Where do I get the citric acid?

 

I need something I can spray on. The block still has the crank, cam, and pistons assembled. I'm not doing a complete rebuild.

 

Here are some more pics:





Anything look out of wack on the engine? Used gas and brushed to scrub the block. It works well, and dries out the remaining grease. I will be using the drill and a wire cup tomorrow to clean it up. I will likely finish with some gas and shop rags.

 

The engine looks typical. You won't really know until ya look at the main and rod bearings and journals. It's worth a peek since you're there already... just pull the caps, inspect, and put 'er back together (torqued) if it looks normal.

'gotta use everything on the toolbox and beyond to remove the muck... scrapers, plexiglass shards, wire brushes/cups, Roloc discs, etc. In the engine machining world, you'll score courtesy points if ya don't bring in parts caked in muck.

 

i was able to let my intake sit for a day or so in a large rubbermaid of diesel fuel. i found out that a mixture of diesel fuel and paint stripper works pretty good too. gets gunk and paint in one application right there.

heads, piston&rods and stuff i usually soak in a rubbermaid full of purple power/castrol superclean type of degreaser. you can strain and re-use it for smaller things later, too.

diesel and a parts brush and putty knifes worked great on my similar looking crossmember.

 

To help get a crap ton of the stuff of....what ever "degreaser" type solovent you use, let it soak for while.....makes a whole lotta sense to let the stuff "break" up the gunk for you.

I personally use Dawn/gas mixture. I Your frame rails and cross members look like mine did......well mine was kinds one sided. One side gunk/oil/pwr steering fluid/grime and the other side was rust...hehe.

 

Does this render the block junk?


Advise? Advice?
This is the cylinder in which the valve dropped.

 

Hard to evaluate from two pics...

I see a witness mark on the piston which will create a hot spot during combustion and could lead to detonation (pre-ignition/knock).

Any deep marks on the cylinder walls? I think I can make out two marks. Run your fingernail up and down and it if hooks anything it's a telltale sign that it will need to be machined.

What say ye?

 

HIO, What is a witness mark? If you recall, I am trying to rebuild this on a LOW budget. A valve head snapped off in that cylinder, but I thought the piston would be ok. Not okay? I'll try running my fingernail over it. Can one cylinder be bored out alone? I can't afford a complete machining of the block. I could probably do one cylinder and buy one new oversized piston head, if that can even be done.

 

Hey tyler call hughes machine shop in Fallon he did a 30 over bore on my 300 for $210

 

IMO, doing one cylinder would be a waste of time and money.

 

I agree. A wise man once said, "Spend your money once."

Save up and do it right the first time so you don't have to tear it down in the near future again to fix something you should've fixed this time.

A "Witness mark" is the pock mark put in the piston by the valve. You can see where it hit and how hard. If the valve raised any material on the piston, it would be good to sand the burr off to help reduce a hot spot on the piston surface. The cylinder walls look dimpled. Not bad, but if you can feel it, so can the piston rings and that cylinder will likely smoke a little. Machining isn't as bad as you think it is. The cost of new pistons can get pricey, but ask the machine shop for prices too. Sometimes they can get better deals than you can.

 

I found these heads on CL. A guy had a 390 and wanted to sell all but he block. I offered him $40 for the driver side head. He said sure. While I was there pulling it off, he said he'd throw in the other head for $20 more. Good salesman...

Here is the block and intake cleaned up and painted:



Waiting for the engine gasket set and the timing set to come in. Then it will be time to assemble.

 

So are you just going to run it with the mark in the piston and cylinder?

 

No. I'm going to get a new stock piston head, and I wet sanded the cylinder wall on that spot, and I will hone it as well. With the new piston head and slightly oversized rings, it should be just fine. No?