228 rebuild...maybe

[chris650]

Good evening everyone! So I put the boat away for the winter and am going to pursue my plans to repair my transom. So needing to pull the engine to do this, I decided to pull it now so I can work on it during the winter. Transom will be done in spring. So my plans were to do a basic rebuild, until yesterday when a friend stopped by and told me he has two 350 4-bolt main blocks sitting on a rack, and if I want one, take one. So now its got me thinking. I still havnt decided anything yet but have decided to research this a little. And from past experiences, this forum is the right place to be for just that! So what do you fellows think? Should I just rebuild the 305, or should I upgrade if I can? It would basically be the same amount of work either way. What things do I need to know about if I decide to go with the 350? As far as I know, the outside dimensions are the same on both blocks and everything should mount right up! But I guess my main concern would be my outdrive....as far as compatibility from going to a 350 from a 305. Any info would be greatly appreciated, thx. Oh ..btw, I have a 22.5 ft 1978 century 5000.

 

[84EdH]

Re: 228 rebuild...maybe

Hi Chris: the 350 will bolt up to the 305 engine mounts no problem, you can use your 305 brackets, ps pump, alt, etc. the outdrive will have no problem with the 350 power (unless you build a hot rod...with over 300 hp. MC1 and alpha 1 drives rated for max 300.)

there are other issues though. is this a bare block or with crank/pistons/cam? car engines have different cranks than boats and would be a bad choice. best cranks are from truck engines. cam profiles can be good for cars, not boats. it may need an intake manifold depending on the year of your buddies 350. is your old carb 2bl or 4? the 350 will be happier with a 4bll.

also, depending on the year of the 350 block it will be one or two piece rear seal. your boat came with a two piece rear seal and if you go to a one piece you will need a special coupler to work, and probably need a different flywheel and starter.

so, the "free" block if not a truck crank, with stainless freeze plugs, compatable crankshaft, and a two piece rear seal......isn't free.

I definitely would not rebuilt the 305 no matter what. your boat is big and would love the torque and extra hp from the 350. I just did a transom and stringer rebuild on my 19.5ft 1979 century 3000 and also replaced the engine with a 350. You must love your boat because everyone will tell you economically, its not worth all that work. At least that's what I ran into, but my boat runs like new and it feels great to cruise around on a 34 year old boat that I rebuilt myself!

 

[chris650]

Re: 228 rebuild...maybe

thanks for the great info 84!! How can I tell just from looking at a bare block if its a one pc or two pc seal? And when it comes time to rebuild my transom, I would definatly like to get your insight on that also!

 

[84EdH]

Re: 228 rebuild...maybe

does this block have a crankshaft? A 1 piece rear seal will have a 3" bolt pattern and a 2 piece will have a 3.5" bolt pattern for the flywheel. you can also look up the block number.

 

[FreeBeeTony]

Re: 228 rebuild...maybe

Take a few lics if you can.......especially of the rear main seal and intake manifold bolt pattern (12 bolts vs 8 bolts).

 

[chris650]

Re: 228 rebuild...maybe

So i took a quick look and the 350 has a 3 1/2" bolt hole dia. on the flywheel. I was fully planning on buying a new cam, bearings etc. Now will the heads swap over from the 305 to the 350? And on the same subject, what about the crank? Will it swap also?

 

[Bondo]

Re: 228 rebuild...maybe

So i took a quick look and the 350 has a 3 1/2" bolt hole dia. on the flywheel. I was fully planning on buying a new cam, bearings etc. Now will the heads swap over from the 305 to the 350? And on the same subject, what about the crank? Will it swap also?

Ayuh,.... To do what ya wanta do, ya need a 350 Long Block, not a Bare block,....

Everything outa yer 305, Ain't gonna work in a bare 350 block,...

The crankshaft is wrong, 'n the heads will yield Much to high of a compression ratio, which would force ya to use the wrong pistons, for satisfactory results,....

While the SBC is Highly interchangeable, 'n adaptable, ya gotta start with the right Recipe to get a solid long lastin' motor,...

Take a few lics if you can.......especially of the rear main seal and intake manifold bolt pattern (12 bolts vs 8 bolts).

Ayuh,.... Jeeeze Tony,.... SBC blocks Taste greasy, 'n the intake bolt count is a Head kinda thing, not Block relevant,... :laugh:

 

[chris650]

Re: 228 rebuild...maybe

Ok bondo.the block im lookin at is basically a complete engine...heads and all. Cant i just rebuild the 350 if thats the case?? Or does it still need to be a long block?

 

[chris650]

Re: 228 rebuild...maybe

In a nutshell...i want the 350 in there.

 

[84EdH]

Re: 228 rebuild...maybe

ok, Bondo, I bow to your experience with the taste of sbc blocks.

Chris, I agree with Bondo, unless you had a 350 long block: heads, crankshaft, camshaft, pistons, oil pump, timing gear/chain, with a compatible crankshaft for boating, the bare block is only of value as a trade in. The peripherals of your 305 will bolt up to a 350.

you can buy a new 350 chevy marine long block from places like Michigan Motorz, or you can buy a rebuilt 350 marine long block from lots of places, Michigan Motorz, Rapido Marine, etc. the easiest way to do it is to get a 2pc rear seal with the setup for a mechanical fuel pump. then you can bolt on your intake manifold, exhaust manifolds, ps pump, alt. etc. IMO trying to work with that bare block will cost you a lot more, and not end up as good as a new or rebuilt long block set up for marine.

if you shop a new engine, you wont need a block trade in. some places that sell rebuilt want a trade in usable block (ie. no cracks) that they can rebuild for the next guy. Rapido has a 350 Long Block for $1500. start adding up heads, machine work, gaskets, crank, pistons etc etc.....you get over $1500 pretty quick!

 

[84EdH]

Re: 228 rebuild...maybe

Chris, I posted over you. The long block is not a size issue, it is a description of how complete the engine is. A short block, is same as long block without heads. a long block has everything inside the engine, crank, camshaft, pistons, heads, usually they have the tin (valve covers and oil pan).

 

[Walt T]

Re: 228 rebuild...maybe

I'd kinda like to have the other 350 4 bolt main

 

[Bondo]

Re: 228 rebuild...maybe

Ok bondo.the block im lookin at is basically a complete engine...heads and all. Cant i just rebuild the 350 if thats the case?? Or does it still need to be a long block?

Ayuh,... Then it Sounds like a Long Block motor, not a Bare motor block,...

Sure, rebuild it,...

As Ed explains, Short block, Long Block, 'n Bobtail motors are descriptions of the extent of the motor build, not the size of anything,...

 

[harleyman1975]

Re: 228 rebuild...maybe

While it seemed like a cheaper solution at first you will be better off (cheaper) in the long run with a purchased, complete, ready to go long block vs having to do all the chasing, parts ordering, machine shop drop offs and pick ups and finally NO WARRANTY with an engine you rebuild yourself.

 

[Bondo]

Re: 228 rebuild...maybe

While it seemed like a cheaper solution at first you will be better off (cheaper) in the long run with a purchased, complete, ready to go long block vs having to do all the chasing, parts ordering, machine shop drop offs and pick ups and finally NO WARRANTY with an engine you rebuild yourself.

Ayuh,.... Couldn't Agree more,....

 

[chris650]

Re: 228 rebuild...maybe

I appreciate all the input. But if i can, let me try to explain things another way...i have a complete 350 engine at my disposal...its just apart, thats all. Heads, crank, pistons...everything is there. How can i make this work in my boat?? The reason im dead set on it is because im a machinest for a living ...have a shop at my disposal. And whatever machining thats required that cant be handled at my shop can be sent out. aka...i have connections. So labor is zero cost.

 

[Bondo]

Re: 228 rebuild...maybe

I appreciate all the input. But if i can, let me try to explain things another way...i have a complete 350 engine at my disposal...its just apart, thats all. Heads, crank, pistons...everything is there. How can i make this work in my boat?? The reason im dead set on it is because im a machinest for a living ...have a shop at my disposal. And whatever machining thats required that cant be handled at my shop can be sent out. aka...i have connections. So labor is zero cost.

Ok,.... Now yer talkin',.... I'll move this to the other forum,....

We've got plenty of SBC guys that can give ya the Right answers,...

Get the block Castin' numbers, 'n the Head Castin' numbers,...
Block numbers on the top of the bellhousin' flange, usually portside,...
Head numbers are on top, 'tween the valve bosses,...

Clean up the block, 'n crank, mic 'em out, inspect, 'n decide what machinin' ya need,...
Resize the cod-rods,...

Everything else is dependent upon the Recipe ya come up with for the rebuild,...
Think Torque, down low, 'n reliability,...

You'll probably replace the cam, 'n lifters,..??
Heads,..?? Perfect time to slap on a set of Vortecs,..??
If so, Piston choice comes into play, to determine compression ratio, 'n squish patterns,...
4bbl. Carb,..??

 

[chris650]

Re: 228 rebuild...maybe

so what exactly "will" work off of the 305? I guess my main concern would be the exhaust manifolds. Will they mount up?

 

[84EdH]

Re: 228 rebuild...maybe

As I said above, the exhaust manifold bolt right up. The starter, flywheel, bell housing, coupler, engine mounts, the brackets that hold ps cooler, the alt& the ps pump, the intake manifold, the thermostat housing, all the hoses, belts, pulleys, carburetor, the fuel separater, fuel pump. all should fit. Whether you want to use all those things is another story. How old are exhaust manifolds? A failure could ruin your engine. Performance issues are your call. Vortec heads give better performance. Camshaft selection affects performance. But with a two piece rear seal engine of the same era as your 305, it almost all transfers.

 

[chris650]

Re: 228 rebuild...maybe

that's pretty much what I needed to know! Not too interested in building performance, just fresh stock power and reliability is good enough for me. Manifolds seem to be in good shape. Can you tell me more about your transom job 84?