help gear heads........
 

not my formula, but my old boat i am trying to sell.


89 454 carb engine
blows big time smoke out starboard side exhaust,
open pipes, not twined.
only after high speed run, then shut down and re start.
doesn't smoke without being turn off.

no blow by on crank vent in valve covers, either side
i am hoping valve seals on one bank.
waasss up

Does sound like valve seals.

I'd agree with ThirdBird. After shutting down, oil is leaking past the seals and laying on top of the pistons, thus lots of oil smoke on restart.

Good place to start.

Dave

thanx for the replies,
it's blows ALOT of smoke, will a seal leak that bad?
my local engine builder/friend fiqures it's a guide if it leaks real bad
I need to pay someone to repair this,
should I bite the bullet and pull the head?
do i need to take off intake to remove head

Yes, you need to pull the intake to remove the head. If you do one, do both. Head gasket, surface the heads , valve job, guides, and springs. Check the retainers, locks, and rockers for wear. How many hours?

Dave

Don't forget the seals too!

Dave

I agree. It's time, it's an '89. Make sure you take them to a good machine shop and get them checked for cracks. I pulled my four heads a few years back just to get them freshened. 3 out of four had cracks between the valves - junk.

Hopefully you won't find that. If there are no cracks, a good head overhaul should be about 400 bucks each.

took the valve cover and exh manifold off, changed the seals.
none were damaged or dried up.
lots of water in exh manifold and one cylinder pumpd out a little water when aired up to change seal.
heads coming off tomorrow,
sure sucks on a boat for sale, already lost one sale,

On the bright side, got the Formula out of storage today,
cleaned it up and checked and lubed etc,
flashed up instantly on 1st hit of the key....gotta like it

Sorry to hear the bad news...Might be good that you caught it this soon though. You will feel better knowing that someone will get it in much better condition.

On the Good note...The Formula is out and running with no problems! 50% is better then 0%!! :drink:

Dave

[QUOTE=nsformula;2877934]lots of water in exh manifold and one cylinder pumpd out a little water when aired up to change seal./QUOTE]

So, it's not smoke you're seeing, it's steam. Could be cracked heads, see my earlier post.

Could be a leaking exhaust manifild gasket or cracked exhaust manifold as well.

had manifold pressure tested and is ok. gaskets looked good
on disassembly, off with her head....

got the head off,
gasket looked ok,
steel seal for cylinder ok, no visible cracks in heads

what we did find is signifcant corrosion in two rear exhaust ports, as well as spot rust in one cylinder wall
ie water,

boat has closed cooling, a/freeze in block and exh manifold below riser, ambient water in riser.
antifreeze apparantly will not cause rust
so....
water is either reversion or cracked riser????riser looks ok, not aware of process to pressure test riser
exhaust pipes are just above water level

engine was changed from origional and new risers lined up perfect with origional exhaust plumbing

boat has mulfflex inboard inline mufflers, have no idea if they have anti-reversion baffles or not, one could be bad on one side.
the odd thing is it only blows smoke on one sde so if there was a reversion issue , u would think it would do both sides unless the is an internal issue with the one muffler.
head is being pressure and vacuum tested

if it tests ok, options are..????
spacers on the risers, baffles at the stern

help me out guys,
i am trying to give as much info as possible

We need to get back to your original problem, it "smokes" or likely steams after it's been shutdown. So, the problem is slow weepage and not reversion.

A leaking riser to elbow or riser to manifold gasket could cause this. That would be evident on disassembly inspection. Cracked riser, manifold, head are the other culprets.

Pressure testing your risers is not that hard. You need a couple of plates, some rubber sheet gasket or other sheet gasket material. Drill and tap one plate to accept an air fitting. Pump it up to 20 pounds or so (don't need to blow your head off with 100 psi) then leak-check the joints. If no leaks, do a few minute leak-down with a gauge. If the gauge looses pressure and the plate-to-riser joints don't leak, the riser is cracked someplace.

My money is on the heads. Either head gasket leak or cracked head. You say there was rust in the cylinder, a leaking riser or elbow or manifold would have to leak alot in order for water to enter a cylinder.

small pits of rust in one cylinder
no cylinder liner fracture line.
corrosion in two rear exh ports in head

head gasket appears ok
manifold/riser gasket ok
exh manifold ok, was pressure tested

why do you say slow seepage,
only place that could come from in closed cooled system is the riser[which has ambient water] which looks good
before a pressure test or magnaflux,
you can see thru most of it from one side or the other
or reversion.
as i said, only happens after shut down, which would include throttle down, stern settling, exh ports low in water, hence
possible water pick up in exhaust.

not challenging your knowlegde,
just trying to understand myself.

the rust in the rear cylinder head exhaust ports is significant, you can pick chucks off with your fingernail, the two front ports are clean as a whistle.

the dudes at the machine shop are very good and do lots of marine work,
i'll have a report tomorrow.
they have a replacement riser for about $100 which would be
cheaper than trying rig up a pressure test for that,
so if the head is ok, i'll replace the riser,
maybe add a spacer between the manifold and riser
and flapper to the exhaust tubing

thanx

I assumed when you said shut down, that you meant shut down for a while. Didn't realize you meant turned off then started right back up again.

So, now that I understand that, maybe it is a reversion issue. Odd that only one bank would experience reversion though.

i agree on the one bank, maybe there is something in the mufflers

UT-O, sounds like a female problem. :eek:

heads checked out ok for pressure and vacuum.
can only assume it was water reversion,
therefore steam not oil smoke.
oh dopey me

going back together and then another sea trial.
there are no flappers in the exhaust so will have to address
that too. although you would think the mufflers would suffice.
one guy told me if you chop the throttle it can create enough vacuum to suck water from the exhaust pipes.
will also do a compression test when heads back on.
learned alot in the last week but it costs....
i have 3 buyers for the boat if stuff checks out after re-assembly. wish me luck