Discussion in 'Chris Craft Roamer Yacht' started by roamer offshore, Jun 25, 2011.
or sterndrive ?
Volvo Penta Diesel aquamatic seems sturdy. i just cannot figure this one out.
Not displacement hull
The Roamer Offshore hull is not a displacement hull. It is very flat aft but with a sharp entry. It should be fine for outboards (other than size and weight).
Bow turns into keel
"Today Proline, Dakota, Midnight Express, Contender, Deep Impact, and Angler all build 30 to 40 foot boats specifically engineered for triple installations. Some of them also offer quadruple outboard powered boats. Obviously the chief attraction of multiple engine installations is extreme high performance. Triple and quadruple powered 30 - to 40- footers blister the water at speeds of 60 to 70 mph. Cruising speeds typically register in the 40 mph range. Clearly these boats are not intended for the feint of heart. One builder joyously boasts that when the Gulfstream lays flat like glass, his boats can make a Miami to Bimini run in 41 minutes flat. When seas are rough, it takes only a little while longer."
Obviously you're not looking for speeds like that, but you aren't looking for triples, either.
Along with the technical paperwork comes an occasional gem, and I have posted one here; a 1961 promotional write-up concerning a 40 foot wooden Elco cruiser that was repowered with twin 75 hp Johnson outboards. Although repowering an older inboard boat with outboards is common now, it was something unusual back then.
The author points out that the outboards not only delivered higher speeds than the 135 hp gasoline inboards that they replaced, but burned less fuel as well.
i cannot open the article. i cannot even find duckworks........ could you email it to me ?
Laurence - that is exactly my hull. i wondered how it could get to 30mph if it was simply a displacement hull. so can you guys help me to decide on outboards ? unless someone has a better idea.... the biggest gasoline ones i can find are Yamaha. or should i go to Diesel ? (the mechanic says the fuel tanks can hold gasoline or diesel without problem)
i am looking for simplicity, economy and quiet. any help is appreciated. and in particular i appreciate all of the help you guys have already given to me !
Email sent. Let me know if you cannot open them. I can reprint the majority of the article as text here. They aren't that big.
Yamaha makes 350HP o/b's, but that would be well over the traditional power that you currently have. I would think 300's would be more in line with your need, but who can complain about more power? If you have nothing but cash to burn, Seven makes a 556HP O/B, but I think it's ranging about $75,000 apiece right now. It's a Cadillac Northstar engine that's used in the CTS-V autos.
the ugly truth:
(oh thank you they both opened just fine)
bought in 2005 with a blown engine. rebuild twice. blown twice.
built 2 more with the most knowledgable guy on the lake. both blew.
built 2 more with the most knowledgable for many many many miles - he set them up and broke them in on the dyno. both blew.
rebuilt both with the previous shop - with ceramic faced pistons and by addition of separate Oxygen sensors for each cylinder (during dyno) so that each cylinder could breathe in an identical fashion.. ran them maybe 15 times over 2 years.
this time the starboard v-drive blew and ruined everything it was attached to.
how do you think the inboards will compare in terms of noise/performance/consumption ? i need to choose based on who is a good dealer for Chicago area. the boat lives in Montrose Harbor. none of the lakefront harbors have boatyards. i have a great mobile mechanic for the boat.
by the way, he is looking at used Diesel inboard set-ups. he assumed the boat was a displacement hull because of its age.
Repetitive blown engines ?? Something's not right. Are you wide open all the time?
I agree, something is wrong there. Anyways, Outboards are easy on maintanence, fuel efficient and quiet if you go with 4 strokes, and you can get long warranties on them.
the engines rebuilt by the NAPA dealer and big time machine shop on the lake all pushed the head gaskets out as if they had too much compression. the first set of engines built by the really big time shop not on the lake burned holes through some of the pistons - showing me just how good the combustion chambers create a swirl. the final set of engines was fine for portions of 3 seasons. i did not get full use out of the boat last season or the season before for a bunch of reasons. they are all related to having an old boat that is too much hassle for most mechanics. that is why i feel like the only choice is to completely modernize it or get rid of it. i cannot work on the boat myself for a bunch of reasons.
Overpropped and bad gas?
i don't think so.
i only use high octane gas and supposedly no one else has had trouble. i put new props on about 4 years ago. at 3,500 rpm i get about 21mph on the speedo. if anything i thought they needed to be tuned for more speed.
on the final motor rebuild, with the oxygen sensors at each cylinder, we discovered that the cylinders were not being fed equally. so both intake manifolds were replaced. the ceramic piston coating + the new manifolds seemingly took care of my engine problems........
all 3 engine re-builders have great reputations and used quality parts in the rebuilds.
Yes, but there is a huge difference between a good rebuilding shop that specializes in automotive and one that specializes in marine. What compression ratio did they rebuild the motors with? Also ignition timing being too high could be another big problem if the gas you're using is high octane and the engines are not overpropped.
it has electronic ignition. it was set up on the dyno and is still at the same settings. the plugs look fine. this time it was the Walter V-Drive that failed. but when that happened it took the flywheel and engine with it.
so i guess i could rebuild or replace both V-Drives and then fix the starboard engine. but that leaves me in the same predicament of 50 year old technology and no one particularly interested in keeping the boat in-service.......
What RPM did you get at WOT? Or was that WOT?
It sounds like simple bad luck. With the latest engine mods and factory rebuilt V-drives you are not exactly stuck with antique worn out machinery. So what if the engines and the drives were designed 50 years ago? Your propeller technology has been around for about 200 years and it still works. "Old technology" isn't necessarily bad, it's just been around long enough to be proven. Bad technology doesn't last long enough to get old. Cast iron actually improves with age and new parts are new parts.
I would send the V-drives back to Walter for overhaul and testing. Rebuild or replace the blown engine and spend the savings on gas and good food for the next few years.
i will look into it.
it just seems like i am pouring good money after bad........
I thought the article was excellent and I can totally appreciate your love/hate feeling on the Roamer Offshore. In nearly 5 years of ownership, I also do not feel that I have gotten full use of the boat because of mechanical reasons. too much down time, too much expense after 20+ years of easy living with diesel sailboats. There certainly is an attraction with outboards.