What would cause 'dimpling' on the engine block face?

[ndutton]

A Design Flaw?

I wouldn't consider it a flaw. Flaw implies the designer overlooked or misunderstood something which is simply not the case with Catalina's Frank Butler and Gerry Douglas. This is more like realizing the limitations of a mid engine installation and the hot section height restriction due to cabinetry. Properly done - as from the factory - it works fine. After a few shoddy replacements by a previous owner or two - or their mechanics - the problems begin. My boat is 37 years old and I'm confident it's never suffered a debilitating incursion. It's not like I treat her with kid gloves either - 6.5 knots (GPS) hard on the wind two days ago - that's theoretical hull speed and a pretty darn good ride.

[hanleyclifford]

I wouldn't consider it a flaw. Flaw implies the designer overlooked or misunderstood something which is simply not the case with Catalina's Frank Butler and Gerry Douglas. This is more like realizing the limitations of a mid engine installation and the hot section height restriction due to cabinetry. Properly done - as from the factory - it works fine. After a few shoddy replacements by a previous owner or two - or their mechanics - the problems begin. My boat is 37 years old and I'm confident it's never suffered a debilitating incursion. It's not like I treat her with kid gloves either - 6.5 knots (GPS) hard on the wind two days ago - that's theoretical hull speed and a pretty darn good ride.

In a significant number of cases it obviously doesn't work "fine". If a vessel is so designed as to have an engine amidships so far below the water line then it should also be designed with cabinetry such that a standpipe exhaust is feasible or failing that a jacketed system should be provided.

[ndutton]

In a significant number of cases it obviously doesn't work "fine".

Are these cases to which you refer equipped with factory hot sections (or exact duplicates) or some P.O. nightmarish facsimile??

If the design were flawed as suggested, wouldn't 100% of them be problematic right out of the factory?

[hanleyclifford]

Are these cases to which you refer equipped with factory hot sections (or exact duplicates) or some P.O. nightmarish facsimile??

If the design were flawed as suggested, wouldn't 100% of them be problematic right out of the factory?

Not necessarily; strict protocols re the water intake can greatly reduce the incidence of the problem or least delay it for many years. The hot section on this thread and Shawn's (original) do look rather similar - maybe they were factory installed. The point is that even the most vulnerable system can be made to work by the very diligent (or OCD) operator but a factory system should be geared to the average operator. The long (relatively) difficult-to-access exhaust hose and check valve only exacerbate the problem.

[Dave Neptune]

Design

A comment, my E-35 MKII suffers the same problem. The boats interior was designed around the placement of the engine in the middle for better weight distribution. The interior had the priority for sales as to not have the exhaust come "UP" through the cabin so it would look appealing instead of functional~u-know male-female because sales win. Then do not underestimate the bean counters as far as developing a shielded exhaust and the additional expense.
In my boat there is nowhere but down for it to go!! I actually have a bit less room in the "up" direction than the C-30 and end up with an exhaust a bit longer. I have had water in my engine at least a dozen times over the 29 years in my service and now have an exhaust that is over 28 feet longl as I put in a second rise for the following sea scenario. I do not have an anti-siphon any longer as having one high enough to "break the siphon" is not possible for the long run. I tried many that are available and they all worked for a bit then stuck!!! Since going away from the "anti-syphon" and installing a "MANUAL" one I have only let the water in twice~totally my error.
As in most thing there are compromises and you get what you pay for.

Dave Neptune

[hanleyclifford]

The Wrong Word?

Perhaps I should have said "complication" rather than "flaw".

[RMark]

Cat 30 hot section

when I repowered from yse 12 to Atomic 4 I built hot section up into cabinet area with bottom of riser approx. 4 inches above cabinet base, also built entirely new peninsula that has section over motor removable separately, just lost a few inches of lower drawer height. Just returned from 3 days in Avalon, 80 degree weather, mostly motored, reduction gear A4 worked GREAT! 5.5 knots at 2000rpm with 12/12 2 blade prop I got on Ebay. I think I could go with slightly taller pitch, but am close.

[Dave Neptune]

Be sure

RMark, those numbers sound great! How big is the boat? Have you checked the load at the 2000 RPM's? What is WOT giving you?

Running these engines "easy" when possible IE low load (hi manifold vac) and moderate RPM like the 2000 is a great set up. I'd look real hard before leaning on the engine to work harder at lower RPM's. The big deal with the reduction unit is that you can get good RPM's out of the A-4 unlike us with the direct drives.

Dave Neptune

[RMark]

It's a 1977 Catalina 30 tall rig, Hull #939. Hauled over Christmas, new bottom paint, Catalina "smile" repair, reworked keel bolts, new shaft, packing and cutlass bearing, buffed and polished hull and rebuilt interior galley area, looks pretty good for 37 year old boat. Have been rail down in the "gulch" several times and no water intrusion issues with hot section redesign. I get 2000 rpm with very little throttle, It will easily rev much higher, but I get some blowby above 2400, Think I need 3 blade 12/14 prop. or 12/15 2 blade.

[ndutton]

The description of your hot section modification tells me you get it, well done. Where are you slipped? My guess based on your location would be Alamitos or Shoreline. Most of the owners I know who drive in prefer the freeway convenience.

[thatch]

Say what?

RMark, After reading your numbers in post #22 I had to say "no way", until I re-read it and realized that you have a "reduction gear" A4 instead of the normal "non reduction" type that is standard on every C-30 that I have ever seen. The standard factory prop, on DD A4's was a 12x7-2 blade, which is considered by many to be a little too much for many of our "aging" A4's. I personally reduced the diameter of mine by 1" which raised my cruising rpm into a more comfortable range. Raising the hot section of your exhaust was certainly a good insurance policy although I have never had a water intrusion problem with my stock setup. Finally, nice work on altering your cabinetry to allow for better engine access, always a good idea whenever possible.
Tom

[hanleyclifford]

Qed

RMark, After reading your numbers in post #22 I had to say "no way", until I re-read it and realized that you have a "reduction gear" A4 instead of the normal "non reduction" type that is standard on every C-30 that I have ever seen. The standard factory prop, on DD A4's was a 12x7-2 blade, which is considered by many to be a little too much for many of our "aging" A4's. I personally reduced the diameter of mine by 1" which raised my cruising rpm into a more comfortable range. Raising the hot section of your exhaust was certainly a good insurance policy although I have never had a water intrusion problem with my stock setup. Finally, nice work on altering your cabinetry to allow for better engine access, always a good idea whenever possible.
Tom

The "flaw" or "inconvenience" re-engineered out of the product.

[thatch]

"Pole Time?"

Hanley, Perhaps it's time to "pole" the Catalina-30 crowd. Since virtually all of these A4 powered boats would have come from the factory with the same type of hot section, I would think that they would have adopted RMark's cure rather than just living with this "flaw". My "innitial" starting protocol is to start the engine at the engine, via parallel engine controls, and then to open the raw water intake. My FWC engine is equipped with an electric collant circulation pump, which is also checked for flow at startup.
Tom

[ndutton]

RMark,
How about some pictures of your reduction gear installation and galley mods? I'd especially like to see the clearance between the output coupling and the stuffing box as well as any mods in the area of the cabin sole in the galley.

[hanleyclifford]

Yeah

RMark,
How about some pictures of your reduction gear installation and galley mods? I'd especially like to see the clearance between the output coupling and the stuffing box as well as any mods in the area of the cabin sole in the galley.

+1 - This is how we keep learning.