Holley EFI Timing tables. Can anyone share what they run
05-29-2022, 11:43 PM
#11
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05-30-2022, 12:19 AM
#12
Compression
One of the biggest fallacies in engine building is the issue of your real compression.
most 9.5:1 pistons in a mild or even radical cam set up is that your DCR (dynamic compression ratio) is very likely 7.9:1 compression.
look online and do yourself favor and calculate your DCR. Tune from the compression ratio.
most 9.5:1 pistons in a mild or even radical cam set up is that your DCR (dynamic compression ratio) is very likely 7.9:1 compression.
look online and do yourself favor and calculate your DCR. Tune from the compression ratio.
05-30-2022, 03:12 PM
#13
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Hi Guys, was hoping you may be able to help me, i know its a big ask but i too have gone down the Holley Road - (and i have no experience at all) I was after some help with timing curve, i have been talking a lot with the guys on the Holley forum and they have been very helpful where they can, but most don't understand boats, and as far as I'm aware total timing on my marine engines ( i have twin setup) should come early in the RPM range for torque. (6 Tonne Searay)
By no way is my setup high performance, i did it for reliability, i always cruise at 3000 - 3500 RPM.
If it helps i have Twin 454,s with new Dart Eagle Iron heads (Dual spring setup) (i know i coulda done better) I ditched the Distributors and have Holley / MSD Cam Plug sensor, Crank Sensors and Smart coils all with Holley HP ECU.
New JE Pistons and Im at approx 9.5 :1 Compression and i use Premium unleaded fuel (By the way I'm in Australia).
I have them running but the guys on Holley site want me to find what the timing curve for the original motors was. Originally Merc 454 Mag MPI Horizon EFI.
If not maybe a safe timing curve so we can enjoy the fruits of all our work...Cheers Aaron...
By no way is my setup high performance, i did it for reliability, i always cruise at 3000 - 3500 RPM.
If it helps i have Twin 454,s with new Dart Eagle Iron heads (Dual spring setup) (i know i coulda done better) I ditched the Distributors and have Holley / MSD Cam Plug sensor, Crank Sensors and Smart coils all with Holley HP ECU.
New JE Pistons and Im at approx 9.5 :1 Compression and i use Premium unleaded fuel (By the way I'm in Australia).
I have them running but the guys on Holley site want me to find what the timing curve for the original motors was. Originally Merc 454 Mag MPI Horizon EFI.
If not maybe a safe timing curve so we can enjoy the fruits of all our work...Cheers Aaron...
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hogie roll (05-30-2022)
05-30-2022, 09:33 PM
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The stock timing curve is so lame on a 454 mpi it will be worthless for what your doing, I dont have a copy on this computer I connect to intranet on and you cant copy a bin file off tunepro and paste it easily BUT at about 29 degrees total at 100 map from 5000 up, 20 nor so total at around 3600, 21 at 4200, 21 at 4400 its clearly meant to be at 100 % load forever on 84 octane!
For a Safe Starting point would this work ok?
Base spark i was thinking 14 Deg from 500 - 1800 rpm then 17 Deg @ 2000, 20 deg @ 2250, 24 deg @ 2500, 28 @ 2750 then 32 onwards
Last edited by Waterlife; 05-30-2022 at 09:34 PM. Reason: mistake
05-30-2022, 11:12 PM
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My Base spark
Hi All, this is my base spark as set by a Holley tuning guy, he has never done a boat, and im not sure about lower torque, i cruise at approx 3200 - 3500 (planning 22-25 knots) I never take it over 4000 rpm. Fuel is 46 PSI at Rail
Any advice here..
Any advice here..
05-31-2022, 06:16 AM
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06-01-2022, 05:02 PM
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No, the numbers I posted are about what merc puts in a 454/502 mpi at 100 map, really lame timing curve at wot. Looking at your timing curve, your 100 map numbers are ok as long as your not seeing any KR. You could possibly put more cruise timing in at 75/80 map, what map are you at when cruising, whats your fuel octane and compression again?
I use Premium Fuel here in OZ which is 98 Octane.
My Compression is 9.58:1 (below pic)
06-02-2023, 09:51 AM
#19
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This post could not have come at a better time, I am just dropping in my fresh 509 with a 9.2:1 compression on the stock iron heads fitted with Inconel valves. It has an Isky cam with these specs:
I have no clue what timing to run on a Big block I'm more in tune with an LS and what heat range plug to start with???
And for knock sensors, do these blocks even have provisions for that? Mine is a brand new GM performance 502 block as my stock one cracked in a water jacket.
- Racing Cam
- Hyd. Roller
- Valve Lift Int/Ext. 0.553/0.578
- Valve Lash Hot Int/Ext. 0.000
- ADV Duration Int/Ext. 275/284
- 0.050 Duration Int/Ext. 228/238
- Lobe Center 112
I have no clue what timing to run on a Big block I'm more in tune with an LS and what heat range plug to start with???
And for knock sensors, do these blocks even have provisions for that? Mine is a brand new GM performance 502 block as my stock one cracked in a water jacket.
Last edited by Joeyboost; 06-02-2023 at 09:55 AM.
06-05-2023, 09:15 AM
#20
keep the cruise timing at 28 till u get to a dyno or something. Dont know why holley doesnt have provision for a knock sensor.
I dont think u will burn anything up too easy. as mentioned keep the timing around 30 max until you can get it on a dyno. Look at the tables and adjust accordingly. I just test drove a gen 4 stock 454 with the first post and the boat ran incredibly well.. do not use automotive files! Im very happy just hoping to share with others. Get it up and running correctly and then run it up and down the rev ranges while recording a data log. After an hour or two, save the data log AND download the ecu to the sd card. Sniper will have the learn tables included with that so youc an what has been going on.
With a cam that big you might want to consider running those o2 extenders or whatever they are..
I dont think u will burn anything up too easy. as mentioned keep the timing around 30 max until you can get it on a dyno. Look at the tables and adjust accordingly. I just test drove a gen 4 stock 454 with the first post and the boat ran incredibly well.. do not use automotive files! Im very happy just hoping to share with others. Get it up and running correctly and then run it up and down the rev ranges while recording a data log. After an hour or two, save the data log AND download the ecu to the sd card. Sniper will have the learn tables included with that so youc an what has been going on.
With a cam that big you might want to consider running those o2 extenders or whatever they are..
Last edited by CamaroMan; 06-05-2023 at 09:17 AM.
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ar300johnson (06-07-2023)
