gemellocattivo.com

It was Lincoln night. I fought the damper off the crank figuring it needs to come off and it will be lighter. Then cleaner up a piston and scared myself a bit when I saw the markings


But its the 06 doesn't mean 60 over, its stock


then knocked the rust out of a couple bores so the piston would slide


rod on piston and bearging in



and piston/rod assembly goes in.



then crank in the block and check clearance....yeah....0 give or take


I'm sure the block can be clearance to make it work but I think I'm going to slim up the rod a touch....it needs to handle about 30hp not 150.

Also I was curious, the stock piston is 390g, the pin 60g. For comparison the frankenferrari piston (3.386 bore vs 2.875) is 300g and the pin is 83g. I'm guessing the new pistons will come in at like 260-280g and new pins 60-70 (the stock pins are scary thin) so it should be over 100g saving.

I slimmed the beam a bit so it will fit better and a few other changes....630g now, just 8g over stock rod weight. Just about time to place an order I think

The rod looks like its printing fine but the cap failed and will need to be reprinted....so it goes. I do want to see the new cap but its not needed for test fitting as the heavier one fits. Once I'm happy with the fit I need to triple check all the dimensions and fits. Then get back to the ferrari, I bumped this job up the list because there's another guy who wats to split the order which will save me quite a bit of money. He's also got a block to practice porting on so flow work will likely be on the winter list and bumped ahead of any chassis work to grab the opportunity to practice on the scrap block....plus having flow numbers means I can start getting numbers I trust a bit more out of dynomation.

The new rod looks more proportional to the piston I think


Then worst case clearance to the block it like 0.060-0.070 (with a feeler gage so I think its fine now.


Then more more as the piston moves lower

The new rods are 7.75" long, stock is 7.4", so the pin moves up 0.350" in the new piston....that will change the side clearance a LITTLE...5%ish to 60-70 becomes 0.057-0.067ish. ..but yeah, I could print a piston if I take the time to design one.



On the skirt I figured shorten it to save weight and take some load off the crank. I'm not sure yet what the top of the piston should look like, or the top of the bore (relieved? radius? so I don't yet know where the top ring goes exactly.

I have heads I plan to use....and would prefer not to weld all new combustion chambers into them....I could, you know how I roll, but I'd prefer not to. because this is supposed to be a car build not a lifetime on 1 engine. So that limits how much cutting I can do in the chambers but the general thought I'm having is.

While I was playing with the block I took some rough port measurements and put those numbers in dynamation, then corrected intake manifold and headers to match and the wave simulation is not looking pretty correct. I was using a simpler model that less less info to ballpark, the wave model gives a lot more info though. This is the sheider 254 mechanical cam (light green/red) compared to their 262H-10 hyrdualic cam (dark green/dard red)....about 15hp gain for the mechanical (only 8 in the basic model).

In in the 2nd graph you can see the intake and exhaust wave tuning...the exhaust is tuned to pull about 5pis vacuum during valve cross-over to get the intake charge moving and scavenge the chamber, then the intake is making about 3 psi as the intake valve closes...that is how "tuned" intake and headers add hp. If I change the runer lengths those pulses change..they shift rpm and the number of reflections will change with bigger length changes. The headers are pretty standard 3rd reflection (3 pusles on the graph...shorties you'd expect 4, long tube headers 2 but 3 is usually optimal for hp. In the intake its a vert short runner at 6.5" valve to trumpet....you see the wave completely disappears there are so many reflections. Normally intake want to also be 3 reflection but the port is much too small and the software is saying the flow restriction of a well tuned runner is higher than the gain the tuning delivers so a very short runner the allow recapture of the flow momentum is about the best I can do....so you only see 2-3 psi where something like the frankenferrari the pulse is 10-12 psi....there will be alot of focus on what can be done to improve the intake port.

The 3rd graph is intake and exhaust velocities ...about 0.5 mach for both which is lower side of right for exhaust but a little high for intake perhaps. But remember I just pulled in flathead ford flow numbers I found, the Lincoln will likely be different but this is a start.

This is an 1/8" pop-up, radius corner, upper ring lowered to be 1/4" from the top of the bore, pin moved for the longer rod. A little porky at 280g but well under the stock 390g and at the high end of what I guessed. It will be off the printer tomorrow

I "honed" the big end (aka ran a flapper wheel through it) to ge the bearings to sit in right.....hmmmm...that's not right

The print ALMOST failed


but good enough although it will need to visit the lathe before it will fit the bore.

With the cap on


And eyeballing TCD, it should be 1/8" pop-up and that looks right

Very cool progress. The engineering part is most interesting to me.

_________________
Wade Williams
Master Ferrari Tech
Restoration Tech
Engine Machinist
Fabricator
Racecar Driver