volvo penta exhaust manifolds

[stujoe20]

just picked up a 77 bellbouy has a volvo 350 and 280 omc leg..found the exhaust manifolds cracked just where the rubber hose joinst it and back 3-5 inches.is this normal for these to crack? It dosent seem to be leaking water or exhaust..?? thanks stu

 

[Don S]

Re: volvo penta exhaust manifolds

It's not NORMAL for anything on an engine to crack.
Probably is full of corrosion, dirt, and rust. Which is keeping it from leaking. Oveheat or water in the cylinders is probably next

 

[captmello]

Re: volvo penta exhaust manifolds

Salt water? Fresh?

Most cracks come from freezing or perhaps exhaust overheating.

Can you take a picture?

 

[jerryjerry05]

Re: volvo penta exhaust manifolds

Fill out the profile so we know where you come from.Salt and fresh water make a difference.
You have a Volvo with a 280 Volvo drive not an OMC.There should be no cracks.
Take some pics and post.Any history on the maint?Jerry

 

[stujoe20]

Re: volvo penta exhaust manifolds

sorry about the lack of info..boat lived in vancouver.bc.canada.probably mostly in the fraser river( salt water).winterized the eng yesterday and i tryed to drain them by pulling out the drain plugs out of the back of them..(i am a mechanic by trade).found lost of fine sedement,so just pulled them off.6 bolts and a hose clamp...gonna clean them out a look just a bit harder..may be get them pressure tested.i pulled this boat from vancouver to prince george which is about 800km...very mountainas..wheew..its a heavy boat...25footer..and command bridge..have to go back down for a furneral today..will try to take pics when i get back..got the boat for big fresh water lakes up here...sorry no history on maintaince yet...thanks for the help...stujoe

 

[captmello]

Re: volvo penta exhaust manifolds

I'm not sure how much time you have to mess with those old mainfolds. You never know, you may be able to get some use out of them. However, If that boat has been in the salt as you mentioned, you would be best off, in my opinion, just buying new manifolds and risers.

Those parts are routine mainenence items on salt water boats, in fact they don't last forever in fresh water. You may spend a 800-1000 for them now but you'll be thankful.

Running those old ones will give you constant overheating problems from decreased water flow through the exhaust. You really can't clean them out.

Anyway, I've got the same engine/outdrive. Very reliable. Go easy on the outdrive ujoints and tilt mechanism as those are commonly abused by accident.

That tow sounded like an adventure!! What were you towing with?

 

[stujoe20]

Re: volvo penta exhaust manifolds

ya it was an adveture all right trailer need lots of work to get it ready to pull it that far..pulling it with a 04 chev 6.0L 3/4 ton chipped up and piped.avarage fuel milage was 10 mpg. got lots of time with the manifolds.got home and had 6 inches of snow on the grnd so it not moving till march.pulled the manifolds right off..seems its like its just the top part of the elbow at the end that has the cracks,looking into the manifolds them selfs they look ok..any tips on the operation of the leg? everything that i have owned has been merc.thanks...stujoe

 

[captmello]

Re: volvo penta exhaust manifolds

tips on the operation of the leg

Fairly simple. Don't run the engine with the drive more than half up. Fully down whenever possible. If you must run with drive half up (shallow water, etc.) only do at idle speed 700-800 RPM.

Unless you have a 280T (power trim model), you do not have power trim, only tilt for shallows, etc.

If you need to raise the drive while running put in nuetral before tilting up.

The bellows on those outdrives need changing more often than Mercs every two years is what i understand. Especially the ujoint bellows. In the spring you'll want to remove your upper gear housing and inspect your ujoints and should change the bellows at that time.

Post a pic of the maifolds and risers, if you can. pics of the surfaces where the maifolds and risers meet can say a lot about the corrosion level.


Who knows the maifolds may be newer.

top part of the elbow at the end that has the cracks

Is the crack just in front of the large rubber exhaust connection? Hummm...

 

[stujoe20]

Re: volvo penta exhaust manifolds

ya thats where it is.on both sides.will try to get pics.down in vancouver right now.have to plod thru 800 km of snow back to pg on monday...yuk.gonna pull the upper elbows off and take a look..if u raise the eng off of idle will the leg be unlocked and flip up to the top and cavitate and wreck the u joint...? thanks stu

 

[captmello]

Re: volvo penta exhaust manifolds

if u raise the eng off of idle will the leg be unlocked and flip up to the top and cavitate and wreck the u joint...?

Not necessarily, but is hard on the ujoints.

If your outdrive is like the two volvos I've owned, the retaining prawl does not work correctly. It is supposed to hold the drive down in reverse but without correct adjustment and maintenence they stop working and wear the lever that is pushed by the trim motor shaft in a way that cannot be fixed without tearing the outdrive apart.

However even if your retaining prawl does work, once you raise the outdrive, even an inch, it has disabled the retainer anyways.

When I reverse, my outdrive bounces up and down no matter what RPM, and is not good for the drive, but not a lot I can do, practically speaking. Hopefully you don't have to reverse to much.

Maybe your outdrive is in great shape and you can reverse with drive fully down and not have the thing kicking up.

 

[jastacey]

Re: volvo penta exhaust manifolds

I had a Volvo 225D engine with a Volvo 280 outdrive ... was a very good running set-up .. I had to replace the exhaust manifolds ( the were semi plugged-up with rust and crap ) I used HGE Manifolds ( do a Google search for HGE Mainfolds ) they worked pretty good ran the boat till I sold it ... as to the reverse pawls ... get a factory shop manual and follow it to the letter, as to how to adjust it, chances are the pawls are worn-out and the tip, where the adustment is made is set wrong ( this is where the lifting screw pushes the drive up.. there is a bullet that protudes .. I don't remember the gap but it's critical that you follow the instructions ) when I reset the tripping assembly I didn't have the drive coming up in reverse and when the boat came off plane from a high seed run