Need new 3.8l OMC Block! please help!

[Wayland McGary]

So today I started to go through my new(to me) boat and motor. And sadly I found that the block is cracked. I have another spare motor and upper outdrive, but the spare is cracked as well the crack on the spare isn't horrible but its still a crack. The one in the boat, I ran water into the inlet hose on the water pump and water came streaming out the side of the motor. I haven't done the same on the spare but I am pretty sure it will be the same story on that one... So does anyone know where I can get another 3.8l block or some other option that will help me get this thing up and running? Any help and advice would be greatly appreciated. Thanks Wayland

 

[Howard Sterndrive]

Re: Need new 3.8l OMC Block! please help!

are the exhaust manifolds cracked too? look at the rear of them on the outsides for cracks where ice has pushed out the casting.
a new pair of exhaust manifolds is $1300

at some point you'll need to make a call about the condition of this boat and whether or not it's worth the money to get it running.
take an ice pick to the floor yet? are the stringers solid and dry?

the engine block is 229 V6 1981 to 1984 Malibu, Monte Carlo, El Camino, and other G body cars with a K as the 5th VIN digit. 229 was never used in trucks
Then swap the cam to an edelbrock EDL2112 and put brass core plugs in the block and you have a marine 3.8

 

[Wayland McGary]

Re: Need new 3.8l OMC Block! please help!

Exhaust manifolds are perfect. It has a custom tower on it that is worth 1200. The hull is in great shape. The interior is in great shape. The outdrive is great. So its kinda hard for me to just let it go without getting it running. So I need to get it going. A gestimate, how much will it cost to rebuild if I find a block?

 

[doral1985]

Re: Need new 3.8l OMC Block! please help!

When I bought my boat the 3.8 l engine was seized, was lucky to find a 84 3.8 l engine in a malibu only had 90 k on it. changed the cam and used all the marine electrics off the old motor. Wasnt aware about changing the frost plugs though, whats the purpose of changing them?

 

[Scott Danforth]

Re: Need new 3.8l OMC Block! please help!

because marine core plugs are brass, automotive core plugs are steel and will rust out

 

[Scott Danforth]

Re: Need new 3.8l OMC Block! please help!

why not replace the chevy 229 (3.8) with a chevy 252 (4.3) one is a 305 with two cylinders missing, the other is a 350 with two cylinders missing.

 

[Howard Sterndrive]

Re: Need new 3.8l OMC Block! please help!

why not replace the chevy 229 (3.8) with a chevy 252 (4.3) one is a 305 with two cylinders missing, the other is a 350 with two cylinders missing.

several reasons, mainly:
1. his stock exhaust manifolds won't clear the wider valve covers of a 4.3
2. there is only a 6 month production run of 4.3s in 1985 that had 2 pc rear main seal. Tough to find a 2 pc rear main 4.3. and the 800 series drive coupler doesn't fit 4.3's made after 1986 (when they went to 1 pc rear main)
3. 4.3 uses a different distributor

 

[Howard Sterndrive]

Re: Need new 3.8l OMC Block! please help!

A gestimate, how much will it cost to rebuild if I find a block?

$1200

 

[Wayland McGary]

Re: Need new 3.8l OMC Block! please help!

found a motor from an 87 olds cutlass 3.8 v6. can i use this motor to do a rebuild? and also i thought they went to 4.3 in like 86? so is it likely that it really is 87? is there anyway i could go to a 305 or 350 with the 800 stringer sterndrive that i have?

 

[Bondo]

Re: Need new 3.8l OMC Block! please help!

found a motor from an 87 olds cutlass 3.8 v6. can i use this motor to do a rebuild? and also i thought they went to 4.3 in like 86? so is it likely that it really is 87? is there anyway i could go to a 305 or 350 with the 800 stringer sterndrive that i have?

Ayuh,.... Any 1987 will be a 1 pc. rear main seal motor, 'n it Won't fit to a 800 Stringer...

Ya need another Pre-87 motor... Up to 1986...

goin' to a V8 will require Regearin' it...

 

[Howard Sterndrive]

Re: Need new 3.8l OMC Block! please help!

found a motor from an 87 olds cutlass 3.8 v6.

that's a completely different Buick based 3.8L engine, not Chevrolet V6 like the one in your boat
you need the fifth VIN character to be a "K",
GM mixed and matched engines in the 80's and that 231 Buick was in a lot of GM cars-so no K, no 229
229s were not used in Oldsmobiles, but maybe some Pontiac Lemans or even Full size
Caprice and Camaro also used 229's in 1981, as did some Checker cabs

is there anyway i could go to a 305 or 350 with the 800 stringer sterndrive that i have?

can't put V6 manifolds on a V8, but with a big enough budget, you can put anything in there. Over 200HP, you'll probably need different upper gears in the outdrive to keep WOT rpm in check

 

[Scott Danforth]

Re: Need new 3.8l OMC Block! please help!

found a motor from an 87 olds cutlass 3.8 v6. can i use this motor to do a rebuild? and also i thought they went to 4.3 in like 86? so is it likely that it really is 87? is there anyway i could go to a 305 or 350 with the 800 stringer sterndrive that i have?

Olds cutlasses were powered with the buick 231, not the chevy 229 GM had two 3.8 liter engines. only some of the chevrolets had the 229. the 231 was the GM corporate V6. all the GM metric chassis had mounting holes for everything from the 2.5 liter pontiac based 4-cylinder up to buicks with 455's.

and yes, you can go with a 350 with your 800 stringer, you will need a different gear set.

 

[Scott Danforth]

Re: Need new 3.8l OMC Block! please help!

go to www.car-part.com and search for your engine

I did an '81 malibu and found a rebuilt engine for $600 in the two pages of engines. you may have to pay for shipping. however at that price, I would start looking at a V8 and changing the outdrive