455 Core Block Bore Pictures

Im sorry but I've used all kinds of crap to clean bores out , scotch brite pad, steel wool, 180 grit sandpaper, razor blades etc, with gas, brake clean, alcohol , carb cleaner etc. Push the piston to the top of the bore and vacuum it what comes out fine what doesn't, oh well. Pitted cylinders , discolored what ever. Engines are pretty tough, tougher than most think imo. Would I do the above to my Tomahawk or something that I had some serious coin in no I wouldn't. But for something I'm going to drive and not looking to drop unnecessary money in of course I will. Done it the other week matter of fact for the shortblock that is going in my 70 X where I have no doubt it will last for many years and run 11's.

 

I had a GN back in 06/07 that run 11.0s at 120 that I drove EVERY SINGLE DAY, ON 28LBS of boost. The shortblock in it had been sitting in a field at Brian Weavers GBodyParts for 3yrs with no heads and was full of grass clippings and a nice lite coat of surface rust. I cleaned it up never took one bolt out of it and drove it for 8k or so miles and sold it to another fella when I parted the car out that put it in his GN and that car ran 3mph faster than the original shortblock he replaced,...it didn't mind apparently. Not looking for argument just another point of view

 

Haha well that gives me a little more confidence. I'm really not spending any serious money attempting to clean and run the engine as is, and if I mess it up then the rebuild will take care of it. I've been meaning to get a run stand . . . up and running for a while

 

Cold is fine. The numbers may be a little less on the compression test, but you're looking for evenness of compression among the cylinders more than for absolute pressure.

The leakdown test is similar. Even with a fully-warm engine, the cold air from the air compressor is going to cool off the rings anyway. The cylinder walls and heads will stay warm due to the mass of hot iron and hot coolant; to a lesser extent the pistons will be warm-ish and the exhaust valve temperature will drop like a broken rubber. "Fully warm" or cold, you'll still get a reasonable idea of what's sealing and what isn't.

 

For peace of mind use some Brakleen on a rag just above the piston. When thoroughly clean of oil use some masking tape on the top of the piston & side of cylinder wall. This should help to keep some debris from getting to the top ring & beyond. Then clean wall the way you see fit. More Brakleen on a rag & remove the tape. Done.

 

If you want to salvage what's there then, upside down with piston at BDC, clean the cylinder you're have in position with brake clean and try to de-rust the cylinder dry.

I would try to rotate the engine as little as possible until all of the cylinders are cleaned out. Use a vacuum to suck as much of the grit left behind out as possible.

But here's my problem doing it the above way;

New rings for factory pistons only cost about $45, you said you're replacing all the gaskets anyway. Removing the pistons and crank while its tore down that far is a piece of cake. You will be able to inspect the bearings and crank for wear while its totally disassembled. The bearings can be re-used if they're still good, just make sure they go back where they came out of. And you'll be able to get everything much cleaner while its apart.

New rings because scraping the rust in the cylinders could cause excessive wear to them. Why do all that work to install the engine for it to possibly start blowing smoke after 20 miles of driving? Besides, removing and re-installing the crank and pistons will be good practice for you for when you do get to the real rebuild.

Spinning a bearing or worse, seizing a rod bearing when doing some spirited driving is a fast way to make your future rebuild a pile of scrap.

A couple of hours of extra work and $45 more for a piece of mind, is up to you.GL

 

Great point! Well I've decided to try tearing it down myself to see what happens.

I did do a cold leakdown test first and I will get the results up tomorrow. Hope I did it correctly, tried to get each piston close to BDC. But basically #3 was a bit lower than all of the rest, and when I squirted some oil in the cylinder it shot up above the others. The others were pretty consistent. I didn't know about tapping the valves with a mallet to make sure they are fully seated (looked this up after) so I guess #3 technically could be leaking from the heads.

I won't have the eye to catch things during the tear down like the pros do, but I guess the trade-off is learning how to do it myself! Plus I'll take lots of pictures. I don't see that I have much to loose in this situation, besides a couple hundred bucks in gaskets and cheap rings.

I think all I really need besides that is a ridge reamer to get the pistons out?

First official expense of the engine: $15.15 for a few packs of Ziploc bags to label and store everything and 40 gallon trash bags to cover the bare engine with. Will use some of the trash bags for trash too

 

Here's the engine as purchased, but I already took off the shorty headers and valve covers:



Nice coating on the thermostat:



And on the bottom of the Edelbrock Performer intake:



Intake off, valley pan is pretty nasty too:



But luckily the valley looks pretty clean:



Except for these parts:



Rockers/shafts off, much quicker then taking off SBC lifters!:



#1 Lifter face, I think it looks ok? This was the dirtiest looking one, most of the others looked cleaner.

 

Nice milkshake on a couple of the lifters. Yes I know it kinda looks like something else :



I blew a bunch of milkshake out of 4 or so of the pushrods too . . .

More progress to come tomorrow!

 

Just make sure you keep those lifters in order so you can put them back where they came from if in you're going to reuse that cam.

The bottom of the lifters still look relatively new, that cam must of been replaced recently?

From the bore scope pics, it doesn't look like the engine has to many miles on it so you can skip the ridge reamer. I have seen guys do more damage with a ridge reamer than good by taking WAY to much out! If there is a ridge I would suspect that it would only be a minimum carbon ridge that can be removed with some scotch-brite. Usually there is no need for ridge reaming a high nickel Buick block, just need to clean the carbon ridge off.

Ridge reaming is for brand X engine blocks that are much softer than the Buick stuff. At the top of the compression stroke when the mixture is ignited, that causes the rings to expand on the down stroke. With the softer blocks when that happens the rings with scrape into the top of the cylinder after hundreds of thousands of cycles that basically scrapes a "ridge"(lower surface at the top of the cylinder where the rings don't travel that last around 1/4" to 3/8" at the top), this is where you need a ridge reamer to scrape down to the worn surface so the rings will pass when removing the pistons.

The Buick blocks usually doesn't have that scraped lower section in the cylinder at the top, it usually just has the raised carbon ridge that can be easily cleaned with scotch-brite or steel wool.

Take and post pics here as you disassemble and I'm sure you'll have enough expert eyes to see what's good and what's not.

That is the best way to learn how to do something, to just do it!

 

Thanks Derek! I bagged each lifter individually and labeled it by cylinder and valve so I should be able to reuse them. Thanks for letting me know about probably not needing the ridge reamer, I'm hopefully going to have the heads off today so I can feel for a carbon ridge.

I was originally going to drain the milkshake oil from the pan through the drain plug, but now I'm thinking it'd be better to take the pan off and clean it out, with the engine still right side up.

 

Drain it AND remove it right side up, that way you're less likely to make a mess!

 

Got those heavy a$$ heads off, in the below pic the head gaskets are still on on the block:




Random pics of the bores right after pulling the heads, no cleaning or anything:



Passenger side head, nice giant open chambers :



Driver side head:


Head gaskets didn't seem to be blown or anything, so I'm still wondering where that milkshake came from. Also I am so new to this that I can't really tell if these are OEM steel shim or composite gaskets:



Pic of the block without the head gaskets:

 

Got the oil pan off, but like an idiot bent up the gasket rail trying to pry it off with one bolt still on that I didn't see Hoping I can hammer that back flat. To be fair, someone put a boatload of RTV on the oil pan gasket:



Mmmmm vanilla milkshake:



I took the pickup off and cleaned it up, no oil present at the pickup hole so I felt safe inverting the block.



Block inverted:




Timing chain . . .



I gave the bores a quick wipe down with brake cleaner and fresh shop towels. I did notice some carbon buildup right below the deck, and used some elbow grease and more break clean and shop towels to wipe it away on one cylinder. Now when running my finger up that bore I can feel a very slight edge, does that mean I need to ridge ream to get the pistons out?



Out of curiosity, why do the stock pitons have a nipple on the center? Wouldn't a regular dish have been easier to produce and better for flame travel? I'm a total novice to piston design.

Lastly, I'm a bit worried about having lots of core shift by looking at the lifter bores. Now I have read Jim Weise's thread on core shift and know that technically a block with lifter bores that "look" bad can still check out ok, but should I be concerned here? To me they look thicker towards the valley and rear pin side (which is left in this picture):



Tomorrow I'm leaving to visit my parents in France (they moved there to retire a year ago) and I'll be gone for 2 weeks. The block will be awaiting my return covered in a 40 gallon trash bag. I will still be reading your responses though! Thanks to all for helping me through this tear down.

 

The above pic to me looks like where your coolant is getting into your oil.

 

Couldn't open pic

 

I tried to copy and paste but I guess it didn't work.
In the pic of the intake gasket, it looks like the coolant was seeping from the water port, then running into the valley of the intake, and into the crankcase.
Its the fourth pic attachment

 

Ah now that I look back at my pictures what you’re saying makes a lot of sense! The little bits of build up near some of the lifter bores and down that back of the valley also point to a coolant leak coming from the top of the engine. I wonder if that’s all that was wrong with this engine and they scrapped it because they couldn’t figure it out? Maybe wishful thinking!

Anywho now I’m glad I didn’t try and run it as is because I probably would have wasted a bunch of fresh oil.

 

Yes that's what I was pointing to, good luck, keep us posted