Looks good man.. So thoughts about my last post on OCO?
Jason, check out this IM I spied earlier...
http://www.onecamonly.com/showthread.php?t=2651
Looks to be pretty efficient with the long runners and no extra compartments in the plenum!
Thoughts? It's off a EDM F18B2, which is basically a de-stroked F23. The hard part would be getting your hands on one.
Thanks! I'd say once I had everything taped up and tools ready to go, it only took 45min to an hour to soak, scrub, spray, then repeat a second time.
I think that's a very interesting find! I actually had the privilege today to speak with my tuner and the owner of a very reputable tuner/engine building company and bounce some ideas around with them, including some talk about manifolds.
First off, I think sourcing the F18 IM would be prohibitively difficult, and probably expensive after paying for shipping from overseas. I like the long runners it has, but I really want to see how they're configured farther down the path since there are obviously two per cylinder at the start. It also concerns me that there appears to be almost no plenum on that manifold at all. After going through all the "what-if's", ruling out H-series manifolds for lack of a way to taper the ports gently into the F23 head, and even discussing building a sheet metal tapered plenum and attaching it to the F23 runners so that they're just off the floor of the plenum, we agreed that an OE F23 IM is the only option short of JGE's one-off giant sheet metal manifold.
The question then, was what could be done to the F23 IM to make it more efficient in a forced induction setup. We tossed up ideas of trumpetting the tops of the runners, and even discussed the modifications Nocture had performed on his IM. My tuner thought the job he had done could potentially be quite beneficial if the runner dividers were knife edged, but with no real evidence or reason. Reid didn't agree, and said the best thing to be done would be to trumpet the runners as much as possible like this photo, and let it be. There seems to be more potential to mess things up than to improve them. In the end my log turbo manifold would be the biggest restriction by far. I'm going to inquire into a top-mount mani from AV Engineering, but I'm almost certain it will be cost prohibitive for my goals.
So I think it's fair to say at this point that I will simply get my stock TB bored to 64mm, open the plenum up slightly larger than that, and port/trumpet the tops of the runners as much as possible. Using a different manifold also opens up a whole can of worms with regards thermostat placement and routing coolant lines, which is something I don't want to deal with again.
On another note, I think I've got most of the clearance and specs that I need to choose how to assemble everything. There are still a couple things in the air, but I'll give Reid a call sometime later in case I think of some other questions to ask.
Things that I finally got some closure with:
-What oil to run
-Bearing selection and clearances
-Potential porting/extrude honing the turbo manifold
-BS delete and oil pump modification
-Reassurance of the stock block's capabilities
-Controlling resonances
...and a bunch of other little things to help me sleep better.
Also, I added some updates to my first post on page 1 highlighted in blue.