engine Knock

[kadkins0929]

So I have a 75 Volvo Penta 170. I just tore it down new bearings in everything, head work, cylinder walls done, new rings the works. Took it out and lost power and started hearing a knock. When I got home saw that I didn't tighten down distributor so timing was off. But after timing again, knock is still there. What are some possible causes of this Knock and where do I begin. Also when I went out I was running at over 5000ft and my home is about 800ft. Could I just have carbon deposits because of timing and elevation that could cause this knock. Thanks for anyone's time.
Kyle

 

[zbnutcase]

Re: engine Knock

Engine noises can come from so many different things its impossible to say without hearing it.

 

[littlebookworm]

Re: engine Knock

It could be that you left something else loose as well, such as a bearing cap. You may have to pull the engine and pull the pan off to check all your bearings. But then, as was just suggested, it could be from any number of other places. By the way, when you put your engine back in the boat, did you align it? You've got quite a bit of checking to do, and I know no short cut. Sorry. Good luck. Hy

 

[jtmarten]

Re: engine Knock

How hard were you running it before losing power?? What was your main/rod bearing clearances? Were they auto-engine spec'd, or marine?

 

[kadkins0929]

Re: engine Knock

Everything was marine spec. Checked main clearance torqued everything to the book. It all looked beautiful. I was not running the boat hard at all. really just kind of taking it easy puttering across the lake.

 

[6meter]

Re: engine Knock

How hard were you running it before losing power?? What was your main/rod bearing clearances? Were they auto-engine spec'd, or marine?

Are main and rod clearances more or less on a marine engine?