[Motorhead4Ever]

Hey Ed--- I did get my chrome- moly tubing to create the spacers to eliminate the rachets on my tensioners. I finally got a local machinist to cut it to the 0.200 length. In the interim I had contacted Tim Elchhorn from MPR in Boyton Beach to see how he addresses this with his engine builds. He advised me as long as the rachet does not extend out from the top more than 7/8th's of an inch the rachet can be removed and no spacers are necessary. He says the spacers can be more disasterous than the rachets in snapping chains and has seen this first hand at his shop. It would be great if some others would chime in on this -that have done this modification and race a bit with a two step. I want to button up my engine and get it back in but now I'm wondering which direction I should go. Life can be a conundrum for sure----Thanks


Can Do

 

[painlessauto]

For what it's worth. I ground the ratchets off but left the ratchet posts on to prevent the plungers from flying off during future disassembly. I used custom spacers that gave me .040" plunger freeplay. I'm running an iron 5.4 block twin turbo build with 7200 rpm max. So far so good. I'm not running a 2-step

Matt

 

[eschaider]

This is a long-standing Hyland modification that has been used for at least 20 some odd years. Properly sized (i.e., 0.200"), they will exactly pick up the slack in a brand-new chain with the engine off. Grinding down the ratchet arm teeth provides a similar but different function.

Without grinding down the ratchet arm teeth, the ratchet will stay extended to whatever length the chain stretched to at high engine speed. So while the plunger on the tensioner will retract, the ratchet foot will not because of the ratchet teeth. The Idea of grinding down the teeth came about as a way of allowing the ratchet to compress back into the tensioner casting and not hold the chain under tension with the engine off.

The problem with this is that the hydraulic piston will compress to the amount the internal spring allows. After your engine has some miles on it, this can represent enough slack to make noise and create potential problems in the engine before the oil pressure rises to the point it extends the piston and pushes the tensioning arm against the chain. You are probably OK the majority of the time. It is the one or two times you are not OK that are problematic.

The spacer never lets the piston retract to the bottom of its well and, at 0.200", maintains a very light tension on the chain with the engine shut off. This mod will not break timing chains. What breaks timing chains is two-step launches that load and unload the cam drive chains as the engine tries to maintain a predetermined launch rpm. The on-again, off-again whipping of the drive chains eventually will break a link somewhere. Two steps with or without the tensioner mod are tough on timing chains. The tensioner mod is designed to maintain a minimum tension on the primary drive chains when the engine is shut down, so the next start is clean and silent. It absolutely will not hurt a primary chain — look at the mechanism and think about how it works.

Cutting teeth off the ratcheting arm will prevent the chains from being held in a stretched and tensioned condition after racing. Removing the ratcheting teeth will not prevent the piston from settling down at spring height or possibly lower after shutdown. The 0.200" spacers will.

When you assemble the tensioner and install it for the first time, you will discover it is best to install a single bolt, compress the plunger in its well, and rotate the tensioner into position. Once in position, put the second bolt in and begin to screw it in while holding the plunger compressed and the tensioner in position. While one person can do this after they develop a little skill for the task, it is much easier with a third hand. You will know what I am speaking about the first time you do an install.

The 0.200" spacers will give you about but a little bit less than what Matt has for free play in his setup. The decision to run the ratcheting arm is a personal choice. If something is not necessary, I tend not to use it. If you choose to, make sure you get enough teeth ground down so it is not accidentally standing proud when you don't want it to.

 

[Motorhead4Ever]

For what it's worth. I ground the ratchets off but left the ratchet posts on to prevent the plungers from flying off during future disassembly. I used custom spacers that gave me .040" plunger freeplay. I'm running an iron 5.4 block twin turbo build with 7200 rpm max. So far so good. I'm not running a 2-step

Matt

Thanks Matt for taking the time to reply to this post-- I am going to run mine without rachets and just be careful not to send them into space upon disassembly.

Can Do

 

[Motorhead4Ever]

This is a long-standing Hyland modification that has been used for at least 20 some odd years. Properly sized (i.e., 0.200"), they will exactly pick up the slack in a brand-new chain with the engine off. Grinding down the ratchet arm teeth provides a similar but different function.

Without grinding down the ratchet arm teeth, the ratchet will stay extended to whatever length the chain stretched to at high engine speed. So while the plunger on the tensioner will retract, the ratchet foot will not because of the ratchet teeth. The Idea of grinding down the teeth came about as a way of allowing the ratchet to compress back into the tensioner casting and not hold the chain under tension with the engine off.

The problem with this is that the hydraulic piston will compress to the amount the internal spring allows. After your engine has some miles on it, this can represent enough slack to make noise and create potential problems in the engine before the oil pressure rises to the point it extends the piston and pushes the tensioning arm against the chain. You are probably OK the majority of the time. It is the one or two times you are not OK that are problematic.

The spacer never lets the piston retract to the bottom of its well and, at 0.200", maintains a very light tension on the chain with the engine shut off. This mod will not break timing chains. What breaks timing chains is two-step launches that load and unload the cam drive chains as the engine tries to maintain a predetermined launch rpm. The on-again, off-again whipping of the drive chains eventually will break a link somewhere. Two steps with or without the tensioner mod are tough on timing chains. The tensioner mod is designed to maintain a minimum tension on the primary drive chains when the engine is shut down, so the next start is clean and silent. It absolutely will not hurt a primary chain — look at the mechanism and think about how it works.

Cutting teeth off the ratcheting arm will prevent the chains from being held in a stretched and tensioned condition after racing. Removing the ratcheting teeth will not prevent the piston from settling down at spring height or possibly lower after shutdown. The 0.200" spacers will.

When you assemble the tensioner and install it for the first time, you will discover it is best to install a single bolt, compress the plunger in its well, and rotate the tensioner into position. Once in position, put the second bolt in and begin to screw it in while holding the plunger compressed and the tensioner in position. While one person can do this after they develop a little skill for the task, it is much easier with a third hand. You will know what I am speaking about the first time you do an install.

The 0.200" spacers will give you about but a little bit less than what Matt has for free play in his setup. The decision to run the ratcheting arm is a personal choice. If something is not necessary, I tend not to use it. If you choose to, make sure you get enough teeth ground down so it is not accidentally standing proud when you don't want it to.

Thanks Ed for clarifying the cause of the failure -- the whipping chains caused by the two step---not the modification itself. I will be installing those spacers once in hand.

Can Do

 

[eschaider]

There is another follow on failure attributable to the sustained chain loading when the engine is shut down.

The sustained chain loading stresses all the links and anchoring pins in the silent driver chain, which is undesirable. It also does something else that is damaging in the extreme. When the engine shuts down, and the primary drive chain tension is not released because of a locked ratcheting plunger, it loads the front cam journal on both sides of the engine pinching off the oil film. The front journal on the driverside is at the end of the lubrication food chain and gets oiled last.

When the engine shuts down, and the primary drive chain tugs downward on the cam nose because the tension has not been released, in the now pinched off oil film between the cam and the head, the #1 cam journal experiences metal-to-metal contact. The repeated metal-to-metal contact continues at each new start and roughs up the cam and the journal bearing in the cam saddle. The cam eventually seizes in the head, and the broken chain, bent valves, and broken guides damage saga plays out.

If you check, many, if not most, broken chain histories will almost always have a seized cam journal in the litany of damaged parts — for the reasons we are talking about. There are three things you can do to mitigate this;

• The Tensioner Mod we have been talking about,
• Use of an Oil Accumulator,
• Use of an oil additive — I highly recommend ProLong

The Oil Accumulator is not widely used or recognized. Canton offers them under the trade name Accusump™ and Moroso as an Oil Accumulator. They can be installed to perform two different functions. The first function is pre-oiling the engine before startup. Both firms offer a kit to allow the oil accumulator to flush into the engine prior to startup. This will protect those tender cam journals that get oiled last. Their second function is to protect from uncovering the oil pickup and drawing air into the lubrication system.

After the accumulator is set up, for example, to discharge below the engine's operating oil pressure, say 45/50 psi, when the oil sloshes to the back of the pan, for example, exposing the pickup, the oil accumulator will begin to discharge its supply of oil into the oil system making up for the temporary reduction in oil volume or quality to the bearing surfaces.

Oil accumulators come in various sizes up to a 3-quart capacity. In general, they only hold about 1/2 of that capacity. Their design uses an o-ring sealed piston with air behind it at atmospheric pressure. As the engine runs, the oil pump pumps oil into the engine, and the accumulator pushes the piston up against the air-filled chamber, compressing it to a pressure equivalent to the engine's oil pressure. Fully compressed, about half or a bit more of the cylinder is oil and the other half is compressed air, so your three-quart accumulator is actually 1.5 quarts or a bit more. Buy the big unit. These things are a poor man's dry-sump!

ProLong and other oil additives are an emotionally charged topic. I was historically an anti-additive guy. I got talked into using ProLong at an NHRA event decades ago — it saved an engine for me, at that event. I have been a ProLong bigot ever since. If you elect to use it buy the gallon bottles off Amazon for $65. They are a better deal than the 12 oz auto parts store bottles for $20.

 

[Motorhead4Ever]

Thanks again Ed for helping myself and others to protect a big investment--I'm going to do all three of the bullets you listed as a fail-safe for my new engine. I want her to live a long and healthy life .

Can Do

 

[KEVINS]

I can imagine when the chain gets hot during operation it is a tad longer than when it cools off possible getting shorter. If so this will also apply more force on the cams/parts during cool down, etc..

ks

 

[Dave R]

I just experienced both secondary chains breaking and my intake cam's seizing up. I don't want a repeat with my new heads and engine. Where can I see and read more on this tensioner mod? I will surely purchase the additive. I believe in some and not others. Never heard of this so I'll give it a shot.

Thanks
Dave

 

[eschaider]

The tensioner mod is in the TToC Dave under the Engine section. It is nine posts from the bottom immediately before the Crank Tech I & II postings.

 

[Dave R]

I'm an idiot. Tech Table of Contents under the 96-98 cobra page? I don't see an "Engine" section unless I'm in the totally wrong forum.

 

[eschaider]

No, you are not, Dave. Check the TToC in the 03/04 SVT Cobra Forum

 

[Dave R]

And there it is. Time to read. I think this is valid. I've seen lots of people with this problem and it's been mostly assumed that the heads take alot of oil and they starve the pan and then the cams seize, breaking the chains. This sounds more viable. Thanks for the help!

 

[Dave R]

Got it. I saw a set of those for sale somewhere and wondered what they did. Do you make them? What would a set cost me?

 

[Motorhead4Ever]

Ordered my Gallon jug of Prolong engine treatment today from ebay for $68 --my machinist told me it would be the middle of the next week before my spacers are ready-- getting 5 sets cut. Will always have a set of these spacers on hand from now on. The 3 qt. Canton Accumulator is next on the list. Ed told me about Mcmasters - Carr for the Chromemoly tubing necessary to make the spacers happen- 3/4 OD x 0.095 ID x 0.200 in length chamfered on both ends.The tubing was around $22.00. I had an engine failure too and am nearing the completion of my new build and looking forward to getting my car back together-- now scattered in pieces in my shop.

 

[Motorhead4Ever]

You can get a set of cloyes left and right tensioners for about 115.00 shipped or contact Ford Performance for theirs. I do not know how much they charge. You will still need to remove the rachets and have machining costs for the spacers unless you have a lathe and can do this yourself. I believe the cloyes part #'s are 9-5338 and 9-5339 respectively. This is my first experience with this mod and Ed is the to go guy for anything you need to know for this and anything else you need to know about your combination--- The only tensioners I have seen without a rachet is the plastic 03/04 cobra style which in my book are an accident waiting to happen. I have a set of these and have never used them for fear of them cracking under chain loads.

Can Do

 

[Dave R]

I have the cast ones from a 94 Mark VIII engine (my shortblock is from there). I'll see if we have any of that tubing in our metal cage. Thanks!!

Dave

 

[eschaider]

Got it. I saw a set of those for sale somewhere and wondered what they did. Do you make them? What would a set cost me?

I don't make them, Dave. They are pretty simple to make, as you can see in the post. The problem is access to a lathe. The easiest way to get them is to go to a machine shop and ask him to make two spacers 0.750" in diameter that are 0.200" long. Use 0.120" wall tubing. Unfortunately, a lot of the stuff floating around was made by someone who never had access to an original part from Hyland or a copy of his print for the part, and most importantly, they do not know how to determine the proper length. As a result, they are all over the map length-wise, making them bad choices. If you point out the length whoops to whoever is selling them, the attitude is frequently something like, 'who made you the arbiter of length for these?' Don't waste your time, go out and get a set made properly — it is cheap money.

 

[eschaider]

Ordered my Gallon jug of Prolong engine treatment today from ebay for $68 --my machinist told me it would be the middle of the next week before my spacers are ready-- getting 5 sets cut. Will always have a set of these spacers on hand from now on. The 3 qt. Canton Accumulator is next on the list. Ed told me about Mcmasters - Carr for the Chromemoly tubing necessary to make the spacers happen- 3/4 OD x 0.095 ID x 0.200 in length chamfered on both ends.The tubing was around $22.00. I had an engine failure too and am nearing the completion of my new build and looking forward to getting my car back together-- now scattered in pieces in my shop.

Not that it is a lot of money, Tom, but when I made mine, I forgot to check aircraft spruce for 4130 tubing. Had I gone to aircraft spruce the tubeing would have been a bit cheaper but not a lot.

 

[eschaider]

I have the cast ones from a 94 Mark VIII engine (my shortblock is from there). I'll see if we have any of that tubing in our metal cage. Thanks!!

Dave

The cast iron tensioners are much preferred over the later plastic body units, Dave. Make up some spacers and you should be good to go.