timing recommendation
08-30-2016, 02:44 PM
#1
timing recommendation Hey guys,
I have a 5.3 in a jet boat. To say its loud would be an understatement.
I was looking for some recommendations on timing guidelines. It is so loud i cant hear any detonation so i rely on what the wideband/plugs show me.
Specs are
Gen 3 5.3 stock internals (arp bolts)
Profesionally built 750 Holley Double pumper. Off the top of my head the jetting i think is 72/83 jetting. Wideband shows a bit on the lean side at part throttle (about 14.5-15:1) but high 12's at WOT
BTR Stage 4 LS1 Cam (235/242 .621/.595" 111lsa)
243 heads milled .030 (if my math is correct the static compression is 10.0:1)
Edelbrock victor jr intake
NOS cheater system (150 shot .63n/.55f jets) AFR is around high 11's on the bottle
daytona smart spark
I run 50/50 91/100LL av fuel on motor, and pure 110 on the bottle
Currently im at 30 degrees total timing. Real simple "curve" 8 degrees at 0rpm -> 30 at 1500 and flat out
I used to retard the timing for the nitrous, but ive done quite a few pulls on the bottle and checking plugs i see 0 signs of detonation on them after a nitrous run without pulling timing.
So currently i run 30* on motor and 30* on the nitrous. Boat runs very strong and has no issues. Im on my 13th bottle so far. I do flow the fuel side before every trip.
My question, is does anyone want to recommend some timing? Its kind of a pain in the *** bringing the laptop in the boat and doing passes then turning the timing up.
I was thinking about trying more towards the 38-40* range on motor of course. think ill leave the nitrous timing where it is.
I have a 5.3 in a jet boat. To say its loud would be an understatement.
I was looking for some recommendations on timing guidelines. It is so loud i cant hear any detonation so i rely on what the wideband/plugs show me.
Specs are
Gen 3 5.3 stock internals (arp bolts)
Profesionally built 750 Holley Double pumper. Off the top of my head the jetting i think is 72/83 jetting. Wideband shows a bit on the lean side at part throttle (about 14.5-15:1) but high 12's at WOT
BTR Stage 4 LS1 Cam (235/242 .621/.595" 111lsa)
243 heads milled .030 (if my math is correct the static compression is 10.0:1)
Edelbrock victor jr intake
NOS cheater system (150 shot .63n/.55f jets) AFR is around high 11's on the bottle
daytona smart spark
I run 50/50 91/100LL av fuel on motor, and pure 110 on the bottle
Currently im at 30 degrees total timing. Real simple "curve" 8 degrees at 0rpm -> 30 at 1500 and flat out
I used to retard the timing for the nitrous, but ive done quite a few pulls on the bottle and checking plugs i see 0 signs of detonation on them after a nitrous run without pulling timing.
So currently i run 30* on motor and 30* on the nitrous. Boat runs very strong and has no issues. Im on my 13th bottle so far. I do flow the fuel side before every trip.
My question, is does anyone want to recommend some timing? Its kind of a pain in the *** bringing the laptop in the boat and doing passes then turning the timing up.
I was thinking about trying more towards the 38-40* range on motor of course. think ill leave the nitrous timing where it is.
08-30-2016, 03:21 PM
#2
10 Second Club
35* flat lined here with a similar cam....but you really don't see a load like a car would/does either.
38* I seen a few black specs and dialed her right back.
38* I seen a few black specs and dialed her right back.
08-30-2016, 03:22 PM
#3
thanks thats a good point
When im cruising theres hardly any load on the engine. Once the RPM gets to 4k and above it really loads down hard htough.
WOT on motor is 5200 rpm or so and thats it.
But it feels liek youre driving somehting with a VERY loose converter
When im cruising theres hardly any load on the engine. Once the RPM gets to 4k and above it really loads down hard htough.
WOT on motor is 5200 rpm or so and thats it.
But it feels liek youre driving somehting with a VERY loose converter
Last edited by steves86ta; 08-30-2016 at 03:44 PM.