Railroadman

The last time I tore down an engine, it was my future ex-wife's '58 Vette and that was in about 1971. So altho I've been through the general process, I'm more than a little out of touch. As background, 327/250, the car had been sitting for anywhere from 15 to 25 years when I bought it. A couple quarts of coolant (looked like pure undiluted antifreeze) came out before the oil started draining.

So this afternoon I decided it was time to at least do some preliminary exploration. Pulled the heads and find overall things are pretty decent. There is NO ridge. Pistons are .030 over. #5 is the problem child, while the others had normal carbon on top of the piston, #5 was very clean. (the "goo" in the pics was just oil I slathered in each cylinder prior to barring it over). Here's 3, 5 and 7:





And the corresponding head, 7, 5 and 3:



So I am guessing the coolant leak has been around prior to the car being parked, I had hoped it was just an intake manifold gasket leak or head gasket leak from sitting through years of hot summers and frigid winters.

I did not have time to really study everything but a real quick glance did not show any cracks. What steps should I take to track this issue down?

Last question for now - with the motor upside down, on the left side there are many numbers stamped into the pan mounting surface, and the bosses nearby. A couple "8"s, other numbers as high as 13 and 14. I have tape pointing to 3 of them but you can see others in that pic, and there were more out of the camera frame. What are those from? I was packing it up for the day getting ready to come home but I don't THINK there were any on the opposite side.




Thanks for the education - I'm sure I'll have many more questions as this moves along.

Robert61

The head is cracked in number 5 in the flat of the chamber. Perfect time to get rid of the 250 horse heads, but that is just me.

Railroadman

Duh, pretty obvious once I see it. Thanks!

cardo0

Find a machine shop that can pressure test the block. Pressure test and magnetic check for cracks before spending money on machine work. May have to spend for cleaning the block first though.

Railroadman

Good point, and one I was already thinking towards. I would "like" to keep the original block, but since the chassis is not original it's not a sacred obligation. I'm not going to assume that one head is the only problem. At some point it's time to just get another motor.

Frankie the Fink

Mmmm.....restomod time ?

I know a guy...

Nowhere Man

If that is the born with block I would do everything within reason to save it. Build it to a L79 and have fun with it.

Robert61

See this chunk missing out of the block at the main cap. This came from someone running the bolts down with an impact or at the very least tightening the cap overlapping the block. This is very bad. In the past I would have always thrown it away but if you want to keep the block it really needs to be repaired. And that is gong to require someone that knows what they are doing. I would highly advise against trying to weld it. I would make a plate that would be recessed into the block and screwed down. That ledge locates the caps and they are tight. I would expect to see the lower main bearing worn at the parting line on the opposite side. Even if it isn't I wouldn't attempt to rebuild the block as is.

Railroadman

Thanks for catching that. We were out there 2 days and between going to a festival, mowing, and a whole bunch of "honey-do" things, I didn't really get into the Vette stuff till yesterday afternoon. I did tear it down as you see, but then began loading stuff to come home and didn't take the time to study everything in detail. (it's 22 miles, 25 minutes, from home to there, and I swear we load enough assorted stuff each time that it seems like we are moving across the country! )

I'm mindful and in agreement with Keith, I want to preserve the original block if possible. But with what Robert just pointed out, and who knows what else will turn up on close examination, I'm thinking I may opt for a different motor to speed up the process and hopefully drive it next year. I would certainly keep this block and as time permits maybe see what can be done. At the very least I will save it for whoever gets the car after I'm gone, unless it is totally junk.

MikeM

If the car hasn't run in 15-25 years since being started, I doubt all that anti-freeze you drained came through that clean cylinder even though, I'd agree, it looks like it's had coolant in it to blow the carbon off. If that much coolant leaked through that cylinder and into the crankcase and sat idle for years. you'd have a very rusty cylinder.

Look for a cracked block, possibly above the lifter bores in the block or on the outside, above the drain plugs. Freeze damage?

Railroadman

Mike, it DOES get damn cold in Iowa where the car did its Rip Van Winkle. I've got to get back out and spend some time on it. Might need to list it on the boat forum as an anchor?

BADBIRDCAGE

If you were hell bent on keeping the original block and heads, providing the block pressure tests good, that main cap could be “pinned” for position and the block align bored on the main saddles. The head could be stitched and repaired in the offending cylinder. These are “fixes” we used in the 70’s on a regular basis. I’ve been out of the automotive machine shop trade for many years now. The processes I describe were valid for saving the customer money back then and the repairs worked well. I don’t know if these repairs are still utilized in the trade.

MarkC

OP, I have a set of L79 heads, intake, carb, rocker arms, 8 inch damper that could be used if you can rebuild your old block. I was going to post them on the parts section when I get time. Send me a PM if you are interested. My car is a 66 and I am now running a Blueprint engine which is another good option for you.

Railroadman

Badbirdcage, the car was low HP and low options, and would never have been a high-dollar car. I have seen frames as bad as this one repaired, with much work and expense. My goals were to have fun turning wrenches and making a driver, so I got a '66 chassis to put under it instead. Now that it's no longer "numbers matching", I'm less inclined to spend big bucks and major headaches on what it came with. I admit I know next to nothing about machine shop work these days, but I find it hard to believe there are enough shops around with the knowledge and experience to do that, at a price that would save me money. Not saying you were wrong about back then, just saying nothing is cheap these days!

I'm weighing my options and am in no hurry to find an answer - there's lots of other stuff to spend time and $ on the car while I mull it over. I could look for another 327/250 or a 327/300 from somebody going the restomod route. I've already looked at Summit for crate 350's. Your suggestion is not impossible either, and I will certainly take it under consideration. Thanks!

Railroadman

Mark, thanks! I'm less than 1 day into understanding what problems I have - and I still need to take a good close look at the rest of it. I'm going to take my time on a decision so if you can get a buyer go ahead. If down the road you still have them, maybe I'll be interested but at the moment I'm still learning and analyzing. I do appreciate the offer. As for the Blueprint engines, they are intriguing but are a bit more potent than what I'll probably go with. Could have used them about 50 years back, no such thing as too much horsepower back then!

Westlotorn

Sounds like you just want a dependable driver, a 350 can plug in and meet your goals pretty well. The 350 is the low cost engine and still offers better torque and horsepower than the 327/250. Install a mild cam and it will sound like a Corvette.
I would think you could be running for well under 2,000 or as you mentioned find a nice 327 ready to run. I think the engine is the smallest part of a old Corvette restore but can be the most fun!

cardo0

Wow! Your really into a project now with replacing that birdcage. I would have to say the engine work will be minor compared to what removing, repairing and replacing that birdcage. So your actually commited to a full frame off. I think you will appreciate how much this forum can help you with it's members and archives. But still that birdcage is gonna take a truckload of labor/grunt work and your looking at a time frame of years rather than months.

My advice is seek shop work for body work, painting and whatever else you can have done with good quality. Bolt in crate motor would save you time and headaches too.

Not to flame you but I don't envy that much of a project at all. Best of luck to you.

Railroadman

Thank you very much for the sympathy, but "BADBIRDCAGE" is the screen name of the person who wrote post #12 - who I was replying to. The bird cage on mine is fine.

Or were you just having a little fun?

ChattanoogaJSB

Don- blueprint engines gets my vote as mark says. Hard to build one for what they can sell you one for, and with a dyno sheet. Move the project ahead!

benton

cardo0

My apologies I miss read that. Recovering from knee surgery now at the hospital and the pain killers have their effects. :o
But even just a chassis swap gonna take more effort than a engine rebuild. FYI I have my corvette body lifted 'bout 4" right now and it'll months before I can get back under it now to replace the body mounts. Life has plenty of left turns and my schedule is blown out the window. Trying to rush a major project takes the fun out of it and adds to the frustration - at least for me it does.

Good luck.