Life Expectancy Of Merc 575 Sci
03-07-2005, 08:20 AM
#2
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Re: Life Expectancy Of Merc 575 Sci
It's a solid motor on a good platform.
Relatively low boost. Low compression blower pistons.
Pretty mild cam and mild springs.
Keep the boost stock, prop for 5000-5100, do not overheat it, warm up the oil before hammering it, keep WOT operation down under 5% of the time, run good quality gas, and stay on top of your fluid changes and you should expect normal (400 hour) service intervals.
Up the boost, run questionable fuel, let it overheat into the alarm buzzer, and do other things to tempt detonation, and you are making your own luck.
Keep in mind that with all BBC's, valvetrain aggressiveness is the determining factor on service intervals. The wilder the cam and stiffer the springs, the sooner you gotta service it. Bottom end parts are usually no worries.
Relatively low boost. Low compression blower pistons.
Pretty mild cam and mild springs.
Keep the boost stock, prop for 5000-5100, do not overheat it, warm up the oil before hammering it, keep WOT operation down under 5% of the time, run good quality gas, and stay on top of your fluid changes and you should expect normal (400 hour) service intervals.
Up the boost, run questionable fuel, let it overheat into the alarm buzzer, and do other things to tempt detonation, and you are making your own luck.
Keep in mind that with all BBC's, valvetrain aggressiveness is the determining factor on service intervals. The wilder the cam and stiffer the springs, the sooner you gotta service it. Bottom end parts are usually no worries.
03-07-2005, 01:09 PM
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Re: Life Expectancy Of Merc 575 Sci
It's my understanding that it is less aggressive than the 500efi but I'm not sure you can compare NA to blower as far as what's needed in a cam.
Anybody know what Merc uses for the major internals such as crank, pistons, valve train. Basic GM parts? or other Brands?
Anybody know what Merc uses for the major internals such as crank, pistons, valve train. Basic GM parts? or other Brands?
03-07-2005, 02:41 PM
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Re: Life Expectancy Of Merc 575 Sci
I am just trying to gage the valve spring stress compared to my hp500efi. If the cam is not as agressive, one would have to believe the springs are not under as much stress.
I do agree with keeping WOT to a minimum! To bad. They sound great!
I do agree with keeping WOT to a minimum! To bad. They sound great!
03-07-2005, 03:29 PM
#6
Re: Life Expectancy Of Merc 575 Sci
Originally Posted by Canada Jeff
I am just trying to gage the valve spring stress compared to my hp500efi. If the cam is not as agressive, one would have to believe the springs are not under as much stress.
I do agree with keeping WOT to a minimum! To bad. They sound great!
I do agree with keeping WOT to a minimum! To bad. They sound great!
I agree with mcollinstn, treated right they will give you good service.
03-07-2005, 08:11 PM
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Re: Life Expectancy Of Merc 575 Sci
Originally Posted by zahndok
It's my understanding that it is less aggressive than the 500efi but I'm not sure you can compare NA to blower as far as what's needed in a cam.
Anybody know what Merc uses for the major internals such as crank, pistons, valve train. Basic GM parts? or other Brands?
Anybody know what Merc uses for the major internals such as crank, pistons, valve train. Basic GM parts? or other Brands?
A 500efi and a 575SCi share the following components:
Gen 6 siamese 4.470" GM 4 bolt block.
Forged steel GM crank.
"Merc Racing" forged rods.
GM rectangular port iron heads.
Crane gold roller rockers.
A 575SCi uses:
Inconel exhaust valves (500 efi "may" have those, but I don't think so)
Flat tappet hydraulic cam
Mild springs
Dished Blower pistons
500efi uses:
A more aggressive hydraulic roller cam
Springs matched to the cam
JE flat top pistons
03-07-2005, 09:02 PM
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Re: Life Expectancy Of Merc 575 Sci
Originally Posted by mcollinstn
500efi is a more aggressive cam. Faster ramps. More lift and duration.
A 500efi and a 575SCi share the following components:
Gen 6 siamese 4.470" GM 4 bolt block.
Forged steel GM crank.
"Merc Racing" forged rods.
GM rectangular port iron heads.
Crane gold roller rockers.
A 575SCi uses:
Inconel exhaust valves (500 efi "may" have those, but I don't think so)
Flat tappet hydraulic cam
Mild springs
Dished Blower pistons
500efi uses:
A more aggressive hydraulic roller cam
Springs matched to the cam
JE flat top pistons
A 500efi and a 575SCi share the following components:
Gen 6 siamese 4.470" GM 4 bolt block.
Forged steel GM crank.
"Merc Racing" forged rods.
GM rectangular port iron heads.
Crane gold roller rockers.
A 575SCi uses:
Inconel exhaust valves (500 efi "may" have those, but I don't think so)
Flat tappet hydraulic cam
Mild springs
Dished Blower pistons
500efi uses:
A more aggressive hydraulic roller cam
Springs matched to the cam
JE flat top pistons
