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My boat mechanic working to put in a remanufactured 350 Chevy into barrelback

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markhondru12
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My boat mechanic working to put in a remanufactured 350 Chevy into barrelback

Post by markhondru12 » Sun Aug 18, 2019 3:23 pm

Hello, my marine mechanic in mchenry md is having a heck of a time retrofitting a 350 Chevy remanufactured marine engine to work in my boat as a replacement to a 1963 Chevy 283 that kicked the bucket on June 29th. It’s been in the shop for 7 weeks with a new engine in crate and he needs walked through what is keeping him from moving forward in getting her back out on the water. Issue with coolant system and the crank shaft placement . Can anyone assist as I am dying to get her back out on the water before summer is over. He is going to be talking to jim Staib tomorrow and I hear jim is one of the best. Any additional advice? Thank you,Mark Hondru

jim g
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Re: My boat mechanic working to put in a remanufactured 350 Chevy into barrelback

Post by jim g » Sun Aug 18, 2019 10:08 pm

Its not a difficult swap. But its not a simple in and out either. There are some modifications that have to be done. I've done at least 20 of these conversions.

Off the top of my head.

It needs to be a marine engine. Not a car crate motor.

You have to drill the nose of the crank for the oil passage to the manual gearbox. If you have the hydraulic box you can skip this. That job alone is not for the faint of heart. If you snap the bit. It over and done.

Do not damage the nose gear getting it off and do not beat the shit out of it putting it back on. It needs to be fully seated against the timing chain gear. If not it pushes the crank forward and will eat up the thrust bearing.

Grind reliefs in the oil pan so the rods won't hit.

Drill holes in the front of the head for the cooling passage. If you reuse the little elbows. I drill them out for more water follow. But now I use 1/2 inch brass pipe.

Tap the oil pump for the pick up.

Probably something I'm forgetting. Its been a year or so since I've done the last one.

Oh. You will need to change the intake manifold to a stock manifold for a 350 and use an Edelbrock marine carb. If you reuse the 283 intake and carb. The engine will run out of air at about 3200 rpm. The 350 should turn 5000 rpm.

One last thing the manual trans needs to be completely disassembled and cleaned. The inside of the drum is usually packed with sludge. Which will make your new oil completely dirty within in an hour or so. Not good for a new engine.

Last but not least make sure he ordered a modern left head turning motor. Yes. Your engine is right hand which is opposite rotating in todays marine world. But when the left engine is turned around so the flywheel is facing forward. It becomes a right hand engine.

I've seen this screw up more then once.

Good Luck.

jfrprops
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Re: My boat mechanic working to put in a remanufactured 350 Chevy into barrelback

Post by jfrprops » Mon Aug 19, 2019 8:04 am

yep, Jim is right on...lots of stuff to prep and precise too. Jim Staib will be a help....isn't he in a McHenry too?
John in Va.
1980 Fairchild Scout 30
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1921 Old Town Charles River 17' (founding Captain, James River Batteau Festival)

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Bilge Rat
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Re: My boat mechanic working to put in a remanufactured 350 Chevy into barrelback

Post by Bilge Rat » Wed Aug 21, 2019 8:27 am

At least with a 283 to 350 swap you shouldn't have to rework the engine stringer supports and wedges. Swapping a V8 for an old 6 cylinder and getting the angle right is another item to worry about for that task.
1966 Lyman Cruisette 25 foot "Serenity Now!"
1953 Chris Craft Sportsman 22 foot "Summerwind"

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