Another winterizing question....

[Gerard1970]

I have never winterized an in board before and have read a lot of ways to do this. I have a king cobra with a 460 engine and was told by a friend of mine that all he does is get the engine to operating temperature and then feeds anti freeze through the muffs until it comes out of the lower unit. My system is a fresh water system and this seems like a fool proof way of doing it. Am I correct? Any coolant will be caught in a drum and saved for later. Thanks for the replies.

 

[81 Checkmate]

I wouldnt do it that way....Heard to many Horror storys about cracked blocks doing it that way. Look in the sticky's (Adult Only section) Don S has a good wright up about how to winterize correctly.

 

[HT32BSX115]

I have never winterized an in board before and have read a lot of ways to do this. I have a king cobra with a 460 engine and was told by a friend of mine that all he does is get the engine to operating temperature and then feeds anti freeze through the muffs until it comes out of the lower unit. My system is a fresh water system and this seems like a fool proof way of doing it. Am I correct? Any coolant will be caught in a drum and saved for later. Thanks for the replies.

Howdy,

Yeah....I had one of those 460 King Kobras.......

When you say yours is a "fresh water system", what exactly do you mean?

Is there a closed cooling heat exchanger installed? If so, are the manifolds also connected to the closed cooling system?

IF you do have a closed cooling system, then all you need to do is drain the raw water 'side' of the heat exchanger. (your block and manifolds will be already (or should be) filled with 50:50 AF/water mix.

If it's a 1/2 system (Block-only + heat exchanger) then you still must drain your heat exchanger AND you MUST drain your manifolds of raw water.

If you have NO HEAT EXCHANGER, then you MUST drain the block and manifolds. DO NOT attempt to run anti-freeze up through the raw water pick-up to winterize or you will be replacing the engine and manifolds next Spring (AND you cannot buy new manifolds for an OMC 460 any more!!)

When you drain the manifolds and block (both sides btw) ensure that you remove petcocks and/or plugs so you can poke a thin screw driver, piece of wire or nail in the holes to clear them of rust flakes and other debris. remove the big hose to drain it and remove the hoses from the bottom of the manifolds to poke in the holes to clear them of rust and debris.

Any water left in the block or manifolds will cause a risk of freeze damage.


Cheers,


Rick

 

[jerryjerry05]

NEVER use the muffs to winterize.
Don't heat the motor(hot motor=burns)
The manuals can cover how to winterize.Get one specific to your motor.
The most important thing is the block drains(2) need to be removed and a screwdriver or something pointy stuck in the hole.
Then the manifolds drained.
Use a good marine approved antifreeze.
Automotive antifreeze is illegal to use in any state.
It's gets flushed into the water and pollutes and kills fish.

 

[Gerard1970]

Thanks for the replies guys...I will have to get a hold of a manual and find where the drain plugs are. Need to do this right!

 

[HT32BSX115]

Thanks for the replies guys...I will have to get a hold of a manual and find where the drain plugs are. Need to do this right!

The drain plugs on a 460 are on the side of the block.

Your exhaust manifolds have hose-bibs at the lowest point of the water jackets, front AND back. there's a hose on one and a "cap" on the other. You also have power steering AND oil coolers and a "big" hose on your circulating pump that must be drained too..........

Now, back to "fresh-water-syatem" Do you have a heat exchanger with a radiator cap on it and does the block have 50/50 mix in it?

If it does, (and you're sure that it contains AF,) AND you just bought the boat, I would drain everything and replace it with a KNOWN concentration of the correct AF.

If the engine is raw water cooled (no heat exchanger) then drain as we previously suggested.

If this boat is new to you, you need to remove the risers, inspect the manifolds and riser/manifold sealing surfaces and replace the riser gaskets. If you don't, and they haven't been serviced in several years, you risk engine damage if they leak.........

Now, I hate to be the guy that tells you this, but unless you're planning to scrap the boat when the drive or engine fails, you probably should start looking for an engine and drive to replace what you have now. OMC went out of business more than 15 years ago. They only made the 460 king Cobra for 3 years, and the drive on the back of a 460 is NOT the same as any other Cobra drive. Also, since the 460 was only offered for 3 years, the after market didn't pick up all the replacement "wear parts" notably the exhaust manifolds. The only choices now are used manifolds (which are "used" =rusty and maybe worse than yours)

There's also Hitek stainless steel manifolds (roughly $3000 + shipping), BARR (good price but they're for jetboats) and an adapter plate system where you use 454 manifolds and risers but they have their own problems......

If you break the drive, you might be able to get it fixed or rebuilt but some of the rebuild parts are going to be used because there's several internal parts that are simply not available anymore.

I removed the 460 + King Cobra from my 1987 Four Winns 211 Liberator in 2006 and replaced the entire mess with a 1997 Mercruiser 7.4L + Bravo III.

Because the drive was in good condition, I was able to sell it to another 460 owner who wanted to have a spare (I shipped it all the way from the NW to the East Coast!) . All totaled, I got $3600 for everything parted out over a 3 year period.

Sorry for the long post..... If you had come here and asked any of us if you should get a boat with a Cobra engine and drive (especially a 460), we would have suggested you keep looking! I like all the prospective 460 King Kobra Owners to know exactly what they will get themselves into!


Good luck,


Rick

 

[Gerard1970]

So the 7.4 and bravo III is the way to go? Just wondering how straight forward it is to swap out. Is it a straight fit or does it require any special adapters or mods? I would be willing to look into it and ANY suggestions would be appreciated. Thank you.

 

[HT32BSX115]

So the 7.4 and bravo III is the way to go? Just wondering how straight forward it is to swap out. Is it a straight fit or does it require any special adapters or mods? I would be willing to look into it and ANY suggestions would be appreciated. Thank you.

Hmm......I have lost count the times I have told this story!!!



Depends on what boat you have I suppose..........My brother bought my Four Winns 211 Liberator new in 1987..........I bought it in 2005............ He specifically wanted it because it test drove well with the 460........ (top speed 60mph but slightly doggy out of the hole)

He even had the engine rebuilt due to freeze damage in the 90's but it didn't do much for the hole-shot. When I got it, it needed a little tune up work which I did but I could never get the engine to exceed 4200 RPM or so at WOT (Brother got 5000 RPM!).

I discovered that the camshaft had several flat lobes and decided to rebuild it. That's when I found out that I couldn't buy exhaust manifolds or a coupler.
You still cannot get manifolds (couplers are available now though)

In 2005 I also started looking for a Volvo Penta or Mercruiser Bigblock eng plus drive and originally wanted either an SX or Bravo I drive to make the swap similar to what I was removing.


I found several complete package Mercruiser 454/496 engines and drives Bravo I, II, III ................but NO Volvos. (I guess people with Volvo powered boats never damage them!!.............I also looked on eBAY for parts and always found about 3 x more Mercruiser "stuff" than Volvo "stuff")


I did find a 2004 model year complete 5.7L MAG MPI (300 prop hp) + Bravo I for $7500. It had 400 salt water hours and was FULL closed cooled and was obviously stored on a trailer.

I offered the guy $6000 and was about to offer $6500 when I found the 1997 7.4L + Bravo III out of a wind damaged 24' Bayliner (tree fall across the bow in the owners yard)

Got it for $5k.

I removed everything OMC and although I needed to do a little fiberglass work to clean up the engine compartment , the Mercruiser gimbal mount bolt pattern matches the OMC Cobra transom cutout exactly. The Bravo mount DOES have 2 extra thru-bolts so you must drill 2 additional holes in the transom. but the cut out and bolt pattern is otherwise identical and the distance between the crankshaft and propshaft is essentially the same.

I was a little leery of the Bravo III because of the VERY expensive props, and the "Conventional Wisdom" of them being "3-5 MPH slower" than a similarly powered Bravo I boat. (I didn't want to lose top speed!)

But I couldn't pass up the good deal. Besides, I could easily swap drives.

Now, I wouldn't trade the Bravo III for any other drive.

The difference in hole-shot was nothing short of spectacular!! Before, it was really slow out of the hole.

I remember my Dad (in his 150hp 66 Mark Twain) racing my brother right after he got the boat. He beat him out of the hole up to about 30 MPH. Then once that thing got on plane, he would rocket past my dad going almost twice that speed! (the 460 was rated at 340 crankshaft hp making roughly 300 prop hp )

After I got it running with the 454 Bravo III, I couldn't believe the difference. It just ROCKETS out of the hole now.........and with 26p props and a 1.81:1 ratio drive I can top 57 mph at 4600 RPM.

My brother drove the boat right after I got it running and still cannot believe the difference.

Slow speed handling around the dock is also pretty nice now. Bravo III's (and Volvo DP's) are known for good low speed handling.

If you have a big boat, you'll benefit from a Bravo III drive. If you have a high speed boat, you would probably be ok with a Bravo I.

Either way, If you want to keep the boat and make it worth something you'll need to eventually get rid of the OMC stuff. It's better to sell it all in running condx instead of as "core" parts......


Cheers

Rick