SoCal Jet Boats

Tech Talk => Engine Mechanical / Electrical => Topic started by: Cadillac on May 01, 2009, 12:45:05 PM

Title: engine compression
Post by: Cadillac on May 01, 2009, 12:45:05 PM
I just checked my engine cylinder compression and want to know if this is good compression or so-so and how long till I may need a rebuid. The motor runs just fine just curious. I have a 460 the #'s are as follows 1-120 2-140 3-130 4-135 5-125 6-130 7-130 8-130 I checked them all twice and this was the highest # for each cylinder, also hooked up a manual oil pressure gauge and am getting 55psi at idle. Any help would be appreciated!
Title: Re: engine compression
Post by: HDriderTH on May 01, 2009, 01:04:09 PM
RUN IT!!!! Check it again next year. Prop your throttle blades open with ALL plugs out when testing.
Title: Re: engine compression
Post by: SLCKREG on May 01, 2009, 01:13:07 PM
For the heck of it try a can of that "restore" I got a buddy that swears by it. It's supposed to raise and even out your compression.
Title: Re: engine compression
Post by: electrowoman on May 01, 2009, 01:18:51 PM
Looks like a stock lincoln type motor.  Go have some fun.
You're fine.
Title: Re: engine compression
Post by: LakesOnly on May 01, 2009, 01:35:35 PM
I just checked my engine cylinder compression and want to know if this is good compression or so-so and how long till I may need a rebuid. The motor runs just fine just curious. I have a 460 the #'s are as follows 1-120 2-140 3-130 4-135 5-125 6-130 7-130 8-130 I checked them all twice and this was the highest # for each cylinder, also hooked up a manual oil pressure gauge and am getting 55psi at idle. Any help would be appreciated!
If this is a standard 460 Marine engine, then your compression ratio is about 7.7:1 and so I'd say your cylinder pressure is almost perfect and damn-near dead even, taking varying valve timing events into account. Keep changing the oil and plugs and run it for another 30 years.

LO
Title: Re: engine compression
Post by: Cadillac on May 01, 2009, 01:44:08 PM
Thanks guys that is exactly whatl I wanted to hear!!!! Might try the Engine Restore heard it works.
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