All Small Six My 200 CI mystery

[awasson]

Well, I finally got the time to pull the inline 6 200 engine out of my 66 Mustang Sprint. Time to post my experiences for better or for worst.

I bought the car in December 2023 after several years looking for a Mustang or Falcon with an inline 6 200 with manual transmission. My rationale was that being an inline 6, it would have been less abused than a 289 and I like the simplicity of the inline 6. Maybe add some boost. It’s definitely getting a 5-speed and some brakes and suspension.

So the engine… The previous owner hadn’t driven the car in 4 or 5 years. He said he added a pertronix ignition, plugs, oil filter, etc… but it never ran right. Factory carb, factory distributor, factory exhaust manifold and single exhaust. I did some prep, oiled the bores, check the oil, check the antifreeze, fresh gas, new battery, wired the pertronix through a relay to +12v and it fired right up. Idle was a bit rough but good enough to drive up and down the street. It seemed fine so I parked it and considered my next steps to get the car roadworthy (check brakes, suspension, minor bodywork, leaky cowl, etc…).

One day I fired it up to do some tuning and it made some screeching noises so I shut it down to investigate. It stopped abruptly. I thought maybe the water pump or alternator bearings were the issue. It seems the harmonic balancer is really close to the timing chain cover and might be rubbing there or at the oil pan. I can’t really tell but when I went to crank the engine, it was not going to move. I tried with a breaker bar on the crank and it will not budge. It’s seized.

So that brings us to today with the engine on a stand and the investigation at its start.

The weird thing is that it seems like the engine was rebuilt recently. The block was spray bombed blue but the paint never adhered to the freeze plugs and they all new. The lifters show no wear. It’s like they’re brand new. The bores don’t have a ridge and it has been rebuilt at some point because someone used a ridge reamer on the top of the bores. I haven’t measured them yet so I don’t know whether it’s been bored out but I don’t think so and the bores are clean and no scuffing as far as I can tell without removing the pistons (that’s next). Five of my push rods are tweaked slightly. The other 7 are arrow straight. The pistons are a bit carbon’d up and so are the valves. It was running extremely rich. The oil was super thin and smells like a gas tank. No head gasket leak though and the oil didn’t have water and the antifreeze didn’t have oil in it.

I’ll do another update tomorrow. I’m planning to pull the crank and pop the pistons out, remove the timing chain and camshaft.

Pictures or it didn’t happen

 

[PSIG]

Hmm. As you disassemble, are you checking rotation torque at each part loosening or removal to find where the issue is? I'm also curious what the bores look like with rich fuel washing the oil off the cylinder walls.

 

[awasson]

Hmm. As you disassemble, are you checking rotation torque at each part loosening or removal to find where the issue is? I'm also curious what the bores look like with rich fuel washing the oil off the cylinder walls.

It won’t rotate now, even with the head off and added oil to the bores.

I have a hunch that someone built/reconditioned the engine and either didn’t gap the rings correctly or didn’t check the clearances on the crankshaft bearings and they’re too tight. It’s weird that it looks so fresh.

The previous owner didn’t say anything about the engine being recently rebuilt but he might not have known. He was a young guy in his early 20 and I think he bought it as a project but it was out of his reach to take it on. It seems it languished in his parents garage for 4 or 5 years before he listed it and I bought it.

 

[TrickSix]

Sounds (smells?) like there might be a leak in the fuel pump diaphram. That dumps gas into the crankcase, and engines don't like having gasoline substituted for their oil. Looking at the paint sprayed over rust on your block and head I get the feeling that whatever was done to that engine was short-cutted or done 1/2 ast. Reminded me of the Vice-Grip Garage guy, when he sprays a little paint on an old engine he says"There, that's reconditioned now!"

 

[drag-200stang]

Please show us a good pic of the front of the engine with the chain and sprockets removed before ripping everything apart.
I like to support the front of engine with a piece of wood when not working on the stand, I feel that it is not good for the thin long compact block, but I may be overly cautious.

 

[awasson]

Well… a few things:

1) Pistons are good and were not seized in the bores. [insert picture of me with relieved look].

They slid right out. The rings feel a little sharp on the edges so I don’t believe they bedded in. I still don’t see any crosshatch so I wonder if they didn’t just ridge ream the block and throw a set of new rings in? I haven’t checked the gap and probably won’t bother. I’ll measure the bores and hopefully I can get away with a hone, rings and reassemble after dealing with the following damage…

2) There was no drive rod between the distributor shaft and the oil pump. This is my first Ford but I’ve had a good half dozen SM Chevy’s in my possession of the years and it seems that in order to spin the oil pump, there needs to be a hexagonal drive rod between the distributor and the pump. Am I wrong?

Somehow, the cam is completely unscathed, the lifters were well oiled and the crankshaft main bearings are fine. Even the valve train and stems were oiled and there was oil pooling under the valve cover. The cam chain wasn’t over stretched but it was relatively dry.

The big end bearings were put in wet, meaning oil or assembly lube on both sides. I can get behind a very thin oil on the bock or rod side, maybe but I’ve always been of the school of inserting the bearings in the caps, dry. These were saturated with heavy lube, which brings me to the issue that stopped this engine from going vroom.

3) Number three big end bearing was spun and the bearing material blocked the oil passageway on the crankshaft. It’s prettty nasty so I’ll have to send it out for repair or maybe replace the crank if it can’t be machined.

In addition two of the pistons have tight rod pins. #3 has a very tight pin and that’s either the cause of the spun big end or a result of the spun big end.

4) One other anomaly is the order of the piston rods. I numbered my piston rods with a sharpie before I pulled them out. Unfortunately it appears when the engine was assembled, whoever did it, didn’t follow the order that is in the casting on the rods. For instance, #2 or #3 piston rod cap has a 1 on the casting.

Anyway, I’m going to take a break for lunch and contemplate next steps. Ie: contacting a machine shop to assist I with the crank and checking the rods.

 

[vssman]

Well… a few things:

1) Pistons are good and were not seized in the bores. [insert picture of me with relieved look].

They slid right out. The rings feel a little sharp on the edges so I don’t believe they bedded in. I still don’t see any crosshatch so I wonder if they didn’t just ridge ream the block and throw a set of new rings in? I haven’t checked the gap and probably won’t bother. I’ll measure the bores and hopefully I can get away with a hone, rings and reassemble after dealing with the following damage…

2) There was no drive rod between the distributor shaft and the oil pump. This is my first Ford but I’ve had a good half dozen SM Chevy’s in my possession of the years and it seems that in order to spin the oil pump, there needs to be a hexagonal drive rod between the distributor and the pump. Am I wrong?

Somehow, the cam is completely unscathed, the lifters were well oiled and the crankshaft main bearings are fine. Even the valve train and stems were oiled and there was oil pooling under the valve cover. The cam chain wasn’t over stretched but it was relatively dry.

The big end bearings were put in wet, meaning oil or assembly lube on both sides. I can get behind a very thin oil on the bock or rod side, maybe but I’ve always been of the school of inserting the bearings in the caps, dry. These were saturated with heavy lube, which brings me to the issue that stopped this engine from going vroom.

3) Number three big end bearing was spun and the bearing material blocked the oil passageway on the crankshaft. It’s prettty nasty so I’ll have to send it out for repair or maybe replace the crank if it can’t be machined.

In addition two of the pistons have tight rod pins. #3 has a very tight pin and that’s either the cause of the spun big end or a result of the spun big end.

4) One other anomaly is the order of the piston rods. I numbered my piston rods with a sharpie before I pulled them out. Unfortunately it appears when the engine was assembled, whoever did it, didn’t follow the order that is in the casting on the rods. For instance, #2 or #3 piston rod cap has a 1 on the casting.

Anyway, I’m going to take a break for lunch and contemplate next steps. Ie: contacting a machine shop to assist I with the crank and checking the rods.

You are correct that there has to be a drive rod between the distributor and oil pump.

 

[TrickSix]

Did you find the oil pump drive shaft in the oil pan? I see lots of reports around here of people removing their distributor and having the shaft pull up with it a bit and then falling down into the pan. But if it isn't there now, how long has it been gone?

 

[awasson]

Did you find the oil pump drive shaft in the oil pan? I see lots of reports around here of people removing their distributor and having the shaft pull up with it a bit and then falling down into the pan. But if it isn't there now, how long has it been gone?

Nope. Pump drive shaft is nowhere to be seen.

The only thing I can assume is that the previous owner, who put in the Pertronix module, pulled the distributor out to install the ignition module and lost it or didn’t notice it was hanging off the distributor and it ended up in his garage somewhere. He wasn’t a malicious kind of guy but just seemed out of his depth.

When he sold the car to me, it didn’t have a battery so I asked him when it had last been driven and why. His answer was that it hadn’t been driven for around 4 years and they could never get it to run right after they put in the Pertronix. Then Covid happened and he got engaged and life goes on. His mustang project got shelved.

I assumed he couldn’t get it to run right because he was powering the Pertronix from the resistor ignition wire. I put in a relay to 12v for the ignition and it roared to life with no hesitation. Fortunately I put oil and ATF in the bores before starting it. That was their saving grace. I’ll still run a hone through them before it goes back together.

I have no idea how the cam managed to not get damaged and also the main bearings appear fine. It’s just two wrist pins and the big end on number 3. Tomorrow I have to find a machine shop to repair the crank and rods. If they can clean up the block and run a hone through it, all the better.

 

[drag-200stang]

Please show us a good pic of the front of the engine with the chain and sprockets removed before ripping everything apart.
I like to support the front of engine with a piece of wood when not working on the stand, I feel that it is not good for the thin long compact block, but I may be overly cautious.

There is a good reason that I asked for a pic of the front of the engine with the sprockets removed. This is were many small six's have been wrecked when rebuilding.

 

[PSIG]

Nasty bearing, but it explains part of it. Yes, it will have to go in to be cleaned-up, but most of the damage appears to be the soft bearing, and little damage to the crank. I'll bet it will clean-up.

Now that the rods and caps were mixed, a rod dimensional check with correct caps and possible resize is in order. The pistons need checking and likely the pins bent in a couple, causing the binding - but again, check everything. The crosshatch likely disappeared with the fuel in the oil, and typically what happens.

The rings on these are usually barrel-faced top ring, and being sharp-edged means they have worn so far they're sharp. Seated (bedded) x10. New ring end gaps (all 24 of them, 4 per-piston) must be checked to spec. The rings must be selected (e.g., 2M586) before the bores are finished, as each ring type uses a specific bore finish for proper seating and sealing. Everything should be checked to spec. No shortcuts to basic procedures to get basic reliability. Have fun!

 

[awasson]

There is a good reason that I asked for a pic of the front of the engine with the sprockets removed. This is were many small six's have been wrecked when rebuilding.

I’ll have to take a photo of it to post tomorrow. I just had a look and I don’t have a good enough photo of just the front of the crankshaft and camshaft.

 

[awasson]

Nasty bearing, but it explains part of it. Yes, it will have to go in to be cleaned-up, but most of the damage appears to be the soft bearing, and little damage to the crank. I'll bet it will clean-up.

Now that the rods and caps were mixed, a rod dimensional check with correct caps and possible resize is in order. The pistons need checking and likely the pins bent in a couple, causing the binding - but again, check everything. The crosshatch likely disappeared with the fuel in the oil, and typically what happens.

The rings on these are usually barrel-faced top ring, and being sharp-edged means they have worn so far they're sharp. Seated (bedded) x10. New ring end gaps (all 24 of them, 4 per-piston) must be checked to spec. The rings must be selected (e.g., 2M586) before the bores are finished, as each ring type uses a specific bore finish for proper seating and sealing. Everything should be checked to spec. No shortcuts to basic procedures to get basic reliability. Have fun!

Yes, I was hoping that most of that is the bearing smeared on the crankshaft as opposed to serious damage to the crank. I’ll have to make some calls tomorrow to see who can machine it.

I had the same concerns about the rods, caps and wrist pins. I’ll be sending the block, rods, pistons and crank (and flywheel) to a machine shop once I’ve made some calls around.

I did not know about selecting the ring per specific bore finish. That is good to know. Most of my experience is with GM small block V8’s where we would deglaze with 3” or 4” long parallel stones and then use a ball hone to give the rings something to bite into. Where can I find some reference info for choosing my rings and specing out the preparation for them?

 

[B RON CO]

Hi, the guy who assembled this engine was in way over his head. Chrome moly rings require a smooth bore finish, not a typical ball hone finish. At this point every rod needs to be checked for correct size and roundness. As you know, if the rod caps are all mixed up, the rods should be resized. The Ford six cam needs a "wedding ring" on the front end. If the wedding ring is not there you must get one. Some cam retainer plates are machined on one side for timing chain lubrication, and some are reversible. You should be able to check the piston the cylinder wall clearance with a feeler gauge, but at this point I would probably let the machine shop measure the bores and decide if you need new pistons. Good luck

 

[nearGettysburg]

Sometimes "luck" is on your side. All the running with no oil pump drive and you have that little bit of damage?! Good for you!
Can you post your general location? Members might be able to suggest machine shops with experience in the 200 six depending on where you are. I found a good shop in Westminster, MD, but that won't help much if you are in Colorado.

 

[PSIG]

Where can I find some reference info for choosing my rings and specing out the preparation for them?

From the manufacturer of the specific piston rings you choose. They are usually available online if you have ordered but not received them yet, or they are usually packed in with the rings.

Terms like parallel and ball hones are no longer enough. Spec's involve surface finish specifications, and manufacturers will usually give specific type of hone, steps of grits, pressure, angles, clearances, etc. The realization of the importance of dimensions and finishes is much greater today due to options and variations of ring types and finishes, but ensure greater success, sealing and lifespan. This isn't your father's Oldsmobile bore honing.

 

[awasson]

There is a good reason that I asked for a pic of the front of the engine with the sprockets removed. This is were many small six's have been wrecked when rebuilding.

I put the balancer on when I put the crank bolt on so as not to bottom out the thread and I'll have to pull it off again to get a good shot. I'll do that tomorrow when I have a moment.

Cheers,
Andrew

 

[awasson]

Hi, the guy who assembled this engine was in way over his head. Chrome moly rings require a smooth bore finish, not a typical ball hone finish. At this point every rod needs to be checked for correct size and roundness. As you know, if the rod caps are all mixed up, the rods should be resized. The Ford six cam needs a "wedding ring" on the front end. If the wedding ring is not there you must get one. Some cam retainer plates are machined on one side for timing chain lubrication, and some are reversible. You should be able to check the piston the cylinder wall clearance with a feeler gauge, but at this point I would probably let the machine shop measure the bores and decide if you need new pistons. Good luck

Thanks for the detailed info. I figured that I would put my order together after the machine shop had a good look at the damage and measured everything.

Is this the wedding ring you mentioned?



Thanks again. This place is a wealth of information. I've been lurking around in the background for a few years in anticipation of getting a inline 6 Mustang (or Falcon) and finally signed up for a login earlier this year. Finally I've got some content to post.

Cheers,
Andrew

 

[awasson]

From the manufacturer of the specific piston rings you choose. They are usually available online if you have ordered but not received them yet, or they are usually packed in with the rings.

Terms like parallel and ball hones are no longer enough. Spec's involve surface finish specifications, and manufacturers will usually give specific type of hone, steps of grits, pressure, angles, clearances, etc. The realization of the importance of dimensions and finishes is much greater today due to options and variations of ring types and finishes, but ensure greater success, sealing and lifespan. This isn't your father's Oldsmobile bore honing.

Good to know. Thanks. It's been many years since I refreshed an engine.

Cheers,
Andrew

 

[awasson]

Sometimes "luck" is on your side. All the running with no oil pump drive and you have that little bit of damage?! Good for you!
Can you post your general location? Members might be able to suggest machine shops with experience in the 200 six depending on where you are. I found a good shop in Westminster, MD, but that won't help much if you are in Colorado.

Yes, Westminster, MD or anywhere in Colorado wouldn't help me out. I'm up in Canada on the west coast. Vancouver BC. I will adjust my info box with those details.