I bought a local, complete '73 455 motor several months ago as a someday swap project for my '72 Cutlass ragtop. Minimal history, reported to have been dropped into '70 Cutlass for a number of years then pulled and garaged for a few more years until I got it. Looked to be pretty original - still has factory 4-barrel intake and J heads. Was said to have been running when pulled and it does turn without any issue.

finally decided to open it up to verify whether truly original and to see what shape the block might be in - I pulled the left head today and luckily the motor does appear to be essentially untouched - still had the steel head gaskets and pistons appear original. Bores don't seem to have any significant ridge issues. There is some minor surface rust in the #1 cylinder and the water jackets are rusty.

Should I be worried about the #1 cylinder rust? I'd presume a .030 overbore would eliminate that.

Until such time this motor is ready for a build project, I plan to simply keep it garaged but the rusty water jackets concern me - any good tips for how to dissolve the jackets out for now? I presume letting it sit even longer without remedy won't do it any favors.

 

I would not be overly concerned, depending on the depth of the corrosion it may be able to bead hone it off before you start cutting cylinder walls and buying new pistons. Drain all water from the block, vacuum all of the yuck out that you can, fog all the internals with corrosion-X,LPS or whatever you prefer or have and keep it in a dry place. Also, now that you’ve committed this far, you might as well try to locate some better heads, C or E can be had pretty reasonably and flow as well as Olds heads do. You can still use the J’s for tent weights, door stops or drag ballast.

 

When you complete the Teardown, find a shop that has a shot pean machine big enough for the block. When you get it back every inch will be clear and clean of any paint, rust, dirt debris, inside and out. It will look like it was freshly cast.

 

This is not uncommon. When you build it, take it to a machine shop with a real caustic hot tank as opposed the the vapor degreasers that most shops have today. You'll likely have a hard time finding one.

 

I will be checking my local shops to see what block cleaning methods they're using these days - I do have a set of virgin big valve E heads to go on it whenever the build starts to go forward. My biggest concern was just ensuring the block doesn't deteriorate while sitting in my garage - I do plan to put heads and intake back on it for further storage until it's ready to be formally machined and built.

Hoping to get with Mark at such time I'm ready to build it but want to make sure it's a good block to start with.

figured it would be a good idea to try treating and flushing the water jackets while I had the top end apart if I could figure out what to use.

 

Any additional corrosion / rust will be from humidity, so that should be minimal. I think you are worrying about something that doesn't need to be worried about.

 

Don't waste your time, it wont get any worse than what it is. I wouldn't even worry about putting heads and manifold back on, they wont help anything unless its just easier for you to store it that way.

Once you get ready to build it, then worry about cleaning it out. The rust in the water jackets does not look any worse than most blocks I see. Our shot blaster does a good job but it is hard for it to reach some of the bottom areas in the block through the freeze plug holes. I have one customer who fills the water jackets with muriatic acid from Home Depot. That does a real nice job getting rid of absolutely all of the rust.

Best thing to do is to leave it up to your engine builder as to the way he wants the block cleaned.

 

I saw a guy on Youtube with a flathead Ford V8 that soaked his block for a few days in a barrel. He made a anode/cathode system for dissolving the rust. I think he used baking soda and some sort of laundry detergent? It worked very well and was cheap

 

A hot vat as Joe mentioned works well, but you don't see many these days. Most shops have hot spray cabinets that never really get all the brown out of the block. Also as mentioned and if the freeze plugs are still in it, you can soak in acid a few days. Don't leave it too long before dumping and rinsing. I've never tried it on a block, but white vinegar does a great job of dissolving rust in motorcycle tanks.

Edit: Yes, #1 will require a bore and will hopefully cleanup at .03".

 

Is it allowed/ possible to obtain chemical needed to bake it yourself with caustic soda at US? I did so to mine- not exactly allowed, but chemicals were avalaible, and i had a free time..

 

The white vinegar solution mentioned does work well. If you get a large tote and brace the bottom inside blocks and put the block bare in it with a gallon of white vinegar and water enough to cover the block. Then cover with the lid or plastic for about a week. When you pull it out then clean with dish soap and water. Often it will be very nice. As Joe said hard to find a machine shot with a true hot tank these days. Also remember cleaning it one of the most important parts of a rebuild. That means many different brushes and tap every hole as well. You can not make it too clean.

This is a very common sight to find. In fact this is actually a pretty decent looking block to rebuild.

Just my 2 cents
Larry

 

Mine was given an Ultrasonic treatment.