ignition timing
02-20-2008, 04:19 PM
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ignition timing
hey guys,i was wondering how many,if any of you have your distributors advance locked out?the guy i bought my motor from says he locked the timing at 35 degrees and it helped it idle and had no starter or starting problems,i know on a car,it is hard to start when the engine is at operating temps with the timing locked,but a boat runs cooler,so i am not sure what to do,put advance in it or lock it??
this is a 509ci custom built motor. 600hp
this is a 509ci custom built motor. 600hp
02-20-2008, 07:41 PM
#2
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Ak,
with a big enough cam, it will work. I have run my boat with a locked dist for years. Give it a try and see how it works for you.
I just recently switched to an advance curve in my EFI ECU that controls my MSD Ignition.
Dick
with a big enough cam, it will work. I have run my boat with a locked dist for years. Give it a try and see how it works for you.
I just recently switched to an advance curve in my EFI ECU that controls my MSD Ignition.
Dick
02-21-2008, 04:07 PM
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Guys, my friend just bought a SC B&M 250 509? something engine which passed through a 'reputable' speed shop here. They claim they locked the timing @ 30 deg after cam swap (to Crane -741). It has the MSD 8650 distributor and MSD Marine ignition. I would have felt more confident with regulated timing and maybe boost retard added, how about you?
02-21-2008, 05:20 PM
#4
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There is nothing wrong with locked out timing. Especially on a supercharged application I run all of them locked out, unless EFI Then a timing map is designed. I have also run N/A engines locked out as well.
02-21-2008, 08:19 PM
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Example: I am taking a lengthy trip on Lake Erie and get low on fuel. I search out a "new" marine fuel stop and pull in. I am faced with the fact that this fuel stop only has 89 octane. I am running the motors at a good pace trying to outrun an approaching storm. I throw in a 4 degree retard chip into my MSD timing computer. Does this give me a little added protection from low octane detonation?
02-21-2008, 09:28 PM
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600 cu.in. blown, When you lock the distributor the timing still has to be set by a timing light or cheat box. I run my engines at 36 and have no starter issues.I do spend the engines over with the ignition off and then fire the msd box.
Also 10 pounds boost and no retard.
just my 2 !!!
Also 10 pounds boost and no retard.
just my 2 !!!
02-22-2008, 06:22 AM
#7
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On the subject of timing, I have a question that relates to ignition retard. In a marine application and let's say between 9.4 to 9.6 to 1 comp ratio, the total advance timing would be let's say 36 degree's. Also given as a baseline the use of a minimum of 91 octane fuel. Question: Would retarding the total timing reduce the chance of detonation when using let's say 87 to 89 octane fuel?
Example: I am taking a lengthy trip on Lake Erie and get low on fuel. I search out a "new" marine fuel stop and pull in. I am faced with the fact that this fuel stop only has 89 octane. I am running the motors at a good pace trying to outrun an approaching storm. I throw in a 4 degree retard chip into my MSD timing computer. Does this give me a little added protection from low octane detonation?
Example: I am taking a lengthy trip on Lake Erie and get low on fuel. I search out a "new" marine fuel stop and pull in. I am faced with the fact that this fuel stop only has 89 octane. I am running the motors at a good pace trying to outrun an approaching storm. I throw in a 4 degree retard chip into my MSD timing computer. Does this give me a little added protection from low octane detonation?
