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Im about to swap the 6.0 drivetrain from my race car to a street car. Anyway i still want that 9.xx but ill need 50+hp to make up for extra weight.
Current combo is:
-6.0 alloy stock bottom end, with new bearings, fly-cut pistons 60/70 thou
-double row timing chain, ls7 lifters
-823 alloy rectangular heads, unported, but decked 100thou (11.9:1 comp), pac beehive springs, trunion upgrade
-236/246 615/615 110 cam
-vic jnr L92 with 2" spacers
-950 (850) custom e85 carb (horsepower innovations)
-ran 10.000@135.5 with 1.43 60ft in ~2600lb car
Still want to keep stock bottom end, keep ls7 lifters and 1.7 rockers with trunion upgrade, happy to redo flycuts.
Ive just purchased another set of square port heads and will get another cam.Thinking cleaning up the heads around the short turns, more to clean up flow, sink the valve seats 40 thou, run a 2.10 ss ferrea valve and possibly smaller exhaust (to help ptv and pull off wall). Deck the heads maybe a fraction more than 100thou. Will run either 30 or 40 thou thinner head gasket. Thinking a cam along 243/258 650/650 107 (111 center), lobes need to suss out. So 35+ deg overlap and IO 10 deg. Try to raise the comp up from 11.9:1 to 12.5+
Was thinking ls3 4150 carb super vic but might be fraction big, so will port vic junior and keep 2" of spacer.
You're probably not going to see much from switching to a super vic LS3. It's a bit much intake for your 6.0. Keep what you've got, it works.
Go with a 1 7/8 stepped 2" header
As for compression, you still need that 0.035 quench rule of thumb. Assuming you're stock bottom end/block, youre probably out of hole 0.004-0.008. So the thinnest head gasket you should go with is 0.040-0.045 depending on your out of hole measurement.
Port the heads, port match the intake runners to the heads and the carb. Keep fly cutting to a minimal to optimize every inch of compression.
Db, I think if you want to find another 50 HP out of your already strong combo, it is going to require more RPM. The guys who are making 50-60 HP than you are shifting between 7200 to 7500+ RPM. So, if you want to put in a 5500+ converter and spin to 7500 RPM, I think you can do it for sure.
I just wonder if you want to work that hard for those last few ponies? That is hairy edge stuff for SBE. If you want to go there for sure, you need to look at Stunningman, ThirdGenBum, DMizzel and 06X6spdGTO. Those guys are all making about 45-60 more HP than you are.
I must say, before you pull your engine, I would LOVE to see what would happen if you advance your existing cam 3 degrees. I can't help but speculate that you would pick up 2 tenths.
Yep, same thought as me with rpm. Currently peaks around 7250, have revved to 7500 whilst tuning, so happy to go 7500-7700 but thats about it. And yep thats really pushing our luck, buts thats the point of this motor. Hence a healthy 242/258 at 50 thou on 107 lobe.
Current convertor is 5200 but will definately flare a bit more with more hp.
Not sure on advancing. All the ls gurus down here say it makes little difference. Bit tricky with current combo and engine plate. In new car going back to normal mounts so will be easier to try. Inlet opens at 8 deg via the calculators and overlap is 21 degs, so thats spot on.
Also thought about go to lsx 1.8 rockers with trunion upgrade, keep lift down on cam and easier on valvetrain
this car is not typical at all. majority of ls is big dollar big cube builds or lots of turbo combo's coming out. majority minitubbed with 275 radials.
this will be street driven and remain looking as near 100% factory as possible. with the right offset i can squeeze a 255 radial under the rear without mods, running modified steelies.
about to be sent to get the bay cleaned up then will swap everything over.
My mate who is doing the bay has an unused tsp 251/259 660/663 111lsa cam. Going to grab this as overlap is 33 degs, spot on. But inlet open is 14degs, so you get just advance the cam 6-7degs to get on 8ish deg inlet open. Fractionally more lift, comp lsk lobes arent too bad
You will need to mill the stands for that cam to work with stock rockers. You need way better springs and pushrods than what you have. IMO I think your running in circles. You have a heavier car you want to put it in and your killing torque with this huge cam looking for more RPM's.
My camshaft only has 236 @ .050 on the intake side and will RPM past 8000 rpms's if I needed.
Yes, i need revs. Only way i will make up hp. Going to nice doubles, thats no problem. Not that heavy, 2850 lb.
Not going solid roller or jesels, im not made of money. Keeping the engine as close to factory as possible. Yes, pushing things to the max. I have faith in the old girl.
Ok, engine buddy twisted my arm with crazy parts prices so we are going to go solid roller (think 250/258 730/730 106, probably change knowing me, lol).
Ok, engine buddy twisted my arm with crazy parts prices so we are going to go solid roller (think 250/258 730/730 106, probably change knowing me, lol).
Already got the jesels. Stay tuned
I think the duration numbers might be to small for a solid roller. You need to subtract 10 degrees for the fact its a mechanical roller with a lash. So basically that cam is close to the equivalent of a 240 @ .050 hydraulic. I am sure the split is to narrow.
Talk to Martin @ tick on the specs. He has been willing to share knowledge whether he sells you anything or not. You are better off calling him as he doesn't do PM's here.
09-01-2014, 01:59 AM
pushing limits stock 6.0 
