308 V12 conversion begins

I'm pretty certain I'm going to warp the snot out of them. If you look at the pics you can see the cam cover surface is pulled down toward the weld zone. There are a lot of reasons way moving ports is never a very good idea once you get past the idea part.

The heads are already going to need quite a bit of machining because of other changes I'm making so straightening them first doesn't add much more work. I am going to clamp them th the welding table before I weld the rest of the ports to keep them as straight as possible, but they are going to need to be faced and have the cam jounals cleaned up after this.

 

I did notice the warping, hence my suggestion and comment.
What do you think about clamping a false camshaft the length of the head, using the journals and caps?
As you haven't posted any pics looking down into the top of the head, I can't tell if that would get into the way of your work.
Do you think you will significantly warp the valve guide holes also?

 

Putting something in the jounals and putting the caps on is a good idea. I'll probaly just install the stock cams.

The guide hole are all geting re-cut 2mm oversize to allow me to change the valve to valve distance 2mm so it doesn't reall matter if they are warped. The seats also need to be oversize and moves, so again there is not real concern.

 

While I concurr that a lot of US interior trim 'chrome' is just vacuum sputtered Al, usually with a protective clearcoat, there are shops that can put an true electroplated show-chrome finish on plastic.

A good example of true electroplated show chrome is the 308 lever bezels. The OEM ones were electroplated chrome on plastic.

The shop chemically deposits a layer of 'electroless zinc' on the plastic to make the surface conductive, then plate a fairly heavy copper layer, polish it to a mirror finish, then repeat with a polished layer of electroplated nickel, and finally the electroplated chrome.

Some shops get the conductive layer by spraying with a high copper powder content paint instead of the electroless zinc.

Not many shops have the process tho. When I was making lever bezels out of plastic 4-5 years ago, I was having them show chrome electroplated. It was pricey tho, about 2x the cost of plating a same size metal part.

 

I measured whereI am with the port area wise. Right now it has an effective diameter of 42.5mm so just bigger than a 360 and just a touch under what I think would be ideal. I'll clean it up on the mill and it should be in the 43-44mm effective dia range....I still might like the bottom up a tough more. We'll see how it flows.

I took a couple picture to show that it's not as big as it looks. The port is at about a 45 degree angle to the manifold flange so up and down it appears 1.4 times it's actual size. It's not that much larger than stock really, something like 40% at the flange and about 25% at the seats.

I need to add this would not have been possible without the way cool mini tig torch Wil lent me. The thing worked great for getting down inside the port. I posted these pics before, but here they are again because it just works so good. I had trouble with the tungsten the 45 degree setup in the picture falling out which caused the holder to literally vaporized instantly, but the 90 degree setup worked very well. A big thank you to Wil on this one...i didn't even know they made torches like this.

I owe Thank Yous to a lot of people so far. There is a ducati intake manifold and 2 different sets of ducati TBs on the way for me to test along with an offer to help me find 12 at a reasonable price if I can use them. A guy that is going to roll the threads on the head studs whenever I get the blanks made. Another fchatter is helping me track down valve train parts at a great price. Steve (race engine) is helping with cam design and the simulation. Dave in SA who owns the 360 engine and has been sharing/swapting parts. And everyone one else who's chimed in with suggestions, support or other help. This is a huge project that wouldn't be nearly what it is so far without all this help.
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Now that its getting even more complicated I was wondering if you plan to do stepped headers rather than uniform in size primaries? Less power left on the table if you do. The question is how do you find the ideal location for the steps to yield the biggest return?

 

This is one of the greatest project threads in the history of the Internet machine!

But did you know it's been done before? I was poking through my library of old car mags last night, and was surprised to see a banner headline on a Road and Track - "Tests: Ferrari 12-Cylinder 308."

Thought you might find it interesting (sorry for the bad pics, no scanner)
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Respost a couple of pages ago ...

Pete

 

Yes, step headers for sure, I can't believing any hp on the table.

The simulation software tunes step headers. It says 1.625 at the engine and 1.75 at the collector, 22" long. I'll play around some more when I know exact flow numbers, port sizes, cam specs. Where to put the steps is tough. The software manual says the stepped tube acts like a true taper pretty closely....so that leads me to believe I shold be putting thre step about in the middle...but I think the better answer and what I'm going to do is to calculate the volume of a true tapered tube and put the step in the place that gives the same volume Unless someone chimes in with a better idea anyway

 

I did know about it. I still remember reading the article as an Airman 1st class when it first came out and thinking "that's what I need". I have a copy of the book/manual he wrote.....and decide to ignore all the really sound advice like "only the single cam engines fit" and do what has become by far the most complicated project I've ever even thought about. Had I followed the instructions this think would have been running last spring.

 

FWIW

You can take it a few steps further. On my SC-308 I cleaned up the stock headers and had them JetHot coated but once the exhaust gases leave the lower flange of the header, the pipes in the rest of the exhaust system get progressively larger in diameter to allow for expansion. I'm not an engineer so I did it intuitively and have no idea how effective it is but it probably doesn't hurt.

Since you're making your own cam-shafts you can make the journals oversize to compensate for line-boring the bearing saddles but I imagine you've already had that in the plans.

Bolting the heads to a 3" thick steel plate would be more effective for keeping warp to a minimum.

Aluminum heads can be straightened in an oven at around 500*F with the same steel plate and some shim stock in strategic places.

 

You do realize of course, that because of the uniqueness of this build that this car cannot and should not ever be disassembled for historical reasons, except for repairs and improvements within the original design ......................................................................................................................................................................................................................................................


(like a cough blower cough cough ................).














........

 

Spray conductive paint on a hunk of wood and you can chrome plate it but 99% of "chromed" plastic is done with aluminum vapor. As far as the heater/choke bezels go, I prefer your CNC pieces. I was stunned at the beauty of them holding one in my hand.

 

I still think we've gone somewhat overboard with this port realigning ... a cross over manifold design would have worked and looks just as cool.

By the time you have done all that port reshaping 12 times you will hate the engine ... but hopefully not.
Best
Pete

 

Well of course we've gone overboard

There were a couple issues. First was the for a cross over to be possible the TB have to be above the X and when I do that the runner length is about 13.5” and way out of tune. I need to be 10.5 or about 17. 17 sticks out of the hood, so 10.5 is what I need to have and that means no X.

Second was the port size, it was too small to support the flow I need and I’d already opened it up as far as I could so I was looking at welding in a new roof in the port…..and everything went downhill from there because the new roof can go anyplace I please.

Last was the x design required a kick in the runner to get past each other and I wasn't sure how it would flow that way. I know straight works.



I cleaned the port up a bit tonight and it flows 150. Add the clay manifold with about a 2” stack and it flows 150 so the manifold shape is right. Replaced the stack with the 46mm TB and the flow drops to 145. We’ll see what the Ducati TBs flow. If I find any TB is a problem I can’t solve I guess I can go to a plenum intake…but one way or the other I’m going to get 160 out of this head.

 

Well, I hesitate to suggest anything after my brush with the rotary valves , but, if you really don't want to leave any HP on the table, you might want to talk to these folks. http://www.swaintech.com/. They are the real deal.

 

Until I can see satisfactory data that these coatings hold up long term, and perform long term, I would just stay away from them in long term situations. They do work in the short term, there is no doubt. But evidence of flaking and deterioration in long term use is still prevalent. Most people who put a motor together expect it to stay together for a long time. Some of the old 308's and Dino's still have not been torn down for major repairs or overhaul since they left the factory more than 30 years ago. Expecting these coatings to survive over the long haul is not supported by any available evidence.

A Sikorsky S-76 Helicopter lost control and crashed, killing all 12 aboard, when a hydraulic control actuator extended unintentionally. Testing found that the plasma coating applied to the piston ends, which was intended to prevent wear, flaked off the actuator and blocked hydraulic passageways. That was in 2005, and while they are still using those coatings in that application, inspection intervals have been accelerated. Those coatings are virtual rocket science, the absolute best that humans are capable of, yet it failed. If you have any belief that an automotive grade coating is somehow going to hold up better, or that more science has been excercised on automotive engine coatings than in aerospace, your fooling yourself.

If your going to be tearing the machine down occasionally for inspection, as one would a racing engine (or Helicopter components), I would seriously consider coating technology. But not on something you have no intention of ever looking inside of again in the reasonable future. If the coating flakes off and fouls your piston rings (or worse), you'll be back inside (or picking up the pieces) sooner then you thought.

 

I am scared of most coatings for the reasons you state. I use the moto if it's supposed to add hp and it's not OEM on anyting there is probably a reason. I have used coated pistons in the past with no problem, but that was 20 years ago when it was new and it still hasn't really caught on...there has to be a reason.

 

Understood, however if nothing else I have heard that Swaintech's heat containment coating (white stuff on the outside) for headers is far superior as far as reducing radiated heat to anyone else's.

As far as piston coatings they seem to have fans in drag racing and snowmobile racing. In both engines are regularly torn down I expect.

 

As far as piston coatings go, Nissan use a Molybdenum coating on the pistons skirts of the VQ engine range and possibly others as well, and have done so for a number of years. I assume it is for friction reduction.
Regards.

 

About 10 years ago I sent a set of 12 pistons to Swain Coatings for the insulating coating on the crowns and the anti-friction coating on the skirts. I was doing some experimentation and installed a set of Deves rings which, it turned out, would not seat, causing oil smoke, so I removed the pistons to install to OEM rings. I was shocked to find that after only about 100 miles, the coatings were flaking off already. I never again used any kind of coatings for internal parts again after that.

 

The ducati TBs arrived yesterday and I got a chance to have a look at them today. Nice!

Tehy still cost me a little flow. It's looks like I lose 2 cfm with the 54mm Tbs vs almost 6 with the suzuki TBs, that's about 25hp. The effective exit diameter is 48mm which is baout a perfect match to the port when with the taper up to the TB. It looks like we have a winner.

These TBs are setup with shower injectors only so I'll need to add port injectors. It looks to me like I can sneak them into the manifold down in the V and get a pretty good angle toward the back of the valve. I'll need a shorter injector then I had laying around but that's no problem it's the same size that fits the shower bracket. The ducati only uses 1 injector so it's really got to much flow for what I want to do. OEM harley injectors are the same physical size but just about 2/3 the flow, so perfect and common.
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You say you lose 2cfm with the DC parts, so does that mean they now flow 158? (your goal is 160)
Can you trick the DC parts out to make them flow a little better? (knife edge the butterflies, open them up, etc?)
How are you planning to make the intake manfolds? I wonder if you could use a Stereolithography part for an Aluminum casting mold. (allowed for shrink)

 

No, 148. I need to spend a few more nights working the port but I wanted to wait until I had the TBs and I make up a test manifold to hold it so I'm working with a set. All the TBs flow plenty of air by themselves, but not on the engine. I think the 2 cfm drop is just the buttery itself is buggering the air a little. I might play with them a bit but I'll wait until last....I'd love if something could be unmodified.

Now I'll make up a metal test manifold that I can work with and see if I can find the last 10 cfm. I'll probably test the 5mm TB too, no sense in going bigger then I need.

Most likely I'll end up making the manifolds as weldments. SLAs are a good way to go for a quick easy mold pattern but here the stud pattern means I need to make at least 3 cylinders together and a front and back version so I'd be looking at $500-$1000 in SLAs then the casting price. If I do it as a weldment it's well under $100 of material.

 

They look fantastic.
If i were you i would forget about enlarging the original plenum, i would make a see through one.
Than if you open the bonnet it will look like a transverse f1 engine