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-   -   22 classic HP/speed Question (https://www.offshoreonly.com/forums/donzi/331196-22-classic-hp-speed-question.html)

snave8 09-28-2015 08:09 PM

22 classic HP/speed Question
 
I'm purchasing a 2004 40th anniversary 22 classic. The boat has a 496 (non HO) Merc. The previous owner says it runs 65-68 mph..... I'll find out for myself in a few days when I test drive it.
My question is: What amount of HP does it take to get these boats into the low to mid 70's? I figure someone here must have a pretty good idea.

Mark

Pat McPherson 09-29-2015 09:42 AM

My 1996 22C with stock 502, 750cfm carb, Gil exhaust will top out at 73mph GPS at about 5000rpm.

tommymonza 09-29-2015 10:57 AM

www.Donzi.net Seek and you will Find

donzi matt 09-29-2015 11:37 AM

A close friend had a 22 classic with a bone stock 502 mag, the boat ran 72-73 on GPS all day long. My 22 classic with a warmed over 454 with peanut port heads ran 68 on GPS. To get you over 70 with that setup, switch to the 496HO cam and either replace your ECM with an HO computer or have Whipple reprogram it. That will put you at 425 horsepower and will get you in the low 70's. I will probably have an HO cam for sale later this fall.

snave8 09-29-2015 02:01 PM

Thanks.
Converting to the HO setup seems to be the way to go.
Is there any way to replace the cam in a 22C without pulling the engine? I'm thinking not but can't hurt to ask

Mark

joefitness123 09-29-2015 08:18 PM


Originally Posted by snave8 (Post 4360294)
Thanks.
Converting to the HO setup seems to be the way to go.
Is there any way to replace the cam in a 22C without pulling the engine? I'm thinking not but can't hurt to ask

Mark



I've owned 4 with different power packages.. By far the nicest one was the 2006 Shelby with the 496HO 425HP the boat ran 77-78 all day long.. Great little boats..

SB 09-29-2015 08:33 PM


Originally Posted by snave8 (Post 4360294)
Thanks.
Converting to the HO setup seems to be the way to go.
Is there any way to replace the cam in a 22C without pulling the engine? I'm thinking not but can't hurt to ask

Mark

Yes.




Have someone else do it. LOL.

snave8 09-30-2015 11:54 AM

If I upgrade to the 496 HO setup, would it be possible to duplicate the top speed of the Shelby model by shortening the drive, such as with an Imco shorty lower unit or the like?
If I understand correctly, the Shelby got it's extra speed by raising the X dimension by about 2"
If this is a viable mod.......If so, what do these lower units cost and whats involved?
Thanks.

Mark

Pat McPherson 09-30-2015 12:21 PM

Yes, you can bolt on a short lower; they're are not cheap though. I've thought about it a couple of time but haven't found one for under 3K.
I believe you're $$ are better spent on HP upgrade and adding external steering first.

Pat McPherson 10-09-2015 08:15 AM

Clocked my boat last night.
3 guys, 1/2 tank, 55deg, on glass.
VDO speedo past its 75mph max
Phone GPS read 72.6 and climbing
Tach read 4800 witch is in reality 5000rpm
Got to love those cool fall days for making HP...


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