A sacrificial broach. That's clever!
A sacrificial broach. That's clever!
APEowner said:A sacrificial broach. That's clever!
Clever but sadly slow, stupid and resulted in a broken broach on the 1st cut tonight
So tonight I took a section of the broach and welded it to an shaft. I could have used a tool bit but since I'd already scrapped the broach this seems easier
Then broach the splines on the mill. About .002" per pass seemed about right and its mostly done now. The tooth profile is supposed to be a radius so tomorrow I'll grind that into the tool and finish it up, there is a few thou left to cut so it should go quick.
My least favorite thing to do on a mill table. My arm is sore just contemplating your progress.
My previous employer had a big broaching machine, mostly used for roll form rolls. I mostly made round holes square or added single key slots manually. Carry on.
We had a nice Hanford Davis key seater at a place I worked, produced beautiful key ways!
Nice work sir!
Every now and then I wonder if Ferrari checks in on this thread.
Yesterday was not a great day. I pulled the broach and put a little radius on
The back in the mill and cut the first, then..what the???
with a little age and dirt the 50 and 60 looks about identical
Luckily the bar I bought was long enough to make a 2nd so I remade the big end and got back to broaching but the broach was just not cutting, I spent like 2 hours cutting 2 grooves. and I was working
Finally decide to reshape the broach tooth and 40 minutes later it was mostly fitting the trans shaft. a little clean up to get it fitting better then recut the other end. everything's nice, cuz I make it all twice.....
In reply to mke :
do you treat the part post-machining to reduce stress concentrations etc?
AngryCorvair (Forum Supporter) said:In reply to mke :
do you treat the part post-machining to reduce stress concentrations etc?
It will be heat treated to harden it. 4340 should come up to RC50-52 the process involves getting it pretty hot which will stress relieve the machining before adding quenching stresses I guess. Because this fits over the existing shaft math wise is about 3 or 4x the strength of the trans shaft so I doubt that would be where it would fail. the weakest part is where the gear goes on, but clutch gear I'm using has a bigger ID than the original trans gear, so like 1.5x stronger iirc. My biggest concern in all this is that I put the trans gear up on the clutch shaft, which meant making a new small weaker clutch shaft and then put a stupid light flywheel and clutch to pass a lot more of the engine power spikes straight into the shaft.....I'm betting is something is going to break its the clutch shaft 
Back on track. The gear fits the shaft, the shaft fits the trans shaft, the gear ends up in the drop gear case where it belongs.
Next items are the welding bugger the middle bearing fit a bit, I need to fix that. Then set up the new angular contact bearing in the cover to get a slip fit and just a little preload on the bearing set. The shaft still needs a thread I can't cut and to be heat treated so I need to ship it to a buddy once I'm done test fitting everything then to heat treater. I'll work on the the bent valves and head gasket stuff while I wait.
Oh, the 12 pt nuts came yesterday and look good. They are shiny black so hopefully that is something that doesn't just burn off
Insert superlative here. This thread delivers.
This puts the super into superlative!
superB
Vintage Ferrari parts are being conjured out of thin air.
Amazing!
After pushing the last couple days, today I was slow. I figured I should confirm the shaft is sitting right and since its hollow it was as easy as measuring the drop then removing the housing and resetting the drop...perfect
I forgot to cut the locking detents in the shaft so I took care of that.
then the outer bearing needed a spacer, Its a slip fit over the shaft and light press into the bearing
Then it's more obvious where the nut goes once the thread is cut
Then fixed the idles bearing a quick test fit...working gears.
I did check the outer bearing and cover quickly and discovered the existing bearing pocket is just a touch too deep. tomorrow project.
I'm not very good at getting square corners to weld in fully so I ground it away a bit then welded
Then on to the mill to fit the bearing.
Clean it up a little
and it fits. the new bearings need a bit of preload, I used .004" figuring the case will flex a touch
All that remains is add a little cover to the cover to make room for the added length needed for the nut , then I can clean up and tear into fixing the engine.
This reminds me of the guy who made his own uprights to take press in bearings. He had some thick round stock machined for the land and circlip groove, then added the ball joint and tie rod mounts... and couldn't press in the bearings because the housings had warped all to hell. Oops.
The little cover took longer than I hoped....I didn't have much useful stock
Eyeball a radius cuz I can't find a cutter
Weld
then I always spend more time giving it the "obviously its original" treatment but its done and time to clean the shop for engine work.
In reply to Pete. (l33t FS) :
You're not wrong. I did have to polish the bearing bore a touch to get it back to right. Not sure you caught it near the start of the thread, I wrapped and twisted the whole block so the main bores were out like .050" and had to weld and recut them. But it's all sorted and everything is straight now, as far as I can tell anyway.
tear down day. every time I look at these end plates Brian G made for me I smile, they just look like they belong
I'm clearly not professional mechanic material ...I cut 2 orings installing the cam covers
When I originally set it up I made the studs in the top of the timing cover removable thinking they could go on last,
but then I need to compress the oring while installing the cover so I switched to installing the cam cover last. This time I will remove the razor sharp edge on the inside corner and maybe replace it with a radius...I am curious where the missing piece might have gotten though.
The buckets and cams still look very good, that's a plus
Slight bend exhaust valves in #12, so the no compression is an easy fix
Found the missing piece of oring, yay
Now the important item the liners are basically flush with the deck. I don't know is something moved or I had a corner touching a radius or some such when I originally measured everything but they are flush now so I think I make the copper flame ring and aluminum head shim the same thickness and see what happens.
Looking at the pistons there was clearly still some leaking happening, hopefully viton orings work some magic.
The pistons cleaned up nice with a little lacquer thinner and the bores look great, yay again
any theory on how the valve got bent?
AngryCorvair (Forum Supporter) said:any theory on how the valve got bent?
Sadly I know exactly how it happened...me. I have pretty high lift longish duration cams that come pretty close to the pistons, and 12 cylinders means something new will want to hit every 60 degrees. Then its a single long timing chain that goes bank 1 ex, in, bank 2 in, ex and what hit was bank 2 exhaust or the last cam on the chain which is generally the most out of time once all the slack is pulled out of the system. I start with #1 TDC and all cams at there marks but the slack means they all shift and require adjustment and what I've been doing is start with the 1st cam and work to the 4th and its been ok, but this last time that last exhaust cam was just a little too far. The new assembly plan is move the crank 10 degrees and reset all the cams to be off there marks by the same amount, basically the width of the marking line. Basically just a more care to details which anyone how's read my posts and seen the typos knows is not my strength.
OK, shims and flame rings ordered...hopefully this gets it sealed. Delivery is Feb 2 so time to get the valves sorted and everyhting cleaned up in the mean time.
Shims are under the buckets so you have to pull the cams to change them?
TurboFource said:Shims are under the buckets so you have to pull the cams to change them?
Yes. That's an "upgrade' I made that seemed like a good idea at the time. I use aftermarket Hayabusa oversize valves, springs, retainers, shims, seals and motorcycle buckets that fit the bores I had. All very light, the valve train should be good to 12 or 13k rpm...which I clearly don't need but the OEM shim over setup has a habit of flipping out the shims with aggressive high lift cams so they had to go or I had to pick a sad cam profile.
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