SOHC 4.0 general engine timing - TDC

[Vette76]

After a LONG time working on replacing both front and rear timing cassettes (and not working on it over the Winter) I'm finally at that point where I'm in the last week of this project

I would like some advice before I turn the key. I have timed both camshafts and I think I have it right. However, here's my issue:

I got the engine on the compression stroke for the #1 cylinder. As the instructions state for the crankshaft timing tool at this point when you're on the compression stroke, "rotate the crankshaft counter clockwise until the crankshaft timing tool is in place". When I do that, which requires the wider slot on the damper to be almost exactly in the 12 o'clock position relative to the engine block, I watch the timing marks on the damper move past the pointer on the crankshaft positioning indicator. In fact, I watch the 10 degree mark go by and then the 0 degree mark and where it lands (which is the only place where the crankshaft timing tool will fit properly underneath and up against its resting place under the block) is roughly 5 degrees "before" the 0 mark on the damper.

I don't know if this is right or not but I have done this a dozen times to see what I come up with and the damper is in the only position that it can be with the timing tool on and seated properly.

Any thoughts?

 

[Sedition]

Sohc tdc

I prefer not to use the timing tools because it keeps my mind sharp.

Firstly set both of your camshafts to TDC using the slot in the rear of the shafts.
Have the smaller half of the slot facing downwards.
Place a 6mm Hex Wrench in the slot.
Take measurements from the mating surface on the top of the head to the bottom edge of the Hex Wrench at equal distances from the center of the camshaft outward along the Hex Wrench. I can't remember what the measurements are but they MUST be equal. Make this measurement as acurate as possible.
Place two pairs of vice grips on the camshafts to lock their position.

Secondly attach your new timing chain cassettes, leaving the camshaft bolts loose.
Tighten the Jackshft bolts.
Because you already have the timing tools use the tensioner looking tool in the tensioner hole in the side of the head to place tension on the jackshaft to camshaft chains.


Thirdly set your Crankshaft to TDC as indicated by the crank angle sensor bracket and the 0 degree mark on the harmonic balancer. Please note: the crankshaft in the following picture is set to 12 degrees retarded, not TDC.

Lastly recheck position of camshafts and crankshaft then tighten the camshaft bolts. Your crankshaft won't move because you have held your camshafts directly.

Remove the tensioner looking tool and install hydraulic tensioner.

Fill with fresh oil and rotate crankshaft by hand to build oil pressure in oil galleries and tensioners. Also to enjoy first hand a freshly timed SOHC engine...

 

[Vette76]

Sedition - I love the hex wrench idea! Good thinking.

I'm going to give that a thought. I have the timing tool but that crankshaft timing tool is basically garbage. If the angle of that tool is a fraction off (and it's hard to figure out what is the right application) it throws the angle off on the camshaft timing slot.

I think I'll time it with the tools and then give the hex wrench method the final check.

Thanks!

 

[jmcgarvie]

upside down

ok i timed the same engine with the cams upside down from the way you describe but if you turn the engine over 360% it is the other way dose it matter when there is no distributor

 

[2000StreetRod]

tool set?

I assume that you did not use the OTC 6488 timing tool kit to time the camshafts since it would not fit properly with the camshafts 180 degrees off (upside down). Be advised that when the tool kit is not used, the tension on the chain from the spring tensioner is not adequate to keep the chain taught on the traction side. The tensioner spring is weaker than the valve spring when a valve is extended. Consequently, the timing may be a few degrees off from designed timing.

If both camshafts were timed 180 degrees off without moving the crankshaft from TDC then I can't think of any reason there would be a problem. The "nub" on the left bank camshaft notifies the PCM when the camshaft is on the compression stroke for #1 piston. In your case the camshafts were timed with #1 at TDC on the exhaust stroke. I strongly encourage you to check the timing with #1 at TDC on the compression stroke before cranking the engine with the starter.

 

[FordRanger04]

I assume that you did not use the OTC 6488 timing tool kit to time the camshafts since it would not fit properly with the camshafts 180 degrees off (upside down). Be advised that when the tool kit is not used, the tension on the chain from the spring tensioner is not adequate to keep the chain taught on the traction side. The tensioner spring is weaker than the valve spring when a valve is extended. Consequently, the timing may be a few degrees off from designed timing.

If both camshafts were timed 180 degrees off without moving the crankshaft from TDC then I can't think of any reason there would be a problem. The "nub" on the left bank camshaft notifies the PCM when the camshaft is on the compression stroke for #1 piston. In your case the camshafts were timed with #1 at TDC on the exhaust stroke. I strongly encourage you to check the timing with #1 at TDC on the compression stroke before cranking the engine with the starter.

WOW, I'm very impressed with your knowledge of the 4.0 SOHC. I have a 2001 4.0 and I just bought the OCT 6488 tool kit.
I want to do this, but I'm a little intimidated, Is there any YouTube videos in English on how to do this. There's one in Spanish but I don't know that language. If someone could help me out with this I would donate them some coins.

 

[FordRanger04]

Bump
I would seriously pay someone to show me how to use the OCT tool kit and install some new timing chains and guides.

 

[jmcgarvie]

I dont have the issue any more but i have an old engine that i could take a vidio of

 

[JustanOilman]

For Sedition:
I realize this is an old post and I may not get a reply but it's worth a shot, and thanks in advance for any help you can provide.
I currently have the pleasure of repairing a broken chain guide on my Explorer. I am only doing the drivers side but did check out the passenger side which looks ok, and I don't want to pull the motor. I got a little carried away taking things apart and did not mark any cam or chain positions, which after doing more research into this nightmare of engineering, wish I had. I did not make any changes to the passenger side chains or cams. So what I am replacing is the drivers side cassette, chain, cam sprocket, Jackshaft sprocket, Jackshaft chain and left and right side chain guides.
Your timing system looks to be the easiest way to go after much internet research.
What I would like to know is:
1) Is #1 set to TDC compression stroke with crankshaft key at 12 o'clock first?
2) I do not have the "Tensioner Looking Tool", what do you use to apply the necessary tension?

 

[cathyvan]

just replaced both cylinder heads on my 2004 ford explore sohc, the time chains were not taking off, but the timing had moved after the left head camshaft bolt was being taking off, the new heads are on and need help on getting the setting back to the right mark. but with the new heads and over head cams, not sure how to do this to make sure they all line up right, the #one cam is all the way to the top and the #5 . but the two dots on the balancer shaft sprocket are not lined up to the hole on the reversal shaft at the bottom for the timing, does anyone have a solution on setting this right?

 

[2000StreetRod]

balance shaft timing

It can take multiple revolutions of the crankshaft before the balance shaft marks align. If you did not remove the balance shaft chain or the crankshaft sprocket that drives the balance shaft chain the balance shaft timing should still be correct.

It is not possible to remove the heads without disconnecting the camshaft sprockets. I also doubt it is possible to remove the heads without removing the timing chains from the camshaft sprockets. So I assume you meant that you did not disconnect the chains from the jackshaft sprockets. There are no timing marks on the camshaft sprockets. There are only timing slots on the end of the camshafts.

Do you have the OTC 6488 timing too kit?

There is information on timing the camshafts in my helpful threads.

 

[JustanOilman]

Streetrod, I have read all of your info on the SOHC marvel of engineering, and appreciate that you share your expertise with others, thank you very much. I am currently working on my step sons 1998 Explorer and have it to the point that the timing needs to be set. I had to replace the drivers side valve cover and timing cassette after a broken chain tensioner came out through the valve cover. The passenger side stuff looks ok so I left it as is. My question is, do I need to loosen the passenger side cam bolt in order to get the timing set? So basically I removed and replaced all of the chains, sprockets etc that I could on the front of the engine. I do not have the Ford tool kit and want to time the cams using your method. I have been reluctant to go any further on this until I know for sure I'm doing it right. Any insight you can share is greatly appreciated, thanks in advance.

 

[2000StreetRod]

must retime both camshafts

If you replaced the left (driver side) camshaft timing chain then you must have removed the jackshaft front sprocket.

That means that the jackshaft relationship to the crankshaft was lost. Therefore the right (passenger side) camshaft must be timed in addition to the left camshaft. The camshafts can be timed without the OTC 6488 tool kit but the timing may be off a few degrees without using a tensioner for the chains. The spring pressure of the hydraulic tensioners cannot overcome the compressed valve spring pressures. Since I couldn't find a bolt the same size and thread of the tensioners I used my old one after applying epoxy to the piston and cylinder so it wouldn't move from the extended position. If you didn't replace the hydraulic tensioners then you can't use my method. However, many forum members have timed their engine just using the spring tension and not reported any noticeable performance difference.

Because of the restricted space between the firewall and the right camshaft sprocket retaining bolt head it will be difficult to use a torque wrench with a socket. Normally the engine front cover is installed before timing the camshafts because the balancer marks and the timing pointer are used to determine TDC. In that case the right and left camshaft sprocket retaining bolts must be loose to allow rotation of the crankshaft and jackshaft without rotating the camshafts. The right camshaft could be timed without loosening the sprocket retaining bolt if there is an accurate way to determine TDC on cylinder 1 and the crankshaft can be prevented from rotating when tightening the jackshaft front sprocket retaining bolt. I've never tried it that way but it might be possible. It's probably best to follow the standard method so you'll have to devise a way to keep the camshaft from rotating when you loosen and tighten the camshaft sprocket retaining bolt. I do not recommend using the plastic inserts under the camshaft bearing caps. It is too easy to bind the caps when tightening them and break one. If you break a bearing cap you'll need a new head. Many members have been successful using the adjustable locking pliers method. Some members have built a timing slot holder equivalent to two of the tools in the kit. Remember that the right camshaft sprocket retaining bolt has left hand threads (tightens counter-clockwise when facing the head of the bolt). Some members have broken the bolt attempting to loosen it in the wrong direction. Another caution is that many "click type" torque wrenches do no click when tightening counter-clockwise (mine doesn't). I use a deflection bar torque wrench on left hand threads.

 

[JustanOilman]

Thanks for your prompt reply StreetRod. I will attempt to do the job in the next few days. You are correct, I did remove the Jackshaft sprocket. I will replace the hydraulic tensioners, as they came in the kit. I'm a bit of a McGuyver type guy and just thought of a way to provide the tension needed that you described with the epoxy idea. How about using the old tensioner and drill a hole in the top of it and thread the hole for a bolt, install the old tensioner and then tighten the bolt as much as needed so it pushes against the bottom of the tensioner to provide the needed tension? Then keep it as a tool in your special tools collection. How much tension needs to be put on the chain? I have a vacuum/pressure gauge that screws into the spark plug hole to determine TDC. Do you know where I can get all of the recommended torque specs for the engine? I found a wrench set that should work great on that hard to get at cam bolt, open end/box end with a swivel head that ratchets.

 

[2000StreetRod]

hard metal

I had a similar idea and tried enlarging the oil pressure relief hole in the piston. The metal is very hard and I could not drill it. The first time I just used a socket as a spacer and tightened the old tensioner to 20 in-lbs. See post 280 of SOHC V6 Timing Chain Saga

Then I resorted to epoxy. See post 301 of SOHC V6 Timing Chain Saga

If you decide to use the epoxy method use the old front tensioner. It is longer than the rear and will work in both positions as a tool. I have all of the torque specifications and should probably generate another helpful thread with them listed.

 

[JustanOilman]

Did you try drilling with a cobalt bit? I did a project a little while ago using stainless steel and went through several titanium bits before switching to cobalt, cobalt bits went through the stainless like butter.

 

[2000StreetRod]

titanium bit

I think my bit was titanium. I'll remember about cobalt for future use.

I've started generating a torque specification thread. I should everything you need listed by tomorrow.

 

[JustanOilman]

I drilled out the tensioner with no problem, tapped the hole and it works perfect. Not sure how to upload pics on here but I'm sure you can picture it.

 

[2000StreetRod]

SOHC V6 Torque Specifications

Nice going! Another low cost, creative "precision tool".

I've posted most of the SOHC V6 torque values: SOHC V6 Torque Specifications I started with the Haynes values because they were easily available. Now I'm comparing them to my workshop manual and correcting as required.

I can't remember if I've sent you a copy of the SOHC V6 assembly instructions. If not, PM me your email address and I'll send it to you.

 

[MtExplorer Guy]

I am going to resurrect this for a moment, 2000street, you have been offering advise on the other thread I have been posting to, I have a question..... When I pulled down my motor, I took both front sprockets off and replaced the chains and the left hand cassette and timed the left hand cam shaft, BUT, I did not do anything on the right hand side, if I am reading this correctly, you have to time both cam shafts if you pull the front sprockets on the motor?, so I need to pull the intake and BOTH valve covers to to both cam shafts? If so, that is my problem as I did not do anything to the passinger side when I put this back together..