Brian_17

After countless hours of searching and reading and looking I am looking for suggestions on timing settings and curve. I have a 2001 Serria that is used for sled pulling. It has a stock 6.0l bottom end with a comp cam, 608/612 max lift (cant remember all the specs right now). Matched springs hardened retainers, push rods, comp roller rockers, Victor jr intake, quick fuel 850 carb jetted 3 sizes bigger, and schoenfeld headers 1 7/8 primarys. Ignition is controlled by an msd 6010 box and can be adjusted by computer.
What I am looking for is what anyone else is doing with timing. I am at 34* right now and ramp it up slowly until around 4000 rpm when I dump all the timing to it through 8000 rpm. Any thoughts on this? Should I slow the timing down? Plugs are good all the way around, just looking to get anymore out of it that I can.

dirt track racer 81

iTrader: (45)

15 degree heads you don't need 34 degrees timing. I'd stay in the 26-28 degree range..
What jets are in your carb?

03sierraslt

iTrader: (22)

8000 rpm on a stock bottom end?

Atomic

iTrader: (42)

Have you had it on a dyno to see where it makes peak torque?

TXsilverado

iTrader: (19)

for some reason these carbureted motors take more timing than EFI. 28* wont be enough. I don't know why, but they take it and make more power. I run 31 at close to 11.5:1 compression. maybe they take more timing because they are less efficient than EFI? I have no clue...


did I read that right? 8,000 RPM through a stock 6.0 bottom end. that's not going to last long at all.


most guys on stock compression carbed setups end up between 32-36* on pump gas and stock compression. I've seen people run nearly 40 on race gas.

you never said what your total timing is at WOT. Do you have a wideband? I have the same carb with a 6.0, aftermarket heads, a much larger cam and didn't jet up that much. did you jet front and rear 3 or just the secondary? I'm willing to bet you're rich with too much timing.

Brian_17

You read it correctly, the engine has 185,000 miles on the bottom end. The rev limiter is set at 8000 rpm. It hits thevrev at about 125 feet until 175 feet where the sled pulls it back down. I run 110 race fuel because its what both my trucks run and I have it. I know that motor does not need it. If I could figure how to post videos I would but I'm too dumb lol.
I believe right now total timing is 34* but I have to double check that. No I do not run a wideband, looking into that now......
The whole carb is three sizes larger, my plugs read good after a hook. I shut it down and pulled plugs to verify. This motor has never seen a dyno. It was thrown together quickly after my 377ci ate a rod bearing and ruined a crankshaft.
The truck works good, I am just putting feelers out to see where other people are going with timing.

Thanks

TXsilverado

iTrader: (19)

you motor is probably making more power in the 6500 range than 8,000, and the motor is taking a pounding on that 8k limiter. maybe knock the limiter back to 7,500? it will take that a lot longer than 8 any video of the events you do?


search the carb section on ls1tech. your same log in will work over there. there is another guy over there that has a dedicated pulling tractor with a lsx swap. he could probably help you

Brian_17

I agree with making more power at 6500, but I need to get and keep the rpms up because the sled will drag it down. The name of the game is wheel speed. I need to get it up and keep it there. I'm trying to make a you tube channel tonight, I will post links then

TXsilverado

iTrader: (19)

at the very least, put some rod bolts in that motor. I typically never touch the rod bolts, but I've never touched 8k either. I have shifted 7,500 several times on stock bottom ends playing around.

Brian_17

I am building a 427 right now that has all the good parts in it. This motor was to get the truck running and out working out the chassis until I get the big motor done. Working on a you tube channel for videos right now.