308 V12 conversion begins

I played with the simulator a bit to see if I can just restrict the air flow and get the low power fuel flow info for baseline/rough tuning….no, it gets very angry.

That’s ok though because I realized it’s much easier than I was thinking. TPS tuning is a bit of a pain because the air flow is not at all a linear relationship to throttle position so you don’t really know what the table should look like to guess at numbers. Now, fuel is a linear relationship to manifold pressure so when the barometric correction for the TPS tuning is done using the MAP signal the fuel flow numbers in the tuning table are scaled by the manifold pressure, and here’s where it gets easy, so the TSP fuel table is basically just the WOT fuel flow numbers at all throttle positions…… and I have the WOT throttle fuel flows from the simulator so I just need to plug them in for each rpm point then copy then copy the same numbers into every throttle position and it should be close.

 

I don't think you did fix it. There might be turbulence around the butterfly, but that is not the simulation problem. The problem is that the simulator has a lot of empirical correction built into it and when I start restricting the intake flow the results get outside the system limits. Before it actually crashes it starts telling me things like the manifold pressure is -182 psia. Basically it’s designed to work at WOT and that is the only throttle condition where the numbers mean anything.

 

What is that 2V junk?

I'm thinking I'll have a proper 4V short block in 3 months, long in 5, runig in 6-7.....we'll see.

 

At a glance it's basically the same block as the 400i I have.....you should put TR heads on it


Is that a second project engine you have going then?

 

Runner welding complete. It's now time to grind.
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I've got the heavy grinding on the outside done, I just need to hit them with something finer to make a decent finish. I hate grinding. Insides are next.

I'm thinking I'm going to mount the TBs a little different than I was thinking. I planned a 5-10* angle, but it wold be easier to do the QV looking air box if the TBs sit verticle. I'm also thinking that I can cut most of what was the mounting snout off the TBs and that will let me put the new manifold flange on plane with the top of the head...which will make machining much easier.....you'll see what I mean when I get there in a couople days.
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Maybe, but I've done similar things plenty of times with no problems so I'm quite certain your fears are unjustified.

If you are right though the worst thing that happens is I end up going cylinder by cylinder though the tuning using the cylinder tuning maps in the motec (which is a BIG part of why I picked this ECU) and match the fuel to the air I have.....but I will be very surprised if I need to do this.

 

Right, they get matched to the port at the bottom and the TB at the top, smooth in between and they are good to go. The wy I did the ports with a taper top to bottom the 99% of the action happens within an inch of the valve and the rest of the port makes very little difference. There will be small differences in total volume because I don't care enough to match them and the effect will be to reduce and broaden the hp peak a bit.

That would be the easiest way to make lots the same....but I'd have more time into the mold then this whole job so they get fabbed. As I've said, I've done basically this same thing many times and it always works just fine. The blower manifold I had on the QV engine had 73 parts .....this one only has 38 part for 12 cylinders, child's play

 

I could but it's more trouble than it's worth.....all the ports will be flow matched and these "manifolds" are part of the ports.

Yes! Thank you so much.....I thought I pm'd a thank you but appearently not.....Thank you!

 

I got the inside cleaned up on 11 or the runners. I'll get the last one in the morning, give the outsides a quick sand and I'll be ready to start fitting them. I know they start out looking pretty rough, but at this point there is just no way you could tell how they were made if you hadn't seen the pictures.
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Yes.

 

Finisded the grinding and started the fitting....and realized I can not go quite as low with the TBs as I was thinking if I want to be able to remove the cam covers without removing the TBs but that's ok. I think I'll mill the ears off the TBs so I can see for sur that they will fit in the space but it looks like it will be fine. I need to make the flange plates too I think so when I start tacking I'll know both ends line up where they belong. Hopefully I can get this finished up by next weekend.
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I'm serious, I'm going to get htis thing put together if it kills me.

 

I thought about that why back and almost did it….. then I decided to raise the intake ports and make the TBs fit with basically straight manifold runners because it’s way more work this way