CA 383 Questions

[McCauleyWB]

Figured I'd create a new post to address questions since some may not follow build threads. There will be more questions to follow I'm sure. I'm attempting to put together a CA "legal" forged 383. This also means it will need to run on 91 octane. After putting together a list of parts I have lying around and those I commonly see used in comparable builds, the math does not bode well.

My main issues are trying to balance compression and performance with emissions and available petrol.

- Compression high enough to produce or support worth while power gains (be it now or in the future), but low enough compression to run on 91 without issues. IIRC, Lloyd stated a static compression ratio under 12 and dynamic CR of 8.7 - 8.8 with mail order tune is the highest he'd recommend. This is pretty close to what I have read elsewhere.

- Smog "legal" cam that will also be sufficient for the stroker. This may be a paradox but I have seen them done. There are plenty of people running the Hotcam, CC305, some XFI grinds, etc with success. Of course this whole thing is subjective and others would jump in saying they 'should' be running something larger. More commonly though, I'd see the "minimum" sized cam most suggested not at all being emissions friendly in CA. If I stick to something that will certainly pass, I'd never be able to run pump gas.

Already have the following lying around:

AI 220/230 .560"/.555" 112 LSA HR cam (57.5 IVC)
AI 200cc heads (Phil said they were ~53cc in the end)
0.026 head gasket
Most everything else being standard (ie. 3.75" stroke, 1.6rr, yada, yada)
Was shooting for static CR of 11.2:1-ish with .010" deck height. Most concerned with the DCR though.

All math says the cam above will not work. It was originally intended for a basic rebuild anyway. No biggie. I've come up with a couple options after spending a good amount of time on research and cam specs. As I see it, the following options give me the overlap needed to keep the dynamic CR down, reach my static goal and utilize more power on the table. I was using off the shelf options as a reference point to start with.

1) CC503. Popular choice. It has been said to pass smog (especially on a 114 LSA) so there is a glimmer of hope. There are just as many people saying it wouldn't though. This, or one similar, seems like the most logical choice. With the aforementioned setup, the CC503 should put me around 11.23:1 static and 8.89:1 dynamic compression. This is the absolute tip top of the pump gas realm. In fact...it may be a little too high since there will be zero wiggle room. An LSA of 114 brings it down a bit.

2) Disregard smog entirely and go straight to a CC306 (or similar). I wouldn't hold my breath that this would come close to passing. However, it is better performing and drops the dynamic CR down to 8.38 (same static as above) which is well within range. I wouldn't need to worry about detonation at all. As long as I'm not worrying about emissions, there is also the XE230/236.

3) Have a custom grind done to dial it in even more. Obviously.

Questions:

First and foremost -- am I missing something relevant? This is my first time building a short block. Is there something else that may work?
I have seen so many 383 builds running the smaller cams. What's the deal?
Is there anyone running higher than 8.9 DCR on 91 (namely)?
112 vs 114 LSAs. It doesn't change the numbers much but how would it change the feel / power? How much would this affect smog?
Any experiences to share regarding a CC503, CC306 or the like? Other recommendations?
Should I be concerned about cam to rod clearances -- especially if choosing 6"?
Speaking of 6", is there any benefit over a shorter option? Granted, the rotating assembly can weigh less and there may be less cylinder wear but do those benefits outweigh having to mind the wrist pin and watch oil consumption?
I've done the reading about I-beams vs H-beams. Without doing in to detail, is there a legitimate reason at all to choose one over the other?

On a side note, what is the proper way to determine the IVC? It only seems to make ~3* (and around 2 tenths of a difference when calculating the CR) in the end, but I'd like to know for my own reference. Looks like AI used "intake duration - intake opening - 180" according to the cam card I got. On the other hand, various calculators seem to use the result of "(intake duration / 2) + LSA - advance -180."

[McCauleyWB]

Aside from the usual tech bickering, the following thread covered the LSA question...using the CC503 as an example to boot. Citing links for reference in the event someone stumbles on this down the road.

http://m.ls1tech.com/forums/showthread.php?t=1020977

...and

http://www.camaroz28.com/forums/lt1-...14-lsa-650285/

...and one more discussing it for CA.

http://www.camaroz28.com/forums/lt1-...3-lope-515705/

Informative post here too.

http://www.ls1lt1.com/forum/lt1-%7C-...-clips.html#12

Still not sure exactly how much the difference of 112 & 114 LSA affects smog or powerband but the concensus is the latter is more forgiving of course.

[McCauleyWB]

Did some wrenching today and looked over what I needed to finish my fan install. With the vertical radiator setup, I decided to go with a single 15" fan for now. This lead to a couple more questions. I make a habit or reusing or leaving as much from the factory as possible. I have looked at fan controllers in the past, but I'd prefer to power the new fan using the factory wires to keep things simple. Plus, it would still be computer controlled and I can always throw the factory fans back in if need be. I also have a manual fan switch already installed f so that's an added benefit.

Do you see any issues with running a single fan this way? I have the two relay high/low setup so it would function normally for the most part. Would it recognize that there is no high fan should it ever kick over? If so, is there a way to temporarily mimic something plugged in to the high side for troubleshooting purposes? I could have sworn I've seen a similar setup in the past but I wasn't able to find it. Will I have any issues with codes as long as all of the relays are left in place (ie. code 77 pertains to fans I believe)? Wouldn't want to tune anything out if it would alert me to issues.