crate engine or rebuild original 350?

[wildcatjason]

Has anyone ever come across NOS parts for these old chevy engines? I wonder what cost would be for original, unused heads, same as what I have?

Im looking at the Vortec heads and they seem to only supply 67cc per cyl, while my factory heads supply 76cc per cyl. How do the Vortecs give better performance?

And I see the rocker arms and nuts are NOT included - and steam holes arent drilled out. Arent these aftermarket heads sold ready to bolt on?

The smaller the combustion chamber the higher the compression. When fuel and air have a smaller space at ignition the more force is produced. Light a firecracker in a upside down coffee can vs a trash can and see what happens.

 

[wildcatjason]

Ebay search turned up reconditioned stock heads for 400/pair and he said he'd thrown in a good used set of rocker arms and nuts. He mentioned I would have to adjust each rocker arm nut with the engine running, oil squirting in my face, to get them just right??!! I think he was "having a laugh" as the brits say. He also mentioned many guys just reuse their existing rocker arms, pushrods, etc. The book Im using to guide my hand through this process - HP Books "How to rebuild your small block chevy" indicates just the opposite - that most of the time heads and their components like rocker arms, etc are too work to be reused. How do I tell if mine are too worn? I dont have a micrometer.

Im still astounded these heads arent sold ready to bolt on. Being a precision piece, Id think the adjustment would be a known clearance amount and pushrods and arms installed to that measurement. no?

Those hydraulic lifters don't need exact clearances. Just make sure the lifter is all the way down in the valley off the cam lobe, tighten the rocker until the push rod wiggle is just barely gone and give it a half turn in tight. It is very easy.

 

[wildcatjason]

Do the lifters look burnt? Are they cracked? Do they bottom out? Did it tap when running after a proper adjustment? Do you have a bent push rod? Do the rockers look scored, burnt, or bent? Do a proper inspection, clean them, lubricate, and reinstall. Discard if necessary. I don't know how many times I've done it.

 

[HotRodPC]

You HAVE to hone a cylinder to get a crosshatch pattern on the wall.

That's what the arguement is here. Some say NO you do NOT. The purpose of a crosshatch pattern it for seating the rings. If the rings seat without it, then what's the purpose other than tearing off a bit more cylinder wall.

I have a feeling this could be true today since ring technology has also advanced. Rings usually seat farily quick unlike in the 50's and 60's.

 

[philjafo]

The heads are sold ready to bolt on, the rocker arms are just another component that bolts to them, like the valve covers. Solid lifters need to be adjusted with the engine running, hydraulic lifter don't wildcatjason has it right. If your reusing the cam with flat tappet lifters check them by placing the face of one to the side of another. The face should be slightly convex, if its flat or concave its worn out and in need of replacement. Also if reusing the lifters they need to go back in the same hole they came out of or you will destroy the cam in a very short time because the lifter wears to match the cam lobe. New cam needs new lifters. If its roller lifters check for wear or damage, they last almost indefinetely though and can be replaced individually. Your engine likely doesn't have roller lifters though.

 

[belay70]

Your engine likely doesn't have roller lifters though.

how do I identify diff types of lifters? Mine look like the small hand grenades the colonial marines used in Aliens (1982).

 

[philjafo]

Ummm, a roller lifter has a roller on one end and flat tappet lifters are flat.

 

[belay70]

Ummm, a roller lifter has a roller on one end and flat tappet lifters are flat.

gotcha, never done this before. mine are flat but in very good condition. guess I'll be re-using them.

 

[Driver4r]

Its easy to adjust rockers while an engine is running, you can do it with valve covers off, but if it runs long enough youll have oil to clean up. Alot of guys buy a cheap set of valve covers and take a hole-saw to it so they can slide a socket on the rocker.
You are basically just listening for the engines happy spot

 

[DoubleDingo]

I guess Id rather have the guarantee and warranty of a bought engine, knowing I'll spend the same money on either scenario. But the act of restoration isnt about simply buying new parts and bolting them on. Its supposed to be hard, because thats what makes it fun/valuable/worthwhile. its respected because its hard. if it was easy, then everyone would do it. Saying you restored a vehicle by buying items and paying for service work to be done is ********. Now, if you simply cannot perform certain services like block washing, magnaflux, etc then Im fine with that. But the majority of work should be done by you, and I want to achieve that. I want to look back on the difficulty and heartache of the process, as I drive her down the road.

So, I have decided to rebuild the block I have assuming its not cracked or otherwise dead-ended.

Well said! Knuckles!

 

[DoubleDingo]

When I was 15 my stepdad helped me rebuild a 350 that came out of '76 K10 Stepside. The engine had been run hard in the truck it came out of and my '56 Chevy Sedan up to that point. We plasti-gauged the connecting rods on the crank, stamped numbers on the ends of the connecting rods so they went back in the right spot and didn't get oriented the wrong way, checked the bore of the cylinders, cut the ridge at the top of the cylinders, hot-tanked everything, honed the cylinders with the ball type honer only to get the cross hatch in them, honed the lifter bores with a ball type honer, used a very fine grit emery cloth to clean up the bearing surfaces on the crank and cam, put new rings on the pistons, new bearings all around, new timing set, reused the cam, crank, connecting rods, pistons, but got new lifters, and assembled it. That engine ran great, and I didn't baby it, and it never burned any oil. In 1991 I put that engine in my '65 3/4 ton and drove the piss out it, the truck loved running 80 mph on the highway, and that was turning 3,000 rpms regularly. In 1998 I pulled the heads to have him freshen them up. There wasn't any ridge on the tops of the cylinders this time, and I calculated it to be around 194,000 miles on the engine between the '56 and the '65 at that point because I drove it daily around town and on the highway and made a many trips between the LA area and my hometown between 1986 and 1998 which is a 5 hour round trip. Whatever he did to the heads made the engine run even better. Easily added 30 hp and more torque that was very noticeable when passing cars or going up hills. So yes, you can do a rebuild on the cheap and get excellent results. Just do it right and you will have no worries. All we got new was lifters, seals, rings, bearings, timing set, high volume oil pump, plugs, wires, cap, rotor, coil, water pump, freeze plugs.

 

[HotRodPC]

At the same time guys, you can say what you want about a bought engine with a warranty, but I know of 2 people who bought motors came with a 3yr 36,000 mile warranty. 1 was 4 years old with a little over 40,000 miles on it and put a rod thru the block. The lady had oil changed every 3,000 miles and had receipts to prove it. The shop who installed did not a thing for her. And I know of another with the same 3yr 36K warranty and just over 50,000 in year #2, lost a crank thrust and was walking the crank until it finally spun a couple rod bearing from low oil pressure caused by worn main bearings.

It's an opinion thing, and for some it's the right thing to do for th peace of mind. I know many happy campers too that bought motors and at least a couple of those were quite capable of building their own but chose to buy a motor. For me, I'll build my own, and then I know I can throw all the abuse and neglect I want at it, and KNOW it'll hold up since I KNOW what was done to it and how it was done. I don't use a 1/2 drive air impact wrench as my torque wrench. Simply refuse to do so.

 

[wildcatjason]

I don't know man. A carbureted chevy 350 is so easy to rebuild and parts are cheap comparably to other brands and engines. It doesn't even make sense to buy a crate. The first time you do it can be intimidating, but get a good book and you do it once you won't regret it.

 

[muddyman184]

I'll build my own, and then I know I can throw all the abuse and neglect I want at it, and KNOW it'll hold up since I KNOW what was done to it and how it was done. I don't use a 1/2 drive air impact wrench as my torque wrench. Simply refuse to do so.

Got a very good point there

 

[belay70]

how about a good book? I have an older manual written in the late 70s, but wonder whats changed since then. ANyone prefer a certain book, or is there a 350 bible?