Greetings MMI/A-4 Braintrust,
First of all, thanks to MMI for a superb forum. I've been looking to move from my Catalina 25 to a bigger boat for the last few months and many of the boats in my budget are powered by the Atomic 4. As such, I've been a frequent reader of this forum and have been truly impressed with the camaraderie and knowledge I have witnessed. My humble thanks to you all.
I very recently (as in yesterday) became the owner of a Tartan-30 powered by a rebuilt (2008) MMI Atomic 4. The engine is in great shape, but the currently installed water-lift muffler is shot. As I was removing panels yesterday to get access to the exhaust system, and contemplating a replacement hot section and new water-lift muffler, what I found has truly perplexed me. I was hoping to tap into the vast reservoir of knowledge this forum offers in helping me understand what exactly is going on with this current system.
The Tartan 30 (and 34) have the engine mounted very low just abaft the mast with the exhaust exiting amidships on the port side. There are certainly many positives with this design, but one of the trade-offs is the exhaust system. It's difficult to get enough vertical drop in the hot section without running into the issue of cooling water backing up into the manifold.
That said, the current set-up is puzzling. I have the "usual" water injection point just downstream of the hot section and just prior to the water-lift:
What is puzzling is this arrangement in the top of the exhaust loop:
What I'm wondering is, is this a wise set-up? Is there a method to the madness?
Since I need a new water-lift muffler anyway, I'm thinking about getting the new Moyer Standpipe muffler for Tartans.
Thoughts?
First of all, thanks to MMI for a superb forum. I've been looking to move from my Catalina 25 to a bigger boat for the last few months and many of the boats in my budget are powered by the Atomic 4. As such, I've been a frequent reader of this forum and have been truly impressed with the camaraderie and knowledge I have witnessed. My humble thanks to you all.
I very recently (as in yesterday) became the owner of a Tartan-30 powered by a rebuilt (2008) MMI Atomic 4. The engine is in great shape, but the currently installed water-lift muffler is shot. As I was removing panels yesterday to get access to the exhaust system, and contemplating a replacement hot section and new water-lift muffler, what I found has truly perplexed me. I was hoping to tap into the vast reservoir of knowledge this forum offers in helping me understand what exactly is going on with this current system.
The Tartan 30 (and 34) have the engine mounted very low just abaft the mast with the exhaust exiting amidships on the port side. There are certainly many positives with this design, but one of the trade-offs is the exhaust system. It's difficult to get enough vertical drop in the hot section without running into the issue of cooling water backing up into the manifold.
That said, the current set-up is puzzling. I have the "usual" water injection point just downstream of the hot section and just prior to the water-lift:
What is puzzling is this arrangement in the top of the exhaust loop:
What I'm wondering is, is this a wise set-up? Is there a method to the madness?
Since I need a new water-lift muffler anyway, I'm thinking about getting the new Moyer Standpipe muffler for Tartans.
Thoughts?
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