no more fouled plugs

[hanleyclifford]

Thinking about what Bill wrote in post #2 above, perhaps we could come up with a set of design criteria specific to the installation of Atomic 4s into sailboats. If half the fleet is affected such a "check list" would be useful. Maybe we could start with some easy non-contoversial ones: 1) The system should maximize resistance to intrusion of a following sea. 2) The system should minimize unproductive work load on the engine. Who's got #3?

[ndutton]

Sorry about the dead link. Howze dis?

[Joesailboater]

Got it! Thanks Neil.

Any atomic-4 specific design info or equipment would be on my "next purchase" list. Any of you engineer/entrepreneur types out there are greatly appreciated. This back pressure issue sounds as if it's been around for a while. It would be great if someone could come up with the definitive solution.

[hanleyclifford]

Neil - That link does indeed provide a solid framework for our discussion in ths forum. However, I would add that the suggested dimensions are quite unrealistic for most of us. In addition we must also consider the issue of performance in light of our limited horsepower. The system as configured in "Figure 4" would choke most Atomic 4s. That said, I have to agree that it is useful and cautionary. Regards, Hanley

[ndutton]

The link was intended as conceptual, a reasonable description of the waterlift system. The dimensions provided just happened to be there, weren't my doing. More often than not the dimensions are dictated by the limitations of our personal boat and the mid-engine Catalina 30 is the poster child for exhaust system limitations.

Wish I could find a standpipe system drawing for comparison.

[hanleyclifford]

Sorry Neil, I did not mean to suggest those were your numbers. The link is a good discussion because it makes us focus on the details. Before I joined this forum I thought I had the best exhaust system in the fleet; now the more I hear and read, the more uncertain I get. I really like those long jacketed copper or bronze systems because they are so direct and eliminate the injection and lift issues. But they sure look expensive.

[ndutton]

I put something together that might help. After opening, scroll down to see both pages. Sorry for the fuzzy drawings.

[Laker]

Please define and describe "Batching".

[hanleyclifford]

Neil - Those drawings clearly demonstrate the conceptual superiority of the standpipe from the efficiency viewpoint - no use of engine energy to drive water uphill or issue with water getting to the manifold (which I believe is what originally motivated this thread). However, it's dimensional requirements are daunting for most of us. But I would do it if I could. The water lift concept is clearly inferior. I think for most of us the solution lies in creating the best possible water lift system our dimensions allow unless we can spring for the long jacket such as the ones Russ and 67 and Kelly use. I did a little checking on copper and bronze pricing - my materials cost for even a two foot jacket would exceed $300. Laker - I'm going to leave it to others to render that definition. I can only describe it as the process we observe when water comes out the transom unevenly because the pressure varies in the wet system. When I pressure tested at the hot section I observed variation between 0 and 1psi.

[ndutton]

Please define and describe "Batching".

"Batching" describes the way the water exits the exhaust in a waterlift system at low engine RPM. There will be a short period of dry exhaust then a burp of water. The higher the RPM, the steadier the water stream.

Neil - Those drawings clearly demonstrate the conceptual superiority of the standpipe from the efficiency viewpoint - no use of engine energy to drive water uphill or issue with water getting to the manifold (which I believe is what originally motivated this thread). However, it's dimensional requirements are daunting for most of us.

Like the waterlift, a properly designed and installed standpipe exhaust is an excellent system but you're right, available space is often an issue. In Joe's case, his Newport 30 was originally built with one so it has the space. Given the choice I would opt for the standpipe as well. The trick is finding a shop that understands the system to fabricate one. Unlike the waterlift, a standpipe system won't be cobbled together with parts off the shelf.

Somewhat off topic, it raises an interesting thought. In addition to Moyer Marine, what specialty vendors/fabricators (other than West Marine) do y'all keep handy to support your boating addiction? For me with my background, I do much of my fabrication myself but I still have two stainless fabricators, sailmaker, rigger, canvas shop, dedicated fiberglass supplier, teak supplier, an excellent stainless fastener supplier, bottom cleaner and in conjunction with a major project described on two other forums, a stainless foundry to make custom castings.

[sastanley]

Well, I just gave Defender $1,300 at the boat show this weekend for some boat bling.

But in addition to that I need to find me a good teak supplier..It is time to start building my new chart table so I can get to the re-wiring project.

[Laker]

"I need to find me a good teak supplier"

Consider using a South American hardwood called "pao lope" , "epae" (sp?) pronounced eepay , sometimes sold as hardwood decking. I have used it in a number of marine applications. It is as hard or harder than teak , has much the same appearance , holds a finish beautifully , and costs a heck of a lot less. Everyone in my marina thinks that the huge swim platform on my powerboat is teak.

Sorry for going off topic.

Laker

[tenders]

"eepay" is actually spelled simply "ipe."

The only thing I know about it is that it's very hard on woodworking tools.

[rigspelt]

I've used jatoba wood instead of teak inside. Hard, much cheaper, looks great.

[rigspelt]

Please define and describe "Batching".

In our exhaust, the exhaust gas flow probably is constant, but the water does not get pushed out of the waterlift muffler evenly. It flows evenly from the heat exchanger, but builds up at the low point in the muffler to where a few cupfuls get pushed up by the gas in a "batch" into the looped exhaust hose running from the muffler to the transom. That's what I see, not a technical engineering explaination.