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Discussion Starter · #1 ·
I've always had the best luck with 4* adv. on my cam in my N/A motors (jetboats) but i've herd that you don't need the adv. on a forced induction motor. Is this true? I've got the motor apart right now so i'm just wondering where i should degree the cam in at.

Thanks, Dallas
 

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Playing with cam timing or cams, porting, oversize valves, etc and trying to optimize a setup for some small hp gains is more for something that doesn't have "adjustable power"

If you did those and verified on a dyno the small hp that (maybe) could have been had it would be insignificant to what one more # of turbo boost would add.
8 - 10% additional torque per # of boost.
 

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Discussion Starter · #4 ·
Thanks guys, i have the motor apart (lowering the cr to 8.5:1) with the cam at 0* and timming @20* adv. make this motor a total turd when not in boost? This is really just a lake boat that will be running on 91 pump gas and 99% of the time not be in boost. The 514 i'm running was an honest 700+hp motor with a single dominator and 10.2:1 cr, i'd be happy with 1000hp with the turbos. I was thinking of setting it up to run about 5-15lbs of boost (in dash adjustible deal) do you think that will get the job done? Its intercooled and i also have a water/meth injection setup to ensure no detonation too. Thanks.:)
 

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Some guy
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Thanks guys, i have the motor apart (lowering the cr to 8.5:1) with the cam at 0* and timming @20* adv. make this motor a total turd when not in boost? This is really just a lake boat that will be running on 91 pump gas and 99% of the time not be in boost. The 514 i'm running was an honest 700+hp motor with a single dominator and 10.2:1 cr, i'd be happy with 1000hp with the turbos. I was thinking of setting it up to run about 5-15lbs of boost (in dash adjustible deal) do you think that will get the job done? Its intercooled and i also have a water/meth injection setup to ensure no detonation too. Thanks.:)
You can put the cam in 1 degree advanced to allow for timing chain stretch if you want.

Are you saying you plan to have 20 degrees total ignition timing in it?
 

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mo balls than $cents$
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You can put the cam in 1 degree advanced to allow for timing chain stretch if you want.

Are you saying you plan to have 20 degrees total ignition timing in it?
i saw that too:D man, give that thing some timing! try 28 degrees locked and check plugs from there. if you're intercooling and using water methanol when under boost, 28dergrees of advance is still plenty safe at 15lbs of boost, and at 28 advance, when just on the motor it'll run soooooooo much better:)bulb
 

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Discussion Starter · #7 ·
Yes 20* on ignition timing.:) I think i would have to drill out some holes in the pistons to run 20* cam timing.:D I really just want to get this motor done and some test and tune time in before winter so i have a good idea of what needs to be changed or upgraded. Thanks guys. Dallas:)
 

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i saw that too:D man, give that thing some timing! try 28 degrees locked and check plugs from there. if you're intercooling and using water methanol when under boost, 28dergrees of advance is still plenty safe at 15lbs of boost, and at 28 advance, when just on the motor it'll run soooooooo much better:)bulb
Yes 20* on ignition timing.:) I think i would have to drill out some holes in the pistons to run 20* cam timing.:D I really just want to get this motor done and some test and tune time in before winter so i have a good idea of what needs to be changed or upgraded. Thanks guys. Dallas:)
I completely understand the difference in cam and ignition timing, I just could not believe you would consider only 20 degrees ignition timing. When I worked at Banks in the late 70's, 28 degrees was the standard recomendation.

28 degrees total would be a good place to get started. Perhaps I would put a little more in it now days, based on my experience, fuel and amount of boost, among other things.

One other option might be a boost-retard setup if you run mostly out of boost.
 

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Discussion Starter · #9 ·
"One other option might be a boost-retard setup if you run mostly out of boost. "

I think this sounds like a very good idea, i have a timing retard box from my old hi compression motors for easier starting. Is it the same box with the addition of some kind of device that measures the boost?
 

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"One other option might be a boost-retard setup if you run mostly out of boost. "

I think this sounds like a very good idea, i have a timing retard box from my old hi compression motors for easier starting. Is it the same box with the addition of some kind of device that measures the boost?
sell all the stuff you got and buy a 6btm msd ignition box, its the same thing as a 6al but it has a built in boost retard and a adjustable knob you can mount up frt.. they're about 400 bucks new from summit but as i said, it replaces the msd box.
 

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my mag is lock out at 35 degrees ,I run 15 pounds of boost on a 461 bbc.my buddy has 42 degrees on his mag but he runs alky.:)hand
 

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Discussion Starter · #12 ·
my mag is lock out at 35 degrees ,I run 15 pounds of boost on a 461 bbc.my buddy has 42 degrees on his mag but he runs alky.:)hand
On 91 pump gas i don't think i would be able to hear the motor over the ping'n noise.:D
 

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Discussion Starter · #13 ·
sell all the stuff you got and buy a 6btm msd ignition box, its the same thing as a 6al but it has a built in boost retard and a adjustable knob you can mount up frt.. they're about 400 bucks new from summit but as i said, it replaces the msd box.
Cool, that sounds like the way to go to me.:))THumbsUp
 

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i run @ 32* timing with 1/3 110 sunoco & 2/3 91 octaine , twin turbo ,12 lbs of boost & innercooled ( old banks set-up)
 

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Right now I run 30* of timing locked out and have made a few good pulls at 14psi on 91 pump gas, plugs look great and have no detonation. I run the programable 6 box wich has a boost curve retard option wich will pull up to .1* of timing for every .1* of boost on a map sensor set up. I have not had time to set this option up yet so I just have it locked at 30*

When I do set it up I will start at 39* and slowly pull it back to say 34* as the vaccume goes away with the run retard option then let the boost retart do the rest from there. That way you will get optimal fuel burn when cruising around and the responce when you hit it hard will be much better.

Travis
 

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Discussion Starter · #17 ·


Heres a progress pic. Just in the middle of fab'n up some spacers between the manafolds and turbos. It used to be a pull thru setup, if you look you can see where i welded a carb hat ring to the bottom of the intercooler and then built up with weld and ground it all back down. I'll run some thread-all from the intake, thru the carb base plate then into the intercooler, bolting each piece separately. Also this way i could add waste-gates to control boost on the fly.:)
 

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Discussion Starter · #18 ·


Heres with the other side done, well ruff'd up anyways.:) I still have alot of work to do but its getting closer.
 

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Heres a progress pic. Just in the middle of fab'n up some spacers between the manafolds and turbos. It used to be a pull thru setup, if you look you can see where i welded a carb hat ring to the bottom of the intercooler and then built up with weld and ground it all back down. I'll run some thread-all from the intake, thru the carb base plate then into the intercooler, bolting each piece separately. Also this way i could add waste-gates to control boost on the fly.:)
do you think that the all-thread under extreme boost will stretch & crate a vacuum leak, you might want hardened studs or grade 8 ? looks good though !
 

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Discussion Starter · #20 ·
I might be money and time ahead to get some nice studs made, thread-all is some pretty cheap stuff.:)bulb
 
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