Is my merc. 5.7 flat tappet or roller cam lifters, how can i tell?

BETZ954

BETZ954

Seaman
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Jun 6, 2009
Messages
52
my mercuiser is an 91' Alpha one 5.7

engine serial # 0D521372

I am going to be replacing the long block, but to buy my new one they need to know if its roller or flat lifters. how can i identify this.
 
AZSenza

AZSenza

Chief Petty Officer
Joined
Mar 11, 2008
Messages
521
Re: Is my merc. 5.7 flat tappet or roller cam lifters, how can i tell?

Go to a mercruiser parts website and plug in the serial number. However this will usually only tell you if it MIGHT have had rollers. I pulled the intake off and to my surprise I had rollers. There will be a metal "Spider" in the center of the engine under the intake (Lifter Valley) and a metal link (tiebar) between each two rollers to keep them from spinning (BAD with roller lifters GOOD with flats), I was even told by Mercruiser I had flat tappets so I was pleasantly surprised to see my rollers.
http://www.mercurymarine.com/parts-and-accessories/parts-catalog/
 
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Bt Doctur

Bt Doctur

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Messages
19,111
Re: Is my merc. 5.7 flat tappet or roller cam lifters, how can i tell?

serial number comes back as having both types ,have to pull your manifold and see whats there
I don't see what difference it would make if your buying a complete engine
 
AZSenza

AZSenza

Chief Petty Officer
Joined
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Messages
521
Re: Is my merc. 5.7 flat tappet or roller cam lifters, how can i tell?

Core Charge?
 
BETZ954

BETZ954

Seaman
Joined
Jun 6, 2009
Messages
52
Re: Is my merc. 5.7 flat tappet or roller cam lifters, how can i tell?

Yes core charge. I've heard if I go from flats to rollers that I must change distributor gear.
 
Bt Doctur

Bt Doctur

Supreme Mariner
Joined
Aug 29, 2004
Messages
19,111
Re: Is my merc. 5.7 flat tappet or roller cam lifters, how can i tell?

? the cam dosent care if its flats or rollers ,neither does the dist gear
 
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