455 Core Block Bore Pictures

Sorry in advance for the long post(s) and thread!

So I bought this 455 for $400 a while back and it's been sitting in my garage for a few months. I pulled it out of a 1976 LeSabre convertible. It actually came with what I'm pretty sure are TA shorty headers and an MSD Pro Billet distributor, so the engine was basically free (if I sold those parts). The LeSabre was supposedly sitting outside for 2 years but with the hood closed, and it shows because the oil was total milkshake. I stupidly didn't look at the mileage on the LeSabre.

The plan is to build it to go into my 1970 Skylark 90% street and 10% (maybe less) track car. I'm not sure of the exact direction I want to go for this build but I've been debating in my head between a zero deck NA build with nice Stage 2 TA heads or a twin turbo build using one of Mark's kits and keeping the stock 76 low compression heads and pistons to see how they do with 4 - 6psi of boost, limiting revs to somewhere around 5,500 rpm either way so it's durable on the street . . . Shooting for an easy 400hp/475tq drivable engine. Maybe more if my car doesn't break behind it (all of this years into the future when I have $$$)

Anyhoo today I decided to use my new cheap borescope that I recently picked up on Amazon to check out the bores. I am going to post pictures of each bore with my comments, but I am very new to working on the inside of an engine. I'm really posting this thread to see if you all think I need to take it to a machine shop to have it bored or if I can get away with a home rebuild. I would love to be able to do all of the work myself since I am pretty untrusting of shops and I'm also poor haha.

Now to me it looks like all of the bores have nice crosshatching left on them, which would lead me to believe that they are all pretty in-round still? Can I get away with a re-ring on this engine? That would save me a lot of machining costs which would let me save $$$ to buy custom pistons (for zero deck) or low compression forged pistons (for boost). I do see a little surface rust here and there which worries me . . .

Let me know what you think!

 

Here's #1. That looks like crosshatching to me . . . but also a little bit of rust?

 

Here we go with #3. Looks similar to #1 with crosshatching but maybe a spot of rust or pitting?

 

Moving on with #5. Looks good to me, but not sure if my definition of "good" is accurate haha.

 

And here's #7. Looks more like just "hatching" instead of crosshatching, not sure why but sometimes it's hard to capture the scratches going the other way with the borescope. Also in the 3rd, 4th, and 5th pictures there is what appears to be the ghost imprint of an oil control ring? Is that something to worry about?

 

Now we move on the the even side, here's #2. Looks similar to the others but maybe a bit cleaner.

 

Moving on in with #4. This one looks like the worst to me. Very obvious rust in the bore and maybe vertical scoring caused by the rust? Is this something I can clean up with a flexhone? I've only turned this engine over by hand, haven't tried to start it yet or anything but I was planning on building a cheap run stand for it. Glad I took pictures first!

 

Here's #6. This one looks ok to me, but it does have some weird discoloration going on near the top of the bore.

 

Last but not least the mighty #8! This one looks ok but has a little bit of rust here and there. Nice crosshatching though!

 

Looks like someone already did a re-ring re-build but they had it machine shop honed.

In some of the pics you can see cylinder wall scuffing underneath the crosshatch. The uni-directional swirl honing marks are caused when the honing stones are removed from the cylinder while it is still spinning, nothing to be concerned about.

You should take it apart and clean the rust out with some scotch-brite to make sure there isn't any pitting from the rust. If it cleans up good with the scotch-brite I think from looking at the pics that you can get away with ball honing it. If you're getting different pistons make sure to measure the bore size before ordering. Use a bore gauge if you have one, to measure the bore size and the out of round on all of the bores.

Why would you spend thousands of $$ on a twin turbo setup to get a measly 400 HP/475 torque? A set of off the shelf un-ported stage 2 heads will get you closer to 500 HP or more and over 500 ft lbs of torque!

 

X2 on what Derek said, why bother buying new pistons if you are not going to plate it to hone the bores straight? I'll say it again like it was said to me " the 3 most important things on building a motor is ring seal, ring seal, ring seal"

 

Thanks for the insight. I guess I'll start taking the motor apart now. I was originally going to try and run it on a stand but if you think cleaning it first is safer I will do that. I guess I should take the whole thing apart so I can look at the rings and bearings and properly clean it.

As far as my power goals, I was thinking of just dropping the motor in as is but from what I've read I'll be disappointed with the stock 1976 455. I want something that'll move the Skylark but isn't mega expensive. 500hp/500tq would be great, but it seems like I'll need either nicer heads or boost to get there. Almost bought some 430 heads the other day but they sold before I could get there. I feel like Aluminum heads are a better investment than irons anyways . . .

So you think I'd need to get it professionally honed or bored regardless of the condition of the bores now? I would want to get it sonic tested and magnafluxed first to see if there's any room for more bore. By doing a home rebuild I was hoping to maybe extend the life of the block as well as save some $$$. But like Dereck said I should check the current bore size, it could be bored out already! Those pistons look stock though right?

 

"Sitting outside with the hood on" doesn't contaminate the oil like that.

Wild guess: the thing wasn't being driven because they knew there was a coolant-in-the-oil problem.

As said...that can be achieved without exotic parts.

As a neophyte to engine building, you'd be money ahead to haul the block and crank to a machine shop for measuring and inspection. Rods and heads and intake manifold, too, if you're going to re-use them. I'd have them pay particular attention to cracks in the lifter valley, or anything else that would milkshake the oil. In fact, you should be looking for leak paths through gaskets and perhaps pinholes in the front cover, as you pull it apart. Aside from "zero decking" the block, you may need to cut it just to make it flat again. Same goes for re-used heads, or re-used intake manifold.

Might be you can get by with a dingleberry brush, rings, bearings, and gaskets. I'm working a similar deal on a '98 5.7L Vortec engine. I'm gonna need one piston due to pitting in #8 that requires boring--all the other cylinders are within .002 for taper.

Ring seal, Intake valve seal, Exhaust valve seal???

 

Interesting about the oil, guess I may be in for a surprise . . . I've heard others say that a GOOD shop will want to do the disassembly so they can inspect at the same time. Since this sounds like the safest route I think I will try and take my engine in, instead of tearing it down myself?

The problem is finding a good shop here. I'm thinking of trying this one called Al Hubbard Machine, but is there anyone on here who can suggest a Buick friendly shop anywhere near the San Francisco Bay Area? I know that Buick engines have special needs in terms of bearing clearances and that most shops that do SBCs all day won't do things correctly, or so I've read.

My plan is to approach a shop and ask for the following:

Disassemble/inspect bores, bearings, rings, etc.
Hot tank/clean block
Sonic test cylinder walls
Magnaflux/check block for cracks

I will tell them not to really worry about the heads as I'll most likely be switching to either aluminum or iron closed chamber.

Does this sound like a good start? Is this really better than me trying to do it myself?

 

Yes. This will cost more, and you will learn less about the process...but you could learn more about the engine itself.

I just sent a Chevy 5.7L block 250 miles to get it bored. My town of ~70K people doesn't have an automotive machine shop.

There are--probably--numerous qualified shops in the Bay area. I don't know of any. You haul that thing North a couple hundred miles, and I could recommend Mike Lewis, Lewis Racing Engines. I don't know him personally, but I've seen his posts for years on various automotive forums. He always has good advice.
http://www.lewisracingengines.com/
Contact him and discuss options.

You go to a Pontiac forum, and they all insist that only a Pontiac specialist can truly understand the Pontiac engine family.
You go to a Cadillac forum, they'll insist that only a Cadillac engine specialist can understand a Cadillac engine.
You go to an Olds forum...only an "Olds" guy can build an Olds engine.
I'm sure the same is true at the Mopar, Ford, AMC, Toyota, Honda...forums.

Anyone who cares about their work can do a fine job. Anyone who want to shove work through the shop as fast as possible will do a terrible job. There's a few "tricks of the trade" with every brand (except Chevy, of course) but they tend to be well-publicized.

 

Patrick, that's a good start. if you have never done this, it is sometimes overwhelming of all the little things that need attention. I hate to see you half ass the motor with all the $ and time, and in short time it has problems like I constantly are reading on this board. Fine a reputable shop that at least give you some guidance on what you have there. 500 hp like you want and having durability is something everyone wants. You need to think about it and decide how much $ you want to spend. Money goes quick doing a motor today and especially one that is going to run strong. I'm sure someone will advice you on a shop near you, but you might have to travel a little for that peace of mind. Do it right from the start and cry only once!

 

Yeah, that always cracks me up when I read when someone post that.

 

Thanks all for the guidance. I have decided to a little compromise. I'm going to remove the heads and give the bores a good cleaning with (fine scotchbrite and simple green?). Then I'm going to run the engine on a stand with fresh oil and new head gaskets. I'll warm it up and do a compression and leak down test. See how the oil pressure looks. If there are any serious problems, I will take it into a shop and start the long, expensive rebuild process. But if the rings and bores seem to do ok, then I'm going to find some earlier heads and slap 'em on and call it good in the interest of enjoying my car sooner rather than in 2+ years. Probably re-gasket the whole engine if it gets to that point and maybe check on the bearings while I'm there.

How does that sound for a realistic, low buck goal? Maybe I can squeeze 200hp/250tq out of it with stock pistons and some early heads?

 

Scotchbrite and Simple Green? You're going to do this with the pistons INSTALLED? Not my first choice. You'll have fun getting the abrasive out of the ring package.

Why don't you do the compression and leakdown tests NOW, before you remove the heads? Drop the pan to inspect/remove sludge and deposits, maybe pull a main cap or two, and a rod cap or two. If you get ambitious, replace the rear main seal. If it all looks good--or looks good after you rinse the "milkshake" off--you could replace the pan, put the engine on the test stand. Fill the pan with clean oil, prime the system, and fire that mother up. See how it runs. Pressurize the cooling system, see if there's steam coming out the crankcase vents as it warms up.

If everything looks OK...swap heads, swap cams. Maybe you never need to do the pistons, bores, rings, bearings.

There are no guarantees with this. You can have good compression and good leakdown numbers, and still burn oil. Maybe the front cam bearing is cooked. There's also minimal investment to go with the minimal guarantee.

 

Haha that's why I put a question mark after scotchbrite and simple green. Is there no easy way to clean up the bores with the pistons still installed? Even if I turn the engine upside down while cleaning? (obviously removing the oil sludge before inverting the engine)

And I thought that I had to have a warm engine to get accurate results from either a leak down or a compression test? Can I do them cold?