Tartan 30 exhaust system rebuild

[jacques debauche]

The A4 in our newly-purchased Tartan 30 runs like a charm except under one condition. If allowed to idle for more than a few minutes, the A4 stalls and will not restart, and water appears in cylinders 3 and 4. Apparently, at low idle the exhaust flow in insufficient to lift water from the lift box so that water builds up and eventually reaches the exhaust manifold.

The exhaust arrangement in this boat is one I am not fond of. From the manifold the exhaust angles down to the lift box, with cooling water injected on this downward run. From the lift box the exhaust rises to above sea level, (almost three feet) then down to the portside exhaust. Our previous boat had a more sensible system in which the exhaust ran from the manifold to a point above sea level, then down to the lift box, then to the transom exhaust. Cooling water was injected into the downward leg which means that it is unlikely that it could ever reach the manifold.

I would like to emulate that type of system in the Tartan 30, but there are barriers. Since the system is between the midship bulkhead and the head cabinetry, it would be difficult to fit a metal upriser and rubber downcomer into the limited space. Also, since the upriser would be hot, even if double-wrapped with glass tape, there would be a fire danger.

In older Tartan 30s I have seen an arrangement in which the metal upriser is surrounded by a jacket into which the cooling water is injected and through which the exhaust flows downward. This coaxial arrangement (standpipe?) certainly looks attractive because it solves both the space and fire problems, and guarantees that cooling water cannot get back to the exhaust manifold. However, since this arrangement seems to have all but disappeared (and does not seem to be available for purchase) it must have some disadvantages that I have not seen.

What advice or comments do we have out there?

[ArtJ]

Re exhaust T30

I have a Tartan 34C with the standpipe as you mention on the T30
I replaced all the black iron exhaust about 10 years ago, wrapped it
with Exhaust wrap and it has been totally trouble free ever since.
I suggest checking with TONE (tartan owners website) or elsewhere to
see if someone has a standpipe they are no longer using.

Regards

[Rick Estabrook]

Exhaust rebuild

I have a T30, hull #308, built in '75. After two seasons of overheating - the final stages of which were 5 minutes running time before redline, I bit the bullet and went into the hidden parts of the exhaust system. I found a strange casting at the top of the riser configuration (MMI calls the "inline cooling water exhaust fitting") that had corroded to the point that no water could pass. My guess is that the fitting was original. It was the last thing I checked after trying many other routes. That fitting arrangement is within the bulkhead between the cabin and the head, and requires removing much of the head interior to service. Once I was that far in, I decided to go all new. I replaced the black pipe, purchased MMI's replacement fitting, installed new hoses. The engine runs uniformly, stays happy at cruising RPM, with lots of cooling water exiting the boat.