Hey guys, I've been doing a lot of reading and research and think i have my setup pretty much figured out. I just want to throw it out there and see what you guys think as well as get some opinions. As the list goes so far

Lt1 385
Forged Scat Crank 3.75
Forged Scat H-beam rods 5.7
Forged pistons (haven't really decided on a brand but they will be around 12.0-1 cr)
Afr 210's or Trickflow 195's (actually looking for some opinions on this, if i get the TF's I'll be getting them from AI ported out, not sure if the AFR would get ported or not)
Cam (I'm looking hard into the Lunati Voodoo series or a custom grind. I know custom would probably work better and be tailored to my setup but i love the voodoo cams and believe one of the 2 larger ones would make enough to satisfy me. Opinions very welcome on this)
Ported intake/58mm
All needed fuel upgrades
Rebuilt trans and new beefed up clutch

All of this paired with the mods already in my sig. The car would be tuned at Futral Motorsports. Like I said this is more of a R&D thing, its pretty much certain that its going to be a 385; i'm looking mostly for input on the heads and cam. Also what do you guys think it would make either setup? Obviously this would be a ballbark kind of thing. Just for arguments sake lets say i'd like to see 450+rwhp.

 

ported stock heads are best for this kind of build ~ with lighter, bigger valves (min intake 2.00 & 1.55 exhaust) all exhaust passages polished to a mirror finish, there are pictures on this board and on the web of the exact areas needing removal of materials: upper intake port, bowl, 3 angle valve job, push rod shroud-back & all around, the sharp turn on both exhaust and intake. An experienced shop will charge you about the same for labor as new aftermarket heads which have tested lightly lower on various dynos.

 

Hmm, i honestly wasnt aware of that. I always figured a good set of aftermarket heads ported would work better. I can chalk that up to one more thing to ask when calling around about which heads would be best.

 

This is VERY subjective. What do you mean by BEST?? Many aftermarket ported heads will outflow ported stock LT1's.
If your talking cheapest? Possibly!!! But usually because you already have them.

 

Port work depends on who is doing the porting. A guy like myself could port a set of stock heads, but they may never flow as good as a set of aftermarket heads. If done incorrectly you can even decrease the flow of the stock heads. Make sure you find a good shop to do the porting if you do. I would just pick up a set of stock heads and have them ported be advanced inductions.com or elliottsportworks.com and have them match a cam to the flow of the heads. Here is a 385 build done on ls1tech it should put down over 450 out of a m6.http://www.ls1tech.com/forums/wester...o-numbers.html the heads were done by advanced induction

 

Thanks guys. I'm pretty sure i'm going to use some aftermarket heads. That could change though, its still in the planning phases

 

How did you decide on 12:1? It will ping like a bastard on pump fuel at 12:1 unless the cam is HUGE. Way too high, IMNSHO.

Rich

 

my car is 12.3:1 and i have a 245/253 with .612/.612 on a 107lsa. and it runs on 91. just sayin

 

That would qualify as a huge cam, particularly with regard to overlap.... and that's what gives you a liveable DCR.

 

^^I would say that is a HUGE cam as Rich suggested.

 

A little elaboration and further calculations:

The DCR for your combo is ~9.8:1, ASSuming the adv duration is 285/293. That is way high for 91 octane. Amazing that it runs well, kudos to you or your engine builder. But that's not how I would build it. My methanol burning BBC motor has SCR of ~14.2:1 and a DCR = ~9.1:1 and it does detonate a bit with optimal timing and mixture. I have to run it rich and back off the timing to avoid detonation. Costs a few ponies but helps it last. Methanol technically is 100 octane but due to the large amount of charge cooling has an "apparent" octane of ~114.

With a typical street cam, I'd advise the OP to look at about 11:1 at most.

Rich

 

adv. is 300/308 if i remember correctly.. can't locate the cam card at the moment.

 

DCR is just one tiney variable. The majority of the time its completely over analyzed. And intake close changes the DCR not overlap.

 

I'm going to be running a pretty big cam, which will help to drop it some. We have 93 at the pump down here which is what it will be tuned on. I'll have Futral Motorsorts doing the tuning, i talked to them a while back and was told it wouldn't be a problem.

 

its really not all that bad. even with it not even close to a good tune it is not all that worse then other cams that i had.