Southernmost

Hi Guys, I hope you all may be able to help guide me in a direction. I have 1984 Camaro Sport Coupe with a remanufactured 305 that was put in when I was a teenager, about 30 years ago. The original engine was just dogged out and they put a reman 305 in it. I'm not sure if they put my heads back on it or just put the intake and q-jet on and sent it on its way. Anywho, as a project, I thought I would look into getting a 350 and see if I could build a 300 or so HP fun weekend engine. I already know I have to replace the 700r4. So, I got a short block from a guy and he told me it was pulled out of a running truck but there is rust in the water jackets and dirt dobber nests everywhere. So it has not run in years. The pistons have a thick grease coating on them and took some coaxing to get out. The main bearings and the rod bearings do not look too bad, just look like a high mileage engine. BUT, all of the pistons have scoring on the side of them. Some have light scoring and some have bad scoring. Plus, I noticed that the #7 cylinder has been sleeved. The sleeve info was not given to me, I found that one on my own. The block number points to a 72ish Camaro/Nova application. My question is, with a sleeved #7 cylinder is this nothing but a boat anchor and not reliable enough to make a fun little engine? Second, Knowing that there is a sleeve in #7 would that have anything to do with the piston skirt damage or could it possibly have gotten too hot or? Or do I just need to take to a machine shop and let them do some work on it and make the call from there?
Thanks in advance for advice or criticism

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Komet

Depends on how the sleeve was done, but most likely it's ok if it already lasted long enough to get worn out again. What's really going to make or break a rusty block is pitting in the cylinder walls. If you can't bore them clean, it's junk. So, how bad is the pitting, and how much has the block already been bored?

Southernmost

The pistons have STD stamped on them and from what I can tell that means they are standard bore. Correct me if I am wrong. I will see about uploading a picture of the piston skirt wear and the sleeve job when I get back in town on Friday. Thanks for your reply.

ironwill

Unless you were dealing with a high-value vehicle and wanted to keep a 'numbers-matching' engine, why even bother with an ancient block that's been sleeved? Good, standard-bore blocks that will clean up with an .030 overbore aren't that hard to find; you'd do well to look elsewhere.

Vader

...And that include blocks with a better bore/stroke ratio than a 305.

AlkyIROC

Already mentioned but unless you're after something numbers matching, it's not really worth all the effort to try and build an engine when you can get a basic replacement longblock for less money than what it will cost you do have all the machine work done.

Just doing a quick google search. Basic drop in longblock from Jegs. Pre 1986 Iron heads. Typical daily driver replacement engine for $2200. You can get a kit that also includes, distributor, intake, carb etc for $2760. Those are entry level and prices go up depending on what options you want to use.

Finding a core engine and wanting to rebuild it only becomes economical if you have your own machine shop to do all the work yourself.

Lets look at basics. You have a block that has a sleeve in it. Not an issue. Expensive aftermarket blocks survive with 8 sleeves. Sleeve is damaged? Was there an engine failure? Is there other unforeseen damage? I blew up a Dart big M block. Took it in for some repairs and it didn't pass a magnaflux. One of the mains webbing had a crack. $3000 piece of scrap metal. Bought another block. So lets say you have a block that can be rebuild. If it's got a lot of rust, a good hot tanking will be needed. Cam bearings should be replaced and you'll probably want a better camshaft. Before boring out the cylinders, you need the new pistons so that they can be sized properly. Average V8 engine boring is around $300 but you need to call around. You probably will want new pistons. Since the piston pins are pressed into the rods, add the cost to replace the pistons onto the stock rods. Small things like bearings, gaskets, timing chain set, piston rings and fasteners can easy add another $500+. A rebuild kit saves some money but doesn't include every little thing required. I always recommend new head bolts.

In the end, you can always say that you built the engine. Will it last 100,000+ miles, hard to say. Depends on the quality of the work done. Assembling and engine and building an engine are 2 different things. An engine that is built with attention to detail will be torn apart a minimum of 3 times to do adjustments. At least if you buy a replacement longblock, you'll know the entire bottom end has been assembled properly. Adding up all the costs, the replacement engine will be cheaper in the long run.

The only "core" I would consider using for a simple rebuild is one that is still running or one that's been sealed up in storage waiting for a rebuild. A 305 and a 350 cost the same to rebuild however the 350 will give you more bang for the buck.