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Mine is a 1987 2.0L 150, but I bet this might just as well apply to all the classic V6’es...
anyway, just did my five yearly compression check and everything was 120psi, except the top two, which were both 110psi.
Is is that kind of typical for this family of motors?
-Peter
I’ve seen it on heavy boats and heavy pitch. Most see it on 5-6 from the last cylinder time issue.
Cooling issue - Steam pockets?, or last 2 cyls. in line to receive cooling water, or both?
Crud in the carb(s) leaning those 2 cyls. out?
Got a 1988 2.4 175 HP. that compression tested @135 all holes except BOTTOM 2 @130.
What's with the last cyl. time issue? Please elaborate!Quote:
Originally Posted by Motv18
Would it then be good practice to "jet up " on these cyls. to avoid issues, or is there another remedy?
It tends to run about a degree or two more then #1, so if you’re doing performance setups you time off the most advanced hole which is normally #6.
Its just rod length and wrist pin depths and crank twist all in spec but that all add up to a fast hole. Theirs quite a few write ups on timing I don’t have time to link currently. I think it’s also the lean side on some it’s the most common hole to fail.
So my numbers yesterday morning were:
110/110
120/120
120/120
Went back and checked my numbers from five years ago and they were about the same. Somebody in a post back then advised that I use 89 and let her rip. I’ve been using 91 anyway. I get the feeling I could use 87, but not sure. It is a 1987 motor so that was well into the 87 octane era.
-Peter
76-78 2.0 1750's had tight heads and need good fuel. By '79 the chambers were opened up so lower octane isn't a problem. By '83 or '84 the floats were plastic instead of foam so ethanol gas is no problem...
Merc put out a letter saying 87 was good when lead went bye. Unless specific noted in the ownership manual.
Tolerance stack up, gotcha. Thanks!Quote:
Originally Posted by Motv18