Can this engine be repaired?
 

I've bought this engine as "a well restored engine" about a year ago to replace my aging engine in the Model A. This winter should have been the winter to swap engines. Removed the head and everything looked fine, 4 new valves - except cylinder #3, two about 1mm deep scratches.


Can this block be rescued?



Sadly I'm in Europe and Model A engines are really rare

Re: Can this engine be repaired?
 

you can sleeve it or bore it if it will clean . I myself would run it . that's a shame ........ steve

Re: Can this engine be repaired?
 

I've seen similar scratches in engines that ran PERFECTLY, for YEARS.
Bill W.

Re: Can this engine be repaired?
 

Well I would at least pull the piston to look at the rings and try to determine what caused it but like others said that could go away with a new bore or just run it the way it is.

Re: Can this engine be repaired?
 

Looks like the mark the end of a wrist pin makes ---check rod alignment, circlip, piston
I have seen much worse not have problems running as long as the root cause is cured

Re: Can this engine be repaired?
 

The groove is from the wrist pin coming lose or never was locked in place to begin with.
I would not run it anymore without at least fixing the wrist pin. It will keep wearing the groove deeper if you just leave it.
You can remove just that one piston Rod assembly and see if they left out the retainer lock.
It maybe the type that lock into the rod also. Once you re lock the pin you could put it all back together and run it. That cylinder will be down on compression and use oil though.
The best fix would be to sleeve that one cylinder and have it machined to the current piston size.
If the other bores are not in good shape I would do a complete rebuild with a sleeve and new Pistons and rings.
My engine has had all four cylinders sleeved back to standard bore size.

Re: Can this engine be repaired?
 

Thanks guys. The rod alignment and the piston looks fine.

I'm mainly worried about reduced compression in no. 3 when gases pass the piston rings going into the oil. That scratches are 0.04 inch deep. I was planning to put a 6.5:1 head on.

Would it be fine to just bore / sleeve cylinder no. 3 - or shall all cylinder be done?

Re: Can this engine be repaired?
 

Believe it or not those wrist pin grooves will eventually fill with hard carbon and will seal fine. Until that happens, it will smoke and have low compression. Who ever did the rebuild should hide their head in shame.

Re: Can this engine be repaired?
 

Per reply #8, saw engine carbon & old oil fill groves like that before where it was not a problem.

Re: Can this engine be repaired?
 

Can't see very good, but does it look to others like the cylinder was honed at least some AFTER the grooves were made?

Re: Can this engine be repaired?
 

FWIW:

I remember having an oil burning, smoking Model A engine years ago in my well-used coupe which I bought as a teenager.

A kind neighbor over 55 years ago gave me a new set of piston rings that he had stored for about 20 years ...... but .... they 0.010" larger than my engine bore.

I asked a vintage professional machinist/mechanic if he thought installing these rings could harm the engine.

He said the cylinders may become slightly egg-shaped ...... but since this is a Model A, rest assured that these oversized rings will never be the next thing to go wrong with a Model A.

Unfortunately, he was correct.

Re: Can this engine be repaired?
 

Its out and the head is off. You could just sleeve that one cylinder and bore it to fit the
piston in it. It looks like it was apart already and some one tried to hone it but didn't
get any cross hatch in it. You might as well pull the motor down and check everything
out so you know what your starting with. If your lucky it has new rings in it already.
If the taper is not bad on the other cylinders and the bearing look good. Put a Model B or
touring cam in it with your 6.5 head and go....

Re: Can this engine be repaired?
 

Well, so much for 'well restored engine', eh :( !
Did you ever get a chance to talk to seller and happen to ask , about who did the engine work on this engine ?
IMO, it looks like someone (amateur ?) did take engine apart. The grooves may have been worse and honed a bit. The hone job , alone, tells a big story here...i.e.-not what a hone job is supposed to be and/or look like !
So, the 'hone' job in indicative of a guy who dismantled/maybe did some cleaning/adjusting to best of his ability, and reassembled.

Here is where I differ, with the others who say run it. If this is what / how was done....what else :confused:
Since it is partially disassembled already, out of the car and somewhat clean...take the pan and valve cover off and check further before even thinking of running. Just one opinion, but once this is in the car it will be a whole lot of work to undo 'stuff', that may be wrong, then.
Now.....if all else is to your liking, I'd run it with these 'grooves', as I done that myself in the past and like said, it ran in fine :)

Re: Can this engine be repaired?
 

I think the piston part has already been fixed.

You can see where they used a hone, with out cross hatching.

You can see where the hone droped in to and out of the two grooves.

The grooves extends to high in the cylinder, not to burn oil.

Herm.

Re: Can this engine be repaired?
 

it looks like the marks were there when the engine was rebuilt by looking at the hone lines, looks to me it was honed over the marks, just run it the marks will probly get filled in with carbon

Re: Can this engine be repaired?
 

If you run this, it will get worse. The wrist pin is loose and "falls" to the rear. Over time, It will wear to the water jacket if you let it.

My view is, once you find a mistake in an engine, it's usually got other problems. How do you know the other wrist pins are right? - -Where'd the clip that retains the wrist pin go?

I'd take everything apart. If that's the only problem, I'm with the guys who say you can sleeve this one cylinder. You've got to take it mostly apart the bore it anyway - -

I can't tell from the pics, but I'd put in stainless steel valve seats if you don't have them already.

Re: Can this engine be repaired?
 

you avoid valve seats in an A and especially a B at all costs unless absolutely necessary...

Re: Can this engine be repaired?
 

We have put valve seats in every A, B, and T block, and every engine that we ever built, and never had one come out, or leak.

You just have to know how to do them.

Herm.

Re: Can this engine be repaired?
 

tbirdtbird could you please justify your statement about valve seats. I have also replaced all valve seats in four engine with no problems.

Re: Can this engine be repaired?
 

my statement stands. do you think everyone knows how to do them correctly? ever seen a B ruined? many shops do them to charge more? in case no one noticed this thread began asking a question about a bore?

Re: Can this engine be repaired?
 

It's not all that unusual for the clip retaining the gudgeon pin to come out. I suspect some pistons are not dome properly by the manufacturers. The problem may not be with the person who rebuilt the engine, rather the quality of the parts supplied to him.:eek:

Re: Can this engine be repaired?
 

I would tear the engine down and check it out for other issues. based on the grooves in the #3 bore and the poor hone job I suspect there may be other issues. If the only problems found are the grooves and the cross hatch, I would sleeve #3 and bore/hone all bores to the next larger size to clean the bores up properly. Here in the USA the cost would be only about $400-500

Re: Can this engine be repaired?
 

If you have a twist or a bent rod it can cause the clips to come out. It will force the wrist pin over against the retaining pin until it forces it out.
You will not see the twist or bend with your eye you need to check it with a rod checker made for the job. Ever piston rod assembly should be checked when you build a engine.

Re: Can this engine be repaired?
 

Thanks, really appreciate your help.
The only solution seems to be the sleeve after talking to several restoration workshops today, cost are in the range of 400$. I've had the hope that welding would close the grooves, but welded steel is harder than the engine block and can't be honed.
Let me take the engine apart and let's hope there are no further surprises

Re: Can this engine be repaired?
 

Those grooves stop low enough in the cylinder that compression won't be affected much at all. The engine makes most of it's compression in upper part of the cylinder anyway. It may allow some oil usage, but in the real world I've seen a lot of engines run just fine for a long time that way. Now, perfectionists, engineers, machinists and OCD people will obsess over these grooves and lose a good deal of sleep!

Re: Can this engine be repaired?
 

I wouldn't run that engine as is. With the grooves at .040" deep, that means it would take at least .080" oversize to get rid of them. Measure the bore and add .080" to see what size you end up with. I'd bore to the oversize and buy new pistons and rings, or sleeve that cylinder if the rest of the engine is OK.

I would never install valve seats unless it was really needed to repair a crack or recessed seats.

The rough hone and no crosshatch makes me wonder about the babbit and rest of the engine work. I'd take it all apart and check everything. Maybe the valve contact is 1/4" wide and other such faults.

Re: Can this engine be repaired?
 

Besides what George said about Rod alignment taking the snap rings out, is putting the open end of the snap ring side ways.

The open end should be either up, or down.

Herm.

Re: Can this engine be repaired?
 

Herm, I was taught the same thing about snap rings over 50 years ago, but I've always wondered if this is just another "old mechanic's tale". I can't envision Model A piston speed ever being high enough for inertia to overcome the light weight of a circlip. I'm more inclined to blame Harry Hammerhand for overstressing or distorting the clip by over squeezing, or reusing one where the pin has worn a notch.

Re: Can this engine be repaired?
 

Check pin, ignore scratches until oil use is a problem,then sleeve only 1 cylinder. Less worry, better smilespergallon.

Re: Can this engine be repaired?
 

I've always put the retainer ring gap down, but have also wondered at just what speed the piston would have to reverse to collapse the ring. I just can't imagine any car engine having the rings collapse. I did buy an engine at Iola that seemed to be a perfect running engine, but when I removed the head I found all 4 cylinders had deep wrist pin damage due to missing retainers.

Re: Can this engine be repaired?
 

I've dismantled the "well restored" engine today as preparation for sleeving.
I found some cracks in the lower babbits - how bad is this, shall this be repaired? How can this be repaired, soldering?

Re: Can this engine be repaired?
 

Dumb question - What creates crosshatch, moving in and out as the hone spins?

Re: Can this engine be repaired?
 

I don't think they look that bad. If the clearance is good I'd run them.

Re: Can this engine be repaired?
 

Not the best Babbitt job I've ever seen but as stated above, I would just run them.

Re: Can this engine be repaired?
 

Really strange that both caps have different grooving techniques. Almost looks like they were from different engines and fitted to this one.

Re: Can this engine be repaired?
 

Yes, moving the hone up and down at the correct rate to correspond with RPM of the hone will give a nice crosshatch pattern. Doing it freehand you have to be careful to not go so low that the hone stone hits the bearing saddle, or it will ruin the hone or chip the stone.

Re: Can this engine be repaired?
 

No, Mr. 40 I have seen this many times, I think that any engine machine shop can tell you this also.

Thank's,

Herm.

Re: Can this engine be repaired?
 

The babbitt is not Ford factory.

Herm.

Re: Can this engine be repaired?
 

Thanks guys. Will keep the babbits.

Looks like I've found the cause of the grooves in the cylinder. I could move the piston pin of #3 out of the piston by just pressing the thumb against the piston pin. #3 is the cylinder with the grooves.

However, I don't understand the way the piston pin shall be fixed in the position. There is no space for any piston pin retainers? The piston pins are as wide as the pistons - where shall the retainers be placed? - see pictures from left and right side of pistion #3 - All the same with the other pistons - there is no space for an retainers. The only difference is that the #3 rod is tight on piston pin #3 with remarkable friction. The other rods move without friction on the pins, but also can be pushed out of the pistons with just a little pressure....

best regards from Germany

Re: Can this engine be repaired?
 

I think those factory pistons are for the Pins that locked into the center of the piston Pin Bushing area in the Rods.