Official Cummins QSC-500 Thread

[Stpetelsu64]

I did drill and tap on to the cap. I bought a new set of caps and kept the old ones as spares. It works like a charm.

I just purchased the cap for the Perko 493/9 strainer. ONce I get it I need to find someone to I guess drill, tap then put in a brass fitting then add the seacock on top and then add the hose connection above that? Does that sound like the correct procedure? From what I have read and seen it seems to be the right process. If anyone can simplify it for me and let me know the fittings i will need to supply the machine shop I sure would appreciate it. I am not much of a mechanical guy

 

[fwebster]

Perko strainer lids are very thin. I uised to makw a few flush caps for CSR members but I got weary of having to buy new caps for people who stepped on the strainers and broke the fitting off.

The strainers have a common pipe thread T or an ell where the water enters the strainer. A better solution than boriong a hole in the cap and trying to thread a fitting into metal that is too thin to hold the threads it is to take the last fitting off and replace it with a a T the assemble your flushing device with bronze pipe fittings.

Frank​

 

[becnme]

Anyone replace the front crank seal? My mechanic stopped by to take a peak at my motors and told me this year when I change oil to replace my crank seals as they have a small drip and it is common QSC's. I want to figure out how it is done so I can order any special tools and learn to do it myself.

I just did it on 06 500 QSC's and it is easy. No special tools, but a cordless impact made it much easier. You should torque the bolts especially the ones on the vibration damper. The worst part was cleaning the old silicone under the old seals.
The first engine had a learning curve, the second engine took about 1.5 hours.
You can download a service manual which was very helpful. I think it came from Seaboard Marine. This job was done by Cummins on a friends boat and was over 1K for both engines.

 

[Stpetelsu64]

Perko strainer lids are very thin. I uised to makw a few flush caps for CSR members but I got weary of having to buy new caps for people who stepped on the strainers and broke the fitting off.

The strainers have a common pipe thread T or an ell where the water enters the strainer. A better solution than boriong a hole in the cap and trying to thread a fitting into metal that is too thin to hold the threads it is to take the last fitting off and replace it with a a T the assemble your flushing device with bronze pipe fittings.

Frank​

When you say take the last fitting off I am not sure I follow you? so buy a T and connect which parts to the T? I am assuming at the top is the hose fitting and the T has 2 inch opening for my model but just to clarify and I am not the best at saying this but then you would clamp hoses on both ends of the T?

 

[fwebster]

r

When you say take the last fitting off I am not sure I follow you? so buy a T and connect which parts to the T? I am assuming at the top is the hose fitting and the T has 2 inch opening for my model but just to clarify and I am not the best at saying this but then you would clamp hoses on both ends of the T?

Typically SeaRay plumbs the strainers with an ell as the last fitting before the water enters the strainer. Remove that ell and replace it with a T. That leaves you with an open leg on the T. Then put a ball valve and your flushing adapter on the open leg of the T. Keep the ball valve closed except when you are flushing the cooling system, winterizing ,etc. I used garden hose fittings and a quick-connect to make hooking up to city water much easier.

On the air conditioner strainer, you do not need to run the AC to flush the system because the cooling pump has a magnetic impeller that free-wheels when the pump is off. fresh water just runs thru the system and is expeller out of the cooling water outlets.

Wish I could draw pictures on a lap top, because it is difficult to write this in an understandable way, even though I spend a lot of years technical writing for a living.

 

[Captsteve427]

I did drill and tap on to the cap. I bought a new set of caps and kept the old ones as spares. It works like a charm.

Looking forward to flushing the engines from now on, after I do my 1k service this spring. $13.00 for the 3/4" drill bit from Home Depot, $14.00 for a 3/4" tap and some elbow grease. Thnx for the idea Mark!

 

[Stpetelsu64]

Looking forward to flushing the engines from now on, after I do my 1k service this spring. $13.00 for the 3/4" drill bit from Home Depot, $14.00 for a 3/4" tap and some elbow grease. Thnx for the idea Mark!

That is exactly what I want to do. I just got the perko cap in. It seems awful thin in the middle to drill and tap it ? Maybe not tho as I see you have it. Not sure how you can do it but can you tell me exactly what you bought? What 3/4 inch tap did you get? I have a machine shop close that will do the work as it is out of my expertise. The ball valve or seacock is easy to find. But the other pieces I need. But what you posted in you pic is exactly what I want to do. But need to know exactly what parts to buy. It looks like you have a couple of pieces . I guess it doesnt need a seacock if you just take off the top and put this one on while flushing then remove and put the original back. ONly need the seacock if you keep it on while running your boat.

 

[Captsteve427]

That is exactly what I want to do. I just got the perko cap in. It seems awful thin in the middle to drill and tap it ? Maybe not tho as I see you have it. Not sure how you can do it but can you tell me exactly what you bought? What 3/4 inch tap did you get? I have a machine shop close that will do the work as it is out of my expertise. The ball valve or seacock is easy to find. But the other pieces I need. But what you posted in you pic is exactly what I want to do. But need to know exactly what parts to buy. It looks like you have a couple of pieces . I guess it doesnt need a seacock if you just take off the top and put this one on while flushing then remove and put the original back. ONly need the seacock if you keep it on while running your boat.

I found my caps were not thin at all, but noticed the bronze material is soft. I purchased the hardware from H/Depot. If you're going to have a machine shop do the drilling/tapping, supply them with the hardware, they should have the bit and tap to match the tread on the nipple that screws into the cap.

Honestly, if you're looking for a set up that will just be used when winterizing, you don't even need any of this. I fabricated a winterizing system used for my last two boats that had gas inboards, which consisted of a five gallon bucket, 6' of 3/4" hose, two 3/4" plastic through hull fittings and some starboard material cut in the shape of the strainer caps with gasket material beneath it and a through hull fitting in it. See photos. Just remove the strainer cap and screw the starboard down in its place.

With this boat, I've decided to drill and tap the engine strainer caps because when winterizing, they are too large for even 3/4" starboard to not flex and leak when screwed down with the wing nuts and the bucket too small to hold all the antifreeze that the diesels require. I will also be flushing the engines after every use and a permanent install is the most convenient way to go for that purpose.

 

[Stpetelsu64]

I found my caps were not thin at all, but noticed the bronze material is soft. I purchased the hardware from H/Depot. If you're going to have a machine shop do the drilling/tapping, supply them with the hardware, they should have the bit and tap to match the tread on the nipple that screws into the cap.

Honestly, if you're looking for a set up that will just be used when winterizing, you don't even need any of this. I fabricated a winterizing system used for my last two boats that had gas inboards, which consisted of a five gallon bucket, 6' of 3/4" hose, two 3/4" plastic through hull fittings and some starboard material cut in the shape of the strainer caps with gasket material beneath it and a through hull fitting in it. See photos. Just remove the strainer cap and screw the starboard down in its place.

With this boat, I've decided to drill and tap the engine strainer caps because when winterizing, they are too large for even 3/4" starboard to not flex and leak when screwed down with the wing nuts and the bucket too small to hold all the antifreeze that the diesels require. I will also be flushing the engines after every use and a permanent install is the most convenient way to go for that purpose.

CaptSteve, I dont need for winterizing as I use the boat all 12 months in Florida. I was off a bit on my response. I need to the hardware you purchased in order to get your strainers looking like the 2 pics a few responses back. I need to know what nipple you purchased. I can get the ball valve and the part that sits on top of the ball valve for the hose to connect to. Although I see you have the female on top so use the male end of the hose. I guess that would work but for me I would plan on using the female end to connect. Howerver I guess I could use a male end piece also
So I guess what I would need to know is the hardward you bought starting with the nipple, then the seacock which is not too hard, and then the piece on top of the seacock. I just want to be able to flush after each weekend use of the boat. Like I said I pretty much use it all year round. Sorry on the confusion. I printed your 2 pics and can bring it to the shop and ask what to buy. The main part I need to know tho is the peice that screws into the cap.

 

[Captsteve427]

CaptSteve, I dont need for winterizing as I use the boat all 12 months in Florida. I was off a bit on my response. I need to the hardware you purchased in order to get your strainers looking like the 2 pics a few responses back. I need to know what nipple you purchased. I can get the ball valve and the part that sits on top of the ball valve for the hose to connect to. Although I see you have the female on top so use the male end of the hose. I guess that would work but for me I would plan on using the female end to connect. Howerver I guess I could use a male end piece also
So I guess what I would need to know is the hardward you bought starting with the nipple, then the seacock which is not too hard, and then the piece on top of the seacock. I just want to be able to flush after each weekend use of the boat. Like I said I pretty much use it all year round. Sorry on the confusion. I printed your 2 pics and can bring it to the shop and ask what to buy. The main part I need to know tho is the peice that screws into the cap.

Below is a link to the tap that matches the thread on the close nipple that is screwed into the strainer cap/ball valve:

https://redirect.viglink.com/?forma...vlocphy=9031624&hvtargid=pla-439296128812

 

[lawndoctor]

I'm having the caps on the Guidi bronze strainers on the main engines of my Princess drilled and tapped so I can install a ball valve to allow fresh water flushing like you guys are describing.

I was concerned about the cap being thin and thus only providing a few threads for a fitting to screw into. I talked to SB Marine and they said they could solder a fitting in place, but I was concerned about how the solder would hold up in terms of cracking and leakage, and also whether it could give rise to galvanic corrosion, particularly if the solder they use contains zinc.

So I'm installing a bronze thru hull fitting into the caps then threading a bronze ball valve onto that. The combination of the mushroom cap on the inside/water side and the large nut on the outside will provide a solid, reinforced connection. Also, the threads are tapered on the fitting (at its end, the reason why they should never be cut to shorten them) and the valve, so this setup avoids the danger of mismatching tapered and straight threads. I talked to Groco and they warned me to be very careful in choosing the fittings, because with mismatched threads only a few threads engage, resulting in a weak connection. Groco said this is a surprisingly common problem in sea valve installations, and has caused sinkings.

Maybe the thru hull fitting is overkill, but it seems like a stronger setup than tapping the cap and screwing a fitting into the cap's relatively few threads. If anyone's interested, I'll post some photos when I get this done.

 

[Stpetelsu64]

I'm having the caps on the Guidi bronze strainers on the main engines of my Princess drilled and tapped so I can install a ball valve to allow fresh water flushing like you guys are describing.

I was concerned about the cap being thin and thus only providing a few threads for a fitting to screw into. I talked to SB Marine and they said they could solder a fitting in place, but I was concerned about how the solder would hold up in terms of cracking and leakage, and also whether it could give rise to galvanic corrosion, particularly if the solder they use contains zinc.

So I'm installing a bronze thru hull fitting into the caps then threading a bronze ball valve onto that. The combination of the mushroom cap on the inside/water side and the large nut on the outside will provide a solid, reinforced connection. Also, the threads are tapered on the fitting (at its end, the reason why they should never be cut to shorten them) and the valve, so this setup avoids the danger of mismatching tapered and straight threads. I talked to Groco and they warned me to be very careful in choosing the fittings, because with mismatched threads only a few threads engage, resulting in a weak connection. Groco said this is a surprisingly common problem in sea valve installations, and has caused sinkings.

Maybe the thru hull fitting is overkill, but it seems like a stronger setup than tapping the cap and screwing a fitting into the cap's relatively few threads. If anyone's interested, I'll post some photos when I get this done.

Sounds like a great idea. I too am worried about the thickness and how weak it will be now that I purchased the parts. I have the closed nipple on the bottom connecting to the cap. Then I put on the ball valve. Then I added a hex nipple and finally the hose attachment on that. My concern is the first piece the closed nipple. It is so thin in the middle of the cap I am thinking I need some kind of "bushing"? Not sure if that is what you call it but similar to a thru hull. Or add a nut underneath the cap or use a part like the thru hull. If you dont mind shooting a pic of the part you are talkng about to put thru the cap. It is so think on the Perko cap I will send a pic later when I get it set up I edited to add the pics

One pic shows the parts. The other I connected all of them. The closed nipple on the bottom worries me. It there was something under the cap that would tighten it up I would feel better. Like a hex on one end where you would screw it in from underneath which should strengthen it. Hope that makes sense and apologies for my lack of knowledge on what the plumber parts are called Well I may have to add the pics in next post

 

[Stpetelsu64]

I'm having the caps on the Guidi bronze strainers on the main engines of my Princess drilled and tapped so I can install a ball valve to allow fresh water flushing like you guys are describing.

I was concerned about the cap being thin and thus only providing a few threads for a fitting to screw into. I talked to SB Marine and they said they could solder a fitting in place, but I was concerned about how the solder would hold up in terms of cracking and leakage, and also whether it could give rise to galvanic corrosion, particularly if the solder they use contains zinc.

So I'm installing a bronze thru hull fitting into the caps then threading a bronze ball valve onto that. The combination of the mushroom cap on the inside/water side and the large nut on the outside will provide a solid, reinforced connection. Also, the threads are tapered on the fitting (at its end, the reason why they should never be cut to shorten them) and the valve, so this setup avoids the danger of mismatching tapered and straight threads. I talked to Groco and they warned me to be very careful in choosing the fittings, because with mismatched threads only a few threads engage, resulting in a weak connection. Groco said this is a surprisingly common problem in sea valve installations, and has caused sinkings.

Maybe the thru hull fitting is overkill, but it seems like a stronger setup than tapping the cap and screwing a fitting into the cap's relatively few threads. If anyone's interested, I'll post some photos when I get this done.

Here are the pics I referred to

 

[lawndoctor]

Sounds like a great idea. I too am worried about the thickness and how weak it will be now that I purchased the parts. I have the closed nipple on the bottom connecting to the cap. Then I put on the ball valve. Then I added a hex nipple and finally the hose attachment on that. My concern is the first piece the closed nipple. It is so thin in the middle of the cap I am thinking I need some kind of "bushing"? Not sure if that is what you call it but similar to a thru hull. Or add a nut underneath the cap or use a part like the thru hull. If you dont mind shooting a pic of the part you are talkng about to put thru the cap. It is so think on the Perko cap I will send a pic later when I get it set up I edited to add the pics

One pic shows the parts. The other I connected all of them. The closed nipple on the bottom worries me. It there was something under the cap that would tighten it up I would feel better. Like a hex on one end where you would screw it in from underneath which should strengthen it. Hope that makes sense and apologies for my lack of knowledge on what the plumber parts are called Well I may have to add the pics in next post

Here is the Groco "thru hull fitting" I am taking about. https://www.groco.net/products/fittings/thru-hull-fittings/th-series/th-750-w. My thinking is that installing this "thru hull fitting" through the hole drilled in the cap, and thus having the "mushroom" cap of the "thru hull fitting" on one side and the lock nut on the other side, reinforces the penetration through the relatively thin cap, and thus makes the overall installation stronger than just threading in a "nipple" fitting. Given that we're threading a ball valve onto this connection and then connecting a hose to it, it would seem best to have the penetration through the cap as strong and reinforced as possible.

 

[Mjresq4]

I love this idea. It looks like there is no need for adding threads to the cap, just drill the hole and insert the thru hull making the thickness of the cap irrelevant. @lawndoctor is there an o-ring that sits on the mushroom side of the thru hull? I don't see it in the picture but it looks like there is a groove for one.

 

[lawndoctor]

I love this idea. It looks like there is no need for adding threads to the cap, just drill the hole and insert the thru hull making the thickness of the cap irrelevant. @lawndoctor is there an o-ring that sits on the mushroom side of the thru hull? I don't see it in the picture but it looks like there is a groove for one.

Agree threads in the cap may not be needed, although they would make the connection tighter, so I may have that done if feasible. It depends on how far down the threads extend on the fitting. It looks like there is a slight shoulder where the threads return into the cap, which could interfere with screwing it all the way into threads in the cap.

I think that groove is to hold caulk, but I haven't bought the fitting yet so I'm not sure if it comes with a gasket or o ring. I plan to use 4200 or maybe 5200 around the base of the fitting to ensure the connection is sealed.

One other thing to think about. The strainer basket on the Guidi strainers does not have a handle sticking up toward the cap. It looks like the Groco and Perko strainers do. If so, you'll want to make sure the handle is not in the way of the space taken by the mushroom cap on the underside of the cap. It's only a fraction of an inch so probably not an issue, but I think worth confirming before going down this road. They make thru hull fittings with the mushroom cap tapered so it fits flush on the surface it screws into, but to use that would require countersink-drilling the cap, which may be doable but would add complexity to the project, not to mention potentially weakening the cap.

 

[Stpetelsu64]

Agree threads in the cap may not be needed, although they would make the connection tighter, so I may have that done if feasible. It depends on how far down the threads extend on the fitting. It looks like there is a slight shoulder where the threads return into the cap, which could interfere with screwing it all the way into threads in the cap.

I think that groove is to hold caulk, but I haven't bought the fitting yet so I'm not sure if it comes with a gasket or o ring. I plan to use 4200 or maybe 5200 around the base of the fitting to ensure the connection is sealed.

One other thing to think about. The strainer basket on the Guidi strainers does not have a handle sticking up toward the cap. It looks like the Groco and Perko strainers do. If so, you'll want to make sure the handle is not in the way of the space taken by the mushroom cap on the underside of the cap. It's only a fraction of an inch so probably not an issue, but I think worth confirming before going down this road. They make thru hull fittings with the mushroom cap tapered so it fits flush on the surface it screws into, but to use that would require countersink-drilling the cap, which may be doable but would add complexity to the project, not to mention potentially weakening the cap.

YOu noted one thing I didnt think of. I have all the parts I need except for what I can attach to the nipple that goes thru the cap. I had thought about capping it off with just a female hose fitting with a rubber waster. Or a reducer. But you brought up the unevenness of the cap. So now I am concerned about 2 things. One is do I do threads or not? Since there may be room for 2 threads or maybe 3 so will be hard to take. Or do a thru hull. But then once done how do you tighten it up so water doesnt leak. If you have a washer there if it doesnt fit flush against the under side of the cap then what?

 

[lawndoctor]

To use the thru hull fitting, the cap has to be flat on both sides, or at least have a big enough flat spot at the center so the mushroom cap can tighten against it on the bottom and the nut can tighten against it on the top. The caps on my strainers are flat. If yours are not, I guess you have to figure out if the center area has a flat spot that is big enough to accomodate whatever you are going to put there. If not, then the thru hull idea probably won't work. Maybe you could thread a bronze nut onto the nipple on the bottom of the cap to support it, but you'd probably still have the problem of trying to tighten something flat against a rounded surface. Plus, I suppose the nut could loosen up and wind up in your strainer.

One other thing I wanted to mention. In the photos it looked like you are putting a brass nipple into the cap. I wouldn't use brass for anything on the salt water side of the ball valve. It could lead to galvanic corrossion in the form of "dezincification," meaning the zinc in the brass will get eaten away by electrolysis.

 

[Stpetelsu64]

To use the thru hull fitting, the cap has to be flat on both sides, or at least have a big enough flat spot at the center so the mushroom cap can tighten against it on the bottom and the nut can tighten against it on the top. The caps on my strainers are flat. If yours are not, I guess you have to figure out if the center area has a flat spot that is big enough to accomodate whatever you are going to put there. If not, then the thru hull idea probably won't work. Maybe you could thread a bronze nut onto the nipple on the bottom of the cap to support it, but you'd probably still have the problem of trying to tighten something flat against a rounded surface. Plus, I suppose the nut could loosen up and wind up in your strainer.

One other thing I wanted to mention. In the photos it looked like you are putting a brass nipple into the cap. I wouldn't use brass for anything on the salt water side of the ball valve. It could lead to galvanic corrossion in the form of "dezincification," meaning the zinc in the brass will get eaten away by electrolysis.

Now on your last point on the brass. If I only use this to flush and then replace the cap after would that matter? I am talking flushing each engine maybe twice a week. But even tho it is a pain I have nothing else to do so I take off the cap and replace it with this one.
ON the flat surface I thought you had said it wasnt flat. Maybe I read it somewhere else. I put a coin on it and it looks flat.
Thanks for the reply!

 

[ttmott]

Here are the pics I referred to

I'd not use brass in any seawater application; it will be gone in short order and you'll have a hole in the boat.
Groco makes cast bronze pipe nipples; Defender has them. I've gotta ask though - why the valve? Just a cap on the nipple - then when you want to flush take the cap off and thread on a hose adapter. The sea cock, it seems to me is the only valve needed...