Piston Rings Worn Out, Time for a Rebuild

Katahdin said:

My experience has been different. I purchased a NOS OEM starter for $440. It got stuck cranking almost immediately, I had to pull the dogbone to stop the cranking. I paid (my dime) to ship it back to the seller, he shipped me another NOS OEM that failed after maybe a dozen starts in less than year. That's when I gave up on OEM and purchased the new gear-reduction starter, its been 100% reliable for 3 years. In any event, lets not derail the thread further. Back to the engine rebuild!

Click to expand...

You are spot on for Delco Remy.

74M35A2 said:

There are no valve stem seals because there is no vacuum on the intake side. Pressure on both manifolds is either zero or positive.

Click to expand...

Actually that is wrong. All Intake valves will experience a vacuum when operating . Just having the air flow past the valve will create a vacuum. The reason they didn't use seals then was to lubricate the valve stems. They ( the manufacturers ) felt a little oil use was an acceptable alternative to having a scored up valve stem. Now with better metals for the valves and better material for the guides all intake and exhaust valves have oil seals ( and to meet emissions) . If you stop and think about it, how would there ever be any "oil" on the backside of an intake valve ? unless the turbo is leaking. But you will see this on non-turbo units also. As far as "harmonics" causing a back flow thingy all I have to say is "what ?" . I have never heard of such a thing in all my years of wrenching and all the years of schooling I have.

How did you get the liners to come out? Did they come out as you were turning the engine over or did you need to pull them?

wb1895 said:

How did you get the liners to come out? Did they come out as you were turning the engine over or did you need to pull them?

Click to expand...

They came out relatively easy. I rotated the crank so the given cylinder was at bottom dead center. I then took the bearing caps off and used a long piece of wood to go all the way up the cylinder to push the piston up (and being careful the crank does not get scratched during the process). Once the piston reached the top of the sleeve, the rings would catch on the sleeve, so i kept tapping/pounding and the sleeve came right up. I see no real need for a sleeve puller with the method I used. It seemed to work good when Soldier B up top helped catch the piston/sleeve when it came out.

I found some more wear limits and sizes that would be useful for a rebuild. I wanted to post them so they would be easier for people to see. In the pictures is also the TM which is TM 9-2815-210-34-2-2. The specs I posted below are for a standard size crankshaft.

Wildchild467 said:

They came out relatively easy. I rotated the crank so the given cylinder was at bottom dead center. I then took the bearing caps off and used a long piece of wood to go all the way up the cylinder to push the piston up (and being careful the crank does not get scratched during the process). Once the piston reached the top of the sleeve, the rings would catch on the sleeve, so i kept tapping/pounding and the sleeve came right up. I see no real need for a sleeve puller with the method I used. It seemed to work good when Soldier B up top helped catch the piston/sleeve when it came out.

Click to expand...

Is "soldier B" your neighbor that asked to borrow $4 and drive him up to buy smokes?

74M35A2 said:

Is "soldier B" your neighbor that asked to borrow $4 and drive him up to buy smokes?

Click to expand...

Negative ghost rider.

I have made more progress on the truck tonight. I checked the end play on the crank and it was only .0085" so that was within spec. The new pistons I bought came with the 2 hole oil nozzles for cooling the piston. So I installed them and that went well. I then cleaned up the top of the block so I could put the new sleeves in. I pulled the new pistons out of the sleeves and to my amazement, they only had 2 compression rings and one oil ring. I thought LDS pistons had 4 piston rings but not much I can do about it, these might have some better quality materials and maybe they don't need 4 rings? I checked the rod bearing clearance and it came up at .003" which is within spec. One thing I noticed is the bearing cap. for some reason there were some burrs on the cap. Make sure the seating surface of the bolt is completely flat. I am going to lightly file these burrs off. It wont be much material at all. I just want to make sure that I don't torque down the bolts on a burr and then have the bolts loosen up later because of it. Just something to look out for if somebody puts in new rod bolts in their engine. That is where i left off tonight, one piston in.

Hopefully tomorrow I can get the rest of the pistons in and a final cleaning of the block deck surface. I ended up buying NOS cylinder heads because it was cheaper than rebuilding the old heads with machine work and all. Hopefully Wednesday I can get the heads bolted down and manifolds installed. That is my hope anyway!

All that and you only stuffed one piston in? Better step on it kid, Woodward Dream Cruise is days away. Looks like my 9-ball may be flying it solo, but you can borrow it if you want.

well tonight i hope to have more done, so relax. I would have had more in before but you thought i should wait until i get all the pistons. you need to kick that cold and help me drop some pistons in!

If anybody has any questions so far in the rebuild, ask them now while I have it apart!

Wildchild467 said:

If anybody has any questions so far in the rebuild, ask them now while I have it apart!

Click to expand...

Yes, I do: Why did I spend 7 hours there last night pulling on wrenches so you could call it a completed long block by the time we went to bed (4am on weekday, ugh)? You're buying wings at the next UFC fight, as many as I can eat. Progress below: new pistons, rings, wrist pins, circlips, liners (dry), gaskets, rod bearings, rod bolts, and cylinder heads. This F'er had better run like a top. Hang the manifolds tonight, set and adjust the rockers, add oil, and let's go for a ride:

Whats with all the red wires? You got that wired for cat6?

gimpyrobb said:

Whats with all the red wires? You got that wired for cat6?

Click to expand...

Awesome sauce! And that is why I gave you a free reduction starter. Your humor is nothing but home runs!

I'm riding the struggle bus tonight. Staying up late last night really kicked my rear end. Come to think a guy that has 10 years on me can handle it better than I can. Thanks for your help 74M35A2!

I'm just getting some torque specs and then heading back out to the shop. I hope to have it ready to run tonight/tomorrow morning. Wish me luck!

Good luck!

74M35A2 said:

Yes, I do: Why did I spend 7 hours there last night pulling on wrenches so you could call it a completed long block by the time we went to bed (4am on weekday, ugh)? You're buying wings at the next UFC fight, as many as I can eat. Progress below: new pistons, rings, wrist pins, circlips, liners (dry), gaskets, rod bearings, rod bolts, and cylinder heads. This F'er had better run like a top. Hang the manifolds tonight, set and adjust the rockers, add oil, and let's go for a ride:

View attachment 575275View attachment 575276View attachment 575277

Click to expand...

I have found out that engine rebuilds always go better and faster with a team mate.

Nice! Thanks for sharing and best wishes. Would love to be there for the first turnover.

Lotta work but looks thorough and something to be proud of.

Thanks for the love. He rolled it over to build oil pressure with the injectors out, bled the injection, and it is ready to fire. He has worked till 4am each morning doing so during the week, so doesn't leave much time for sleep, post updates, etc....hence my input. We are filling it with coolant, firing it up, looking for leaks, bolting the hood back on, and taking it for a long drive tonight (Woodward Dream Cruise for anybody familiar with it, see you there). It will cool overnight, and he can re-torque the heads the next day and call it done. He is very interested to see how it will behave, as many of the pistons had broken rings as his daily driver and it still ran, vs now everything is fresh and correct. He also exclusively runs WMO thinned about 10% with gasoline or whatever he can find, so that plays a slight mystery card into all of this. Stay tuned, story at 11.....