Nothing worse than full bad box. :)

For sure something is damaged. A healthy engine will have a light flow of air & vapor out the breather, not puffing smoke.

The volume in the crankcase does not change as the pistons go up and down. For each piston moving down there is one moving up. Any flow out the breathers is from combustion gases getting past the rings or piston.

https://www.aa1car.com/library/engine_blowby.htm

Just for grins crank the engine with the ignition off for a few seconds. You can tell by the sound when a leaky or dead cylinder hits the compression stroke. Once you learn that sound the only reason for a compression test is to figure out which one (or more than one) are hurt.

Unfortunately no. According to him it was previously owned by a marina owner who absolutely loved the boat and bought it brand new and that's who did the full build on it. He only owned the boat for maybe 3 or 4 months and only put 2 hours on it before realizing his wife and 3 kids were a bad fit for this little boat so he sold it to me.

What further damage could I do exactly?? If the piston or pistons are already screwed, i assume it couldn't get much worse?? Maybe, well probably, I am wrong here.

If it were me id first start with a compression test...and if that doesnt point to one or more piston holes to look at i would then do a leak down test and make the call from there.......that smoke coming out of the valve covers reminds me of a steam locomotive! :D sorry dont mean to hit a guy if he's down....just making light of it ;)

whats the oil pressure ? sounds like a bunch of rockers rattling, I wouldn't run it till the valves are adjusted properly

Gauge says its right around 70- 80 but that's rather hard for me to believe.

when you started it in the video did you have water hose hooked to the engine ?

I think the boat is in the water Ken.

At this point i dont think you'll do any more damage to the piston or cyl walls then there is all-ready....if oil pressure is good and the motor will stay running and its not making any bad knocking noises then i say go for it to the launch ramp...
I once threw a piston and rod out the bottom of the engine cause the builder forgot to tighten one of the rod cap bolts....other then the fact all the oil was gone and it was shaking a little bit the motor still ran! i drove it home at idle for 3hrs to the launch ramp on the other engine then started up the hurt motor at the dock to load it on to the trailer! I was shocked

that things making more noise than a 8V 92 detroit

Quick question...........what geographical location did this boat come from, or to be more precise, what ASL?

Originally from Illinois, then Michigan, now Ohio

Payupp - My box is clean. :)

Update, tried firing the boat with ignition switched off and it sounded like it was skipping through 1 cylinder?? I believe that was the sound referenced before?

tmi

me and CFM..............i mean SB are cool

See post #41

I like good head and clean box. You figure it out. :) :ban?::party-smiley-004::lolhit:

I had a fresh 383 that puked oil from dipstick tube when running it hard. Made my own puke tank very similar to yours and ran it that way for a while. I did help keep oil off the exh manifold (lots of smoke) Finally did a compression check and found a low cyl. On tear down, discovered a piston that broke off a piece just above the top compression ring. Suspect it may have happened when installing pistons (ring popped out of the ring compressor). Replaced the one piston and eng ran great. It wasn't an easy fix but I did get out pretty cheap compared to what the orig build cost. Best of luck to ya.

Just an FYI the harbor freight borescope wont fit through the spark plug hole and they wont take back electronics if its been opened. :mad:

if the motors hurt i would look for a cheapo 454 and swap all the acc over and finish out the season.....i had one summer where i blew up 3 engines...long story but each time a motor blew up i found a 454 for about a grand or less...rolled some new bearings on the crank and rods and off i went while i had the original motors getting rebuilt...the thing that sucks is most machine shop will not get engines done fast no matter what the timeline is they tell you....i once dropped off a motor at a shop in October and told him i ABSOLUTELY need it by April 1st......didn't get it till mid May :mad: thats what you get with good machine shops that are busy...and this one was HEAVY into racing and had a car on the NHRA circuit so they kept pushing off jobs for some of their stuff... :rolleyes:

Not a bad idea, my question there is what would that do for my performance ?? Supposedly this 400 makes "500 horsepower" I'd beg to differ and venture a guess more like 400. I'm not well versed on this subject, but with the added weight of the 454 and I am assuming drop in power. I may be left with significantly less performance wouldn't I?? Getting back on the water for a relatively inexpensive cost would be nice though.

He has a small block..........

Ah i forgot you have the SBC that would be cheaper to find a good longblock engine then....if the heads are good then i would just swap the heads/intake/cam and lifters and all the acc on the outside of the engine and get back on the water....then either get that short block rebuilt and bullet proof and then swap the motors again in the winter to be ready for next year :)

Milwaukee makes a reasonably priced scope that fits thru spark plug hole. I cant remember the model number??

Could do a compression and leak down check which would let U know where the engine health is, but I think it in serious need of a rebuild/replacement.

Gonna find a hole in piston I bet, probably broke valve or detonated, that blow by is all cylinder pressure in the video.

I would find a 350 merc for 500 and go boating while you fix this one gonna be a full rebuld I bet.

He'd be better off swapping to a mild 454/502.

needs some time and education first, he said he was not used to bigger power, start small and work your way up..

motor looks to be nice . l am willing to buy it , if op wants to swap to ls bbc whatever

I agree. Whoever rigged it did a nice job, especially given the fact that it has a little age on it.