Timing on a 540ci N/A
08-30-2010, 08:36 AM
#1
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Timing on a 540ci N/A
Just curious where the timing should be set. Its at 32 at 3000rpm right now and my rpms are short at least 500-700rpm. Im sure the easiest way is turn it up til it clatters and back it down, but just curious on opinions. Only gettin about 4400rpm now and its rated for 4800-5200. Prop is not the issue. I have tried a range from 26p to 32p. Thanks.
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08-31-2010, 01:05 AM
#4
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suprised that no one asked for more information, like what is your compression ratio? What gas do you want to run in it? How much HP?
If you have tried a range of props and still cant get your RPM's up, it sounds like the engine is not getting enough air/fuel, either one or both of those. I doubt that timing will give you another 700rpm.
I have a N/A 598ci with 10:1 that I have set at 33º total by 3000rpm solely due to the fact that I would rather keep it conservative and safe with 93 octane, then to hang it out and run the risk of getting bad gas. Mid 700hp range.
If you have tried a range of props and still cant get your RPM's up, it sounds like the engine is not getting enough air/fuel, either one or both of those. I doubt that timing will give you another 700rpm.
I have a N/A 598ci with 10:1 that I have set at 33º total by 3000rpm solely due to the fact that I would rather keep it conservative and safe with 93 octane, then to hang it out and run the risk of getting bad gas. Mid 700hp range.
08-31-2010, 01:23 AM
#5
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There is no way to give you good advice on timing with the little info provided. Somewhere between 32 and 36 is most common. Is it at max advance at 3000rpms????? What if you rev to 3600rpms or higher???
........and no you don't set timing higher and wait for the clatter.
Sounds like it could be a fuel starvation problem if you don't see any differences in rpm with 26-32" props. That or something else is wrong. I doubt that a few more degrees of timing will make that much difference.
........and no you don't set timing higher and wait for the clatter.
Sounds like it could be a fuel starvation problem if you don't see any differences in rpm with 26-32" props. That or something else is wrong. I doubt that a few more degrees of timing will make that much difference.
08-31-2010, 08:56 AM
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Be very careful with your problem! I had/have a similar issue on my new engine and I was bumping the timing up and i ended up melting one piston and started on another. It all happened within a minute and was do to a fuel issue. I believe the carb was set up way to lean as well as a possible startvation issue on the secondary. Either way now I'm out of the water and waiting for the new pistons to arrive! IMO you have bigger issues than timing, take your time on this.
08-31-2010, 02:20 PM
#8
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Assuming you are 9.5 CR or less @ 5200 RPM, based on our dyno testing the diference in HP from 32 to 38 degrees is likely less than 10 HP....not enough to show on the GPS. As you are looking for 500-700 RPM, you have other issues beyond timing.
08-31-2010, 02:48 PM
#9
Ive seen weak valve springs keep it from reving also.
Prob need to ck fuel pres first, then bump the timming up just to see if the rpm comes up.dont go past 36
Prob need to ck fuel pres first, then bump the timming up just to see if the rpm comes up.dont go past 36
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