Frank Tate

Help...YBlock Engine Rebuild Problems

Recommended Posts

So, I am asking this in the Technical section rather than the Ford section due to the Ford section seemingly being more of a parts for sale forum.

 

I am working on a basket-case 55 TBird.  It came to me in parts and I am slowly trying to resurrect it.  It has a 292 YBlock that was sent out to the machine shop, along with the cylinder heads, crank, rods, heads, rockers and valves.  The block and heads were cleaned up and pressure tested.  The block bored 60 over with new pistons and rings.  Heads redone with new valves, springs and rocker shafts.  I got it back and put it all together using the YBlock rebuild book and of course, the various YBlock internet sites.  Got it installed in the frame and wanted to get it started before I started hanging everything else on it.

 

It seemed a little hard to turn over by hand, but I attributed that to the new rings and compression.  When I installed the starter and tried, is seemed to turn over slowly without the plugs in it and very slowly with the plugs in it.  I thought it may be the 60 year old starter, so I rebuilt that...no joy.  So I bought a new 12volt starter and installed that.  A little better, but not spinning it fast enough to start it.  So I went looking for other issues.  I have consistently pressurized the oil system and have oil up to the heads.  Some folks I talked to have suggested the rings might be too tight, but according to my notes, they are within spec.  Others have suggested the pushrods being adjusted too tight.  So, I pulled the valve covers and pulled all the pushrods.  They all look good, but I have 2 different types of pushrods.  One is skinny and solid and the other is fat and tubular..

 

IMG_2485.thumb.JPG.f4509bbe0d85e19198f72a444efd5c5f.JPG

 

I think one is old style and one is new... But that got me thinking and I remembered that the block is not original to the care.  My research shows that it is a 1959 292.  The pushrods are for a 1955 292, while 1956 thru 1962 uses slightly shorter pushrods.  The heads are 1955 292 TBird heads.  Could the difficulty in spinning the engine be a result of the pushrods being too long?  If not, then I guess I would need to tear it back down and build it back up again, double checking my clearances on all the bearing surfaces.

 

Thanks for any help or suggestions you may have!

 

Frank

Edited by Frank Tate (see edit history)

Share this post


Link to post
Share on other sites

Did you plastigauge the bearings?

The crank shaft should spin freely before hooking up the rods.

Then a bit more resistance for the rings (lots of oil on them).

Plastigauge on the rod bearings is a must.

 

None of this is specific to Fords.

  • Like 1

Share this post


Link to post
Share on other sites

Yup.....Have pulled it out and will go back through it and make sure all the clearances are correct. Dammit!

 

Definitely a learning experience.

Share this post


Link to post
Share on other sites
5 hours ago, Frank Tate said:

Yup.....Have pulled it out and will go back through it and make sure all the clearances are correct. Dammit!

 

Definitely a learning experience.

Dip everything in oil before assembling then use a good moly based assembly lube on the bearings.

Share this post


Link to post
Share on other sites

If any shop has a problem assembeling a post war V-8 engine, I would take it to another shop and tear it down.(all the way)    A "Y" engine is simple, and if you can't get it right on the first try, you shouldn't get another chance. 

  • Like 3
  • Thanks 1

Share this post


Link to post
Share on other sites
On 1/21/2020 at 3:44 PM, edinmass said:

If any shop has a problem assembeling a post war V-8 engine, I would take it to another shop and tear it down.(all the way)    A "Y" engine is simple, and if you can't get it right on the first try, you shouldn't get another chance. 

Well, the guy in the shop responsible for assembling the engine (me) is now responsible for tearing it down and figuring out what he did wrong and correcting it.  🙄

 

I guess it is only fair that I am not going to pay myself for my crappy work....🤣

  • Like 1
  • Haha 1

Share this post


Link to post
Share on other sites

Pushrods too long could cause the engine not to start, but shouldn't cause it to crank slow. Does this have solid lifters? If so, you shouldn't have been able to set the valve clearance if the pushrods were too long.

  • Like 1

Share this post


Link to post
Share on other sites

Sorry Frank, I thought you had a commercial enterprise build it. Everyone today thinks “it’s just an old car, fixing it is easy”, well, it isn’t true. While rebuilding an engine from the 50’s for me is about as difficult as drinking a glass of water, most engine shops today can’t handle stuff built before 1990. Pre war is just off the list for 99 percent of the shops still around.  

Edited by edinmass (see edit history)

Share this post


Link to post
Share on other sites

Your story reminds me of my building a 1952 Ford V-8 in high school. No real help from the instructor (what was his job supposed to be anyway?) I made every mistake in the book.   It still hurts to think about it. 😞

 

It seems like perhaps you assembled the engine and THEN tried to turn it?

 

FYI - An engine should be turned over at every step to check that everything is OK at that point. 

Put crank in block, tighten mains, make sure crank spins easily. . . . 

Install rods/pistons, tighten rods, spin over the crank after each piston. . . . 

 

An assembled block should spin easily without ANY BINDING. There will be some piston drag from the rings, but a socket on the front pulley should spin it easily without issues. (use assembly lube of course) 

Does it stop spinning? then you know that problem is with the last thing you installed. 😉

 

Even after you install the cam/heads/valves it should not appreciably add to the effort it takes to spin the engine. (no plugs installed of course) 

 

The High school shop teacher told me that a 'tight engine is OK, it will free up during the break in"  

Yikes! How do these people qualify for their jobs??

 

Oh and BTW ..... Pull it out and do it again ? . . . . Dont feel too bad, we have all been there at one time or another 

Edited by m-mman (see edit history)

Share this post


Link to post
Share on other sites

Are your timing marks(cam/crank)correct? Y-block marks are both at approx. the 3 o`clock position, 12 link pins between.

Share this post


Link to post
Share on other sites
56 minutes ago, m-mman said:

FYI - An engine should be turned over at every step to check that everything is OK at that point. 

Put crank in block, tighten mains, make sure crank spins easily. . . . 

Install rods/pistons, tighten rods, spin over the crank after each piston. . . . 

If you leave it for several days It does not hurt to turn it over every day.

We had a mechanic in a dealership where I worked that mic'd everything, every ring, every land, every piston in it's cylinder, every wrist pin, etc. used plastiguage on every bearing.

You could tell the difference when his engines started up first and tens of thousands of miles later.

 

Good Luck.

  • Like 1

Share this post


Link to post
Share on other sites
13 hours ago, edinmass said:

Sorry Frank, I thought you had a commercial enterprise build it. Everyone today thinks “it’s just an old car, fixing it is easy”, well, it isn’t true. While rebuilding an engine from the 50’s for me is about as difficult as drinking a glass of water, most engine shops today can’t handle stuff built before 1990. Pre war is just off the list for 99 percent of the shops still around.  

No worries Ed!  Just a learning experience....I know I screwed something up, just gotta figure out what I did!  lol

Share this post


Link to post
Share on other sites

Thanks guys.  Trying to follow all the books and best practices, tips and tricks.  It doesn't help that it is a 59/60 block with 55 heads and manifolds, etc.  Like the Tbird specific water pump.  Everything seemed to turn smoothly, but then once it was all together it got real notchy....if that is a word.  Hard to break free and then stiff to turn.

 

Got it down to the block with only the water pump still attached.   Will pull that off and then go after the crank and cam thrust clearances to see if those are the problems.  Rod/crank side clearances are right on the money at .007/.008.

Share this post


Link to post
Share on other sites
4 hours ago, Frank Tate said:

Thanks guys.  Trying to follow all the books and best practices, tips and tricks.  It doesn't help that it is a 59/60 block with 55 heads and manifolds, etc.  Like the Tbird specific water pump.  Everything seemed to turn smoothly, but then once it was all together it got real notchy....if that is a word.  Hard to break free and then stiff to turn.

 

Got it down to the block with only the water pump still attached.   Will pull that off and then go after the crank and cam thrust clearances to see if those are the problems.  Rod/crank side clearances are right on the money at .007/.008.

Frank, my first two cars were 55 Fords so I did a lot of rebuild work on Y- blocks back then. (50 plus years ago!) My bet is either bearing clearance or ring end gaps but I am no expert. The good thing is that in my experience Y-blocks were pretty bulletproof and very dependable, you will figure it out.

IMG_0005.jpg

IMG_0006.jpg

  • Like 2

Share this post


Link to post
Share on other sites
On 1/21/2020 at 2:34 PM, TexRiv_63 said:

use a good moly based assembly lube on the bearings

 And the camshaft, unless you have some cam supplier special lube.

  • Like 1

Share this post


Link to post
Share on other sites

True confession time. I had built several engines following proper procedures, and all went well. Then I was taking a 194 Chevy six apart for a friend and said, why am I marking these main caps, they all have the same casting number.... Must be the same, except for the obvious thrust bearing cap. So,  after mixing them up to clean them, new mains went in and the crank got hard to turn. Hmmm, maybe there is something to marking the main caps to keep them where GM put them in the beginning.....Oh *^*^&% they are line bored after the first assembly. Great, what to do? Ah, Plastigauge to the rescue.👍

 

I set three runs of plastigauge on each main cap, torqued to spec, made a chart of too tight and too loose readings. Swapped the caps to get even readings. That was at 100K on a 1964 Nova. He still owns the car, was his daily driver way past 200K miles! I guess the caps are close enough to correct placement!😉

  • Like 2

Share this post


Link to post
Share on other sites
21 hours ago, Frank DuVal said:

True confession time. I had built several engines following proper procedures, and all went well. Then I was taking a 194 Chevy six apart for a friend and said, why am I marking these main caps, they all have the same casting number.... Must be the same, except for the obvious thrust bearing cap. So,  after mixing them up to clean them, new mains went in and the crank got hard to turn. Hmmm, maybe there is something to marking the main caps to keep them where GM put them in the beginning.....Oh *^*^&% they are line bored after the first assembly. Great, what to do? Ah, Plastigauge to the rescue.👍

 

I set three runs of plastigauge on each main cap, torqued to spec, made a chart of too tight and too loose readings. Swapped the caps to get even readings. That was at 100K on a 1964 Nova. He still owns the car, was his daily driver way past 200K miles! I guess the caps are close enough to correct placement!😉

 

 

Yes, a good place to look.

I had a guy bring me a disassembled engine once and I made him buy me a strong magnifying glass so that I could inspect the machine marks on each  of the main caps to the block. Rods were marked.

Share this post


Link to post
Share on other sites

Well, I got it out and torn down again. Turning it over by hand and checking clearances as each piece of the rotating assembly was removed. Pulled the timing chain off and the cam thrust was in spec and the cam turned nice and smooth. The crank was still very stiff, so I bit the bullet and took out the pistons and rods. The crank now turns smooth as silk. The connecting rod nuts were a bear to break loose and the bearings all have a shiny spot on the top. And two of the crank journals have a scratch that I can feel with my nail.

So I am assuming I torqued the rod nuts down too much and there must have been a piece of trash on the bearing.

Share this post


Link to post
Share on other sites

I don't think over torqueing the rod bolts would bind up the engine.

It may stretch the bolts some but the rod cap to main rod area would have to squish to crimp a bearing and I just don't see that happening.

Yes, a piece of trash could bind things up. but you mention shiny spots on the bearings. That suggests to me that there is not enough clearance on the bearings.

Did you measure those clearances either physically or with plastigauge?

It sounds to me that the rod bearings may not match the crankshaft.

While things are apart I would also take the rings off of the pistons and check that they are not to tight in the bores.

  • Like 2
  • Thanks 1

Share this post


Link to post
Share on other sites

I'm not real sure but. I think you had the rods reversed they should be paired up so that the rod has clearance on the radius on the crank ( at the cheek of the crank)  just a thought. The rods should move some on the crank journal side to side.  Hope this . Helps. 

 

 

 

Share this post


Link to post
Share on other sites
7 hours ago, Frank Tate said:

Well, I got it out and torn down again. Turning it over by hand and checking clearances as each piece of the rotating assembly was removed. Pulled the timing chain off and the cam thrust was in spec and the cam turned nice and smooth. The crank was still very stiff, so I bit the bullet and took out the pistons and rods. The crank now turns smooth as silk. The connecting rod nuts were a bear to break loose and the bearings all have a shiny spot on the top. And two of the crank journals have a scratch that I can feel with my nail.

So I am assuming I torqued the rod nuts down too much and there must have been a piece of trash on the bearing.

 

As my Chinese friend sometimes says......"Sum Ting Wong"...........Bob

Share this post


Link to post
Share on other sites

I would check the con rod caps to see if they have been filed to take up the slop of worn bearings. 

  • Like 1

Share this post


Link to post
Share on other sites

Highly unlikely, since this is an insert bearing engine, not babbit..

Share this post


Link to post
Share on other sites

I will have to assume that the rod caps are sorted to their respective rods and installed in the right direction.

The rod and cap are almost always marked as to which bore they go in and those marks go next to each other and should end up on the outside. (easiest to see when installed, not where you have to crane your neck to see the markings.

These marks are usually a number stamp, but I have seen some that have dots. Sometimes there are no markings, if this is the case you should have a professional take a look at things.

I have also seen where a builder will not put the rods in their respective holes, this is not a problem as long as they are on the correct sides.

Some race applications will put the pistons  backwards on the rods to reduce friction but highly unlikely this is one of those engines.

  • Like 1

Share this post


Link to post
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now