Okay guys I have a 77 with a 350 that I recently installed last summer it supposedly had 500 miles on the rebuild and drove pretty good. By the end of summer it was smoking (white smoke) out of the driver side muffler pretty bad after warming up for a minute. The motor had the stock heads that I was going to replace anyway so I just pulled the heads and found that the driver side had a bad valve seal the the head gasket was on its way out. I left the motor disassembled over winter in the garage covered and I even covered the whole car with the cover. I uncovered it for the first time this weekend to check it out and saw that the block has some very slight surface rust that has actually made its way down into a couple of the cylinders. Its the kind of rust you can basically rub out with your fingers, now in a week or two im going to have a set of dart Iron Eagle Platniums custom made and top it off with a weiand air strike intake based on the feedback I got on here about my engine combo. My question is can I just sand this rust off with like 1,500 grit paper and be good to go or is my block going to need some serious work. I plan on spending about 1500 bucks on heads and intake and I dont want to do it if my motor is trashed or needs another rebuild or machine work. Also Ive never dug this far into a motor before so Ive never seen what the pistons are supposed to look like after about 1000 miles of driving, they are pretty nasty looking carbon covered and what not, how are they supposed to look? I have pictures of everything I described that I can post later. Any input would be greatly appreciated.
Thanks again guys
-Todd

Todd,
Clean the rust off with WD-40 and a paper towel where possible, then use scotchbrite on the deck surface, make sure you razor blade all the old gasket material off.
Clean it good with brake-clean afterwards, you can also clean the tops of the pistons with carb cleaner or brake-clean. Vacuum out the cylinders and the top of the motor thoroughly and blow with compressed air to get any material out.

Re-assemble.

I would be a little concerned about the bottom end. Since you plan to go with Darts and the Air Strike, I assume you will be expecting to get some performance out of the motor and therefore running it hard on occasion. If you can, try to find out the extent of the rebuild. If the entire motor was rebuilt, there should be little or no carbon buildup on the pistons. It might be the previous owner just did a quick valve job and ignored the bottom end.

Look in the lifter valley and see how clean it is. If you find more than a light coating of oil, such as crusty or gooped up (technical terms) oil in the corners and on the bottom of the intake or inside the valve covers, you might assume that very little was done for the engine rebuild.

At the very least, before you run the engine with the new parts, do a compression and leakdown test to determine the condition of the bottom end. Good luck.

Chief,

+1 to Jake - you don't want to go hitting any part of an assembled engine with any type of sand paper. Way to big of a risk of getting grit and particles in the engine that is just going to tear up your engine.

-Warped its going to be mainly a street motor that will see very little track time maybe once or twice per summer. The history behind the motor is pretty inconclusive I got it from a guy who traded his car to a guy for a bunch of stuff and the motor was part of the deal but he didnt have a use for it, but everything he told me seemed to check out so I guess Im just going on good faith. The lifter valleys look good the oil is light and smooth and is also that way in the pan. My timing was bad for a while before I got it set perfect could early detonation have caused that carbon buildup?

-Jake thanks for the advice that sounds like a pretty easy fix and cleanup

If the entire motor was rebuilt, there should be little or no carbon buildup on the pistons.

At the very least, before you run the engine with the new parts, do a compression and leakdown test to determine the condition of the bottom end. Good luck.

Carbon buildup is dependent on how clean the engine was burning, you can have a coating of carbon on tops of the pistons very quickly, and most street motors will. Especially since he mentioned a bad guide seal.

Now how is he going to do a compression and leakdown test when the heads are already off? :rolleyes:

yea, i wouldnt worry about the carbon build up, i bought a motor a couple months ago and when it was all torn down the tops of the pistons were carbon coated, and it was rebuilt like a thousand miles previously. just follow jakes good advice and you should be good to go, pics are always good anyways though.

Todd, I am always leery of claims such as 500 miles since a complete rebuild (the check is in the mail!). this is particularly important with a third party involved, but that is just my preference. I like to know what I am getting into, and sometimes it’s not enough to take things on faith.

Zeke, I understand that engine performance, state of tune, quality of gasoline, etc are all factors in carbon buildup. The original post described this as “pretty ugly”, which is non-specific and open to interpretation. I took it to mean something like we used to see on the piston tops when cars ran on leaded fuel, not just a light coating of ash or carbon. The fact that there was a bad valve seal would account for more buildup on one piston, but would not have an effect on the rest.

In my first post, I said
Before you run the engine ** with the new parts **, do a leakdown and compression test.

Maybe this was not clear to you, but I meant that the new Darts and the Air Strike would be installed so that these tests could be done. This leads me back to my original concern. Todd has an engine with a questionable history, a claimed rebuild within the last 1000 miles +/-, and which has a leaky valve seal and a bad head gasket. This makes me wonder about the accuracy of the recent rebuild claims, the skills and effort expended by the rebuilder, or both. If it were my engine, I would want to know what shape it is in before I added better heads and manifold and felt the urge to open it up. Just my $.02.

Okay it was nice and warm outside today so I cleaned it up going off of jakes advice and I think it came out pretty good I have the before and after pics they are too big to post here so just follow the link thanks to everybody for the advice, just hope it runs as good as it looks.


http://new.photos.yahoo.com/chieft82/