Retro fitting OMC 140 exh.bubble and filler blocks.

[Bajaha]

I have my 1984 115 apart for cylinder reboring (830 hours on it) and want to know what is involved in installing the exhaust filler blocks from the 140. I think i heard that some machining is required,from where and how much is my question. also could used filler blocks be installed.
If so does anyone have the blocks and exhaust manifold for sale,also any o/s pistons, engine bearings for crank ,small end,big end, upper , centre and lower mains all gaskets and seals etc. let me know before i place my order with Rick racer.
Thanks,
Glen

[B.Leonard]

The pads where the blocks sit in the block need machined. Then the bottom of the block needs opened up where the exhaust exits, then the ports should be matched to the blocks and the entire surface (with blocks installed) where the chest bolts to should be machined flat.

The last two aren't necessary but will keep the blocks from distorting. Use new blocks only! If you use old blocks they've already taken the shape of the original motor and will distort when heated up in a different block. You'll be picking chunks of filler block out of your lower unit if you don't :rolleyes:

-BL

[Rickracer]

....but I'd say machining the back of the block flat with everything installed is fairly crucial to heat transfer and the stability of the exhaust chamber as a whole. When I pulled my V-4 apart the first time, the filler blocks were warped all over the place, and after I had it machined flat, they never moved anymore.

[delawarerick]

BL your last paragraph is interesting. I have a problem with a block that sent something threw the water passage and chipped the cyclinder block down to the sleeve in the water passage. Have you ever seen this and is there a fix. JB weld? Rick

[B.Leonard]

Yes machining the entire surface perfectly flat with blocks installed would be best. It makes the blocks touch the bubble back and therefore dissipate heat better.

I think the V4 exhaust design was really bad. They should've did it like the 235, w/ just one block on each side.

DE-Rick, not sure where the chip is that you're describing. It may work, I know there was a lot of JB-Weld going around the pits up in Jasper :rolleyes:


-BL

[Bajaha]

Thanks ,for the info, if i can find used covers p.n. 390015 and 323468 , i will do this mod (with new filler blocks).
luckily? it will be 5-6 months before the boat is in the water again , so i have lots of time for working on it.
Thanks
Glen

[Nosubforcid]

This kind of conversion just doesn't make economic sense. A factory 110/140 block in the same condition as yours, needing all four bored, can be purchased quite inexpensively. Sell your old block to somebody for a fishing boat motor rebuild then buy a used 110/140 block and start with that. You also may be willing to find a supplier who will trade with you for a reasonable cost if he has excess bubble block cores.

[B.Leonard]

I would have to agree with NoSub. It's not easy. Even the exhaust chest/cover can take the shape of the original motor and leak if you're not real cognizant of how it's all going together. They're not as rigid as the 235.

I heard someone tell me the 85/90 blocks were stronger and so a better for a build up. I don't know for sure on that. I do know finding a 140 that is in good shape is no easy task so it may be necessary. But then again I built mine just before finding Scream and Fly. Who knows with all these connections now.

-BL

[Bajaha]

Nosub...buying a used 140 block is a good idea.
Anyone have one or any leads on one would be appreciated.
Glen

[delawarerick]

Also be looking for a later model 110 this is a more easy to find in decent condition. The 110 is what I built and its easy to mod and already got the bubble. Unlimited possiblites from the 110 let me know if I should look for one for you. Rick ( I have class tonight at an omc dealership I always check out the used motors when away from home.)

[Bajaha]

Rick , Please ask around for the 110 block you mentioned. I figure this is a good time to increase the h.p. while i have it apart anyway.
So if i use 110 block with my 115 carbs and a set of the 140heads 326502-3 i will end up with a 140?
Thanks for the info
Glen

[Laker]

I have at least one 140 X flow powerhead for sale.
I should be back intown wednesday, Let me know
thanks
Chris 414-698-4270

[Dhadley]

Just a thought -- we tried cutting, opening , matching the filler blocks and stumbled on the fact that on a V4 the motor picks up rpm with them out. At 6000 we picked up about 200 and about 200 - 250 at 6900. Saves a bunch of time and money too. Unfortunately the V6 lost a few rpm when we tried that.

We also noticed that when we found the exhaust blocks warpped, the motor was set up in the low to mid 5000 range. Motors that were in the 5800 + range had much less warping.