In situ rebuild.....

[oscarvan]

53MY DD

Since the sleeves come out, the pistons have to come out, which means you have to get to the bottom of the connecting rod, so I am assuming there's enough room to get under the engine....

Question: Is there enough room to get the crank shaft out and check the upper bearing halves of same?

 

[rob71]

I am not sure of the clearance under the engines on the 53s. My neighbor has a 55 Conv. with 12V71s and he was able to get under and change all the bearings. Did not have to remove crank, just rolled bearings out and in.

 

[oscarvan]

I'll make plastigauging a challenge....

 

[Glory]

It can be don in the ER but the engine will likely need to be jacked up and the trans has to come off. AN 8V71 crank weighs 400 pounds. It is a time consuming job!

JM

 

[oscarvan]

Sounds like a pain and inherent lesser quality. No power washers, no rotissery etc etc.....

When, ok IF, I end up with one of these I plan on buying a third motor, rebuilding it and pickling it, and have it sitting in the barn....

I can probably R&R one of those lumps in a week or so.....

So if I blow one, it won't ruin my whole season. And the bad one can go in the barn for rehab. Think NASCAR... LOL. I'd be saving a boatload of money that way.

Better start shopping for some Aluminium to build the A-frame.

 

[rsmith]

Usually people strip the engine down to a short block to remove or cut a access panel in the side of the hull for removal. A very large hole. I'm thinking instead of an a frame you could build tracks and a cart to take it out through the transom. It would be a smaller profile hole and you could flange the access panel for future uses.

 

[captddis]

Sounds like a pain and inherent lesser quality. No power washers, no rotissery etc etc.....

When, ok IF, I end up with one of these I plan on buying a third motor, rebuilding it and pickling it, and have it sitting in the barn....

I can probably R&R one of those lumps in a week or so.....

So if I blow one, it won't ruin my whole season. And the bad one can go in the barn for rehab. Think NASCAR... LOL. I'd be saving a boatload of money that way.

Better start shopping for some Aluminium to build the A-frame.

Which engine are you going to build, The RH or LH engine? If the boat has Allision's the engines are counter rotating.

 

[saltshaker]

Why not buy the boat first. If I needs a rebuild then figure out what needs to be done. Most of these boats run a long time between majors. Seems like a lot of pre planned work when you haven't chosen the boat yet. I respect your wanting to know what's involved in a major overhaul but much of that will depend on the specific boat and condition of the engines. Most of the time an in frame is fine and can be done in place or with the engine jacked up a bit. If the crank or block is damaged then they need to come out.

 

[bigbill]

i agree with jack.....if you dont have it yet why worry about the problems you may or may not have.. if you are that worried about engine and trans. why not buy something that has been repowered.

 

[oscarvan]

Not worried. It would be a fun challenge. I do like to know what I'm getting into before I do so. I, for instance, would not like a boat that you have to cut a hole in to to get the lungs out.

 

[Pascal]

The original 53 ( and 58 YF) has two large hatches in the saloon so the engines can come out so no need to cut anything.

In fact it seems that if you take out the heat exchangers, the hatches are long enough for the engines to come out with the trannies attached.

Any bottom end work requires some significant jacking up of the engines, so I m not sure I see why you wouldn't just take them out. I think the key is to find a skilled crane operator. I ve been going over this with the cummins dealer who's going to pull them out and install the C series, they have done many repowers and alwwys use the same guy and crane.

I ll make sure I post picture, should happen late January or february

 

[oscarvan]

The original 53 ( and 58 YF) has two large hatches in the saloon so the engines can come out so no need to cut anything.

In fact it seems that if you take out the heat exchangers, the hatches are long enough for the engines to come out with the trannies attached.

Any bottom end work requires some significant jacking up of the engines, so I m not sure I see why you wouldn't just take them out. I think the key is to find a skilled crane operator. I ve been going over this with the cummins dealer who's going to pull them out and install the C series, they have done many repowers and alwwys use the same guy and crane.

I ll make sure I post picture, should happen late January or february

Thanks. Yes, I knew the engines come straight up. I've seen the re-power video and they built an a-frame over the hatch, then let it down on a dolly, to the aft deck and then off with a fork lift. (Forks above with chains.)

 

[Pascal]

Thanks. Yes, I knew the engines come straight up. I've seen the re-power video and they built an a-frame over the hatch, then let it down on a dolly, to the aft deck and then off with a fork lift. (Forks above with chains.)

I am a little concerned about all that weight resting on the saloon floor and aft deck . I like the use of a crane reaching in the saloon better.

 

[oscarvan]

I am a little concerned about all that weight resting on the saloon floor and aft deck . I like the use of a crane reaching in the saloon better.

That thought did cross my mind. The folks in the video did it, the concern wasn't mentioned. I will have to take a good look at it if/when the time comes, and probably fabricate a dolly of sufficient size to spread the load, and possibly six inflated wheels.

 

[Glory]

They may have laid down some 3/4" ply wood, and some method to get across the salon door saddle.

Even without the manifolds and trans you likely have 3,000 #s. That 750 #s on. Each wheel with a very small foot print.

JM

 

[oscarvan]

Yes, plywood will help. So will taking the tranny off. (Tranny weights for buses, Marine probably lighter.)

2-cycle DDA, dry weight:

6-71 = 2150 lbs.
6-71TA = 2195 lbs.
6V-71 = 1960 lbs.
8V-71 = 2345 lbs.
8V-71TA = 2415 lbs.
12V-71 = 3300 lbs.
6V-92TA = 2020 lbs.
8V-92TA = 2415 lbs.

Three of the most popular Allison transmission dry weights:

V-730 series (3-speed): 890 lbs.
HT740 series (4-speed): 840 stock, 979 with retarder
HT750 series (5-speed): 940

 

[Pascal]

Marine 8V71 specs I have from a Dd flyer shows 3130 lb for the Naturals and 3430 lbs for the Turbos. I also found 400lbs for the Allison but it appears to be included in the above weights q

Plywood helps spread the weight but the saloon floor is still supported by aging 1x3 lumber spaced 12". Except maybe for the act ER bulkhead, none of the walls around the SR and heads are load bearing. There are gaps at the top filled with generous amount of caulking. I know that in a couple of spots (incl near the side door) I have some rot due to water intrusion.

And the lumber doesn't extend all the way to the hull but stops roughly 20" from the hull sides where they are attached to lengthwise frames running under the side decks.

Not sure if it has been changed on later boats, mine is an early one (1970)

Then once you reach the aft deck, you are on an unsupported deck that's roughly 14x14 and rely on balsa core for strength... From what I can see on mine, the core ends a few inches from the edge so th whole deck is suspended by single layer of glass. Not sure I want to roll over 3000lbs over that.

 

[rsmith]

What Pascal said if it dosent fall through the deck it could cause some permant saging.

 

[rsmith]

Marinised 12/71 is 5400 lbs your #'s may be for truck or industrial

 

[saltshaker]

A pro will add supports from the stringers to the salon deck. My engines came out that way using an A frame.