Fear the inevitable...

[Searay205]

I just found two 350 carburated engines out of 340 Sundancer on Craiglist complete in Houston for $750 each. Manifolds, bell housing, coupling included. They pulled out of boat for repower. I believe closed cooling to boot.

How you got more speed out of a 190-210hp v6 versus a 220 hp V8 is beyond me EXCEPT if you had synthetic oil in the V6.......

 

[Searay205]

Found two more out of 1998 for $550. They look a little rough but again closed cooling. Seller says must buy both but they probably roll if they get $650.

 

[Scott Danforth]

Hey Searay205 before you go rambling on V8's the OP cant use...... read post #19 from the OP. he is on a motor regulated lake and already has the largest motor allowed.

getting more speed out of a V6 weighing 100# less than the same HP V8 is easy, the torque curve on the V6 is better than the small bore V8 simply because of the diameter of the pistons

Back to the OP.

need to pull the motor and do a tear down before anyone could answer. since you have a local recommended machine shop, let them do the tear down.

many times a new GM crank is cheaper than spending money to recon your existing crank.

 

[AShipShow]

Even carburetor 5.0 better than dog 4.3. Probably get whole engine under $3K

Jumping on the train... I couldn't disagree more

A 4.3 is a fantastic motor. They can be found at 99% of auto salvage yards which means you could be up and running for under 1k... Or you can find a machine shop to fully rebuild one just about anywhere because most places know chevy motors inside and out and parts can be gotten anywhere.

My previous 20' bowrider had a 4.3 (even prevortec) and had more than enough power to pull tubes, skis, and hit 52mph (which is terrifying)...

 

[Searay205]

My dog Mercruiser 5.0 mpi pushes my Searay 205 62 mph with stock prop (that is very scary, like black ice). With High Five it does 55 mph regardless if one person or eight.

As far as OP and reading the post he isn't interested in junk yards and craigslist motors like I am. Translation $3.5K repair vs $1K? and 4-8 weeks vs 2-3 days.

If you wanted a 3.0 liter complete with about 10 hours on it my buddy would have given it to you for free if you took his old checkmate and trailer with it. His drive went out which they haven't made since 198? boat wasn't worth retrofitting.

My suggestion find a reputable guy with 1 or 2 employees to do the repair. He knows if he gets it wrong he eats it. The corporate groups MarineMax employees screw up they still get the same pay check.....

 

[FBCoach]

Would love to tell you i know what to do next! . Time to learn something!

 

[Rick Stephens]

Start unbolting accessories and external stuff. Can't really go far wrong :^)

 

[FBCoach]

Ok. Got most of the externals off. What’s left is oil pan, head covers, valve cover and exhaust manifold. Any advice on the order to now attack this?

 

[Rick Stephens]

Exhaust, intake, valve covers, heads. Pan last when you rotate over.

 

[FBCoach]

Checked the rod bearings. They all looked seated and like this. Ideas?

 

[Scott06]

You need to look at main bearings as well and have the crank journals rod and main caps measured to see what bearing clearance is or if rod big ends are out of round. I don’t like the scoring on up side of bearing is that on all the bearings . Only time I saw that was when my dad an I rebuilt an engine the machinist messed up resizing they big end of the rods- bored them at an angle so the bearing was canted vs the crank created a wear pattern like that on opposite sides of rod bearings

at the very least did you plastigauge the bearings to get rough bearing clearance?

 

[FBCoach]

I’m really not sure what to do. The block casting number is 090. I can buy a referb long block and do all the switch over myself.

To rebuild this one I’ll need help. I haven’t messed with the heads yet. If i decide to rebuild it what would you recommend?
-Me taking it all the way apart, Then have a machinist check the structure of block, heads, etc to see if it can be rebuilt? If it can then get all new internal parts and then have the machinist to hone what ever then needs to be honed for these?
-If it can let the machinist hone what ever can be and only replace what can’t be?
-Other?

 

[tank1949]

Ok. Got most of the externals off. What’s left is oil pan, head covers, valve cover and exhaust manifold. Any advice on the order to now attack this?

Try your best to label stuff, especially wiring. Oil may have been sucked out through coolant/water. It went somewhere but not in bilge? Only one place it could have gone. Thank God boat was fresh water used. Good luck!

 

[FBCoach]

Waiting on a local guy to come by. In the mean time, see anything obvious? There was oil in the two Bow cylinders.

 

[Scott06]

If you want to be back in the water fast order a long block either remanufactured or new from a place Like Michigan motorz, Center state engine, or rapido marine. You’ll spend $2-3.5 k on this route and you could be back running within a weekend of work.

option two find a machinist and take the engine to him. Couldn’t see much of the bores but didn’t look bad. Until someone measures the bearing clearances on rods and mains hard to tell what machine work you need. They can measure the bores as well and determine if they need a hone or overbore and new pistons. Would think unless something is really messed up that this would be a bit cheaper maybe 1200-1500 range

 

[achris]

Noticed batwing exhaust manifolds. Consider (strongly!) changing over to a 2 piece dry-joint system.

Chris........

 

[FBCoach]

First - hope all have been well during this past year. Update and question:
Took the engine to machinest this past fall. Had it rebored .030. New crank, timing chain, oil, pump, pistons, rings, bearings, gaskets, seals.
Sat on the engine mount until two weeks ago. Put it back together and reinstalled this past weekend. Talked myself into gambling with the original batwing exhaust simply for financial reasons. Now am talking myself into replacing them with the two piece dry joint set as well. Feel it only makes sense. Can you guide me on a full replacement set - all parts needed. Hoping to not have to break the bank as well. Motor serial number 0K158135. Thanks much.

 

[achris]

Consider HGE for the manifolds and elbows... Mercruiser parts for the rubber and lower elbow parts.

2 PC. Exhuast manifold conversion

Looking to do a 2pc conversion on my manifolds. I currently have one piece "bat wings" I was wondering if I could convert to the a dry joint system like this and if so what else do need? *BEST VALUE* Mercruiser 1983-2005 V6 Coated Cast Iron Dry Joint Exhaust Manifold & Riser Kit | Performance...

forums.iboats.com

Chris......

 

[nola mike]

How you got more speed out of a 190-210hp v6 versus a 220 hp V8 is beyond me EXCEPT if you had synthetic oil in the V6.......

And put like 3 cans of seafoam in there, LOL