8BA Piston Removal...Success!!!

[Fortunateson]

To make a short story long I had a good turning 8BA. Removed the heads and plugs to check ridge at top of bore. Not too bad so I put the heads back on but didn't put the plugs in for some reason. I also didn't know I had a small leak in the roof. Up here where rain was invented some got into the driver's side piston bores. I have had ATF/acetone sitting in them for quite awhile and nothing is moving. It doesn't look like any rain water got into the valley but perhaps into the valves.

So I thought I'd just remove the pistons. I was planning on removing the timing chain, main bearing caps, con rod caps, and then remove crank. After that gently tapping on the pistons either from top to bottom or vice versa.

What say you all, can I do it this way? I'm really hoping for a quick honing to cure any ills but I know it may need to be re-bored with oversize pistons...

[Mart]

No timing chain, just gears.

I had a french motor that was lightly seized on one cylinder. I pulled both heads and the oil pan. I was able to identify which cylinder was sticking by moving the crank back and forth and feeling for movement on the pistons. I loosened the big end on the rod on the stuck piston and was able to rotate the crank away from it, just a bit. I was then able to knock the piston down because it now had somewhere to go, and was able to move on it's own.
I kept moving the crank away and knocking the piston and rod down to meet it. With plenty of lube applied I was then able to rotate it and push that piston up.

What I'm saying is that you have a better chance of moving a piston if it can be moved in isolation rather than trying to move the crank and all the other pistons at the same time.

It isn't actually easy to take out the crank if you can't rotate it. Some of the nuts are hard to get to.

Mart.

[Fortunateson]

Thanks Mart. I know what you mean about it being difficult removing a crank if all the pistons are stuck and the crank can't rotate... I watched a very educational video by some bloke in Solihull, England. Actually he's been doing a whole series on rebuilding a crusty old flathead, even did his own boring, sleeving, and valve job! Highly recommended! LOL

Thanks for the advice....

[Fortunateson]

Well Mart, and any other readers, I tackled the pistons today. I checked the dipstick again and as I remembered the pan was dry. Since my engine stand was tied up with a Y-block I decided to tip the engine on its front. First my brother and I removed the timing cover and the bellhousing and the starter. I had previously removed the water pumps. Up she goes and out comes an oil field! Support the block and run for my oil absorbent. Clean up most of the mess. We then removed the oil pan and the stubborn oil pump.mm I'm going to double check the length of at dipstick!

We went after the the piston #5 first and it was frozen good and tight. We then decided to remove the easiest ones they came out fairly easily, even one of the frozen ones I would hammer down on the con rod bolts with a brass drift. The last little bit I used the con rod cap as a guide for the drift. When we were down to the last three pistons, two of which were frozen, we could not access the little retaining tabs for the nuts. BUGGER! Then my brother suggested that we try and pry the crank over a bit. Well that was enough to gain clearance to bend the tabs and we they used a "bit of stick" to convince the two frozen pistons "begone serpent" and the last non frozen piston came out easily.

We spun the crank and t my delight none of the valves were stuck! I was hoping they weren't all this time.We then removed the crank and set it up on its end securely.

Most of the con rod bearings look pretty good as well as the main bearings. The crank may just polish up and the bores that had the frozen pistons may just need honing. I'll take everything into a old time and well respected engine rebuilder for this thoughts.

I'll measure the bore diameter to see if this engine was ever bored out, it may not have been. There is only a very slight ridge at the top of the bores and the previous owner said it was removed in the early fifties from the original car, an early fifties vehichle, to put in a newer v8. No visible cracks anywhere either!

And though your recent experiences were much more difficult than mine your videos helped a lot and gave me a little more courage. However, in solidarity with you the engine gods had one of the oil pan bolts break off. Plenty left to try vise grips but I leaning towards having my son tig a nut onto it to take if out with a wrench.

[Fortunateson]

Going to try a little cylinder honing this evening. I'll also check dimensions to see if it has ever been "reborn" / re-bored and if it needs to be now. Maybe a simple overhaul may be in order...

[V8COOPMAN]

Sponsored Links (Register now to hide all advertisements)

Originally Posted by Fortunateson

Thanks Mart. I know what you mean about it being difficult removing a crank if all the pistons are stuck and the crank can't rotate... I watched a very educational video by some bloke in Solihull, England. Actually he's been doing a whole series on rebuilding a crusty old flathead, even did his own boring, sleeping, and valve job! Highly recommended! LOL

Thanks for the advice....

You do realize that Mart is the bloke in Solihull, England that did the videos you speak of, right? DD

[VeryTangled]

Ya gotta admit, they are REALLY GOOD videos.

[Tinker]

like the videos. Making some progress Fortunateson, look forward to updates... As Mart said there is never been a timing chain on a flathead. Ever.

[Fortunateson]

Of course I knew
Mart made those excellent videos, I was pulling his leg...

Regarding the “timing chain” thing I knew that but had some dietary turbulence which originated in my brain!

LOL

[Fortunateson]

Some pics...

[Fortunateson]

Some more...

[Fortunateson]

Not quite done and I have to get the telescoping gauges to measure bore to determine if has been bored out before. Maybe just a good overhaul is in order...

[Tinker]

they really don't look that bad really. If there is not a heavy ridge that you can physical feel with a finger nail in the cylinder. Hone and re-ring might do it. Or not depending on what you want. A full rebuild is always preferred for most.

Big fan of yblocks, heavy blocks with some great torque.

telescoping gauge, caliper.
https://www.youtube.com/watch?v=1qy3PzrxX4o






.

[Fortunateson]

I may do a full rebuild but I always find it cool when a "will it run" scenario comes true, within reason of course. I realized that I don't have a bore Guage but rather a telescoping Guage set. So my son measured each cylinder twice, 90* to each other, and we have a range of 3.190-3.192. Now I believe stock is 3.1875 so these bores are roughly .0025-.0045 oversize. What do you all think about that. Re-bore or could I get away with an overhaul? I'm looking for a cruiser with a mild cam.

[Tinker]

What do you all think about that... Hog it out. You know what you want. stop asking. Seriously do what you want and post.


If you can afford a short block rebuild do that. If not... well if long block...do that


If you are looking to replace the cam, you should line bore on a old engine, pull the engine and do a mild rebuild. Find a good shop.


respectfully, this is not a small block chevy made in 2005. Cam bearings will need attention on a flathead swap.





.

[Fortunateson]

Cost really isn't the problem at all. I'm not the kind of guy that likes to "fix" things that already working. My Y block just took a .020 cleanup bore nothing outrageous since I just want a reliable cruiser. Same for this flatty. I still have to have a proper cylinder measurement done and determine bore taper. But I still want to know the upper limit for bore wear which I can't seem to find. New main, Rod, and cam bearings regardless of anything else. Even the cam needs a good look to see if it is stock or not. If it is stock I may purchase a new one or have the original reground at an old time cam grinding establishment locally.

[cadillac512]

I have always considered taper of .007" to be the upper limit of a re-ring job. I've done MANY engines for customers who didn't need or want a complete rebuild and never had any trouble. I've also re-ringed a few that were worn far more than that and had acceptable results as well, but the .007" figure always works for me. Cast iron rings or moly...your choice.



Terry

[tubman]

I agree with the above. When we were kids, a little "piston slap" was an acceptable component of one of our rebuilds. If we did use different pistons, they came from the "piston pile" at the junkyard, not the parts store. My dad had been a mechanic and had a set of micrometers, so I was a hot shot in our neighborhood. I shudder to think of some of the work we did, but we kept 'em on the road. If someone did a particularly bad job and took out a block, crank, or a couple of rods, replacements were cheap and only 15 minutes away. With the availability of major components today as it is (excluding 3 3/4" cranks), you really should be a little more careful than we were.

[Fortunateson]

Cadillac512 and Tubman,

Thanks for the comments. I re-did the math to get a preliminary wear of between .0025-.0045 in the bores. Still need official measurements especially taper. But if I'm at the wear indicated a re-ring would be fine? Not trying to build or drive crazy but it will get what it needs. Price isn't the issue but what does it need....

[tubman]

Back in the day, they sold "oversize rings" for situations just such as yours. I think they still do today, but call 'em "file to fit" to escape liability. I would check for excessive taper.