Repowering from 3.8 V6 to 454 Magnums on OMC 800.DISASTER or?...

[Offshoreboat]

I have a 1984 Sea Ray 270 Sundancer with 2 OMC I/O V6 3.8 L 170 HP each.Running without problems but boat is underpowered.Now my friend is repowering his 34 Welcraft Scarab with 502 engines and would like to give me his 2 454 Magnums 365 HP each to put in my boat.Does annybody knows if my OMC 800 would survive this change even when I am VERRY easy on take offs...?<br />Both 800s are in fine condition.<br />thanks

 

[tommays]

Re: Repowering from 3.8 V6 to 454 Magnums on OMC 800.DISASTER or?...

off<br /><br />I may get hammered for this answerer but I think that its way to much power for these drives and I am not sure you would be able to get a bell housing that would connect the big block up to the drive<br /><br /><br />tommays

 

[Don S]

Re: Repowering from 3.8 V6 to 454 Magnums on OMC 800.DISASTER or?...

Not only would the drives NOT hold up, they are the wrong gear ratio for a big block. I also doubt you could adapt the engine to the bellhousing or exhaust. Even if you did, would there be enough room between the engines to fit.

 

[Offshoreboat]

Re: Repowering from 3.8 V6 to 454 Magnums on OMC 800.DISASTER or?...

Thanks for reply.I do have the room tho fit the engines.I know it is the wrong gear ratio but would the bellhousing from my chevy v6 not fit on the BB chevy ?It fit on the 350 ci.small block.<br />It is only a trial that I would like to do.Later on I could change the drives to.Boating on a budged you know..<br />Thanks <br />Roland

 

[KaGee]

Re: Repowering from 3.8 V6 to 454 Magnums on OMC 800.DISASTER or?...

The bellhousing will fit all small bock Chevy.<br />Not sure about Large block bolt pattern. You will also have to consider the "Selecta-Trim" setup and the front motor mounts.<br /><br />I just replaced my 3.8 with another. The reasons I considered 1) gear ratios 2) hydralics.<br /><br />I did not want to chance burning up the upper unit. I did not want to mess with modding the hydro lines to accomodate the longer length.<br />The "Selecta Trim" also messes with any ideas of <br />Thru-hull exhausting.... It can be done I'm told, with flexible hose.

 

[16Pilot]

Re: Repowering from 3.8 V6 to 454 Magnums on OMC 800.DISASTER or?...

if you are on a budget that definitley is not the way to try to stay in budget. as you do it, it will be one thing after another.

 

[keelhauled]

Re: Repowering from 3.8 V6 to 454 Magnums on OMC 800.DISASTER or?...

I am an OMC 800 owner myself and usually come to the defense of these poor old drives...<br /><br />...but in this case I'm having visions of scattered gears and broken cases!

 

[Bondo]

Re: Repowering from 3.8 V6 to 454 Magnums on OMC 800.DISASTER or?...

DISASTER

Gets My Vote......... <br /><br />BTW,<br />All Chevy Bellhousings are the Same Pattern.......<br />On the Big Blocks you just don't use the top center bolt.........