The Stovebolt Site Forums The Shop Area Engine Shop Rebuilding info on Chevy 230 & 250 CID Engines?

I was wondering if a Lighter weight Connecting Rods. Are better to use on a engine that will run wide open-High RPM'S for a long time?
And is there any differance in the following parts from a 230 cid & 250 cid engines?
Connecting Rods,Hyd-Lifters,Lifter Rods,All the Crank Shaft Bearings,Cam shaft Bearings.
ANY Advice on Brand of parts or Type to use to rebuild the engine to run Wide Open for very long times.
It needs to last a long time befor next overhaul?

What's the intended use? The only application I can think of where an engine would run at constant full throttle would be a marine engine, and those have to be built with the same porecision and attention to detail as race engines. (Blueprinted, balanced, and heavy-duty parts) A constant-speed application like a water pump drive or a generator, etc. will have a governed speed well below full throttle, somewhere near the torque peak. Definitely DO NOT use lightweight rods such as aluminum for marine or round track applications.
Jerry

the 230 and 250 are essentially the same engine, just the 250 has a longer stroke. everything is the same, as far as i know, except for that.

and yes, the intended use would be nice to know...as WOT and high rpms is not exactley a norm for road driven vehicles...?

-Sam.

I have a Low hour Chevy 250 cid engine built by OMC. Yes Marine engine. Pistons are standard.
Crank Mic's out at Standard.
The manifold side of the block was crack; only on the outside of the Block.
No other part of block was crack. And no water in oil. Internal parts are in Very good condition. Yes it seems the CrankShaft,Conecting Rods & Pistons are all balanced as one.
Now I got my hands on a 230cid Chevy Truck engine. I intended to use the 230 block as a replacement to my 250 cid marine engine block.
As I disassembled the 230 cid engine. I notice that the Conecting Rods are thicker Heavy duty.
Than what I found on the OMC Marine 250 cid engine. They both have Cast Steel Rods.
But Im surprized to see the Truck 230 engine has thicker stronger Rods.
My only thought is lighter rods & pistons might not fly apart as easy as Heavy one's at WOT?
Are the 230&250 Rods the same length?
230 Piston & CrankShaft seem different?

Stay with the complete OMC rotating assembly. They're in the business of making their engines stay together, so don't second-guess their choice of parts. I did a similar buildup on a low-hour 454 with 4-bolt main bearings from a houseboat. The dummy owner let both engines freeze up. One pushed the "freeze" plugs out, but the other one cracked the whole side out of the block. I got a new, semi-finished block and bored/honed the cylinders to fit the standard bore pistons. Parts & labor plus dynamometer time cost him about $4,000.00 before I was done. That was an expensive stupid attack! I'll bet he doesn't procrastinate about winterizing the boat again!
Jerry

Yes I want to use the complete OMC rotating assembly. Was thinking of replacing with all NEW Bearings. And all NEW Rings. After bore&Hone with/in Standard cylinder bore spec.
Should I use ALL New Bearings & Rings?
Or use the old OMC one's? They all dont look very worn. May be the replacement Chevy 230 cid block main & Caps would be different Dia?
And Yes the Dummy owner I purchase the boat from did not drain ALL water out of the block.
Im puting on a Marine Heat Exchanger. Filled with antifreeze. No more chance of water in block to freeze. Plus antifreeze will keep my block from rusting. Unlike Water runing through a Marine engine block. Anyone that owns a boat knows what I mean. Marine Engines are not cheap to replace.

How many hours does the engine have on it at the moment? If the bearings look good, and the clearances pan out OK with a Plastigage check, I see no reason to replace them. All new gaskets and seals, of course! Replacing the rings is just about a necessity, because they will have to establish a running fit with a new block. Is your replacement block standard bore, and straight enough in the cylinder walls that it won't require a rebore and new pistons? My rule of thumb has always been no more than .003" taper wear in the cylinders before I insist on a rebore. Be sure to do a good glaze-breaking job on the cylinders, followed by a thorough scrubdown with HOT water and Tide to get all the hone grit removed, followed by a pressure wash with 180 degree or hotter water. A properly-cleaned cylinder will begin to surface rust within seconds of the final rinse water drying away. Apply a generous coat of 30 weight oil to the cylinders to prevent rusting until you can assemble the engine. Good luck!
Jerry