DD 8v71s and 8v92s info

[Scarlett]

I thought the 61 MY’s all had 1271’s in them. John

[JohnEasley]

I thought the 61 MY’s all had 1271’s in them. John

Perhaps most do. The ad for this one specifies 892s. Maybe it's a misprint or maybe it was repowered.

[Scarlett]

Would’nt be the first time a Yacht broker got something wrong in an ad. John

[rustybucket]

Recently new to DD 8v92TA's last year. Came from Cat 3208 powered Ocean. I read a bunch online about them being loud, smokey and leaky. After running our new boat I don't really get it....

The engines smoke very little, can you smell diesel fumes? well, yeah, it's 1200hp of diesel engines, you gonna smell some exhuast in the cockpit.

Can you hear them? well, yeah, it's 1200hp of diesel engines running! lol. Honestly I'm surprised at how quiet they are. It is loud in the engine room but hatteras did an excellent job insulating the cabin from noise IMO.

Leaky? Well, if you find a leak, fix it. Honestly it's that simple. If you find a leak you can't fix (within reason) then put a diaper under it to contain the fluid. I think lack of maintenance and leaks adding up gives the engines this reputation.

They are easy to work on, fairly easy access to everything. Parts are VERY reasonable and widely available. They are mechanical engines so no ECU/PCM's to worry about or have to replace to the tune of several thousand dollars.

I try to explain it this way to my son when something old we have breaks and he says "we need a new car/truck/boat/lawnmower/xxxx" Both new and old stuff break. Much of the old stuff is very cheap and easy to fix/replace. The new stuff is usually very expensive and difficult to replace/source. It's really as simple as that. I see just as many new (or newly re-powered) boats break down as I do older boats (that are properly maintained).

[JohnEasley]

Recently new to DD 8v92TA's last year. Came from Cat 3208 powered Ocean. I read a bunch online about them being loud, smokey and leaky. After running our new boat I don't really get it....

The engines smoke very little, can you smell diesel fumes? well, yeah, it's 1200hp of diesel engines, you gonna smell some exhuast in the cockpit.

Can you hear them? well, yeah, it's 1200hp of diesel engines running! lol. Honestly I'm surprised at how quiet they are. It is loud in the engine room but hatteras did an excellent job insulating the cabin from noise IMO.

Leaky? Well, if you find a leak, fix it. Honestly it's that simple. If you find a leak you can't fix (within reason) then put a diaper under it to contain the fluid. I think lack of maintenance and leaks adding up gives the engines this reputation.

They are easy to work on, fairly easy access to everything. Parts are VERY reasonable and widely available. They are mechanical engines so no ECU/PCM's to worry about or have to replace to the tune of several thousand dollars.

I try to explain it this way to my son when something old we have breaks and he says "we need a new car/truck/boat/lawnmower/xxxx" Both new and old stuff break. Much of the old stuff is very cheap and easy to fix/replace. The new stuff is usually very expensive and difficult to replace/source. It's really as simple as that. I see just as many new (or newly re-powered) boats break down as I do older boats (that are properly maintained).

Interesting perspective. Thanks, rusty. How easy is it to access and replace the impellers on the 892s?

[scottinsydney]

I’ll echo what Rustybucket says.

I have owned a past boat 11 years with 8V92N engines. New boat has 12V92TI engines. They are simple and reliable. But Detroit’s must be loved. This means yearly oil changes and not always running at low speed. Here in Sydney Harbour we have to run at 850 RPM or the wash is too great. So there lies a problem.

On both boats I set to task to rejuvenate the mechanically sound motors to as new using simple chemicals available in Australia and now exported to the USA. Have a look at www.costeffective.com.au. I use the FTC product, Oil Flush Conentrate and the AW10 product in the engines and gearboxes. The result for both boats over time was no sludge, noticeably cleaner oil, immediate firing, no blue smoke.

On the 12V71TI engines (my newer boat of two years), there is now absolutely no oil consumption on either engine and they fire from cold on first compression stroke. Hocus Pocus? My view is that additive technology has improved over 35 years since the engines were built and can be effectively applied to DDs.

The products I have mentioned got their start in the Australian mining industry. They are particularly effective IF the engine shows signs of aging or you are unsure of previous owner's maintenance. In my two boats the chemicals have worked perfectly to rejuvenate 35 year old mechanically sound engines.)

With regards to the removal of the water pump, I believe the same Jabsco pump is used on 12V71 and 8V92 engines. I’ve changed impellers on the 8V92's and am soon to do so on the 12V92 for the first time. Access to the rear of the engine is easy. The entire pump can be removed by undoing two or three bolts holding it to the back of the engine. Be aware there is a loose gear behind the pump. Ensure it does not fall off into the bilge. Also practice putting this gear back in before you remount the water pump.

If it’s only the impeller to replace, then you can also use large size Jabsco impeller pullers. They work most of the time, depending on how stuck the impeller spline is to the shaft. Removing the entire pump also means you can look at the other internals such as the cam and wear plate and replace if necessary. If you see water drips from base of pump landing on the gearbox, then then seals and/or shaft has worn and needs to be replaced. It’s much easier to bite the bullet and have this repair done at a Jabsco dealer where they have the hydraulic presses required. Shafts are available in bronze or stainless. If replacing the impeller only then I use a rubber mallet to gently tap in the last quarter of the impeller into the pump housing. Make sure the impeller vanes are oriented to the correct pumping direction. A little marine grease on the gasket and tighten up the screws. Start engine and check for leaks as the plate can possibly be wound in a little further after the engine has been run. The screws are brass so tender care is required when removing and replacing.

[JohnEasley]

I’ll echo what Rustybucket says.

I have owned a past boat 11 years with 8V92N engines. New boat has 12V92TI engines. They are simple and reliable. But Detroit’s must be loved. This means yearly oil changes and not always running at low speed. Here in Sydney Harbour we have to run at 850 RPM or the wash is too great. So there lies a problem.

On both boats I set to task to rejuvenate the mechanically sound motors to as new using simple chemicals available in Australia and now exported to the USA. Have a look at www.costeffective.com.au. I use the FTC product, Oil Flush Conentrate and the AW10 product in the engines and gearboxes. The result for both boats over time was no sludge, cleaner oil, immediate firing, no blue smoke. On the 12V71TI engines (my newer boat of two years), there is now absolutely no oil consumption on either engine and they fire from cold on first compression stroke.

The key to DD longevity I believe is care and maintenance in conjunction with a set program of newly developed chemicals ... this offers great improvements for older engines such as the DD two strokes. (The products I have mentioned got their start in the Australian mining industry. They are particularly effective IF the engine shows signs of aging or you are unsure of previous owner's maintenance. In my two boats the products have worked perfectly to rejuvenate 35 year old mechanically sound engines.)

With regards to the removal of the water pump, I believe the same Jabsco pump is used on 12v&1 and *v92 engines. I’ve changed impellers on the 8V92's and am soon to do so on the 12V92 for the first time. Access to the rear of the engine is easy. The entire pump can be removed by undoing two or three bolts holding it to the back of the engine. Be aware there is a loose gear behind the pump. Ensure it does not fall off into the bilge. Also practice putting this gear back in before you remount the water pump.

If it’s only the impeller to replace, then you can also use large size Jabsco impeller pullers. They work most of the time, depending on how stuck the impeller spline is to the shaft. Removing the entire pump also means you can look at the other internals such as the cam and wear plate and replace if necessary. If you see water drips from base of pump landing on the gearbox, then then seals and/or shaft has worn and needs to be replaced. It’s much easier to bite the bullet and have this repair done at a Jabsco dealer where they have the hydraulic presses required. Shafts are available in bronze or stainless. If replacing the impeller only then I use a rubber mallet to gently tap in the last quarter of the impeller into the pump housing. Make sure the impeller vanes are oriented to the correct pumping direction. A little marine grease on the gasket and tighten up the screws. Start engine and check for leaks as the plate can possibly be wound in a little further after the engine has been run. The screws are brass so tender care is required when removing and replacing.

That's awesome information, Scott! Thanks. Just what I wanted to know. Our previous boat had Cummins Diamond Serious 6BTAs. Great engines and highly regarded but replacing the impeller required loosening the front left motor mount and using a jack to life the corner of the motor about 1/4". That procedure is well known for that engine. The DD sounds much, much easier to do.

[Walter P]

John, The sound proofing material is well known and is call Soundown, not Sundown. Let me know if you have problems finding it as I can probably locate a source near you. I actually still have a large roll of it in my container which I would be willing to part with but the shipping cost may be prohibitive because of bulk and weight.

Also regarding the impellers on the raw water pumps, scottinsydney posted some really good info. My experience with changing impellers on my 92 series engines has been good. My major PITA was actually very simple to fix. The bronze screws holding the plate on the pump housing are plain slotted round head originally and I found them to be a pain for me so I just changed them to hex head stainless screws and I use a 1/4" drive ratchet with the proper socket and be careful not to overtighten.

Walt

[jim rosenthal]

With regard to the seawater pumps on Cummins 6BTA5.9s.... I know you have to remove and support the motor mount on the front to change out the pump, but I had the impression you could change the impeller only, without removing the pump and thus having to take out the motor mount.

There is an aftermarket pump made for Cummins Diamond engines, B and C series, from Seaboard Marine in Oxnard, CA. It is a perfect fit, and each pump comes with a spare impeller and the tool to change it. Basically it is an upgrade in materials and design from the Sherwood pump, which have a bad reputation. It is also cheaper than the Sherwood pump. It is made in South Korea, I think, to a design by Tony Athens from SBMar. I have a set of them on my boat and they have done well for me. Sorry for the thread drift.

[JohnEasley]

John, The sound proofing material is well known and is call Soundown, not Sundown. Let me know if you have problems finding it as I can probably locate a source near you. I actually still have a large roll of it in my container which I would be willing to part with but the shipping cost may be prohibitive because of bulk and weight.

Also regarding the impellers on the raw water pumps, scottinsydney posted some really good info. My experience with changing impellers on my 92 series engines has been good. My major PITA was actually very simple to fix. The bronze screws holding the plate on the pump housing are plain slotted round head originally and I found them to be a pain for me so I just changed them to hex head stainless screws and I use a 1/4" drive ratchet with the proper socket and be careful not to overtighten.

Walt

Soundown. Okay, I found that. Sounds like awesome stuff (pun intended). I'm not in a position to need it right now but thanks for the offer.

Great tip about the impeller cover screws. Thanks!