Questions about a Mercury lower on a OMC 4 liter V8 outboard

[John Rork]

Hi guys. I had the pleasure of talking to Kevin Taylor at R&R Propshop today about possible options for mounting Merc lowers on our motors since both motors have hurt lowers and I'm kicking around the idea of just going the Merc route to get a little longer life expectancy. This is a 30' Superboat with both a standard rotation as well as a counter rotation V8's.

It sounds like Kevin has it pretty much figured out when mounting 2.5 Sportmasters and their is a strong possibility I'll end up going that way but one of the things we talked about is whether a 3.0 Merc lower could be adapted. The primary reason would be for increased water flow as the 2.5's don't provide enough water at low speeds so you need to supplement it with external pumps in the boat. It sounds like the 3.0's flow a lot more water and could be a nice alternative to that issue.

Kevin hasn't done that swap but thought that someone here might have some insight regarding whether a 3.0 could be adapted. Also, he mentioned that there might be some pictures available of how the shift linkages hook up to covert from OMC's lift to shift to the Merc twist to shift.

Thanks so much for any thoughts, pictures or advice you'd be willing to share........john

[STV_Keith]

See the last post in this thread: http://www.screamandfly.com/showthre...Sporty-on-a-V8

The 3.0's will flow much more water, which is nice, and are likely even stronger than the 2.5 units. They are also larger (slower) and more expensive. Baja200merk has put the 3.0 cases on an OMC as well. Even used OMC water pumps on a Merc 3.0 case: http://www.screamandfly.com/showthre...h-this-picture

[John Rork]

Thanks so much once again Keith. This is some of the information I've been searching for. I'm not looking for speed as much as strength and availability. Your threads and posts on the Sportmasters makes it really tempting to just go that way but we'd like to look at the 3.0 option as well. I have a good friend that has some old 3.0 cases and I have a spare 20' mid so it's worth a shot to see how they might fit. Kevin at R&R was great to talk to with a wealth of information.

Take care and thanks again for the help and advice. I'll likely be back to you with lots of dumb questions..........john

[STV_Keith]

You could always sell your 8's and buy mine...they are already done! I'll even throw in the hoses and water pumps, no extra charge!

[John Rork]

You could always sell your 8's and buy mine...they are already done! I'll even throw in the hoses and water pumps, no extra charge!

Trust me, between my son sending me your add on here as well as my buddies tagging me in your post on AZ Hot Boats on Facebook, I have seriously considered it. Stranger things could happen but I need 20" setups so I would have to redo a lot of your great work. :-(

[STV_Keith]

Actually, it would probably be less work than you think. Pull the power heads, pull my exhaust adapters and install on your 20" mids. You do have to cut, shorten and respline the driveshafts. My guy Kevin in Henderson NV (R&R Prop Shop) can do that without having to pull the drive shafts out of the gearcases, so no disassembly required. You'll also need to cut the 25" shift shafts down and re-weld the throw arm to the top. If you had all the parts sitting there, it's one Saturday's work...assuming your motors come apart easily. My motors were fresh water only, so I know they will. The gearcases were off in April for fresh lube as well.

[John Rork]

VERY tempting Keith. Thanks for the info. I really appreciate it

[STV_Keith]

I stopped by and talked to Kevin last night as well. We both agree that doing the swap to your motors will be much more work than swapping with the stuff I already have. He estimated about $300 to cut/respline the gear cases for 20", FYI. I could always ship the lowers to him and everything else to you. Just trying to make it easy.

[John Rork]

I stopped by and talked to Kevin last night as well. We both agree that doing the swap to your motors will be much more work than swapping with the stuff I already have. He estimated about $300 to cut/respline the gear cases for 20", FYI. I could always ship the lowers to him and everything else to you. Just trying to make it easy.

Hah! I'm sure and as much as I'd love to have those motors of yours, spending $13,000 vs spending a few thousand to setup some lowers on my motors probably probably doesnt pencil out. Yours are badass though for sure and I would love to have them.