SoCal Jet Boats
Tech Talk => Engine Mechanical / Electrical => Topic started by: Handyman on June 02, 2015, 02:33:40 PM
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Now I have my motor idling and I need to verify the timing... Did a search a read most of the topics related to timing etc.. And watched videos on Google... I read in the Hardin marine manual to time it at 8 BTDC @750rpms. I keep reading total timing should be at around 30-32 at either 2500 or 3000rpms. How do I do this of the timing plate openly I goes to 10? Eye ball it?
Do I really need to bring it up to those RPMs to check the total timing?
If so can adjust the idle screw to bring the RPMs up to check total timing? I ask this because it's just me working on it today.
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Now I have my motor idling and I need to verify the timing... Did a search a read most of the topics related to timing etc.. And watched videos on Google... I read in the Hardin marine manual to time it at 8 BTDC @750rpms. I keep reading total timing should be at around 30-32 at either 2500 or 3000rpms. How do I do this of the timing plate openly I goes to 10? Eye ball it?
You can install either a timing tape on the balancer or use a degree wheel to mark 30, 32, 34, 36, 38 wuth a white paint pen.
Do I really need to bring it up to those RPMs to check the total timing?
Not if you know how much advance the distributor has built into it.
If so can adjust the idle screw to bring the RPMs up to check total timing? I ask this because it's just me working on it today.
No. If anything, use your hand on the throttle linkage. I have used tie wraps in the past. Keep a pair of diagnal pliers in your pocket.
GT
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Not if you know how much advance the distributor has built into it.
GT
I have no idea how much advance it has... It's an HEI DIST.
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Most modern timing lights now have the ability to "dial back" the timing light to see where you are sitting.
How it works is you get the rpm up to the 25-3000 range, and use the dial to get the timing marks to line up at 0, then look to see how many degrees you have on the light dial.
I'll post a pic in a couple minutes.
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Once you have your timing set at high rpm you can recheck it at idle and get a good idea of how much mechanical advance is in the distributor.
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I keep reading total timing should be at around 30-32 at either 2500 or 3000rpms.
What engine is it?
Chevy I'd recommend kicking it up to the 35-36 range.
Ford you should be good at 30-32.
Olds I really don't have any idea.
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It's a Chevy 454.. Right now at 750rpms it's at 8 BTDC... At 2500 it won't advance past 22ish
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The initial setting (idle) really isn't important as long as it starts easily and doesn't diesel when shut off. Most distributors have about 20-22 degrees of mechanical advance built into them meaning that your initial will be around 10-12 degrees to be in the 30-34 range when all in.
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Never did it with an HEI but if you can't get a hold of a dial back timing light you could look for a shop that still has a Sun machine. They would verify the timing curve and total advance in the distributor then you could set it at idle if TDC has been verified on the motor.
Or just take it over to Crewchief, he doesn't have anything else to do anyways ! LOL...
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Never did it with an HEI but if you can't get a hold of a dial back timing light you could look for a shop that still has a Sun machine. They would verify the timing curve and total advance in the distributor then you could set it at idle if TDC has been verified on the motor.
Or just take it over to Crewchief, he doesn't have anything else to do anyways ! LOL...
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I have been looking for an old distributor machine for several years.
You can also use your hand on the rotor and just rotate it to see how far it turns in degrees. Not real scientific, but you can get pretty close.
GT
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I almost bought a dial back timing light but had no idea what it was...should have bought the damn thing
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I almost bought a dial back timing light but had no idea what it was...should have bought the damn thing
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very good tool to have in ur box if ur gonna be playin with boats or cars.
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