The Dark Side of Will wrote:Atilla the Fun wrote:NO-lope 400 HP LS1's been done a million times.
Yep, GM even built a few, but they called them LS6 instead.
Atilla the Fun wrote: See, Texas Speed and others have dynoed pure-stock LS1s to be at 400 HP.
Not sure what you mean by this. Are they factory freaks, underrated, or did their dynos need calibration?
Atilla the Fun wrote: What a truck 5.3 really wants is something more like Howards' 190315: 210 / 214 - 114, 0.595 / 0.598. And just $328. Most LSx cams are around $380. Plus that'll make mid-range torque like a stock LQ4.
But if you're wanting to twist it up, with ARP rod bolts, then the smallest Trick Flow cam is an excellent start. Slightly better idle than the CheaTR, too.
My dad's going to swap to the Corvette oil pan (already in possession), so he may be convinced to replace the rod bolts during that operation. I'll gladly listen to your cam recommendations, but I'll start another thread when we're closer to being ready.
I still maintain it's not such bad bang for the buck. After all, it should *bolt right in* to an E34. We'll see how the electronic side of the house works out. That's the big deal with this swap.
No, NOT the LS6. Even the regular LS1, with #241 heads, NOT the LS6 #243 heads. With the LQ9 cam, NOT the LS6 cam. It's not factory freaks, it's not bad dyno cals. A little research shows it's like 370 with stock manifolds, but able to crack 400 with any 1.75" long-tube headers. And with stock cams having -25 degrees or more of non-overlap, there's no way they'll lope.
Further, study the dyno sub-forum on ls1tech.com. Guys are hitting 380 rwhp with just bolt-ons. Cam and Head guys are getting over 450 RWHP. Add the overpriced FAST intake manifold, and 500 is possible. It's been done.
Think about this: These cars, supposedly making 325 crank HP in the F-twins, were putting down 320 RWHP right off the showroom floor. Does this mean the T56 and 10-bolt axle, combined, have become 98% efficient? Oh hell no! It means GM was under-rating ALL the LS1s.
But I guess it's tough to grasp that, because no other has ever under-rated their engines so drastically.
A pure-stock LS1 with headers is still stock, in my book. It's stock until you change the cam or heads or go beyond the LS6 intake, which was stock on the '01-'02 LS1 F-twins. It's worth about 10 RWHP, and was used to hit 400 on the dyno, in every case I can find.
Now that I've answered what upset me, lets move on. The LS6 heads are better flowing, no doubt. But they also have more efficient combustion chambers. They're casting number 243, but the newer 799s are identical. These are factory fitment on some 5.3s, albeit with the flat top pistons from the 4.8L. It's worth doing, but even at sea level, the LS6 heads, also used on the LS2, still need shaved 0.030" for such small displacement, even with flat-tops. LS2s did not get the trick valves from the S6.
You can safely use head gaskets as thin as 0.045". No thinner, because at TDC the cast aluminum pistons come 0.010" out of the block.
Only the LS6, LQ9 / LS2 and LS3 got hypers. All others were cast, except the LS7, LS9 and LSA which got true forgings.
If you keep the 706 heads you probably have, those should be milled 0.030", even with the LQ9 / LS1 cam. That's still only 10.0:1, while the Q9 was 10.08:1, with similar chambers.
The LS6 springs should be installed, at just $51 / set. Springs are wear items, and the yellow springs are good for 0.570" lift. Also do a new LS2 chain. I can post part numbers if you want them.
It'd still be cool to rear-turbo the Bavarian. Something between T60 and T70 should do. If it has an LSD. Or if you can get one.