308 V12 conversion begins

That's easier said then done though. The Ducati manifold is at about 45 degrees and the flange is right up near the rubber on top. I need 30 degrees which means I need about 3/4" more length for the angle. I could get maybe a 1/4 on the top, may another 1/4" on the bottom if I took the time to cut the flange away to match the outside shape of the tube part and I'm still 1/4" short so I'd need to built it up with weld. Then the rubber TB mount on top appears to be insert molded on to the manifold....it has to come off for me to weld so then the question it how do I get it back on. A bolt-on adapter would be easier, but I'm still not sure I like they manifolds because they work with the 50mm TB not the 54mmTB and I'm also not sure they could be carved to match the shape on my ports.

I'll have to have a careful look at it but I' learn toward to being easier to just start over. It's kind of funny that after months of "wouldn't it have been easier to just make {insert component name} from billet comments, the one time I decide it would be easier to just start over the consensus is I’m doing it the hard way again. I can't win

I might get into the shop today but the weather is getting pretty nice and yard work is starting to call. I've got about a dozen young fruit trees that I kind of let go thelast couple years and now they have branches pointing every which way. I need to get that sorted out and get them looking like propper trees again before it gets much warmer.

 

Thanks.

 

I have just not been able to get much shop time lately. I got an hour tonight and cut out the flange plate for the test manifold. Hopefuly I can weld the tube on and start grinding/flowing it.
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I got the test manifold welded up and roughed in tonight but not quite ready to start flowing.
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Thanks Hans. I always find it amazing just how much work it can be to make things look simple when they're finished.

I'm not quite sure how I want to make the actual manifold yet. As several have pointed out a casting would be nice but it's an expensive option for a one-off project compared to a fabrication when the labor to do the fabricating is free. I think what I'll do is make an engine flange, a TB flange then weld tubes pressed to ovals in between… but I don't really need to think about that just yet. For now I'll use the test manifold to flow all the ports so I know everything is done the same in every port in the heads and when I finally make the real manifold I'll know it's only the manifold I should be porting to get everything back to matching.

My current thought on the heads is I can do these ports with a lot less welding then I did on the 1st one. I should be welding plates into the bottom of the port and up on the flange instead of building it up with weld. What I did on the test port is fine and it lets me grind and re-shape as I please, but doing it to the whole head will warp the snot out of it. Once I get this first port looking the way I want it I can make filler plates for the other 11 I think and save myself most if not all the grief of dealing with warped heads….I think.

 

They are staggered, but on the width of 1 connecting rod, or about 3/4"......I'll have to fix the stack problem with a hacksaw when the time comes



Having to cut the lip off one side of the stack in not ideal, but it normally doesn't hurt much either. I can stand the TBs up a touch more if i need to but I was thinking keeping the port straighter was more important than keeping the stack entrance complete. I haven't completely settled and actually bought these TBs so I'm not cutting or in antway altering them since they are just on loan at this point but the factory stacks are cut for clearance to something similar to what I would want to do. This is one thing I'll look at on the flow bench.
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No, it doesn't have a proper valve job and doing on is high on the the list. I was hoping to see 5cfm...but 5 at 10" H2O is abot 9 at 28" H2O so we are thinking abot the same number it looks like.

At the end of the day I'll get the flow, the only real question is how big I need to go on the valves to do it. I want to see the seat velocity up over 190 ft/min and I'm there so I can afford to go up a little on the seat ID if I need to.....but more velocity is better if i can get it.

 

Exactly

I ordered the tubing for the manifold today with some other things I needed. I think as a fabication the intake will cost about $200-$250 and 20ish hours of my time.

 

Don't be like that....I usually only under estimate by a factor of 2 or 3

 

It's ok if the labor goes 3 times longer then planned, but I can't have the costs going 4 times over.......I don't even have 1 times the estimate

 

Here's a look down the port now. The way I've got the manifold is not quite right how it mates to the port at the head....I'll need to think about that a bit. It flows 150 as is. I think I'll cut the seats next and see what that does then figure out what to do with the intake.....a little grinding on the TB would help, but again I haven't bought them yet and it would be best if they work as is.
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