N/A to FI: AFAccord's 10:1 Comp Turbo F23 Build Thread/Restoration

Awesome man, one more question - how long did it take you? I'll be doin the same!

Russianred said:

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.

Click to expand...

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.

On another note, I've got some brand new ACL Race bearings and some ARP main studs for sale!

That cleaned up nicely. Good job. Keep up the good work

Great update Jason, and thanks for your input - I'll probably have some create some discussion about your new decisions later, if I have some thoughts. About the F18B2 IM and plenum, granted you could get your hands on one and get the correct thermostat etc, you think it would be feasible to weld the JGE-style aluminum plenum to it to increase volume there as shown in the pic, instead of the small one that comes stock on it? Also the TB seems to tilt at a little bit of an angle.. Such a unique piece/engine, just one I heard of for the first time recently!

I don't think you would have room to fit a sheet metal plenum onto the F18 runners because of the way they're so long and facing forward. What I had recommended with the F23 runners is to grind away everything except the four runners themselves, and basically fit a tapered box down on top of it, but having the runners sitting above the floor of the box because air flow around the walls is almost stagnant compared to just a few fractions of an inch off the walls. There's a good article somewhere. I'll post it up if I can find it. We all agreed it would be a good solution, but it would definitely take some work. RLZ actually did the exact same thing on some 90* Ford runners 8-9 years back. I dont remember the exact results, but I remember that it worked out great for them.

Found it:

http://horsepowercalculators.net/intake-manifold-design/intake-manifold-design

It gets interesting about half way down...

I went ahead and ordered a KS balance shaft delete kit with the optional spacer to delete the front pulley. My tuner believes balance shafts are fine on a stock motor, but just another part to break on a modified engine. My primary concerns were harmonic issues and cabin vibrations, which weren't worth the extra few hp, but several people have reassured me that there's no detrimental effects to the engine by not having them. I'm ordering the new OEM oil pump as well, and will have to give everything to the machine shop to have the plugs pressed in.

Since my stock-like cabin comfort is already compromised, I'm looking into filling my mounts with poly. The chassis has almost 1/4 million miles on it, and I don't want things rattling loose, so I still want to be a little conservative here. At the moment, I'm considering a poly filler with ~60A rating. It should be better than the stock mounts/poly inserts I currently have to control the extra energy, without being too harsh in the cabin.

I hope by front pulley, you mean tensioner pulley since you cant get rid of the actual balance shaft gear on the crank, since it triggers tdc and ckp i believe. You wont even notice they're gone.

Geez... not sure what I was thinking there. Yes, it replaces the tensioner pulley.