Biggest engine ever in an 18C

[Donziweasel]

On my other thread, we were discussing the MX 6.2L in a new 18C. Just out of curiosity, I was wondering what the biggest factory installed engine in an 18C since 1965 was. This is not including V-Drives or Jets, just sterndrives. We know that 6 6.2L Scorpions with 350 horsepower were produced. Anyone know of anything bigger from the factory?

How about a 16C?

[Donziweasel]

That sounds like a hell of a package, any idea what years it was offered? Shame they will only do 320 horse now. How about a 16C?

[Donziweasel]

Was Rick's factory? Did they ever put a 427 H&M in a 16?

By the way, agree with you 1000% on the no drinking while boating. Give em' hell!

[Donziweasel]

How fast would Rick's boat run? Had to scream!:) :) :)

[boxy]

MadDog, isn't AudioFn running a factory BBC with a TRS up East ???

[gold-n-rod]

The 16 once came with a 350 SBC, but the horsepower was in the 210-240 range. The current 305 SBC w/MPI is rated at 260 hp. So biggest is relative, either 350 displacement or 260 horsepower, but not both (from the factory).

[Donziweasel]

Your right, my 16 C came with a 350, but only rated at 210 hp. 1997, it only had a small 2bbl on it.

[boxy]

Gotcha Poodle, my mind wasn't converting cubes to hp .....

Also didn't the 16 come with a 290 hp Holman Moody motor in late 60's and early seventies and wasn't it also available in the mid 70's with a Chris Craft marinized Corvette motor in excess of 300 horses ??

[Lenny]

How fast would Rick's boat run? Had to scream!:) :) :)

72 I believe... Heavy motor and drive.

You can find about 70 with the 350 MAG MPI and an Alpha as well.

Randy Oak (6' something and more) can find about 69-ish with a 350 MAG MPI and a Bravo.

As for the MOST horsepower in an 18,... I believe Geoo has that one sewn up for many years to come. Somewheres in the neighbourhood of 1100... :eek: Someone else has it now...but it was not a sterndrive, NOT Factory.

Don Tamm has about 450 horsies in his 18 now and a BRAVO or Blackhawk for a drive depending on his mood. He almost sees 85 if it stays in the water and the right side up. Again, not stock. Small blocks and the 18 seem natural and tend to get the best performance numbers. Doug Lovins' 18, with an Alpha SS I believe sees about 78.

Geoo saw about 83 I believe with his Volvo 280 leg and an "E" lower and more "normal" motor horsepower, small block. ZZ4 in the 18 and a stock 280, 1:61 drive, will find 72-ish.

Hope this helps.

[Donziweasel]

Rootsy also had a 16C with a built engine that would do over 80. Not factory though. So far it sounds like the 454 was the biggest factory in an 18. 454 is a big engine, but not what most would consider a great performer.

[olredalert]

-----I bought a 1977 X18 new thru a foreclosure on a dealership in Chicago that was TRS/330 powered. It ran right around 70, maybe a bit above, bone stock with one person aboard and trimmed out to the ragged edge of chine-walk. Kept it a couple of years and never changed one thing. Boat was very stern heavy. Boot-stripe was at least 6 inchs under water at the stern, maybe more. John C told me when I asked him about the boat that the factory only built six TRS/330 18s. He said they got a bit worried about the liability issues...........Bill S

[Donziweasel]

Who has the boat now? Sounds nice but I bet it would be ass heavy. How did it plane?

I guess if we are talking fatory 18 we could include jets and v-drives. I seem to remember a jet discussion of an 18C with a Olds 455. For jet drives in the 70's, it seemed that most boats with a jet had either the olds 455 or a ford 460. I have no idea what was mated to the few v-drives produced. Anyone have any idea on the jets or v-drives?

They ever make an 18C outboard? I know they made the 16C with an outboard as an option, usually a 150 Evinrude if I am not mistaken.

Also, something else that I have always wondered, why do 18's seem faster than 16's with basically the same power. Is it the hook in the 16? For example, a 265 hp 18 seems to run well over 60 while a 16 will only run in the mid 50's. Any ideas?

[Donziweasel]

No idea.

[RedDog]

Ricks was factory.. Cobra drive no less..
The 427 was not available in the 16 from the factory I do not believe.. Some of the 16 experts might chime in and tellus differently though...

I don't think Rick's (and later mine and now Blackie's) came from the factory (1990 model) with the 454. I think it was a dealer installation.

73.4 (GPS) @ 5300rpm
BBC 454, 420HP, 1988 Mark IV built by “Second Effort”
• 4 Bolt Main, 7/16 rods
• GM Forged domed pistons (8.75 to 1 compression ratio)
• Forged Crank
• Crane Cam 132561, hydraulic flat tappet Crane lifters, Crane roller rockers
• Intake GM Marine High Perf Aluminum High-rise
• GM High Perf Rectangular Port Heads w/stainless exhaust valves. Seats replaced @ 500 Hrs
• Holly 4831 (4150)
o Jets 78 Primary, 82 Secondary
o Power Valve 65 Primary, 65 Secondary
o Accelerator pump 015 gap
o w/annular discharge nozzles
o 4 corner idle and choke horn removed
• Plugs AC R43T or R43TS - Gap .040 to .045
• Distributor MSD Extra Heavy Duty
o Black bushing (18 degrees total)
o 2x Light Blue Springs
o w/soft touch rev limiter - the MSD ignition has a plug in chip (on the bottom?) in the rev limiter set at 6000 RPM.
• Total Seal Rings
• Clevite Rod and Main bearings (standard size)
• Felpro Head Gaskets
• Cotles True Roller timing chain
• Melling high volume oil pump
• IMCO S/S Exhaust

[Lenny]

They ever make an 18C outboard? Yes, there was one or two. none that we have recently seen but depicted in photos.Also, something else that I have always wondered, why do 18's seem faster than 16's with basically the same power. Is it the hook in the 16? No For example, a 265 hp 18 seems to run well over 60 while a 16 will only run in the mid 50's. Any ideas? Waterline length and balance


:) :) :)

[Magicallbill]

Aren't the older packages you all are discussing not Propshaft HP rated?
I have 377 HP with my Scorpion, 350 PSHP.
What would be the PSHP on say, the TRS/330 mentioned earlier?
Or the 427's?
When did they start rating HP at the prop,anyway?

On my '67 16 Ski Sporter, I have an engine that was anyalized to produce 397HP at 5900RPM.
I'm told my Volvo 280 causes the engine to lose roughly 50 HP before it gets to the prop, so I never know what to tell the people who ask me how much HP I have.

[MOP]

Whats a Flagship 450??

Scot that I believe is their mildly super charged 502 that was at the NY boat show, they build a full range of SB's and up to 572's. Flagship is an old/big name in the industry, they used to supply OEM engines but went the accessory route over the years. They have quite a variety on their site!

Phil

[Donziweasel]

Was the 454 installed by the dealer and then at a later date modified with all the extra goodies? 400+ hp is pretty good for a 454. I know the stock 454 from Mercruiser was around 310 hp (I had a new one in a 20ft Milan in 1997) and HEAVY as hell. I did love the sound of that engine though.

[RickR]

My 18C did have a 454 built by Second Effort inistalled by a dealer in Indianapolis. Second Effort was building engines to compete with Mercs 454/420HP.
While I owned it I rebuilt the engine and installed a larger cam and carb.
Exhaust was too restrictive (wet). Best speed was in the low 70s. She sure has a sweet cruise speed, effortless in the 60s:wink:

Donziweasel
She did not have any problem coming out of the hole :eek:

[Donziweasel]

Rick, great looking engine!

[RedDog]

My 18C did have a 454 built by Second Effort installed by a dealer in Indianapolis. Second Effort was building engines to compete with Mercs 454/425HP.
While I owned it I rebuilt the engine and installed a larger cam and carb.
Exhaust was too restrictive (wet). Best speed was in the low 70s. She sure has a sweet cruise speed, effortless in the 60s:wink:

Hey Rick - you sure have been a stranger of late. Glad to see you're still keeping tabs on the DonziNet. Are you going to the LSU game? I am and if the weather is nice and there is a moon out I may take the boat - most likely the last run this year. Following the 'Bama game there was no moon and it was pretty hairy at a couple of points on the 10 mile run back to Maxey's. The big cruisers were hard to see that had their interior lights out and stern lights way high.

[Ed Donnelly]

Madpoodle; You forgot the 454 370 h.p. from the 1985 era..........Ed

[Donziweasel]

Rick, surprised it didn't go faster. Think the weight of the 454 held it back?

[Bug]

I recently purchased a '82 18' Donzi 2+3 with the 454/330 TRS, all factory
original set up. I've only had her out twice and runs really nice. My guess on speed is the upper 60s low 70s. I liked the extra weight in the aft end it seemed to help settle the boat in at higher speed.

[RedDog]

Rick, surprised it didn't go faster. Think the weight of the 454 held it back?
I may be stepping on your question to Rick, but I also owned Genuine Risk (Genuine Trouble when I had her) for a while after him. I suspect the OMC King Cobra drive created a bit more drag than an Alpha or Bravo would have.
And yes, the weight did make her sit lower in the rear - at least at rest

[RedDog]

Maybe a better question is "what is the most HP in an 18 Classic?"
Do a DonziNet search on "GEOO" and on "Mighty Mouse"
Also try a search Google search on Arneson Drives Donzi - well I'll help you out - http://www.arneson-industries.com/18'_donzi.htm