bit off more than i can chew 2000 challenger with blown merc

[FlounderPounder]

Struggling to find a block...I believe my block is too far gone for a weld/sleeve job haha. luckily my crank is still fine.....anyone have any leads on a good block not too far from Ontario Canada? stupid plastic oil drive gear. :facepalm:

 

[Coastiejoe]

Though [MENTION=16022]Dr Honda[/MENTION] lives here in the states, he knows pretty much everything when it comes to the Mercs. He may have some guidance for you..

 

[FlounderPounder]

Thanks CoastieJoe, I hope someone can point me in the right direction for sure. I have read a few of Dr Honda's threads but so far no welder/machine shop will touch mine for less than the price of a long block! I've heard 92-99 2.5L carbed/efi motor blocks will work (I can machine the cathedrals no problem) from 150hp up?

 

[Dr Honda]

She's ugly... but it's reparable. Unfortunately... as you found... if you are paying for someone to do the work... it's probably more expensive than a new block.

Now... "Silver lining" for you... the hard part on the sportjet engine is the crank, since it was a different drive spline than the outboard engine. And, since yours is still good... you can use (more or less) any of the 2.5L Mercury outboard blocks.

With that said... yes, there are some differences with the HP levels... but even if you find a 175... and bolt on the big reed cages... you will make almost the same power. Also... the book says "The front and back of the engine block are matched sets, and you can not interchange them".... well... they are matched sets... but you can swap fronts and backs NORMALLY without an issue. So, all you need is the back side of any of the 2.5L, since you want to retain the 240 intake. SO... you will only need to fix damage to that. (unless you can find a used 240 intake)


I would start with ebay. It seems to be the best place to find used parts.

 

[Dr Honda]

Then again.............

Since your crank is good... a brand spak'in new 240 block is only $800. (p/n 858257T19 from boats.net) A WSM rebuild kit will be less than $1k. and a good used rod will be less than $30 normally. I think I paid $15 for a used rod when I put mine back together.

I know it's not cheap... but if you buy a used block, you will probably still have to send it out to be bored/honed... and you will have to fix your intake. That will probably be more than $800.

 

[Coastiejoe]

See,, THIS is why I sad Dr Honda,,,,

 

[FlounderPounder]

I may still rebuild this motor and put it back in....BUT. it's alive!

picked up a 95 200xri offshore complete running motor, swapped the crank over and bolted it up! so far it runs solid on the hose--test run after work today. I'll be down on power a little but since I never rode in one with 240hp I wont know the difference haha.

biggest struggle with the swap was coil mounting--no room for them in the outboard configuration-they interfere with the exhaust. that and not knowing why I had extra wires on the motor until I realized DUH--trim motors haha.

I was hoping to swap the 240 electronics on and mod the exhaust on the block to get 240hp, but the reed adapter would need machine work as well, and I want to be sure I have a solid baseline motor before I turn it up.

so now I'm only into the boat for under 6000 Canadian, and that's before selling the lower unit and cowls and a bunch of extra stuff. I may just leave this motor as it is and sell my sportjet electronics.


Fingers Crossed! (I'm premixing the first tank for sure haha.)

 

[Dr Honda]

Good work.

Please post some pics. I'd love to see the swap in there.

 

[FlounderPounder]

I will take some pics this weekend....because it has to come out lol. was out on the lake and it got louder like a punched a hole in the muffler, then down on power, then would only idle for 30-40seconds and wouldn't throttle up. no visible holes or leaks or damage externally, but I can wiggle the flywheel/crank side to side more than I think I should be able too haha.

I got about 4hours on it since the install so hoping its just the 95 xri motor showing its age needing rings or crank seals/bearings.

 

[Cablebandit]

that block is 2800...not 800

 

[FlounderPounder]

Yea i think that was a typo lol. In any case im hoarding these blocks and cranks. Have have 2 good cranks and 2 good blocks in my garage now haha. Gonna start building a spare to keep or sell to be decided down the road closer to summer.

 

[FlounderPounder]

well I found my problem haha.




I guess the original crankshaft that was in the motor had a crack in it that i missed. luckily it didnt hurt anything at all in the motor except for the oil drive gear (haha go figure) and the stator from the top half of the crank wobbling. I can't believe it was still running!

have one of my spare cranks swapped in now but rain kept me from finishing the install. got a head start on rebuilding my spare motor though!