hey ppl, another new guy :P Looking for some clarification one a few things..

[bigdirty]

so.. i picked up a 1987 bayliner 2850 for $1000.. shes complete, but needs a lot of 'tlc' and is quite a mess right now.. (hence the name i have given her, 'the big dirty' ) Its got the 460 ford, king cobra drive.. boat has been sitting for 4 years, was marina winterized before sitting. Planing on rebuilding/updating it and making it a real nice live abord that i can still take out on weekends.. Now..after poring over posts here, and googling till my eyeballs fell out, i've come to the conclusion this could be bit of a pain in my rear.. i've seen that the 'newer' king cobra drives can be fairly easily converted to a volvo sx (I am a machinist by trade, no problem building brackets, machining flywheels, whatever) but the 'original' kings are NOT so similar to the sx's (raw water pump in drive,shift cables, etc etc.. ) so I'm wondering if anyone here can give me a clear indication of what i might be into, or what other issues I might run into? This is not something i will do this year, planing on just running the existing setup for next season, but wana get my ducks in a row and things in place for next fall..

I've put a gm v8s in mazda rx7, restored rusted out (aka 'scrap') datsuns, made motors run ppl said were "junk, blown" and build all kinds of things ppl said "couldn't be done" not to mention survive an 800 stringer drive that lost reverse, motor tilt let go while ruining once (in 6ft rollers.. ya, rough ride..) the leg tilt mech. let go at the dock (that was fun!) and a bunch of other insane things that have just become my life.. thats boating! lol.. so i'm not afraid of much..

That said, I'm thinking for all the work involved (that i'm figuring at this point) would i be better off just yanking it all out and re-power with a merc 454/b3 setup...? Thoughts and theorys welcome for either option.. thanks

Matt

 

[jerryjerry05]

Re: hey ppl, another new guy Looking for some clarification one a few things..

The impeller for the drive might be hard to find??
I think??You can change it over to a belt driven pump(mercruiser)
The motor had lots of power and the boat was a fair live aboard.
Is it the sun bridge or command bridge?
I had the command and a neighbor had the sun.
I worked on a bunch of them.
If you can find the parts to change to Mercruiser then that would be a better unit.

 

[bigdirty]

Re: hey ppl, another new guy Looking for some clarification one a few things..

Its a sunbridge model, and ya, my marina/parts guy is having a look to see if he can get me a new impeller.. if not, that will probly seal its fate, I'm not taking a chance on an impeller that's been siting for 4 years I was talking to another boating buddy, we're both in the machine trade, we might see if there's a way i can 'convert' this to a bravo 1 as he has one in good shape I can grab cheep.. looks as though center-line of the two bellhousings is the same, may be a way to drill a merc bravo/alpha unit to bolt the the ford 460, or adapt the cobra 'bell' to the B1.. then its fairly simple; raw water pump/bracket and shifter cables to switch over.. although i don't think that has EVER been done.. so i'll be in uncharted waters i guess..

 

[jerryjerry05]

Re: hey ppl, another new guy Looking for some clarification one a few things..

The Ford bell housing won't be easy to adapt.
Just take it all out and replace with the Bravo.

 

[Lou C]

Re: hey ppl, another new guy Looking for some clarification one a few things..

An 87 460 with the dog clutch King Cobra drive has the standard Cobra upper gear housing with a larger V-8 outboard lower gear unit. So if you need to re-do the upper, at least it is the standard Cobra unit, but you have to use the proper gearset for the 460 engine.

 

[bigdirty]

Re: hey ppl, another new guy Looking for some clarification one a few things..

An 87 460 with the dog clutch King Cobra drive has the standard Cobra upper gear housing with a larger V-8 outboard lower gear unit. So if you need to re-do the upper, at least it is the standard Cobra unit, but you have to use the proper gearset for the 460 engine.

Really? I was under the impresion the "king" behind a bb460 was a completely different (and beefier) housing, upper and lower..

 

[Howard Sterndrive]

Re: hey ppl, another new guy Looking for some clarification one a few things..

you can go to shop.evinrude.com and flip through the parts books for your unit and other Cobra models and see what part numbers are the same.

 

[Lou C]

Re: hey ppl, another new guy Looking for some clarification one a few things..

Nope only the lower unit is different from the standard Cobra. The cone clutch models are completely different including the transom mount.
If you wanted to do a conversion, it's more complex because IMHO that boat is too heavy to put an SEI Alpha on it. A Volvo SX would be much better, but its more difficult because of the issue of adding a Volvo style raw water pump to the Ford engine. Don S did this exact conversion years back do it can be done.
If you did have the OMC cone clutch drive, you realm can't do conversion because the whole transom mount is different. In that case a complete re-power would be needed.

 

[bigdirty]

Re: hey ppl, another new guy Looking for some clarification one a few things..

Nope only the lower unit is different from the standard Cobra. The cone clutch models are completely different including the transom mount.
If you wanted to do a conversion, it's more complex because IMHO that boat is too heavy to put an SEI Alpha on it. A Volvo SX would be much better, but its more difficult because of the issue of adding a Volvo style raw water pump to the Ford engine. Don S did this exact conversion years back do it can be done.
If you did have the OMC cone clutch drive, you realm can't do conversion because the whole transom mount is different. In that case a complete re-power would be needed.

Ya i agree an alpha would be a bit stressed trying to push this big tub, and I know the sx would be stronger only 'problem' there is $$$... volvo sx drives are pricey, and kinda hard to come by used (around here anyway) which got me thinking about adapting a bravo unit, seeing as i have a line on one for $1000. Yes it would be the same thing as far as adding a raw water pump to the motor, and I'd ave to sort out shift cables/drive shaft/etc but it would probly be a bit cheaper in the end. Really though, i'm leaning more and more towards just running it as is next season, then doing a complete re-power next winter.. 454/bravo, done deal, reliable and easy to get parts/service.. and sell the 460/king cobra as a package or whatever, im sure I can make a couple $k if its all in running order..

 

[HT32BSX115]

Re: hey ppl, another new guy Looking for some clarification one a few things..

would i be better off just yanking it all out and re-power with a merc 454/b3 setup...? Thoughts and theorys welcome for either option.. thanks

Matt

Well, that's exactly I did with my 1987 460 King Kobra..........yank it and replace it with a 454/Bravo III.

I also sold my OMC "stuff" piece by piece over a 3 year period of time for about $3500, all totaled.

The difference in performance will be spectacular.

Regards,


Rick

 

[HT32BSX115]

Re: hey ppl, another new guy Looking for some clarification one a few things..

The impeller for the drive might be hard to find??

Actually the impeller is quite easy to find and available (as most repair parts with VERY specific exceptions) for that drive.

The OMG 460 exhaust manifolds are not very easy to find at all and when you do find them, they cost a fortune!!

 

[bigdirty]

Re: hey ppl, another new guy Looking for some clarification one a few things..

.....The OMG 460 exhaust manifolds are not very easy to find at all and when you do find them, they cost a fortune!!

Ya, my chris craft 253 was "Oh My Christ" its a stringer 800 drive! Were as this bayliner is more like "Ouch My Checkbook!" :laugh:

 

[HT32BSX115]

Re: hey ppl, another new guy Looking for some clarification one a few things..

Yeah.The problem with the 460 manifolds is, there's no one making them at all.

You either must find new (OEM cast iron old-stock) or after market stainless steel manifolds.

The NOS ones are about 3 times as much as similar 454/etc manifolds (if you can find them......they are very scarce)

Your other choice is Hardin Marine, Hitek or other after-market SS/Alum etc. but the cost could be more than the boat might be worth!! And you may not be able to get certain hard parts for the drive (there are no new vertical drive shafts)

 

[bigdirty]

Re: hey ppl, another new guy Looking for some clarification one a few things..

Yeah.The problem with the 460 manifolds is, there's no one making them at all.

You either must find new (OEM cast iron old-stock) or after market stainless steel manifolds.

The NOS ones are about 3 times as much as similar 454/etc manifolds (if you can find them......they are very scarce)

Your other choice is Hardin Marine, Hitek or other after-market SS/Alum etc. but the cost could be more than the boat might be worth!! And you may not be able to get certain hard parts for the drive (there are no new vertical drive shafts)

Ya, i was aware some drive components are NLA, and as for the manifolds I'm hoping mine will hold out for a season, cause it's pretty clear to me now what i have to do.. :laugh: merc will be the way to go if i keep this boat. I did notice something bothersome yesterday though while poking around in the engine bay (for other reasons, see my other post) namely the risers appear to have been leaking/seeping water at the gasket surface where they join the manifolds. I can see the water mark stains running down, and i know this is a sure sign the water passages inside are likely clogged up with rust and scale (i have seen this before) and I'm just hoping they are salvageable..

 

[HT32BSX115]

Re: hey ppl, another new guy Looking for some clarification one a few things..

I can see the water mark stains running down, and i know this is a sure sign the water passages inside are likely clogged up with rust and scale (i have seen this before) and I'm just hoping they are salvageable..

That is a clear sign that the riser gaskets are leaking from the water jacket to the OUTSIDE of the manifold/riser connection.

If it's the only "direction" they are leaking, no problem. (unless it's a huge "flow" of water........it won't "hurt' anything except get the bilge wet!!)


The problem lies in water leaking the other "way"!

If water is leaking INTO the exhaust area [internally] You'll have small amounts of water leaking back into the exhaust after you shut down.

It won't hurt a thing while the engine is running. The water will just go out with the exhaust overboard.

But when you shut down, the water will run back into a cyl via an open exhaust valve. This WILL cause a hydrolock if it's enough water, and it will do it in any cyl with an open exhaust valve when the engine stops turning.

Sufficient water will cause a hydrolock severe enough to prevent you from restarting the engine right away.(you will not be able to crank the engine)

Not a huge problem, since the little bit of water will eventually (after an hour or more) leak past the rings and allow you to crank normally.

The problem arises when you let it sit over a winter with that water in there causing corrosion. (if it's salt water it'll screw up the engine in a few weeks or so)

My 460 did this for an entire summer. The engine would run fine. I would shut it off (long enough to pick up a skier etc...) If I tried to restart it, it would act like the battery was dead or the starter was failing etc......

After a few start attempts, it would crank well enough to start. If I let it sit for an hour or so or over-night, it would crank normally......That little bit of water in the oil would evaporate quickly with normal running so the oil never looked milky.

I had riser-gasket leaks on both sides and and obvious corrosion in at least 2 cyls on both sides. (in addition to the flat cam!)

The riser gasket-to-manifold seal was severely corroded and leaking internally (NOT externally like yours btw) . Using a belt sander, I was able to clean/flatten both surfaces well enough for new gaskets to seal just fine. But the manifolds and risers would have not made it another season.

I pulled the engine with the idea of rebuilding it. A local machine shop was going to "long-block" my 460 for about $1800 or so. But when I found that I couldn't buy manifolds (AT ALL) Or at the time , a coupler (couplers are available now from Sierra) I decided to pull the entire mess!

You can find manifolds now off and on but they're still about double what you can rebuild the engine for!! I have seen OEM OMC 460 manifolds (less risers) for $1650 each!! That's just "nuts"!!

i know this is a sure sign the water passages inside are likely clogged up with rust and scale (i have seen this before) and I'm just hoping they are salvageable..

IF the insides ARE clogged with rust, they are NOT "salvageable". (period)

When they become clogged with rust that rust is from the walls of the manifolds. That makes them thinner. If you "clean" the rust out, you will not know when the walls become thin enough to leak and you'll almost guarantee a future engine failure and/or destruction. When they become clogged, that is a sign to replace them. That's another reason I didn't rebuild my 460. I didn't want to put a new engine under used manifolds!

You probably already know this.......the 460 is simply not a long term prospect under normal circumstances. If you want to spend a LOT of money on high dollar manifold/risers from Hardin Marine or Hitek etc, your only weak point will be the drive. They're still around and are for the most part repairable. There's still sufficient parts (new/used) to keep one going.

Some other parts are just not available. Back when I was selling my parts, I got a call from a shop in California. He was trying to fix a 460/KC setup for a guy that had a coupler literally disintegrate in his 28' Bayliner on the way out to Catalina island.

The coupler destroyed the flywheel housing and damaged the transom mount pretty badly............. The owner said he might have hit something so his insurance company was "covering " it.

Problem was, the shop COULD NOT find a flywheel housing new or used anyplace!! The insurance company was going to "total" the boat since it wasn't worth doing a complete re-power. He was pretty happy to get my flywheel housing and transom mount.....it put him back on the water.....he had to use a used coupler though. I think that was a ticking time-bomb.

Another guy in Houston couldn't find an exhaust Y-pipe for a 460 and was ready to give up and go to through-hull exhaust when he found mine......... The y-pipes are aluminum and his should have been replaced years ago!..... it was so badly corroded that it almost sank the boat!

OMC only offered the 460 for about 3or 4 years. The after market didn't pick up the parts for them since there's not all that many of them left out there......

Swapping it all out will be the best thing you do for your boat!

 

[Lou C]

Re: hey ppl, another new guy Looking for some clarification one a few things..

Yep that lousy gasket is the Achilles heel of all inboard exhaust designs except the one piece design used by OMC (have em on my V6) and the dry joint system now used by Merc. I'd like to see if that can be adapted to other engines because it does eliminate the problem described above. There is a company called Hy Teck Marine in Australia that makes stainless one piece manifolds but they are very expensive. Here in the salt pond though they might be cheaper over time, once you get past about ten years worth of boating (2 manifold changes for us over that time).

 

[bigdirty]

Re: hey ppl, another new guy Looking for some clarification one a few things..

That is a clear sign that the riser gaskets are leaking from the water jacket to the OUTSIDE of the manifold/riser connection.

If it's the only "direction" they are leaking, no problem. (unless it's a huge "flow" of water........it won't "hurt' anything except get the bilge wet!!)


The problem lies in water leaking the other "way"!

Yes, I realize that, and how do I KNOW its only leaked externally? Well, I dont, because there's no way to know unless I pull them and inspect. Or take a chance in the bay next spring... after redoing the whole interior and all the upholstery/canvas..and maybe it locks up or kills the motor 2 miles from shore... not my idea of a good start to a season..

If water is leaking INTO the exhaust area [internally] You'll have small amounts of water leaking back into the exhaust after you shut down.

It won't hurt a thing while the engine is running. The water will just go out with the exhaust overboard.

But when you shut down, the water will run back into a cyl via an open exhaust valve. This WILL cause a hydrolock if it's enough water, and it will do it in any cyl with an open exhaust valve when the engine stops turning.

Sufficient water will cause a hydrolock severe enough to prevent you from restarting the engine right away.(you will not be able to crank the engine).....

....I had riser-gasket leaks on both sides and and obvious corrosion in at least 2 cyls on both sides. (in addition to the flat cam!)

The riser gasket-to-manifold seal was severely corroded and leaking internally (NOT externally like yours btw)..

IF the insides ARE clogged with rust, they are NOT "salvageable". (period)

weeeelll, i disagree... firstly, no amount of water should be allowed to drain back into the cylinders after shut down and it has always been my understanding that most marine manifolds "mix" water in after a riser of some sort, for that very reason; to prevent any backwash of water entering the motor after shutdown. I've heard of hi performance manifolds that even have flappers or block-off plates to make absolute sure after engine shut down....

Secondly, I've cleaned/cleared out risers (that blew the gaskets out BECAUSE they weren't flowing hardly at all, and the water has to go somewhere..) and they worked/flowed fine afterwards. Also, that motor was on the verge of hydro-lock because of the leak(s) and it got harder and harder to start, rebuilt starter, new battery, etc etc....then I noticed the riser gaskets had started to leak.. but lucky for me it was in the driveway, not out in the bay.. pulled all the plugs and cranked her over to clear the water, motor was fresh built so all was well in the end.. So again, i think if the gasket has leaked externally, then its a safe bet it's leaked internally as well, it has just been my experience.

You probably already know this.......the 460 is simply not a long term prospect under normal circumstances. If you want to spend a LOT of money on high dollar manifold/risers from Hardin Marine or Hitek etc, your only weak point will be the drive. They're still around and are for the most part repairable. There's still sufficient parts (new/used) to keep one going.... Swapping it all out will be the best thing you do for your boat!

And yes, I do agree there, if I pull this motor, its never going back in, and the drive will go with it. I could spend lots of money on it and it would still be a 460/kc drive:laugh:

 

[chriscraft254]

Re: hey ppl, another new guy Looking for some clarification one a few things..

Run Forrest RUN! :bolt:

 

[HT32BSX115]

Re: hey ppl, another new guy Looking for some clarification one a few things..

weeeelll, i disagree... firstly, no amount of water should be allowed to drain back into the cylinders after shut down and it has always been my understanding that most marine manifolds "mix" water in after a riser of some sort, for that very reason; to prevent any backwash of water entering the motor after shutdown. I've heard of hi performance manifolds that even have flappers or block-off plates to make absolute sure after engine shut down....

I think you may have misunderstood me on this. There is no time when it's "ok' for water to EVER drain back into the exhaust.

Block-off plates are used with closed cooling systems. Flappers, exhaust seals, shutters etc, are used in the exhaust Y-pipe to help prevent water from being sloshed back into and up over the riser and into the exhaust manifold.

Secondly, I've cleaned/cleared out risers (that blew the gaskets out BECAUSE they weren't flowing hardly at all, and the water has to go somewhere..) and they worked/flowed fine afterwards. Also, that motor was on the verge of hydro-lock because of the leak(s) and it got harder and harder to start, rebuilt starter, new battery, etc etc....then I noticed the riser gaskets had started to leak.. but lucky for me it was in the driveway, not out in the bay.. pulled all the plugs and cranked her over to clear the water, motor was fresh built so all was well in the end.. So again, i think if the gasket has leaked externally, then its a safe bet it's leaked internally as well, it has just been my experience.

riser gaskets don't necessarily "blow" from raw water pressure bcause the riser is clogged. Clogged risers will cause an overheat though because they do not allow enough raw water flow through the entire system,


"Cleaning" (removing rust) when a manifold OR riser is clogged to blockage is risky because they are not designed to be "fixed" this way. The wall thickness is reduced because of the rusting. There is no way to determine when the thickness will get to the point to rust-through. They don't rust at the same rate everyplace. some areas might be thick and other spots might be paper thin. You won't know until it starts leaking. Then it may be too late...... No cast iron manifold or riser was ever intended to be used to that point. (yes I know people do it all the time..........I wouldn't)

If you have enough rust to clog the passages and severely reduce/prevent water flow, the risers or manifolds are DONE. they should be replaced.


Just saying.....

 

[bigdirty]

Re: hey ppl, another new guy Looking for some clarification one a few things..

I think you may have misunderstood me on this. There is no time when it's "ok' for water to EVER drain back into the exhaust.

Block-off plates are used with closed cooling systems. Flappers, exhaust seals, shutters etc, are used in the exhaust Y-pipe to help prevent water from being sloshed back into and up over the riser and into the exhaust manifold.




riser gaskets don't necessarily "blow" from raw water pressure bcause the riser is clogged. Clogged risers will cause an overheat though because they do not allow enough raw water flow through the entire system,


"Cleaning" (removing rust) when a manifold OR riser is clogged to blockage is risky because they are not designed to be "fixed" this way. The wall thickness is reduced because of the rusting. There is no way to determine when the thickness will get to the point to rust-through. They don't rust at the same rate everyplace. some areas might be thick and other spots might be paper thin. You won't know until it starts leaking. Then it may be too late...... No cast iron manifold or riser was ever intended to be used to that point. (yes I know people do it all the time..........I wouldn't)

If you have enough rust to clog the passages and severely reduce/prevent water flow, the risers or manifolds are DONE. they should be replaced.


Just saying.....

Well, i see signs of leaking, so regardless, Im gona pull the risers and check it out either way and seeing as no aftermarket exists, i'm hoping they are useable at least for a season.. personally I think and overheat is potentially worse, as it usually is too late once you realize it,and the motor is toasted for sure. IF they are clogged up and not flowing well, at least a 'clean out' will let them work 'for now' and if it does start to wear thin/break through and drop water into the motor, there will be a chance of catching it before its catastrophic. As you stated, even with water getting in the open exhast valve after shut down, the motor ussualy will fire back up after siting.