engine swap

[in to deep]

been restoring my boat for a while now! I am at the point to put the motor back in!
i have a very good chevy 4cyl with an onc 400 outdrive! i have asked this question befor i would like to drop a small V6 in this boat instead of the 4cyl!!
now be kind with the comebacks here as i will go at this in a none boating terms! i just dont have much time to read much no more

ya got the engine say a 4 cyl to a v6 then ya got the bellhouseing and on the outside ya got the upper unit and lower unit?? right?
now was told it is about the gear ratio and all that
i have been looking at the omc 800 and from what i see in the pics on this internet the bellhousing looks the same so i take it the gear ratio
and all that is in the outside upper and lower unit??

i have tried to find a parting out boat that has a small v6 and omc 800 or just a motor and omc 800 my transom is all ready cut for the boot seal for the omc 400 but still got that dam ich for a v6

can i reuse the bellhouseing unit off the 4cyl for the v6??

sorry im on a thin budget on this part of the restore
in my mind one of the new fuel wise v6 engines i this would be as good if not better then this 4 cyl??? but with a bit more power

does anyone know what my options are or what can be done? i have seen other post saying they just dropped in a v6 but as things go with the economy they way it is its looks like i will be keeping this boat for a long time so i wish to keep it correct

Thanks for all the help here

 

[Scott Danforth]

Re: engine swap

It would be helpful for you to post which 4-cylinder you have. there were a few over the years. I know the gear ratios are different in the drive between the 4's and 6's. beyond that I cant answer. I assume you have the 2.5 or 3.0 engine, however I can honestly say, I do not recall the specific bell housing pattern that these engines have. I do know that OMC used both the Buick 3.8 liter and Chev 4.3 liter V6's. I do know that these two engines DO NOT have the same bell housing bolt pattern.

my recommendation would be to keep the 4-cylinder if your on a budget. Engine swaps have a habit of getting pricey if you dont find a deal on a complete setup.

 

[in to deep]

Re: engine swap

well it is a omc chevy 140hp i think that is the 3.0L
with the omc 400 outdrive

 

[in to deep]

Re: engine swap

yes i have been looking for a complete setup but am not having much luck i find parts here and there with differant part numbers
it is kind of hard to know what matches what

 

[Bridar]

Re: engine swap

If it were me, I'd get ahold of a parts manual for your existing sterndrive (try eBay) as well as a parts manual for whatever setup you plan on adapting to, especially since you plan on keeping the boat for a while.

You can find part numbers for comparison from several internet sources, such as; http://epc.brp.com . Select "Stern Drive" from the drop down Product menu, then the year, engine size and model.

 

[southkogs]

Re: engine swap

Gear ratios on the OMC 400/800s are here: http://sterndrive.info/1982_gear_ratio.html I don't think your outdrive will marry up to anything bigger due to ratios.

I think your intermediate housing should swap between though. That housing is running the ball gear back to the drive, and I think that's fairly consistent.

 

[Howard Sterndrive]

Re: engine swap

I had a 400 drive and 4 cyl (2.5L) in my 17' Grew. I found an entire boat with a 3.8LV6/800 series drive with a cracked block for $200 delivered.
I replaced the motor with a crate engine and swapped it all over.
Donor boat is the way to go because you'll need the trim system and intermediate from the V6 boat.