Sherwood pump number for Oday 28 with M12 engine

[fourwhitesocks]

Trying to figure out which Sherwood raw water engine pump I have on my 1986 28' Oday. Has the Universal M12 diesel. Will it be a Universal or Sherwood number? Might have to replace or purchase a rebuild kit. Anyone know if the rebuild kit will contain a bearing that will need it being pressed into the old pump? Considering the Oberdorfer replacement, but that might be a different question not sure. There is no number on the impeller cover...any help appreciated.

 

[StanleyJ]

I have a 1988 M 12 diesel. I replaced the Sherwood pump with an Oberdorfer N202M-15 pump from Cardinal Pump in St Louis Missouri (314-628-0100) last year and I could not be happier that I made the switch. It really pumps a lot of water and my diesel never goes above 175 degrees. I paid about $215.00 for the pump at Cardinal vs $300 - $400 at Marine stores. The pump does not come with the pump to engine gasket (I puchased the gasket from Catalina Direct for less than $3.00). It was an easy switch. The pump port size is 3/8". If you want to rebuild the old pump, then Compass Marine (Mainsail) has an excellent tutorial.

 

[LeslieTroyer]

+1 for the oberdorfer. Also check pumpsandpartsonline.com and depco both understand universals.

Les

 

[fourwhitesocks]

OK cool, yesterday I spoke to a guy who can ship me the pump within 24 hours, but the part number he said I needed for the Oberdorfer is N202M-16 ...??

*the difference is the port size, I would think for better cooling I should get the 1/2" one... is that the correct thinking?

 

[StanleyJ]

Probably so. I just matched mine to the size hose and nipple that was on the previous Sherwood pump. You would probably get more volume but less pressure with the 1/2" vs 3/8".

 

[fourwhitesocks]

Ok so which is more important for keeping the engine cool, pressure or volume?

So the side you bolt the pump onto is the same for either part # (the - 15 vs the - 16 Oberdorfer), and it will bolt right on to my M12 with no mods? (well except a longer hose on one side and maybe a brass 90)

 

[StanleyJ]

I am not sure if pressure or volume is more important. My 15 pump is pumping far more water out the exhaust than my Sherwood (with a new impeller). I just matched the size with the brass nipples that were on in the Sherwood. I think that you would be happy with either the 15 or 16. The Oberdorfer is a bolt in replacement. The 15 has 4 bolt holes but my M12 only uses the two horizontal bolts. It took about two hours to remove the old one, clean the gasket surface, apply a gasket sealant,a d bolt the new one in. You can go to Catalina Direct and look under parts for the M12 to see if they list the 15 or 16 pump for your engine.

 

[fourwhitesocks]

Yep, thank you! They do list them both ;-) they just go by the 1/2 or 3/8 tho.

 

[LeslieTroyer]

If I remember correctly the -15 and -16 have exactly the same specs as far as pumping rates, pressure, head..... only oddball in that family of pumps is the -3 which has much lower flow rate

I would think the -16 would be harder to fit 90 degree fittings onto.
Les

 

[odaydokay]

Depco rebuilt my Sherwood in 2012 (1985 O'Day 28 as OE) Has been great other than needing an impeller this year, which is normal. They reversed the cover on it for some reason so Sherwood name and number now inside. I am sure an Oberdorfer will do fine or better. Was only $138 and included new impeller of course.

 

[fourwhitesocks]

I ended up getting the Oberdorfer part number ending in - 15, one from marinepartssource.com today, super great guy helped me, should be here tomorrow, just need to get those fittings out of my old one....

 

[LeslieTroyer]

Ok so which is more important for keeping the engine cool, pressure or volume?

The raw water side is open to atmosphere more or less so there is no pressure to speak of except resistance in the path. That resistance goes up with flow(slightly). But strictly speaking pressure is not a variable we have much control over. We can control flow with bigger/smaller pumps. And it is flow that varies away waste heat. Pressure does increase the capacity of water to hold heat before changing phase, which is why the boats coolant system is pressurized. You better hope the raw water never gets hot enough to change phase (boil) or your going/have big engine problems

So flow (volume) of the raw water side is most important.

Les
Who had to take way too much thermo-damn-naamics in school

 

[fourwhitesocks]

Wait are you saying I purchased the wrong pump? The guy above StanleyJ said the one I purchased worked great on his M12...?

 

[LeslieTroyer]

I’m sure you’ll love either pump. If you have only one 90 there is no problem. If you have 2 90’s you may need to grind one of the barbs a bit shorter (on both -15&-16). Note word may - much depends on length of the barb.

Les

 

[odaydokay]

I have a 1988 M 12 diesel. I replaced the Sherwood pump with an Oberdorfer N202M-15 pump from Cardinal Pump in St Louis Missouri (314-628-0100) last year and I could not be happier that I made the switch. It really pumps a lot of water and my diesel never goes above 175 degrees. I paid about $215.00 for the pump at Cardinal vs $300 - $400 at Marine stores. The pump does not come with the pump to engine gasket (I puchased the gasket from Catalina Direct for less than $3.00). It was an easy switch. The pump port size is 3/8". If you want to rebuild the old pump, then Compass Marine (Mainsail) has an excellent tutorial.

Can I ask what the flange on your Sherwood looked like? There are apparently two flange designs from Oberdorfer, an almost oval two hole (M202-3) and a distorted square, M202-15or 16 Not sure one fits my 1985 M-12 which is a two bolt but distorted square shape flange, but I am guessing the -15 type despite Depco telling me it is probably the -3. The words "two bolt" are misleading.

 

[odaydokay]

Here is my Sherwood.

 

[fourwhitesocks]

My Sherwood looked exactly like that....but that might not answer your question

 

[LeslieTroyer]

I think you want the 202-95? Don’t remover the exact # but pumpsandpartsonline.com or depco can sluth itt out - it’s the only one with a 900 series dash number. This prevents you from grinding down some of the bronze to get it to fit.

Les

 

[StanleyJ]

My old Sherwood looked just like the one pictured above (4 bolt holes with two bolts attaching it to the engine). The Oberdoerfer 15 model was a direct replacement with no fit problems and just used two bolts. My freshwater engine coolant pump seized up today so now I have to replace that pump too. If you do not feel comfortable replacing your Sherwood pump, then you can see it being done on Universal diesel engines on You Tube. I only have moderate mechanical skills and this is not a difficult job.

 

[fourwhitesocks]

I changed my pump myself and had never done it before ;-) I purchased the Oberdorfer is N202M-15 and it was a direct replacement BUT there was a tiny bit of grinding I had to do so it wouldn't run into the idle screw that is sticking out right there on the top area of the flange, but it was very minimal! Super easy switch even the grinding part.