SoCal Jet Boats
Tech Talk => Engine Mechanical / Electrical => Topic started by: barefootin on November 23, 2011, 02:14:03 AM
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Got a new boat (17' Sutphen-1976) that has been redone from stem to stern...but wanted to know what the probable rpm range would be for the following:
Ford 460 bored 20 over w/ Crower 460 cam and mild head work...complete MSD ignition (coil & distributor), Edelbrock performance rpm intake w/ holley (4011) 800 dlb pumper...other: 4" stainless steel manifolds w/ custom exhaust and Berkley Jet rebilt w/ Stuffer by ARS...
Engine has approx 6 hrs on it (30 min my time) and on my initial two runs i am getting hesistation (not bog)from 3000 rpm to WOT...and it tops out at around 4100 rpm and you can tell it wants to get up a go kinda...checking the carb secondaries they dont seem to be opening all the way...maybe 2/3's...but anyway thought i would ask advice here for answer to my question;
what is the rpm range for an engine such as this...cause i never was a ford man...more chevy and harleys...thanx
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Got a new boat (17' Sutphen-1976) that has been redone from stem to stern...but wanted to know what the probable rpm range would be for the following:
Ford 460 bored 20 over w/ Crower 460 cam and mild head work...complete MSD ignition (coil & distributor), Edelbrock performance rpm intake w/ holley (4011) 800 dlb pumper...other: 4" stainless steel manifolds w/ custom exhaust and Berkley Jet rebilt w/ Stuffer by ARS...
Engine has approx 6 hrs on it (30 min my time) and on my initial two runs i am getting hesistation (not bog)from 3000 rpm to WOT...and it tops out at around 4100 rpm and you can tell it wants to get up a go kinda...checking the carb secondaries they dont seem to be opening all the way...maybe 2/3's...but anyway thought i would ask advice here for answer to my question;
what is the rpm range for an engine such as this...cause i never was a ford man...more chevy and harleys...thanx
You should be able to see another 500 to 700 RPM depending on several things...4100 tells me there is something definitely incorrect...
Given you have hesitations and bogging it sounds fuel related. May be time to start with a known good carburetor and go from there....
A jet needs all things to be tip top as far as the tune at WOT. It does not take much to keep the engine from making max HP.
Good luck and welcome!
GT
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GT...thanks for the reply...
the carb is new...but what would you suggest as an alternative
what should be the initial timing...not sure if that is correct...got the secondaries to open so one down...
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12 degrees
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12 degrees
Based on?
The initial timing is somewhat unimportant.
What you are really after is the timing at 2500 RPM and above. Jet pumps do not create much engine load below about 3000 RPM, so tip in on the timing is really unnecessary.
On a relatively stock 460 Ford I would say 34* BTDC at 2500+ would be a safe starting point.
GT
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If that is a vacumn secondary change the spring try the lightest to open all the way.