Engine seized 2 miles after rebuild

Glad you got to the problem and it's bad but not the worst.
Better issue a service bulletin on the Flatty V-8 timing chains locking up engines...

 

Was the crankshaft reground or standard.I looks like rust on crank,there may have been rust on jernals,but the wear in looks like the main cap got mixed with another motor,some thing to check.

 

Good question.

 

George...the crank was .030 under to begin with. The machine shop confirmed that it was good even at .030 under so it was polished. I took it out of my other engine and there were no issues with oil pressure or balance, just the issue of the crack between the exhaust and the cylinder in number 3, causing overheating. Obviously the crank will not be reused again...so now I am on the hunt for another 4" Mercury crank.

 

Amen to that. The inside of a fresh rebuild should look surgically clean. It is apparent that whoever did final assembly left a lot of machining trash in oil passages etc.
BTW -- did you check out the very easily visible crack between a water passage and a stud hole on the deck surface? Is this your "new block" or the cracked one?
Fearless

 

Did not know flatheads don't have timing chains, good to know.

Must have had a big oiling problem to seize up in 2 minles, that's like 5 minutes of driving. Last time I seized a main it made noise before it went... squealed.

 

Just get that one welded up and reground. You know its a good crank and you don't know what you are buying. Or you could buy a scat crank for what a good merc crank is going to set you back.

Oh and after the catastrophe it probably wouldn't hurt to have the main journals sized. It is a good practice to do even if you know you have a good block to build.

 

Regarding the comment on deck cracks- I'm not seeing a pic of the deck surface, but as for cracks between coolant holes and head bolt holes on a flathead Ford block, they're so common they should have part numbers. 95% of them are absolutely nothing to worry about.

The first pic of the main insert shows a very bad alignment problem that needs to be adressed. The crank was only contacting on one end of the shell- something's definately wrong there, for sure!

 

hummmm did you put the center main in correctly? if you put it in wrong that will happen..........

 

Look at post #29

 

It looks kind of dirty for a fresh rebuild, but maybe i am just a bit Anal.

 

I've never been inside of a flatty, but are there also oil holes on the shells that are still in the block? The shells in the main caps have holes in your pix. Are they redundant or did the guy install them wrong and there was no pressure to the mains?

 

They have holes in both halves usually...

If everything checked out fine before the rebuild (plastigauge), and you had good pressure... I guess it has to be a blocked passage...

Or could it have been the oil pump? On a flatty, isn't there an internal valve in the pump to direct the oil to the mains? Or am I thinking of something else?

Did you do any of the 'full flow' mods on this block/pan?

 

How did I miss that? Anyway, that particular spot is a very common crack in these old blocks. Most of these coolant hole-to-bolt hole cracks occured early in life, again nothing to be concerned over. I will usually helicoil these bolt holes for some added strength when torquing the bolts. Otherwise, not a problem.

 

That picture was the old block with the heads off.....before I dissembled it<?xml:namespace prefix = o ns = "urn:schemas-microsoft-comfficeffice" /><o></o>

 

This is the block just before I took it in to be magnafluxed

 

I'm going to assume that you did all the cleaning on the block. When you first got it did the oil stains and maybe crud on the main caps match the rest of the inside of the engine? Most of the time before a block gets cleaned up you can see telltail signs that show that the caps were in that location or something doesn't jive because the oil stains and engine crud doesn't match between the block and main caps.
Did you have the main bores miked?
Did all of the bearing tangs match up with each other. Every engine I ever worked on had both bearing tangs mating up when you assembled the engine. Put a cap on backwards and they don't match up.

If you have an oil pump primer I think before I pulled it down (you can do this on the engine stand) I'd pull the distributor and with a can or pan with enough oil to immerse the pickup screen I'd spin the oil pump and see if oil is getting to the mains. It will run out over the crank if it does. No oil there and you know that somewhere in the oil passages there is a problem. that could be something blocking a passage or a missing plug letting all the oil run right back in the pan.

Keep us posted. I don't really think that the used pistons are that big of deal as some of these guys are hollering about. Mickey Thompson wrote about boring blocks to fit used pistons in his book Challenger. He was running Flatheads in the 50's then and racing with the motors. Go to any bull ring dirt track and half the engines out there on Friday or Saturday night are running pistons that have been in more than one block.

At least you should be able to turn the crank to get the converter bolts out now.

 

Mr48chev:

Here is the engine when I got it from the salvage yard. Not sure if the machine shop miked the bores. The bearing tangs did match up. Thank you for the oil primer suggestion..I will do that. I wish it had been covered here before I started the engine rebuild. I tried to ask and read about everything I could before I started. This is my first flathead but not my first engine.....Porsche, Jags, MG's & Triumphs before...never with an issue.

 

I would check to see if you may have mixed the main caps.Look like the better one must be the front,wear is wrong and if not dirt its wrong cap.Wrong meaning another engine parts.

 

By the look of that front bearing, it appears that this journal has taper or is out of round if you look at the wear pattern on the bearing itself. ie: the front half of the bearing is shiny from wear...the rest of the bearing's surface is as installed.

From experience, there are so many crank "machinists" who take the attitude "near enough is good enough" when it comes to preparing crankshafts.

The centre looks like it may have been too tight and that it was a matter of time before the lack of clearance became too much.

What do the rod bearings look like ?

Rat

 

Yup that would do it

 

Rat bastad:

Haven't pulled the rod caps yet...stopped when I found the main fried...

 

Remove "dist" spin pump to see oil pressure ??? WTF.

Oil pump is driven from rear of cam with idler gear "spin pump" is not gonna happen this is a flathead boy's.

 

Right on, Mr. 48. On the rod tang issue, however there is some Off Topic info: BMW 1600, 2002 four cyl. engines (and some early sixes) assemble rods with the bearing tangs opposite each other.
(Just a 'tab' of info here, nothing else. I was surprised to learn that after a thousand flatheads, Chevs, Jags, Y-Blocks...well, you know.)

 

""If you have an oil pump primer I think before I pulled it down (you can do this on the engine stand) I'd pull the distributor and with a can or pan with enough oil to immerse the pickup screen I'd spin the oil pump and see if oil is getting to the mains. It will run out over the crank if it does. No oil there and you know that somewhere in the oil passages there is a problem. that could be something blocking a passage or a missing plug letting all the oil run right back in the pan.""

I don't grasp how you do the above with a flathead..

 

In your ford barn post you mention that the block has been drilled for a 95% filter. Not according to your pictures in this posting or at least not completed.If it was only half done they may have put the grub screw in the horizontal passage and it was missed this would lead to the two mains starving for oil as the rear main is oiled independently from those two.Look in horizontal oil gallery for the offending grub screw.

Tig

 

Tig Master:

Just a thought...take an old gear off of the rear of an old cam...weld it backwards to a piece of pipe that you can chuck into a drill. Pull the cam and the back cover and use the new set up from the back to power the pump....it seems that this should work if you only want to test the oil pump inplace?

 

Tig Master:

That was an early picture....here is a current one...

 

Check to see if the oil holes in the front & center cam bearings are inline with the vertical oil passage going from the oil gallery to the mains. The oil flows from the gallery to the groove in the camshaft and then to the mains. If that's ok I would check the flow from the pump to the gallery, maybe something didn't get drilled or assembled right, which would still allow oil to the rear main.

 

That's better now.Remove the allen plug from the horizontal passage the one that has some green paint on it closest to your external oil line insert a piece of coat hanger it should go in as far or further than the other allen plug that has been put in the horizontal hole that was drilled and tapped.
This will confirm that the grub screw is not i there If doesn't go that far the plug is in there and has starved the rest of the engine. You could pressureize the oil port with a pre lube system and confirm oil to the rest of the engine but report back first on the grub screw.

Tig