I have always wanted to rebuild an engine from a bear block before I go to that great corvette garage in the sky, so I decide I am not getting any younger and now is a good time to do it. I don't want buy a block already to go, so I need some input as what to look for when picking a use engine block. It needs to be Chevy 350, and someday I might like to drop it in my 89 vette, but no hurry on that. I am looking for it to be putting out about 350 hp at the crank with auto trans. I have read and watched everything I can find on how to rebuild engine but have never done it, so I am looking forward to it and I am going to take my time. I know there are a lot of different types and year blocks out there so it needs to be compatible with my 89. Thanks for any info in advance

Mike

 

Any one piece rear main seal/roller cam block will work. I think any 350 block newer than '88 should do it.

350 chp is not a lot, so no special block needed for that. Even a basic 2 bolt block would work fine for your goals.

 

Howdy neighbor!

What Tom says is true, any 1985+ original SBC block will do. If you get a 2 bolt block and really think you need 4 bolt strength on the bottom end you can drill it out for splayed steel main caps. A block so retrofitted is actually stronger than a factory 4 bolt block.

Anyway, once you get a block you will want to take it to a machine shop and have it cleaned and inspected to make sure it isn't cracked or otherwise not rebuildable. Then you should have it decked, bored and honed and once that is done you will know what oversize pistons you need. Most of the time you can get away with .030" over, but you could go .040 or even up to 0.060 over if you wanted to build a bigger displacement engine (no replacement for displacement). If you get a crank with the block you'll want to have it cleaned and inspected first and then ground and then you'll know what size bearings you need... If you don't get a crank you can decide whether to go stock 350 or stroker like a 383. For 350 HP you can get away with a nodular iron crank... If you were wanting more than that or to turn high RPMs then you'd want to spring for forged steel. If you're going stroker you'll need to have the bottom of the block notched for rod/rod bolt clearance. Anyway... for pistons and rods there are lots of choices... Cast, Hypereutectic, or Forged... you probably don't need to go forged for a 350 HP build, but cast probably isn't a good choice for longevity. With 64cc chambers you should probably go with flat top pistons unless you want to need premium at least if not race gas. You don't need domed pistons to get 350 HP.

Anyway... you'll want a good set of aluminum heads, probably with 64cc chambers, 190cc port size, 2.02 intake, 1.6 exhaust. Those are pretty common specs. I'd go with a hydraulic roller cam with a grind suited to the RPM range you plan to use it in -- you don't need anything exotic for 350 HP, 1.6 ratio roller rockers, double roller timing set...

You don't say what induction or ignition you are planning to run... I'm assuming some kind of HEI distributor and probaby a stock-ish TPI? If so you may need to put in at least a high output coil in the HEI and you may need some upgrades to the TPI to get 350 HP.

Anyway... 350 to 400 HP out of an sbc isn't tough... pretty simple tried and true formulas to get there.

 

DO IT! I like the 96 and up truck motors. They have the PM rods and roller cam. 1 tons have four bolt mains. You can either use or sell the vortec heads. Thats exactly what I did. Wanted to build it from the ground up. I found a 96 chevy truck motor, Disassembled it, bought pistons, gaskets and bearings from Summit, Took the parts to the machine shop and had it bored .030 and balanced. I Assembled it (cloned a zz430) and dropped it in my 86. Even the truck oil pan fits. And I tell people I have an LP1 (my initials) under the hood. Remember, if you didn't build it yourself its not really yours.

 

Vortec heads can be a good low budget option to a set of aftermarket aluminum heads... However they won't give you the approx 30lb weight savings aluminum heads will and you have to be careful of intake bolt pattern issues and gasket fit. Make sure what you are using will all fit and seal properly. They also won't quite match the flow performance of most aluminum heads due to usually having slightly smaller valves and ports plus they don't have the thermal advantages of aluminum over cast iron. But you can often pick up a good set of used Vortec heads for a little bit of nothing and aluminum heads usually aren't cheap even used.

 

I used a truck block also. Did the same thing: started with "seasoned" block, and built it from the bearings up. Very rewarding. Watch out for the little things, though. For instance, a double row timing chain won't fit on a truck "vortec" block without modification to the block. Cloyes, I think, makes a single row, which i used. Also, a stock truck timing cover doesn't have a timing pointer. I'm not sure if a "car" block has these issues. I know it's stupid stuff, but it's a pita to stop an engine build to have to go find, then modify a timing pointer. On the bright side, it runs great. and like RWDsmoke said, it's mine.

 

There is no difference between a gen I "car block" and a gen I "truck block". A double row chain will work fine on a "truck block". The "truck" timing cover is plastic, and isn't supposed to be re-used. Get any basic SBC timing cover FOR 9 BUCKS with a pointer.

 

http://www.s10forum.com/forum/f10/po...sticky-441468/

All i'm sayin' is be careful. I used the plastic cover, and it kisses the water pump.

 

As I said, the plastic cover is not to be reused -says so right ON the cover itself!....and I provided a link to a traditional SBC cover that works for $9


If you read the link that you posted, you'd see that there are no issues w/double roller timing chains as the block is the same as all other SBC blocks -as I said above.
Block:
Vortecs used GM's -880 castings, it's basically a "traditional" cast iron SBC block with provisions for a roller cam and a one-piece rear main seal. Being "traditonal" means that almost any GM SBC part will bolt to it. One thing to watch for though, the timing covers. The Vortec uses a plastic timing cover that uses uses 8 bolts. Regular timing covers use 10 bolts. Some blocks had all 10 holes drilled and tapped, while others only had 8. The timing covers will still interchange, and somewhat seal decently.

With that being said, I would just like to restate that ANY small-block cam will fit. Whether it be the older flat tappet cams, the LT-series cams, or roller cams. Any rotating assembly provided it is a one-piece rear main. Any SBC water pump, flex plate, heads, distributor, etc...


Your posts are adding confusion where there needn't be any.

 

On the contrary, i am trying to avoid confusion.

http://www.thirdgen.org/forums/engin...-chain-fitment.

I've done this build. I'm just trying to tell the OP things aren't always as straight forward as the internet says they are. Also, the stock oil temp sensor does not fit in the stock location. I haven't checked, but i think the treads in the block are metric, anyway, the hole is way too small. I used a new plastic cover because i wanted it to seal well, not "somewhat decently".

 

Another good link.

The requested page was not found.

It's good of you to try to help give a heads up, but it would be a lot MORE helpful if you'd provide complete and accurate details, rather than dropping a bomb such as
"Watch out for the little things, though. For instance, a double row timing chain won't fit on a truck "vortec" block without modification to the block."
..>Then leaving it at that. First, there is no solution or explanation of the problem. Second...it ain't TRUE! Ya DON'T have to modify the block to get a double row timing chain to fit! You MAY have to use a different timing cover (which solves the second issue that you posted -the timing mark) and as it turns out, you're not supposed to reuse the plastic cover anyway...b/c it will leak. So I don't think that you dodged any bullets there.

Threaded holes in block for Oil fittings are NPT. This is true for older SBC's and Newer, "Vortec" or not. There is nothing special about the "Vortec" block...it will work just fine for a swap. I've done it too, into an '84, and even used the Vortec heads w/the stock CFI intake. .

 

@ mlm0: sorry for hijacking your thread with foolishness. Just do your homework. Google is your friend. If you search for " L31 timing chain grind" you'll see what i'm talking about. Good luck.

 

Time for my



That search worked, and apparently it's true. Grinding is required it appears. I apologize for my spreading of misinformation. Not good. Thanks for providing the right search criteria to get to the info.

 

Thanks everyone for all the information. I will now go foward and search for the right block at the right price

Mike

 

I was in the same boat. Might want to get some rough estimates on the cost of the machine work needed on top of a salvage yard block. I wound up buying one of Summit's bare reman. blocks and put together a 383.

 

If i was going to do it over, i'd probably go this route. In fact, there is a shop near me that offered a block ready to go, supposedly with 383 clearance and all, for $750. This is a little more that my machining cost, but it saves traveling all over creation to find a block that you hope is good.

 

Good thought

 

If I would have had an extra grand to play with.