancing to make sure you don't weaken the crank or need mallory metal plugs, or at least know if you do.

 

Those are 90deg/cross-plane crank V8 issues where its all done as sets with bob weightes....no bob weights used/needed to balance these engine. On a straight, straight 6, V/flat 12 the crank is balanced alone, and piston are sets, rods are sets so changing 1 set of pistons or rods for a new set with different weights doesn't change anything meaningful balance wise as long set the rods are a set and all matched weights to each other it's fine.

 

CAD model of the 42up Lincoln rod, but stretched to 7.75" long and small end width cut to match big end.

 

It makes sense to do it that way. Custom rod with improved matching piston, followed by newer tech rings. It might even shed some weight in the process and possibly lighten the crank to balance it out. I can make just about anything from a good blueprint but designing and specifying something like this is out of my league. Should be interesting.

 

You hit the problem with design work kind of right on the head......there are 1000s of choices that will all work fine and that makes picking 1 a problem. If we just made stock replacement but stronger rods, we build our engines, they would run good and we'd be happy. If we stretch the rods and narrow the small end we still build engines and they will still run good and we'll pat ourselves on the back for how much lighter and more stable in the bore the pistons are without having any data to say we actually made a difference but in our hearts we did.....a good design is a series of good choices knowing nothing is ever perfect but trusting each choice was good.

I like to try and focus on what is the problem I'm trying to solve actually is. Here its the rods break, but there is a little more to that.....they break with rpm and if we are going to start porting and boosting then the revs are going up and that brings me to optimize the design for higher rpm....and that means get the pistons light and that means a longer rod. These parts will be good to 9k easy, move on to the next problem.

I'm thinking 6k redline. Some guidance numbers....the crank is the issue. The lincoln cranks are beefier than ford but the standatd piston speed for a cast crank is 37500 so

37500x6/4=6000rpm......that is where I cut off the simulator runs and what I'll be thinking about with valve springs (although flow doesn't really break anything on a flathead ). In my heart and anytime anyone asks me I'll believe 6k is fine ....and then I'll always shift at 3000 because I'm not a complete idiot

 

Talking about design choices and compromises....this is a shared journal V12 so to run smooth the angle must be 60 degrees. The F1 world figured out you can cheat that 5 degrees and not pay any real price so the V8 were 85deg to make them narrower for aero and the V12s 65 deg to give more room for intake systems.

This engine 75 degrees, it will be noticeably rough...well noticeable mostly in the exhaust, 6 cyl engines are smooth so 2 6 cyl engines are also smooth but the pulses don't come evenly. And that will load the drivetrain a bit weirdly, not H-D weird but not great. My guess is they needed room to access the valve train ...or flip that stuff to the outside and use 2 cams and covers and such.....so 75 degree it is. We'll call that personality

 

This one sat in a field for about 20 years before I decorated my yard with it. I think it wants to join in on the discussion.

 

Oh the poor thing!

Have you got a home lined up for your build(s) or a timeline in mind? I really don't want to be doing this engine just yet but the opportunity to divide and concur is tempting.

That probably not good for building could help answer the right porting questions like to relieve the block or not. Conceptually its not different from pop-up pistons and on many builds I've read clearance around the valves in the head add more flow but I just don't know. Your profile says long island which is like 4 hours from Elverson PA .....so not a horrible trip to exchange bits.

 

There's a new post in the regular section, mentioning the Golden Sahara at auction. Looking thru the listings is this. Possible inspiration.
https://www.mecum.com/lots/1151428/2003-delahaye-usa-bugnotti-boattail-speedster/?aa_id=704117-0

 

Wow! That’s a purdy car

 

I’ve got a reasonably oversized garage and enough tooling to make quite a stir. I am in no particular hurry, still tinkering with the Ranchero. This winter I’ll stick the running V12 in my 39 Zephyr just enough so it can move under its own power. After that I’ll start itemizing the core engines.

 

The delahaye stuff is good looking for sure. The low and min-engine nonsense I've gotten stuck on makes the proportions very different and that makes getting a design that looks right a real challenge....which is partly why I shifted to connecting rods as that is something I know I can turn the crank and spit out a solution.

i think my desire to make it small and light is maybe more the issue than the mid-engine. The higher end cars were land yachts, long and sleek.....but I really don't want to build a big car.

Then other things on my mind....I could clean up the cockpit and not need to import a transaxle from Europe if I just make this a paddle shift and use the auto version of the tranaxle....more electronics to sort though I guess. Not a today problem I guess