Repower I/O Qs.

[Hammerhead]

My 165 inline 6 finally croaked. I dunno if it's just a head gasket or worse but since it's over 30 years old I figure it's time to repower. Question is..just replace the 6..go with a V-8 ??? or is there a inline 4 available? Any tho'ts?
Power wise the setup now is OK...I'd like better economy...would a inline 4 be any better?

I also figure a whole engine/outdrive package will what I'll end up doin;....anything other than dumpimng 40 Gs in a NEW boat.

[frayed_knot]

It all kinda depends. I don't know if a V-8 will just bolt into your current configuration. It might if the stringers are the same width. The V-8 motor mounts bolt into the top of the stringers. I wouldn't recommend going with a 4 cyl engine, you wouldn't like it too much I don't think. V-8's are the best way to go IMO. Now about 8 guys on here will tell you to put a bracket on it and slap an OB on there. Now, a new 200 hp OB will run somewhere in the $14,000 + range, new Mercruiser engine is about $5,000 and a brand new outdrive from Sterndrive Engineering is about $1200, you are way ahead with just repowering.

[spareparts]

the v8 repower is the cheapest for hp way to go, check with ebasicpower, call for their repower specials, it changes faster than their website. If you really want to do something different, Yanmar has some diesel packages that will bolt up to a Mercruisr. Mercruiser has soem new ones out that would work as well, but they are all going to be expensive.

[THEFERMANATOR]

A 4.3L V-6 would be a nice repower if you go I/O. You can get them fuel injected at around 200HP.

Maybe this one: http://northamerica.mercurymarine.com/engines/inboards/sterndrives/mpi4-3l.php

[macojoe]

350m will fit in there but you going to have to do some work to get it in there!!

There gear ratio will be different the the leg you have now which will mean a rebuild.

As for some here saying to add a bracket, I am one of them!! Best thing you can do!! I had the same set up as you befotre I converted.

as for it being $14K for a outboard, thats one figure that has been done here for a 07 200 ETec
That doesn't mean thats the only way to go and that all motors cost that much!!

There are left over 2 strokes out there and I am sure you can find one for about $7 or $8 k

Will cost more to convert and bracket, but will out last, with much lower maintance then any I/O out there.
Will extend the season if you are in a cold area also!! With todays motors even the gas in a OB isn't all that bad!

I/O if thats what you like go for it, but converting is only as expenive as you want it to be!

Good Luck with what ever you do!!

[Skools Out]

there has been some I/O's with 502 BBC motors as well. so just up to you but a big block will fit as well.

[regidog]

Can't be a 350. be careful though with the 2000 era EFI. Look on craigslist I see one at least once a month for $1000 or under.

[spareparts]

generally on the repower market, the 4.3s are the most expensive engine per hp available, last time I checked, the 5.0L MPI's @ 260 hp were the best bang for the buck. Personnaly, i would be looking at the 6.2 EFI repower package from Mercruiser @ 330 HP, but thats just me

[THEFERMANATOR]

This link should give you a general idea of the cost of repower(but the packages can be gotten MUCH cheaper).
http://www.mercruiserparts.com/mercruiser_gas_sterndrive_engine.asp

[Hammerhead]

Just dropped it off at the wrench. He's gonna see how bad it is. I can get it to run but, it's awful noisy. Clanking, grinding....not good. I drained the oil ( water in it) and added kerosene and oil, ran it for a minute and drained that out trying to flush whatever water was still in it. I think the main berings are toast. The wrench is suggesting I replace with the same motor if he can find one cuz the outdrive won't work with any other motor....otherwise a 5.7 whole package if I wanna repower completley.

[JeffXJ]

Check out this site for ball park ideas on repowering w/ new power. I think you might be able to find a better deal one way or another, but this should give you a few ideas. http://www.marinepowerservice.com/?gclid=CL6R7pezgYsCFR8wUAodtDVnHw

[spareparts]

some of the older transom plates had a different spread between the rear motor mounts for the 4/6 and the v8s, you will have to replace the inner plate to accomadate the v6/8( can't remember when they changed it to all the same 1982?). the simplest thing is to go with the same engine(250 L6). Theyare good engines, just getting hard to find, if you want to do something different, a 292 truck motor will slide right in there, its the same dimesions except height, its about 3 " higher, Mercruiser used to offer them with a 4BBl( thats why your intake has a flange for a 4BBl, and an adapter to a 2 BBL), rated at 200 hp, they were marketed for comercial use infront of the TR drive. I've seen several people convert their 250's to 292's( just been a while, its coming back slowly), they make a little more torque and HP. Change out your carb to a Q-Jet, buy a new exhaust bellows to make up the height difference(assuming the engine box will clear) and your on the way, with something completely different

[Hammerhead]

ThanX for all the info and links. being as how the icw speed limit is 25 mph and sea isn't hardly ever smooth nuff to do 50 in a 20' boat I'm gonna pass on goin' with a 300hp anything....<would be fun tho'>...What I found is a rebuilt inline 6 from Doug Russel Marine. Then I can make use of the exsisting outdrive and other thingys. Anyone ever deal with'm? TIA.

I'm tempted to just start from scratch and repower with a whole package but, the cheap bastid side of me sez...NOooooooo!!!

[THEFERMANATOR]

Problem solved, get you one of these packages when they become available. Increased milage and plenty of power and TORQUE!!!!! And there pretty lightweight.
http://marine.cummins.com/public_cummins/content.jhtml?tlaId=1&anchorId=444&marketId=13&men uId=1

http://marine.cummins.com/images/contents/Products/Recreational%20Inboard/QSD/QSD%202.0.jpg

[pikfish]

The main thing I would be think about with a "rebuilt" I/B motor is the fact that a saltwater cooled motor block has a limited life spand. Even the best rebuild does not repair the damage to the cast iron if the block has been used for years in saltwater.

[spareparts]

jasper engines used to offer good rebuilt marine engines that came with a 1 year warranty for marine applications, haven't used one in a while, but had good luck with them in the past

[Hammerhead]

Wrench ( highly respected shop) found a rebuilt longblock for 1500.oo and will do all the labor for another grand. That's alot cheaper than I tho't it'd cost.
I should have it back in a week or so. ThanX guys.

[spareparts]

do yourself a favor and replace the riser and manifold while its off( unless you know for a fact its been replaced recently), check with Barr Marine, Osco, Aqua Power/Sierra for an aftermarket replacement. Its good insurance against future failure. Your probably a good canidate for an electronic ignition conversion, pertronix makes agood one for under $100, check the weights and springs in the distributor while you have it apart

[76GMC1500]

Problem solved, get you one of these packages when they become available. Increased milage and plenty of power and TORQUE!!!!! And there pretty lightweight.
http://marine.cummins.com/public_cummins/content.jhtml?tlaId=1&anchorId=444&marketId=13&men uId=1

http://marine.cummins.com/images/contents/Products/Recreational%20Inboard/QSD/QSD%202.0.jpg


That motor has horrible torque. 220ftlbs at 2600 rpm? Your oringinal engine made 350 ftlbs peak and would probably have been close to 300 ftlbs by the Cummins 2600 rpm peak rating.

[Hammerhead]

That motor has horrible torque. *220ftlbs at 2600 rpm? *Your oringinal engine made 350 ftlbs peak and would probably have been close to 300 ftlbs by the Cummins 2600 rpm peak rating.

Sure is purty tho'. Tell yas, I was real tempted to have'm install a 5.7 package dealio. I'm just too ...cheap. :-[

[randlemanboater]

Wrench ( highly respected shop) found a rebuilt longblock for 1500.oo and will do all the labor for another grand. That's alot cheaper than I tho't it'd cost.
I should have it back in a week or so. ThanX guys.

Put it in yourself and save a grand.

[garagenc]

I'm doing the whole thing myself, I pulled my old 305 and am buying a 350 from Rapido marine and installing myself. They use car blocks versus a used marine block. $1450 + 150 for shipping.

[THEFERMANATOR]

I bet this one would push a V-20 plenty fast. 5.7L 315HP MAGNUM, would probably at least plane it ;D.

http://i162.photobucket.com/albums/t271/THEFERMANATOR/boatstuff001.jpg

[spareparts]

take a look at this

http://bpi.ebasicpower.com/c/LONGBLOCKS/Remanufactured+Marine+Long+Block+Engines
they have your 250( listed as a 4.1 L6) on here for $1599, with a two year warranty

[Hammerhead]

ThanX for the links. I tho't about a 5.7 250hp but, went the cheap route with a rebuilt longblock replacement. Paid 1500.oo for it. Wrench is doin' the install for 1000.oo.

Motor is already out and parts off that need to be transferred to the new motor.

[THEFERMANATOR]

That motor has horrible torque. *220ftlbs at 2600 rpm? *Your oringinal engine made 350 ftlbs peak and would probably have been close to 300 ftlbs by the Cummins 2600 rpm peak rating.
I seriously doubt a 250 straight 6 could develop that kind of torque. The 6.5 diesel V-8 in my SUBURBAN was factory rated at around 380-390 ft lbs of torque, and that's a V-8 diesel. The 255HP 5.7L VORTEC truck motors made 330 ft lbs of peak torque. I would say that 165HP straight 6 probably produces peak torque close to the peak HP number, that's normally a good rule of thumb.

[76GMC1500]

I'm talking crankshaft ratings and I thought he was replacing a 260hp 350 Chevy, those are rated at 350 ftlbs at the crankshaft. Torque is kind of a meaningless number, though. If you ever look at a prop curve, the chart will make no mention of torque. Horsepower is all you need to know.

[spareparts]

horsepower readings alone will get you into trouble, horsepower is the timed application of torque( hp=(torqueXrpm)/5250) you have to know what the rpm the hp is rated at. I've seen a 50 trawler with a single 125 hp engine make 7 knots, it would take two 5.7's to do that in this boat. Saw an model airplane engine that would make 5 hp( at something like 15,000 rpm), but I bet it wouldn't push my lawnmotor as well as my 5hp Briggs. Torque alone won't tell you much either, think of a torque wrench, you're applying torque, but you're not going anywhere. I've started to pay attention to Kw ratings(used on modern engines), I haven't made my self familure enough with them to know what I'm looking at.

[76GMC1500]

kW ratings are identical to horsepower, it's just metric units.

But seriously, if you have 2 engines both turning props at the same speed and are both making the same horsepower, the torque seen at the props is the same, regardless of the torque output of the engine. *If the torque output of one engine was half, it would have to run double the rpm. *In order to spin the prop at the same speed, the transmission reduction ratio would also have to be doubled. *Because the transmission ratio is doubled, the torque output on the prop end is also doubled. *So, the engine that had half the torque at the crank still has the same torque at the prop after going through the reduction gear. *The difference between that 125hp motor and the 5.7L is that the 5.7 would have to be run balls to the wall while the other motor could just chug along.

P.S. I'm trying to be a little controversial to get everybody to think about things. Sure, they're are holes in my logic but there are also points to be made.

[THEFERMANATOR]

Simple way to think of it is torque is how much work an engine can do and horsepower is a measure of how fast an engine can do that work.

[macojoe]

Chevy 250, in a boat puts out 165 HP at the motor, from a different came then stock, same motor in car gets 140 hp.
I believe that at the prop this is about 130 or so?? I forgot.
WOT on a cuddy 5000 rpm will get you low 30's But will rode nice in the mid 20's

Thats what I had when I got my boat, I have converted to outboard now by bracket and a 175 hp, I get wot 5500, 40 mph (light load) Ride around all day low 30's

I run 15 X15 1/4 prop on both the I/O and OB, gives me best out of hole with heavy loads, 3 guys + gas + 200 # fish, 100# ice

thats whats best for me.

[spareparts]

that six runs much better proped at 4000 to 4400 rpm

GMC. my point was that without rpm information, horsepower ratings can be missleading
A couple of years ago, Mercruiser introduced the 5.0 MPI rated at 260 Hp at the prop, they were claiming it would do the same as a 5.7 carb, what they neglected to point out was the 5.0 needed to turn 4800 to 5200 rpm to make power( it had a peaky hp curve), while the 5.7 only had to turn 4400 to 4800 to make the same power. the 5.0 would run faster than the 5.7 in a light boat( checked it myself), but put the two in a medium to heavy boat, the 5.7 walked all over the 5.0, it wasn't even close, with out the torque curve referenced to rpm, most people wouold assume the 5.0 would do the same job(thats what they were telling the salesmen, who were telling the same to the customers).

[Hammerhead]

Before the motor went...it'd go 40 mph tops. I usually ran it about 30. I expect the same performance with the new motor. It's turning a 19" SS prop.

A 5.7 sure would'a been nice tho'. :D

[spareparts]

a 5.7 would have been nice, but if it will make you feel better, remind yourself that it would have taken a new inner transom plate, might as well replace the outer transom plate, you would have had to find the correct y-pipe, and you know it would be a shame to bolt up an old drive so might as well...when you're done it only cost you $$$$$$$$$$$$$

[cfelton]

Good luck with that new block. Id have gone the same way,less stuff ta change!

[Hammerhead]

The boat being a '77...and NOW my wife wants us to move to the North Carolina MOUNTAINS !!!!! aacckkk.
( she's skeered of hurricanes ) ::) If I sell it it'll go eaiser at less a loss with less money dumped in it.

If the move happens...I'll list it here first. I'll hang onto the lil'Bonita for lake use up there...or if the river rises during a Hurricane. (There's Nooo escape) ;D

[spareparts]

tell her that Hugo travel North West after making landfall in Charleston, SC, went right up thru Charlotte, NC, then skirted the NC mountains before turning back North East

[Hammerhead]

Big diff is the winds get cut way down by the mountains. We hava place in Hendersonville and are all too aware of the hassle of rising rivers and creeks. The French Broad River rose about 15 ft high in the early 90s it washed thru Chimney Rock.

[chitbob1]

in 89 someone took my inline out and repowered with a 4.3 V6 vortek it has got plenty of power good on gas

[randlemanboater]

Big diff is the winds get cut way down by the mountains. We hava place in Hendersonville and are all too aware of the hassle of rising rivers and creeks. The French Broad River rose about 15 ft high in the early 90s it washed thru Chimney Rock.

If you move to H-ville you should keep the V to use on the lakes along SC Hwy 11 fishin for stripers with REEL.

[Hammerhead]

If you move to H-ville you should keep the V to use on the lakes along SC Hwy 11 fishin for stripers with REEL.

Having just put a new motor in I sure AM gonna keep it.
We'll be looking for a lil' fishin' shack somewhere near the NC/VA border.

[reelapeelin]

Having just put a new motor in I sure AM gonna keep it.
We'll be looking for a lil' fishin' shack somewhere near the NC/VA border.



In Hendersonville, yer fairly close to Lake Cherokee in Tenn. ... it's SLAP-FULL of big, fat striped BASS 8) ...