mercruiser 488

lynnboy021

Chief Petty Officer
Joined
Jan 27, 2008
Messages
553
have a 1986 mercruiser 488 is it the same as the 470 i cant find the manuel to download
 

sdoomaha

Petty Officer 3rd Class
Joined
Oct 6, 2008
Messages
94
Re: mercruiser 488

Very similar...I believe the 488 has a 4 barrel, and I have heard mixed reports of a different cam, other than that are supposed to be identical. Interestingly the 488 has a higher WOT than the 470 from the manuals I have looked at leading me to believe the cam may be different. I have only worked on my 470, so am no expert....others will follow that can tell you definitively.

Take care,
 

guyaverage

Petty Officer 2nd Class
Joined
Aug 4, 2008
Messages
101
Re: mercruiser 488

The 488 is a 4 bbl version of the 470. Manual #3 or #8 will work.

The main difference from the 2bbl, other than the carburetor, intake, and throttle cable, is the engine oil cooler built in to the bottom of the 4bbl intake manifold.

The 4bbl version cams supposedly have a slightly higher exhaust lift, and slightly higher pressure valve springs. Whether or not either of these tidbits are true depends on which manual you are reading. :confused:
 
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