Chris Craft 327QA compression test and analysis

F14CRAZY

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The diagram above is reversed...the engine marked 1 is port, 2 is a starboard.

The two cylinders for reasons unknown had water shoot out when i removed the plugs and turned it oVer via the starter. I swore i removed the plugs and cranked it over when i took delivery of the vessel. There's an issue somewhere which wi will later chase after. Keep in mind that #2 had water in its crankcase. i have not opened it yet but I still feel it's probably a cracked intake manifold. No water in number 1. ive had both engines fire but have not actually ran them.

What do you guys make of the varying compression? Could this be one of those times when the rings are just stuck and compression will shoot back up when i run it, or are the chances of that happening more like the chances of belt dressing actually doing any good? Keep in mind the engines were cold and i've read that compression readings when cold arent of much use.

Are these things bad enough that i be pulling them now for at least a honing and rings or will they last a season with a few hours of uptime?

Ive read that anything more than a 10% variance is bad. i guess my readings show i dont have pistons with holes in them at least, and that my crankcase water isnt from a combustion chamber issue
 

Bondo

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Re: Chris Craft 327QA compression test and analysis

The two cylinders for reasons unknown had water shoot out when i removed the plugs and turned it oVer via the starter. I swore i removed the plugs and cranked it over when i took delivery of the vessel. There's an issue somewhere which wi will later chase after. Keep in mind that #2 had water in its crankcase. i have not opened it yet but I still feel it's probably a cracked intake manifold. No water in number 1. ive had both engines fire but have not actually ran them.

Ayuh,.... I'd sooner think the exhaust manifolds/ risers are failin'....
 

salty87

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Re: Chris Craft 327QA compression test and analysis

how long since they've been run good? cold test on engine's that have sat for a while isn't ideal.

108 and 105 aren't promising but i wouldn't pull yet. how old are these engines? 172 and 162...that's up there.
 

F14CRAZY

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Re: Chris Craft 327QA compression test and analysis

That's what I get for copying and pasting from my post on the Commander board...

Engines are in my '71 33' Chris Craft Coho sedan. I bought it last year for $620. I suspect the engines have not really been run in at least a couple years counting the condition of the boat. I've been working on gutting the interior and soon tearing down the exterior to replace all the rotten wood so I haven't given the engines much attention, though I've been wondering about them ever since so I decided to start by doing a compression test. Aside from my assumptions I have no history on them.

Number 2 had water in the crankcase which is why I suspected that the Q intake manifold was not properly winterized and the water pocket in the middle froze and cracked resulting in the crankcase water (before I bought it. I made sure it was properly winterized since the marina at least attempted to start them). I have not opened it up yet but with the decent compression readings I figure it can't be a cracked cylinder or something. Number 1 (and 2) are sloped downwards toward the two wet cylinders, and the Commander board owner thinks the intake may have cracked and water drained down to there. I suppose pulling off the intakes from 1 and 2 wouldn't be a bad idea at this point.

Thanks guys
 

F14CRAZY

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Re: Chris Craft 327QA compression test and analysis

Any other pieces of input guys?
 
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