Sherwood vs. SeaMax

[Blown284]

Hi folks,
I have the Cummins 480CE engines. Appears the PO replaced the starboard side with the Seamax pump/impeller and I can see why ---- space is exceptionally tight.

Question. Should I consider replacing the port side with the Seamax too or is it personal preference? I just wanted to get your feedback as I believe I've read that some folks have replaced their SeaMax impellers less frequent than Sherwood.


Thoughts?

Thanks,
Tim

 

[Mark.60]

I’m not positive about the 480 but if you go to seaboard marine you will see that they reengineered the pump and sell an upgraded pump assembly. It was most likely replaced due to failure.

 

[my3sons]

Hi folks,
I have the Cummins 480CE engines. Appears the PO replaced the starboard side with the Seamax pump/impeller and I can see why ---- space is exceptionally tight.

Question. Should I consider replacing the port side with the Seamax too or is it personal preference? I just wanted to get your feedback as I believe I've read that some folks have replaced their SeaMax impellers less frequent than Sherwood.


Thoughts?

Thanks,
Tim

It's personal preference if you have a good working sherwood. I replaced one of my Sherwoods with a Seamax because it needed a rebuild. After experiencing how easy it is to replace the impeller on the Seamax with the splined impeller versus the Sherwoods keyed type, and the fact that the Sherwoods were original and getting up there in years, I put in the second Seamax a year and a half later. They're not cheap at about $750 so it's understandable if you don't want to do it, but keep in mind you will have to carry 2 different impellers as spares until you do make the change.

 

[Blown284]

It's personal preference if you have a good working sherwood. I replaced one of my Sherwoods with a Seamax because it needed a rebuild. After experiencing how easy it is to replace the impeller on the Seamax with the splined impeller versus the Sherwoods keyed type, and the fact that the Sherwoods were original and getting up there in years, I put in the second Seamax a year and a half later. They're not cheap at about $750 so it's understandable if you don't want to do it, but keep in mind you will have to carry 2 different impellers as spares until you do make the change.

Thank you very much for that info --- exactly what I was looking for. In your own experience, are you replacing the SeaMax impellers every year or two? How often do you replace the seamax impellers? Any change in frequency you've seen vs. the sherwood?

 

[my3sons]

I replace the Seamax impellers about every three years Normally. But I have taken the boat on some long cruises (loop and Great Lakes to Bahamas) and then I change them by hours. Last change I made was after the Bahamas trip 2 years ago, they had 500+ hours on them. Now they have 300+ hrs on them and I will change them later this year. I only ran the Sherwood impellers 2-3 seasons so hard to tell how much better the Seamax are, if any. YMMV

 

[Blown284]

I replace the Seamax impellers about every three years Normally. But I have taken the boat on some long cruises (loop and Great Lakes to Bahamas) and then I change them by hours. Last change I made was after the Bahamas trip 2 years ago, they had 500+ hours on them. Now they have 300+ hrs on them and I will change them later this year. I only ran the Sherwood impellers 2-3 seasons so hard to tell how much better the Seamax are, if any. YMMV

Great, thanks again for your unbiased info. I went ahead and ordered another Seamax pump to replace that port engine/impeller and time permitting this year, will replace it. If not, I have a spare I'm a "if it ain't broke, don't fix it" type of guy.

 

[LMBoat]

My experience is same as my3sons. I have SM pumps on both engines, and a new one as a spare. They are expensive, but keep in mind that you will get 2 impellers with the pump (as least I did). As they are about $100 a pop, that brings down the cost a bit.

 

[Blown284]

My experience is same as my3sons. I have SM pumps on both engines, and a new one as a spare. They are expensive, but keep in mind that you will get 2 impellers with the pump (as least I did). As they are about $100 a pop, that brings down the cost a bit.

Don't know if it comes with a "Spare" or not and can't tell from what I purchased. Here's what it says:

“Plug & Play” replacement for the SHERWOOD 1730 – Fits All Cummins 6BTA’s & 6CTA’s, 270 / 330 / 370 / 255 / 350 / 450 / 480CE / & Diamonds (since about 1995), & QSL9
Cummins Part # 5265994 – Factory List Price $1,499.15

Price includes spare SUPER 27 impeller with puller, o-rings and gaskets

 

[dtfeld]

I wish he would make a pump that would fit the CAT engines, I'd buck up in a heartbeat. Also, I believe these come with the gear attached, so the price reflects that, and makes a much easier swap out.

I replaced My Sherwood 1732C 2 seasons ago with new and put 125 hours on the impellers. The impellers had taken quite a set and had noticeable groove in the blade tips when I pulled them a couple weeks ago.

I don't run as many hours, but I'm thinking every 250 hours and 2 seasons max is my limit. I just don't want to take a chance overheating a very expensive engine for a $50 impeller.

My 125 hour impellers. Note blade tip wear. The port side was worse.

 

[Blown284]

Is there an easier way to replace impeller on the starboard engine? Anyone done a write up that you know of?

 

[Jaws]

With the original Sherwoods the starboard change was miserable on the 460. First time I lost the key in the intake hose; retrieved it many hours later. I found that the impellers would lose a vane or two into the aftercooler every year so the second year I removed the starboard Sherwood and replaced the impeller on the bench.
Then I got smart and switched both sides to SMX pumps and never regretted it. Impeller changes are easy now (15 minutes starboard and 30 minutes port on the 460DA). Easy to remove and insert the impeller. That was ten years ago. Now I just replace the impellers every three years and they look like new every time. Worth the initial cost in my opinion.

 

[Blown284]

With the original Sherwoods the starboard change was miserable on the 460. First time I lost the key in the intake hose; retrieved it many hours later. I found that the impellers would lose a vane or two into the aftercooler every year so the second year I removed the starboard Sherwood and replaced the impeller on the bench.
Then I got smart and switched both sides to SMX pumps and never regretted it. Impeller changes are easy now (15 minutes starboard and 30 minutes port on the 460DA). Easy to remove and insert the impeller. That was ten years ago. Now I just replace the impellers every three years and they look like new every time. Worth the initial cost in my opinion.

My port engine is Sherwood pump and starboard is already SeaMax. I'm just curious how quickly / difficult it is to change the SeaMax impeller given where it's located? I do plan to replace the port water pump with SeaMax --- have the new pump just waiting for the temps to agree.

 

[Jaws]

I would recommend swapping the port pump to the SMX so both use the same impeller. It's the one you really want to have the easy time with due to limited access. Once you, do I find that I can change the impeller on the port side without much difficulty. I use a mirror just to guide my hands; remove three bolts on the plate; O ring comes with it. The new impeller has a slick removal tool. It just threads into the end of the old impeller and out it comes.
When inserting the new impeller you can use a tomato soup can with the ends cut out. Pre-load the impeller first and it fits right into the body of the SMX. Although I find I don't need to do that any longer. Just soap up the impeller with two tie wraps and insert to the first tie wrap. Then cut the first, push to the second and cut that. Then give it a final push. So there's my two methods with the splined SMX impeller.
Hope that helps.

 

[Blown284]

I would recommend swapping the port pump to the SMX so both use the same impeller. It's the one you really want to have the easy time with due to limited access. Once you, do I find that I can change the impeller on the port side without much difficulty. I use a mirror just to guide my hands; remove three bolts on the plate; O ring comes with it. The new impeller has a slick removal tool. It just threads into the end of the old impeller and out it comes.
When inserting the new impeller you can use a tomato soup can with the ends cut out. Pre-load the impeller first and it fits right into the body of the SMX. Although I find I don't need to do that any longer. Just soap up the impeller with two tie wraps and insert to the first tie wrap. Then cut the first, push to the second and cut that. Then give it a final push. So there's my two methods with the splined SMX impeller.
Hope that helps.

I have the new SeaMax pump already with two new impellers. Therefore, the plan is to swap it out soon as I can.