99 Black Bird T/A

iTrader: (4)

@IronHammer86

What's your main goals and use for the vehicle?

grubinski

I’m not sure a rectangular port head has ever existed that had the same velocity at the same flow as a cathedral port head. The bigger port volume pretty much guarantees lower port velocity.

IronHammer86

450-475whp, with a couple trips to Bandimere a year. 95% streetcar that will get less than 3k miles a year. Just something to drive around on the weekends that performs good and has a decent sound to it. Not real impressed with the current cam and head setup (comp 54-414-11), runs out of steam before 6k I'm guessing because the cam isn't sized properly for the displacement and, more importantly, cylinder heads. The car drives and idles like stock, which is the near opposite of what I'm after.

99 Black Bird T/A

iTrader: (4)

Comp Cam 54-414-11
216 int./220 exh 216 int./220 exh. 114 LSA

That's definitely small for a 383 LS1 in my opinion these days. Probably be really fun in a 5.3 etc. Mamo can definitely deliver exactly what you're looking for etc. For what its worth, I think he'll deliver the fully optimized package and set up best.

BTW - Back in the day, MORE Performance really liked the little cam that could (or one very close spec wise) and had several customers with 400+ whp LS1's with that cam, their heads and an LS6 intake running around. Cars with that set up were stealth sleepers that passed as "stock".

My 383 LS1 also has a small cam 229/229 cam that drives stock and passes for stock. The car is used very to how you describe. I've considered something like Vengeance Racing's Kaotik 235/243 .621/.624 113+2 LSA (13 degrees over lap) for my 383 LS1.

Along with new ported 243 heads, ~a roughly Kaotik size cam would probably get in the ballpark of what you're looking for without getting too extreme.

Bspeck82

Racing at altitude is hard especially NA. You are loosing about 18% of your effective power potential from air density alone. To make up for this, you may want to consider keeping compression fairly high and have it come onto cam a little earlier but have more exhaust duration to keep it pulling longer. Having more gear may help too. If you want to keep this thing on pump gas I would keep dynamic compression at around 8.5:1 at YOUR altitude. Not sea level. I would recommend spending the majority of your budget on the heads. A good set of heads will make or break a NA high DA build. I would put a set of small bore ls3 mast heads on it for the 3.905 bores. I would pair this up with a high hp runner fast intake and a cam specced out by cam motion for this combo. I would keep compression fairly high, around 11.5:1 and don't take quench away to lower compression. This hurts more than helps. Measure your Piston to Deck height. The cam will likely end up in the high 23X intake and 24X or 25X exhaust with a tight lsa to have it come on hard and optimize events for the shorter runner. It will breathe much better up top. I would then put at LEAST a 4000 stall in it, 4500 if no power adder and at least 4.10 gears. This will get the car moving up in that power band and keep it pulling.

Got to build different for high DA especially NA. Otherwise you get a total dog of a car.

I'm spending 7k on a new top end because I've learned this the hard way....6000 DA here.

ZDER

iTrader: (3)

I have a 383 LS1 Stroker with TSP rotating assembly and PRC 220CC heads, Fast 102/102, FTP 104, LS7 MAF, BBK LT headers (could probably use bigger, but I love there fitment), T56 Magnum F, 8.8" w/4.10s Custom rear diff and all the right accompaniments needed to make this motor work.

Motors making around 11.2:1 Compression, I stuffed in a TSP Torquer V4 into it, car made 480whp/450tq on a dyno jet and for what its worth, she ran a 10.95@126mph FULL weight , not one thing taken out, on a Drag pack. That's real world results if it accounts for anything.

IronHammer86

So the saga continues.

Got the old 317s off the car over the weekend and have spent the better part of 3 days checking things out. After a lot of poking around with a dial caliper and cc'ing things, I'm finding out what these heads are. They've been decked approximately .040, then angled milled 1° at some point. They are *not* welded, which would explain the crazy small chambers that cc'd to 50-51ccs on the dot. Intake runners are hogged out to 230ccs, exhaust is 84ccs. They are currently at the machine shop waiting to be put on a flowbench so i have every last bit of data in my arsenal should I decide to sell them or attempt to reuse them. Should be interesting to see what nearly 20 year old, no-name, cnc tech accomplished.

The deck height measurement was around .006 in the hole after some intense cleaning of burnt oil off the tops of the pistons, it definitely didn't have the intake rocker bolts sealed up well (or at all). I should be able to tighten my quench back up to .040 easy.

Cam is ordered, going with the 239/247. Once its degreed in I'm going to clay the piston using the old head and see if there's any way it will work, but I'm going to guess it won't judging by how much material has been taken off.

Here's the big question. Knowing that my compression is going to be low with these 9cc dished pistons and factory style heads (10.4:1), should I spring for some aftermarket castings that I can mill .035 to bring it up to 11:1 or should I risk milling factory 243 heads that far? Or should I go for broke and pull those 9cc slugs out and find some forged flat tops?