SOHC V6 Timing Chain Saga

Tensioner tool

I decided to convert my old rear tensioner into a tensioner tool to use during my future engine rebuild.

Plan A was to drill a .25 inch diameter hole thru the piston and the housing and then install a .25 inch treaded hex stove bolt with a nut at the piston end to adjust the extension to the desired amount and a nut at the housing end to tighten to compress the piston. I quickly learned that the piston was made of tempered steel and my high speed drill bits would not hardly even scratch it. I purchased a small diameter titanium drill bit just to see how thick the piston was. I was thrilled when the bit broke thru the piston but then puzzled when a firm, black substance started traveling up the bit. I realized that it was hardened sludge that probably had been blocking the oil relief hole in the piston. This situation is another reason to change the tensioner every 75,000 miles. The drill bit made rapid progress thru the caked sludge but then hit something hard. It turns out the piston is not open at the other end.

Plan B was to only drill a .25 inch diameter hole thru the hex head end of the housing, thread the opening and screw a long cap bolt into the housing until it pressed against the inner end of the piston to keep it from retracting. Working my way up in diameter from .125 inches I settled for a 3/16 inch hole since the housing was quite thick and hard. Unfortunately, the housing was too thick and hard for a self tapping bolt to thread the hole.

Plan C was much simpler and easier and I should have thought of it first. I merely cleaned the piston and housing at the area where the two intersect, mixed some two part epoxy and applied it to the piston and housing. I stood the tensioner up vertically so the epoxy would seep into the crack between the piston and the housing. I heated the tensioner with epoxy over one of the burners on my wife's electric range and then took it out to the garage to test it. The arrows in the photo below indicate the location of the applied epoxy.


My tensioner tool was easy to hand thread into the rear tensioner opening. As it increasingly pressed against the guide and tensioned the chain I switched to a 1/4 inch drive torque wrench with a 27mm socket. The epoxy held the piston in place as I increased the torque to 20 in-lbs which is adequate to make the chain taught.

Damper installer

The crankshaft damper retaining bolt is not long enough to reach the crankshaft when the damper is first positioned on the crank. Ford uses a special tool to install the damper. The photo below shows my "special tool" consisting of an on hand 36mm 6 point socket and a 4 lb hand sledge hammer.

The socket is larger in diameter than the damper retaining bolt head and it's round seat. I "tapped" the socket with the hammer until the damper was far enough onto the crankshaft that the retaining bolt could screw in at least a half inch to eliminate the possibility of stripping its threads. I continued tapping and screwing until the damper was seated on the crank. I will not be able to torque the bolt to the specified value until the flexplate is installed since I don't have a strap wrench to hold the crank from rotating.

Priming the oil pump

If the oil pump has been removed for any reason it should be primed before starting the engine. Otherwise, it will be filled with air and may not draw oil from the pan for an extended period. A convenient method of priming the pump is when the engine is inverted just prior to installation of the lower oil pan as shown in the photo below.

Simply pour engine oil into the oil pickup tube and then manually rotate the crankshaft until oil is pumped out the port for the spin on oil filter. Install the pan and rotate the engine on the stand to an upright position. Do not rotate the crankshaft unless there is at least several quarts of oil in the pan. Otherwise, air will be drawn into the pump as it forces out the oil and the pump will lose it's prime.

Actually, I was kinda curious about how to prime the oiling system on a 4.0L SOHC. My Explorer has been sitting for almost 2 years, so I would really like to prime the system before I start it, but I'm not sure how. Obviously, if it had a distributor, I could pull that, and use a priming tool and drill, but no such luck with the SOHC.

So, how would you go about priming the oiling system, if the motor weren't out and partially disassemble, like yours?

Priming the oil pump is a problem...

Back in the day when I was much younger one of the tools that we used to do to ensure the oil pump primed was to pack the oil pump gears with lubriplate...

For those who don't know what this is Lubriplate is a lightweight white engine assembly grease that blends with the engine oil as the temperature rises but stays in place before the engine is started...

We did this when we built engines that sat for days or weeks before being used and there wasn't time to pull the distributor to spin the oil pump to prime it... I can't remember ever not getting an engine to prime itself and supply oil throughout the engine within seconds of spinover and initial startup...

On the SOHC, isn't there an oil pump drive that runs off the jackshaft at the back of the block? Something that looks like this...

Pre-oiling

The problem of oiling the engine prior to starting after a rebuild or an extended down period has puzzled me since I started this timing chain saga. It's a problem I'll solve for the future rebuild with the addition of my Accusump. I'll just make sure that the accumulator is pressurized and the valve closed before shutting the engine off and tearing it down. After the rebuild I'll open the valve to pressurize the engine oil system just prior to restart. The problem is getting thru this engine start without starving the bearings of oil.

The priming is just to make sure the pump immediately draws oil as soon as the engine starts. ranger7ltr is correct that there is a drive gear for the oil pump that can be removed. It's access location is shown in the photo below.

The red arrow identifies the bolt that presses a retaining cap against the drive access cover. I removed the bolt and retaining cap but even with the engine out and the upper intake manifold removed I was not able to get the cover off. I can't imagine anyone being able to do it with the engine in the vehicle.

Years ago a home mechanic could rent an electric oil pump at a tool rental shop to pressurize the oil system on a rebuilt engine. I may end up trying to locate one if I don't come up with an alternative.

One thing I'm considering is to fill my Accusump by using my hand vacuum pump and then using a hand tire pump to pressurize the air chamber.

Another idea is to just take apart a tube/tire hand pump, fill it with oil and use the plunger to force the oil into the engine. I already have a "T" at the oil filter sandwich adapter with a hose for the Accusump. I installed that when I added my remote oil filters. Even if you have a sandwich adapter for a remote oil filter, a one way check valve must be installed in addition to the "T" to force the oil to flow into the gallery instead thru the remote filter, into the oil pump and to the oil pan. The photo below shows my block adapter with the check valve prior to pulling the engine.



For those that don't have a sandwich adapter the only oil port available that I know of is at the oil pressure switch which is hard to access. Ford didn't make it easy to pre-oil the engine.

2000StreetRod said:

... I'll just make sure that the accumulator is pressurized and the valve closed before shutting the engine off and tearing it down. ...

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Think about that and the oil you will be using then. You don't want any synthetic oil to start into the new engine. You can change to conventional oil on the last oil change or two.

I won't install my external filters or electric oil pump until I swap my new engine in. I do look forward to that though, I plan to wire the pump into the start circuit and an oil pressure switch. With a switch under hood to provide choice, I plan to wire mine so the starter never runs until there is oil pressure. That should make turning the key interesting, and different.

Conventional oil for break-in

CDW6212R said:

Think about that and the oil you will be using then. You don't want any synthetic oil to start into the new engine. You can change to conventional oil on the last oil change or two.

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Good point Don! I hadn't thought about that.

CDW6212R said:

I won't install my external filters or electric oil pump until I swap my new engine in. I do look forward to that though, I plan to wire the pump into the start circuit and an oil pressure switch. With a switch under hood to provide choice, I plan to wire mine so the starter never runs until there is oil pressure. That should make turning the key interesting, and different.

Click to expand...

Initially, my Accusump will be wired so that the solenoid valve is open when the ignition is On and closed when the ignition is Off. There will also be a toggle switch is series with the wire from the ignition to the solenoid to prevent the valve from opening when the ignition is On. I want the oil to discharge from the cylinder before the starter is engaged.

Prototype Manometer TDC finder

This morning I scrounged together the parts to assemble a prototype manometer style TDC finder as shown in the photo below.

I used the spark plug adapter from my compression tester. The two plastic fittings and short hose were part of my hand vacuum pump kit. The hose adapter reduces the hose inside diameter to 3/16 inch to increase the sensitivity of the device.
The photo below shows the tube with oil in place on the engine.

Determining the TDC using the oil movement was repeatable within 1 degree and agreed with the crankshaft position sensor pointer/crankshaft damper as well as my crude method using a square and the flat on the bottom of the connecting rod big end. I believe the manometer method is just as accurate as the piston stop method and much more convenient.

Rear guide missing pieces found!

When I cleaned the sludge from the oil pickup tube I found the missing pieces from my fractured rear timing chain guide. They were trapped in the pickup tube screen at the extreme edges and caked with sludge. They came loose when I was using a stiff bent wire to clean the screen. I no longer have to worry about them being lodged somewhere in the engine potentially blocking oil flow to a bearing!

Question on the oil pump drive...

Even though I don't have a SOHC block the oil pump is the same and I am about to install a new shortblock this weekend...I have been looking for a primer shaft to pre oil the new engine and can't find one..

Can anyone remember and/or look at their oil pump or driveshaft and see if it a hex drive or is it splines or what? The shortblock is a Motorcraft unit and it has been sitting for a while and I need to ensure the bearings all have oil before I light it off..

Splined oil pump drive

ranger7ltr said:

Even though I don't have a SOHC block the oil pump is the same and I am about to install a new shortblock this weekend...I have been looking for a primer shaft to pre oil the new engine and can't find one..

Can anyone remember and/or look at their oil pump or driveshaft and see if it a hex drive or is it splines or what? The shortblock is a Motorcraft unit and it has been sitting for a while and I need to ensure the bearings all have oil before I light it off..

Click to expand...

As I recall it has splines at both ends with a circular clip at midway to limit its up/down travel.

I can't stand it anymore. I'm coming over to help you clean that engine. (where are you at anyways?) Then we're going to paint it nice and pretty. You can't pull that motor out and put it back in like that.

FYI - and possible for your future rebuild...
Keith Black sells improved hypertech pistons for our motors. (see summit racing) The pistons go thru a heat treat process that is said to strengthen them by 30% over the traditional hypertech pistons. They also have coated skirts. I haven’t seen the tops of the pistons but I bet their free from any sharp points. If it were me, I’ll probably get the piston tops coated with ceramic. (force feed) but for a regular NA engine they should serve a person well.

Anyways, back on topic....

External cleaning & paint, pistons

Jakee said:

I can't stand it anymore. I'm coming over to help you clean that engine. (where are you at anyways?) Then we're going to paint it nice and pretty. You can't pull that motor out and put it back in like that.....

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I plan to clean the exterior before installation but not until I get it reassembled. I almost purchased a spray can of traditional Ford blue but realized it would all come off in the hot tank during the rebuild.

Jakee said:

FYI - and possible for your future rebuild...
Keith Black sells improved hypertech pistons for our motors. (see summit racing) The pistons go thru a heat treat process that is said to strengthen them by 30% over the traditional hypertech pistons. They also have coated skirts. I haven’t seen the tops of the pistons but I bet their free from any sharp points. If it were me, I’ll probably get the piston tops coated with ceramic. (force feed) but for a regular NA engine they should serve a person well.

Anyways, back on topic....

Click to expand...

I read the SuperSix technical writeup about the SOHC engine regarding strengths and weaknesses. They were not impressed with the stock head bolts, pistons, valves and head gaskets. I will consider upgrading all of those during my rebuild.

Today I will be spraying about 5 quarts of my old full synthetic motor oil into the head openings to flush some of the Gunk loosened sludge into the newly installed oil pan. Then I'll install the valve covers, drain the oil, and then add new oil.

Another question about your engine...

When you removed the 4 torque convertor nuts, does the convertor push back and out of the flexplate or do the convertor studs stay stuck through the flexplate holes? I am about to remove my shortblock and cannot get the convertor studs to push out of the flexplate holes...

Found a solution...

2000StreetRod said:

As I recall it has splines at both ends with a circular clip at midway to limit its up/down travel.

Click to expand...

Ford just had to be different and use splines for the oil pump and the driveshaft...Well after wasting time this morning looking for a oil pump primer tool for this one, I found the solution in my toolbox!!!

Using a 7 mm socket on the end of a long 1/4" extension inserted into the hole will engage the flats on the splines enough to drain the oil pan if I choose to with a power drill...

I am letting some bolts soak in PB blaster right now and eating lunch, but I will be at a point to pull the old shortblock and insert the new one late today or first thing in the morning...

At least when I button up the topend and before inserting the cam syncro, I can get proper oil flowing throughout this new Motorcraft shortblock...

I will post pics later...

Yes, I'm pretty sure the guy that wrote that article was Tom Yentzer. (not sure I spelled that correctly) The article is actually pretty old info. I've read it a few times. I also know of a lot of people that have went with the supersix combo. That combo uses the stock rods. If you’re planning on taking the power that high, don't try to use the stock rods - they will break. Hypertech pistons are not known to be friendly with any type of boost but there’s also the older tricks that still apply. Any sharp edges on the top of piston will get hotter quicker than the rest of the piston, and can cause the unfriendly detonation problem. I think the hypertech type piston is pretty strong but is not forgiving when detonation occurs. So to me the solution is to not allow detonation of any kind. This is why TUNING is so important. This is also why the piston top coatings are so popular now. It’s sort of like the space shuttle during re-entry. Ceramic is what keeps the heat at bay. And I don’t think the shuttle nose is forged either. The tops of our pistons look alright to me but the edges (where the chamfers are) are sharp.

Head studs? Yes, ARP studs would give added insurance. Then again, I haven’t heard of the stock head studs giving up, or the head gasket, but I wouldn’t take the chance either. Again, it’s usually the rods that break. I’m sure there are those that have blown head gaskets from some reason or another. (you’ll always have your unique failures when you have a million people with a million different variables)
The rod bolts are small in my opinion. Supersix shot peens the rods and adds bigger rod bolts. Still they won’t make it long under higher HP levels. When I say higher HP, I’m talking 450+. I want to make sure I don’t sound like I’m saying Supersix parts are no good because they are good. It’s not their fault.

I realize I’m getting way off topic now because I don’t think this type of info was the intent of this thread. Just let me know and I’ll come back in and delete later.

Studs pressed into torque converter

ranger7ltr said:

When you removed the 4 torque convertor nuts, does the convertor push back and out of the flexplate or do the convertor studs stay stuck through the flexplate holes? I am about to remove my shortblock and cannot get the convertor studs to push out of the flexplate holes...

Click to expand...

The studs are pressed into the torque converter. The torque converter can only move toward the engine, not away from it. If you're not careful, it will come off when you pull the engine away from the transmission. My engine was higher than the transmission so I didn't have a problem. Otherwise, you have to wire it in place or it might slip off. Don't forget to mark one of the studs and holes so you can return the flexplate and torque converter to the original position.

I had a little problem with the dust cover/spacer sticking to the bell housing and the transmission. I had to pry the two apart a little to get it to break free.

Don't lose the socket!

ranger7ltr said:

Ford just had to be different and use splines for the oil pump and the driveshaft...Well after wasting time this morning looking for a oil pump primer tool for this one, I found the solution in my toolbox!!!

Using a 7 mm socket on the end of a long 1/4" extension inserted into the hole will engage the flats on the splines enough to drain the oil pan if I choose to with a power drill...

I will post pics later...

Click to expand...

Clever idea! The circular clip should keep the oil pump drive shaft from coming up with the socket when you extract it. How are you going to keep the socket from separating from the extension if the socket should stick to the splined shaft end?

Sacrificial Socket and 3/8" extension...

I will weld the 7mm socket to the long extension just in case the socket should get stuck to the driveshaft and I need to use force to remove it...

I am kinda concerned that the convertor will not push forward and the studs out of the flexplate holes...I got them loose but I cannot move the convertor out of the flexplate at all and this is different than any other tranny I have worked with...