Over all timing on a built up l31

[355 chevy]

I have a built-up l31 engine in my '98 Silverado using the stock fuel injection.with lt4 cam and aluminum heads,bored 30 over headers ,roller rockers 1.6 it's been turned.and it's a dog off the line it only has top end power my over all timing is at 34 it feels like it needs way more timing.any ideas?

 

[Deancr11]

What did you do to let the computer know what to do?

 

[Supercharged111]

How do you know what your timing is? 34 is more than stock.

 

[355 chevy]

How do you know what your timing is? 34 is more than stock.

The guy that tuned it with hp tunners

 

[Supercharged111]

If it's been properly tuned then it is what it is. 34 degrees is a lot of timing for a stock headed Vortec. What kind of heads did you go with?

 

[L31MaxExpress]

If it's been properly tuned then it is what it is. 34 degrees is a lot of timing for a stock headed Vortec. What kind of heads did you go with?

Never found a need for more than about 29-31° on the ones I have tuned running 91+ octane. Only one that need 34° for peak power was on E85. Timing curve is way more important than the peak number. That being said I have run as much as 42° with the stock distributor and 50° with CNP at light throttle cruise.

 

[L31MaxExpress]

I have a built-up l31 engine in my '98 Silverado using the stock fuel injection.with lt4 cam and aluminum heads,bored 30 over headers ,roller rockers 1.6 it's been turned.and it's a dog off the line it only has top end power my over all timing is at 34 it feels like it needs way more timing.any ideas?

You really need gears and a decent converter. Then again a LT4 Hotcam is a small cam and really does not give up much torque down low when tuned correctly.