V-12 Engine into 308 Build, over on Grassroots

Yes park & sun, and yeah, just the net goes for $170, the whole set with the poles is more like $1500 and that is the kind of deal Lana simply can't pass, even if we in no way need it. That is done and a permanent part of the yard now so on to more important stuff....

I've picked up tasks at work that have required evening calls all this week and next making it harder to justify turning on the AC out in the shop and doing stuff but I'm free tonight and through the weekend. I still don't have a real plan for how I'm going to pressure test the intake ports beyond I'll need to fix the tig torch to fix the leaks when I find them. And the pistons need to come out so I can fix the valve pockets. I want to inspect all the bearings, i'm pretty sure I left a few in I shouldn't have last time. So plenty to do while I make a port repair plan.

 

So years ago I had water leaks and rigged this up to find them. I air pressured it and found and welded the holes.

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The problem now is oil from the cam galley.....and I'm probably thinking WAY to much. I guess I just install the cam cover and make a plate to seal the timing chain end with a fitting for the leak down tester. Then I need to seal the valve guides so I just ordered some 5mm plugs, they will be here Sunday so I'll target having everything else ready by then and just get on with getting it fixed.

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@mk e I tried sending you an email on the power steering but it bounced back - can you shoot me a note at [email protected] ?

 

This week and last I've had work calls in the evening so little shop time during the week. I filled my time thinking about what to do when this engine is running.....and I'm thinking nothing says "I'm a dumb-a$$" quite like an 8-71 blower with dual quads on a flathead V12 sticking through the hood and mid mounted just because I can....I'm trying to figure out how to add wings that look right.

Hopefully in the shop working on ferari heads tomorrow.

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Look what arrived....

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I took a look at the steering.....and decide I needed some processing time because even thought the new EPA unit is generally smaller, its a bit longer along the steering shaft so there is really no way I'm putting a quickener...well....unless I attack the steering column which I kind of don't want to do.....but I frikin love the quick steering so I really don't want to give that up.....but I don't need another big or expensive project.....processing time.

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I've now got myself about 3/4 talked into gut building a steering rack......

 

I set the steering stuff aside and got back to the engine. I cleaned up the decks which seemed to take forever then checked the liner protrusion. I got 2-4 which should seal fine.....but I set them to 5+ last time so that kind of confirms the deck is not really strong enough to support the liners and things are moving.....but they are high enough to seal

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I got the bottom end torn down
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Piston vise on the mill (Thanks Wade!)
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pocket set up.
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first cut done
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24 cuts done
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I had targeted 050/080" but measured 045/080". The new target is 100/100 so I cut the intakes 055" deeper. I try and take care of the exhausts tomorrow with a 020" cut.

 

I'm not an engineer, but those valve relief cuts seem awfully close to the outside edge of the top of the piston. Will the piston be compromised in any way as a result? I've been following your journey with this build off and on. Hope you're getting close to fulfilling your dream.

 

That is an excellent question and one I do not know the answer to. I've never seen/read anything beyond sand the sharp edges which I will do once I finish machining....but how aggressive I need to be radiusing I'm just not sure....1/16" maybe? that would mean nothing thinned than 1/8" remains....1/32? I'll see what it looks like when I start sand I guess.

 

It's fine. Factory pistons have the radial relief cut going down the side of the piston. What matters is the amount of material above the ring.

 

Forgot to show the angle blocks, they make setting the valve angle pretty easy.
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Then same as yesterday, set up the cut
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do it 24 times.

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I was looking at a bunch of cars for you. It looks like you are on a similar track. I think one of the most beautiful cars out there is the Delage D8-120 S, which I was lucky to see in a museum once. Otherwise look at the custom's by Rick Dore, who nails art deco inspired cars.

 

Very nice, but all front engine.....I'm just not getting my head around the right look in a mid-engine. I've been busy trying to figure out how to get about 400hp from a 125hp engine to make the project worth doing and I think that starts with rods that won't fly apart.....about ready to order some I think that should fit, save 100g (rod+piston) and EASILY handle 35hp/cylinder.....I don't have time for this right now but another guy wants to split the order and that about cuts the price in 1/2 so....now it is. I'll get back to play with body design on the 308 is running.

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Yes, the ring land to deck is critical to avoid collapse. Also the pockets can create thin walls and that's where it gets tricky. Leave the thin wall? Window it out?
The consideration is down to combustion pressure and temperatures and the material thickness.
There's a crossover point where it's too thin and it creates a hot spot that risks detonation. But what that is, is really a combination of a bunch of factors.
Various gas laws and some calculus will get a decent ballpark number when you've got the peak pressures and temperatures for a given combustion event. Then using the thermal conductivity of the material, it's thickness etc.. easy peasy..

Honestly outside of crazy knife edge walls, ring gap is a bigger risk for detonation and problems.