1967 Thunderbird 390 engine lock...help

Ok sounds good. I will post some before and after photos.

Another question. I ordered a kit via Rock that comes with standard size bearings, rings, and gaskets. The kit is from EngineTech and it had a comment that the rings do not fit OE pistons.....which I find odd. I ordered it anyway but do you know why it would say that? Other rings from other manufacturers were the same exact size as the EngineTech ones I ordered but did not have the 'no fit' comment.

Regards, G
 

64ZCODE

Well-Known Member
Sorry, no idea. I would recommend getting the help of an automotive machine shop to make sure the parts you are ordering are right for what you're doing. Are you going to reassemble the engine with new rings and bearings? That would be a good outcome and avoid a lot of cost if appropriate.
 
Sorry, no idea. I would recommend getting the help of an automotive machine shop to make sure the parts you are ordering are right for what you're doing. Are you going to reassemble the engine with new rings and bearings? That would be a good outcome and avoid a lot of cost if appropriate.
Hello 64ZCODE,
Yes the plan is to do the work myself. How else am I going to learn how to do it?

I spent a few hours last week removing the rings from the pistons. With the exception of one, all of the rings were seized hard into the piston and required a small punch to get them out. Most came out in pieces, only one set came out intact. I was unsure whether or not to use heat for this, so in the end I did not and just worked the gaps, spraying in lubricant until I got enough space to get the punch in to bust it out. Some dings and nicks occurred around the rings channel edges so I need to figure out how to deal with that. Also the ring channels will need to be cleaned out so any suggestions on a tool or process to do that is appreciated.

I am going to clean the block DIY. Some hot water, brushes, and elbow grease and a cocktail of degreaser and a power washer. I have some KrudKutter that has worked magic for me in many other nasty greasy places so I am going to give it a shot. Yeah I know the suggestion is a shop hot tank.....but as the guys on the YouTube channel "Cold War Motors" (I highly recommend watching these characters) often say, this is a nearly $0 budget project. There is little to no ridge at the top of the pistons so we will hone and check the dimensions, same for the cam and crank. I have a spare 390 to use from another vehicle if this fails :) My automotive machine shop are twos crusty old guys helping me with this that know what they are doing, and this forum.

Regards,
G
 

64ZCODE

Well-Known Member
Hello 64ZCODE,
Yes the plan is to do the work myself. How else am I going to learn how to do it?

I spent a few hours last week removing the rings from the pistons. With the exception of one, all of the rings were seized hard into the piston and required a small punch to get them out. Most came out in pieces, only one set came out intact. I was unsure whether or not to use heat for this, so in the end I did not and just worked the gaps, spraying in lubricant until I got enough space to get the punch in to bust it out. Some dings and nicks occurred around the rings channel edges so I need to figure out how to deal with that. Also the ring channels will need to be cleaned out so any suggestions on a tool or process to do that is appreciated.

I am going to clean the block DIY. Some hot water, brushes, and elbow grease and a cocktail of degreaser and a power washer. I have some KrudKutter that has worked magic for me in many other nasty greasy places so I am going to give it a shot. Yeah I know the suggestion is a shop hot tank.....but as the guys on the YouTube channel "Cold War Motors" (I highly recommend watching these characters) often say, this is a nearly $0 budget project. There is little to no ridge at the top of the pistons so we will hone and check the dimensions, same for the cam and crank. I have a spare 390 to use from another vehicle if this fails :) My automotive machine shop are twos crusty old guys helping me with this that know what they are doing, and this forum.

Regards,
G
Hey there Gbird. You might want to replace the pistons. Reason is, if the rings were that difficult to remove, it's possible that the pistons are deformed or the ring grooves are no longer to spec because of the forces exerted at the piston ring/ring groove interface. Plus, the dings and nicks from removing the old rings. A machine shop can verify whether or not the old pistons are still useable.
 
Hey there Gbird. You might want to replace the pistons. Reason is, if the rings were that difficult to remove, it's possible that the pistons are deformed or the ring grooves are no longer to spec because of the forces exerted at the piston ring/ring groove interface. Plus, the dings and nicks from removing the old rings. A machine shop can verify whether or not the old pistons are still useable.
Pistons are dirt cheap. Just replace them in my opinion. Going that far only to put old parts back in is setting up for failure.
 

64ZCODE

Well-Known Member
Agreed, and having a machinist check all the clearances is important at this stage. Make sure the cylinders don't need to be bored oversized, make sure the engine block and a head surfaces are flat and will successfully seal, checking the valves, in fact at this point, it would make a lot of sense to put in hardened valve seats. check to see if the journals on the crankshaft are okay or it needs to be ground and therefore what size bearings should be used, that the wrist pins and rods are okay to reuse. An ounce of prevention now will avoid much cussing later.
 
I would think that the norm on engine rebuilds on older motors with tired cylinders is to have them bored .30 or .60 over and put in oversized pistons. Not really much of a difference in terms of original engine, but it’s nice to know you got good clean cylinders again. Also make sure you get the heads and block magnafluxed! You want to make absolutely sure there is no cracks. 50+ year old parts with a lot of use this is especially important. Also while the heads are off you might as well have someone install hardened valve seats.
 
Background: Bought car in July 18, verified engine cranked (did not start), it sat for 4 months while the seller got a title, then we flat bedded it to my place, no issues. Since Nov I have been cleaning the engine up as it has rust from a rodent peeing on it, and sitting in a somewhat damp basement since 1977. Car has 60,000 original verified miles, and is in really great shape for a PA car. I have not tried to crank it since I first bought it. The engine and every part I've removed is original and I've been excited to play with it, until yesterday!

I'm to the point where the front of the engine and intake area are ready for prime paint and putting it back together (new carb, water pump, nicely painted parts, etc.), and I was going to do that this weekend. I have recently changed the oil, added Marvel Mystery to the cylinders, and dribbled Lucas over the rockers. Yesterday I tried to crank it to TDC, big click from the starter, no crank. Replaced rusty solenoid, verified the ground and voltage, same issue. Battery cables and starter warm! Battery on tender and new so I know it's good. Crank pulley appeared to move very little, like slight nudging, but no crank. Pulled the starter (original), tested on the ground, and it works! Oh crap!

Tried to move the flywheel via the starter hole, nothing but could not get much leverage. Put a chain wrench on the crank pulley and pulled, nothing. Verified the car was in park by moving the gear level to and fro, tried again, nope.

So what the!? Did this engine freeze up somehow just sitting or is it possible the transmission is in drive and an issue with the linkage, or locked in some other way preventing crank? The car is up on ramps and I have not attempted to lower it and see if it rolls in neutral, which is my next step. If that is fine, I'm bummed and need some help. When we move it out of its tomb, it shifted fine into neutral and rolled ok. It is not in the budget to pull this engine and trans to rebuild! Any suggestions from the group?
View attachment 3609
Trans fluid works as well for soaking the cyls
 
I would agree with some of the previous posts on getting hard seats installed in the heads. I didn't do that when I was working on mine, and I have since wished that I would have spent the money. The crap that we have for gas nowadays is pathetic, to say the least, and these engines were designed to run on a lot higher octane leaded gas. Besides, the valves are "non-adjustable" on these engines. That means that the installed height of the valve tip from the valve spring seat is set by machining the valve/valve tip/valve seat (or alternatively by different length push rods, but who wants to go there?). Bite the bullet and take the heads to a reputable machine shop and at least get this part done!
 
I would agree with some of the previous posts on getting hard seats installed in the heads. I didn't do that when I was working on mine, and I have since wished that I would have spent the money. The crap that we have for gas nowadays is pathetic, to say the least, and these engines were designed to run on a lot higher octane leaded gas. Besides, the valves are "non-adjustable" on these engines. That means that the installed height of the valve tip from the valve spring seat is set by machining the valve/valve tip/valve seat (or alternatively by different length push rods, but who wants to go there?). Bite the bullet and take the heads to a reputable machine shop and at least get this part done!
On a side note a I received a message yesterday for a new thread for a 67 Tbird for sale. When I clicked it, it reported 'Post Not Found'. This has happened a couple of times in the past. Anyone know why this happens?
 
Top