V-12 Engine into 308 Build, over on Grassroots

The last unflanged liner I am aware of is the 330. Lousy design because unsupported pressure over the length of the liner just caused distortion and ring seal was never good. If liner protrusion has changed since assembly you have a far more serious issue than just poor sealing. That should never change.
These engines do not do well with wire o rings or any solid fire ring. The heads are just not rigid enough. It requires compressibility in the gasket to work, not just clamping pressure. The entire design revolved around that head gasket feature. Ferrari engines are not unlike aviation recip engines. No single component has a great deal of structural strength. Its like a laminated beam. It gets its strength from many pieces being bolted together into a solid unit. When assembling them I don't even torque the mains until the heads are on because there will be so much movement under stress of the heads being torqued.

 

For sure the original 400i liner were straight throught the deck and seated down at the spigot.

I added the flanges and yes I'm concerned it was not my best decision....I'll see what I have in a week or 2 and go from there.

 

I have a set of drop gears I was about to list on ebay so PM me of you are interested.




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Thats a distraction and makes no difference. Point is a non compressible gasket/fire ring design will not work with that head. Some 2 valve heads got away with it because they are a much more rigid design. The only difference a flanged vs non flanged liner will make is how much you distort the liner under linear pressure. They balloon. Its a well known issue. When I ran into it on TR heads I was surprised how little it took to distort the head. It can lose valve sealing too.

 

I think the deck flexes and the liner sinks at torque was my point meaning it will never seal and your info on the head also moving just makes it worse.

The current plan it the flame ring is that and only that, it sits there and stops the fire from touching the viton sealing ring.

The other option is add an .032 SS wire to bit into the copper.... but I'd need to pull the liners to make that a reality I guess

 

Adding more solid material between the liner and head will just make a bad situation worse.

 

That was why the viton, it will conform to whatever shape the head takes and close whatever gap. My thought was if the li ers are were I left them then I match the shim and flame ring thickness, if they've moved I compensate but the copper is not intended to seal anything, just sit there between the fire and the rubber.....at least that was the idea.

 

Mark I think you're onto it as I swear I heard old drag racers Dan Garlitts (Big Daddy) mention a similar head sealing system on some supercharged hemi he couldn't get to seal he built 50 odd years ago. Note I would suggest using highest grade FDA approved viton. It’s super tough and can support 10,000psi.

 

I made the broach support. My small endmills are all pretty dull so I was mostly beating the metal off but it worked
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Then cut the end with no teeth off the broach
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and got on with it.
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The SS shim stock I bought to wrap the old adapter is about right for shimming the broach so the plan is get it deep enough to index well then do the rest and then start shortening the broach until its straight so like just the last 2 teeth then back to shimming to get the final depth. Its going to take a while but it seems doable.
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Yesterday's plan was sadly slow, stupid and resulted in a broken broach on the 1st cut tonight
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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
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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.
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Yesterday was not a great day. I pulled the broach and put a little radius on
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The back in the mill and cut the first, then..what the???
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with a little age and dirt the 50 and 60 looks about identical
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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
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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.....
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I'm generally pretty happy with my skills and how my projects turn out. But sometimes you make me feel like an amateur or a hack sometimes. It gives me motivation to keep trying harder though.

 

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.
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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
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It's a week of gearbox projects...
Hydrolic TO conversion myself..
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I like the splined adapter route you went this time. Cleaner, simpler and should work nicely. How much lash are you giving the M/F connection? Slip or press fit?

 

welcome to the club
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The slip fits are about .001 clearance rand, the press fits about .001 interference.

Chrome seems to really hate this website, I got 4 close or wait warning typing this. My PC has been a problem for a while but now my phone has the same issue. 6 warnings.

 

I've been going back and forth with tilton engineering to find the most suitable HRB. I'm just going to have the machine shop make a new pilot base plate that will allow mounting of the HRB vs modifying the stock unit.

Not having measured before I was surprised that the stock pilot tube actually passes thru the clutch splines. Getting the gap tilton wants puts the base of the HRB ~ 13mm off the base. I'm going to get engineering to get me a par file on the 6000 series as that one uses an adjustable thread base. Have to wait till Monday.

 

I don't think there will be an issue, I was wondering about shock loads. The gears are pinned in place under the nut, so those don't really move freely. Probably over thinking it, but having gone down the high HP/tq road and wrecking drop gears as well.. Yeah it makes me wonder about the coupled slip end.
The gear box is a beast, it'll handle the power. The Ferrari drop gear train... 328 iteration is best.
Gentle shifting.. Feather touch

 

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Be ready for a crazy light clutch when its fitted!

 

That is a concern. Damaged gears, like the used 2v clutch gear I got? It looks like the OEM setup didn't fully engage the splines but I corrected that so fingers crossed.
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Mine is stupid light but that happened when I installed the tilton clutch and modified the stock clutch linkage and cable to work with it. I remember there was a spring that held the cable tight that I had to remove because it alone was pulling the pedal down enough to make the clutch slip. I'm not sure I noticed a change with the hydraulic conversion, I did it so save space and let me cut the bellhousing shorter

 

I should clarify, the conversion is for a clients build. I've got a Mondial and thankfully that sports a hydrolic TO from the factory. Should've been on the 308 or at least the 328.

Needs to be all neat and tidy with simple access and ease of use/repair etc.. Future.

 

Not sure because I've never done it but would it be easier to drop an end mill down first to rough out most of the material and then follow with the broach?

 

The broach has to cut it's own path or it'll tend to "walk" about and make a mess of the cut.