Author Topic: changing a timing chain  (Read 1600 times)

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Kestrel

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changing a timing chain
« on: Oct 15, 2018, 07:53:26 PM »
I just joined the forum and hope to gain some useful information. I am replacing the timing chain, sprockets, guides, and tensioner in my 1993 Toyota pickup (22RE engine). The repair manual says, "remove the head".  Is that really necessary? Can I do this swap with the head in place or not?

Thanks for your answers.
The Kestrel

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Re: changing a timing chain
« Reply #1 on: Oct 15, 2018, 08:07:06 PM »
You don't remove the head, just bolt in the front of the head that bolts to the timing cover.



What manual are you using?
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Kestrel [OP]

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Re: changing a timing chain
« Reply #2 on: Oct 16, 2018, 05:22:53 AM »
Thanks!
The Kestrel

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Re: changing a timing chain
« Reply #3 on: Oct 16, 2018, 06:47:45 AM »
Hey Krestel,

I’ve done a timing chain R&R twice, once on my 22R and once on my 22RE.  I had the head removed for a head job on my 22R.  On my current 22RE, I replaced the t-chain kit without removing the head.  Keep in mind there is a very small piece of the head gasket that extends over the front edge of the head and mates with the top of the timing chain cover.  This piece is somewhat fragile.  It seals the timing chain cover to the head around the top chain sprocket.  If that section is damaged as you remove the cover, you may have a difficult time getting it resealed, and then have oil leaking from the top edge of the timing cover.  I used Permatex Ultra Gray on that piece and was lucky not to damage the head gasket.  There is one bolt that pulls the cover up to the head.  Be very careful not to over torque that bolt.  Also, you will want to torque that bolt after putting sealer on the gasket, before you bolt down the t-cover on to the block.  That will help seal the top of the cover to the head and that small section of gasket.

Gnarls.
« Last Edit: Oct 16, 2018, 06:57:37 AM by Gnarly4X »
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Slabzilla

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Re: changing a timing chain
« Reply #4 on: Oct 16, 2018, 12:21:18 PM »
I'd do the oil pan gasket at the same time as you need the room to get the timing cover back in there.  just my  :twocents: from many chain replacements.
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Re: changing a timing chain
« Reply #5 on: Oct 16, 2018, 01:38:33 PM »
not trying to hijack thread, but somewhat relevant.  One of ya'll used the directions that came w/ this kit to reference torque spec on my 20R.  What's the general consensus on this dual chain LC kit for 22R/RE engines?  Does it effect the fan/shrowd/radiator location or will it go in without modifying everything in front of the engine?

https://www.lceperformance.com/22R-RE-LCE-Dual-Row-Timing-Chain-Conversion-Kit-p/1015012.htm

Kestrel may be interested in this option also.....I didn't know about it until recently, but I haven't had a 22R(E) in 6 or 7 years now....I sure the kit's been around that long just, I didn't know about it.


Also Kestrel, get the good kit w/ metal guides......you can find the brands that people like here if you search around.  Topic has been heavily discussed here and Pirate.
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Re: changing a timing chain
« Reply #6 on: Oct 16, 2018, 01:58:37 PM »
I would pull the head.  What Gnarly mentioned has a lot to do with why I feel this way about out it.  Pulling the head isn't that much more work. Do it once and be done.  :twocents:
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     Also 84 toy DD 22R 4.88s,33'' toyo mt'z, marlin clutch,4inch lift/63's, HA drivelines.

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Re: changing a timing chain
« Reply #7 on: Oct 16, 2018, 08:37:17 PM »
I have the LC dual chain conversion.

Doesn't affect anything at all.     Everything lines up as before.      I had to reuse some cover bolts as some of the supplied bolts weren't long enough because I have AC.
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Re: changing a timing chain
« Reply #8 on: Oct 17, 2018, 06:55:19 AM »
I am not a fan of the dual row t-chains.  First, it takes power to move them.  With 2 chains there is twice the chance of a failure.  And, thirdly chain breaks are not very common on the 22s.

What is the engineering design objective of a dual chains?  :dunno:

Gnarls. :inthedark:
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Re: changing a timing chain
« Reply #9 on: Oct 17, 2018, 06:58:22 AM »
I would pull the head.  What Gnarly mentioned has a lot to do with why I feel this way about out it.  Pulling the head isn't that much more work. Do it once and be done.  :twocents:

Pulling the head on 22RE is WAY more work and time consuming!!  :yikes:

Gnarls. :spin:
1986 XtraCab SR5 22RE 5speed W56B, ~26,000 MI after break-in, DIM (Did It Myself) rebuilt engine - .020" over, engnbldr RV head, OS valves, 261C cam, DT Header. https://imgur.com/oACTHTR

toyodaaddict

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Re: changing a timing chain
« Reply #10 on: Oct 17, 2018, 10:56:15 AM »
Pulling the head on 22RE is WAY more work and time consuming!!  :yikes:

Gnarls. :spin:

I suppose your right. I would still pull the head if it was my truck though.  I've had to do a couple 22r/re HG's for family recently so it all feels pretty routine to me right now.
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     Also 84 toy DD 22R 4.88s,33'' toyo mt'z, marlin clutch,4inch lift/63's, HA drivelines.

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Re: changing a timing chain
« Reply #11 on: Oct 17, 2018, 11:13:30 AM »
I am not a fan of the dual row t-chains.  First, it takes power to move them.  With 2 chains there is twice the chance of a failure.  And, thirdly chain breaks are not very common on the 22s.

What is the engineering design objective of a dual chains?  :dunno:

Gnarls. :inthedark:

Blehblehbleh if those toyota engineers did it it must be rite!
:)bestgen4runner [12:45 PM]:   I am so stupid.

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jmac80

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Re: changing a timing chain
« Reply #12 on: Oct 17, 2018, 03:39:09 PM »
With 2 chains there is twice the chance of a failure.  And, thirdly chain breaks are not very common on the 22s.

What is the engineering design objective of a dual chains?  :dunno:

Gnarls. :inthedark:

What does twice the chance of not very common equate to?....just being a smart@ss, no offense Gnarls. 

I can see where two would split the force and result in less stretching and guide and tooth wear.  Also, reduced chances of jumping a tooth, but you got other issues if that's possible with chain.
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Re: changing a timing chain
« Reply #13 on: Oct 17, 2018, 06:44:28 PM »
With 248k on my 77's double-row chain it had zero stretch when measured, try that with a single-row chain. I'm runnin' a 22RE single chain and it was stretched when I replaced it, all the single-rows I've done required replacements. I've never had one that broke, though. Just my 2 cents.   :twocents:
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Re: changing a timing chain
« Reply #14 on: Oct 17, 2018, 08:34:00 PM »
The single row chain also cut right thru the tensioner block.  (been there done that)

Then there isn't enough tension and the timing chain skips some teeth advancing the camshaft timing. (BTDT)


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Gnarly4X

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Re: changing a timing chain
« Reply #15 on: Oct 18, 2018, 05:40:09 AM »
With 248k on my 77's double-row chain it had zero stretch when measured, try that with a single-row chain. I'm runnin' a 22RE single chain and it was stretched when I replaced it, all the single-rows I've done required replacements. I've never had one that broke, though. Just my 2 cents.   :twocents:

The amount of stretch in thousandths of inches, on a single row 22 timing chain is so small that is has ZERO affect on the most common reason for timing chain failures!! Three times, I've measured my old chains against the new one I was about to install and the amount clearly has nothing to do with WHY the timing chain and guides fail.

Further, the amount of wear on the two sprockets was insignificant on my 22R and 22RE engines.

Please explain why there are millions and millions of miles on single row chains in 10s of thousands of high mileage early Toyota 22s that DO NOT have a timing chain system failure issue caused by the chain failure.

The primary reason timing chains system failure is because the uneducated, unaware, or ignorant driver does not pay attention to the sound that the timing chain makes when it slaps against the timing chain cover, especially at a cold start.  The chain slaps against the cover because the factory driver side plastic guide has a design flaw that allows the top bolt hole in the guide to fracture and then does not keep the chain in line with top cam sprocket.  The metal backed guides are the solution to the design defect by Toyota.

If the dual row chain was critical to preventing failure, why did Toyota stop manufacturing that dual row design in 1984? 

LCE's website says "The factory single chain has proven to be a problem even in stock engines"....but doesn't explain WHY.

That's just my opinion - it may be worthless.

Gnarls.
1986 XtraCab SR5 22RE 5speed W56B, ~26,000 MI after break-in, DIM (Did It Myself) rebuilt engine - .020" over, engnbldr RV head, OS valves, 261C cam, DT Header. https://imgur.com/oACTHTR

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Re: changing a timing chain
« Reply #16 on: Oct 18, 2018, 05:48:09 AM »
The single row chain also cut right thru the tensioner block.  (been there done that)

Then there isn't enough tension and the timing chain skips some teeth advancing the camshaft timing. (BTDT)

The tensioner block will sustain wear, but in my engines and timing chain kit replacements, the amount of wear caused by the chain was NOT enough to cause the failures.

That's just my experience.

Gnarls.


1986 XtraCab SR5 22RE 5speed W56B, ~26,000 MI after break-in, DIM (Did It Myself) rebuilt engine - .020" over, engnbldr RV head, OS valves, 261C cam, DT Header. https://imgur.com/oACTHTR

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Re: changing a timing chain
« Reply #17 on: Oct 18, 2018, 06:01:48 AM »
What does twice the chance of not very common equate to?....just being a smart@ss, no offense Gnarls. 

I can see where two would split the force and result in less stretching and guide and tooth wear.  Also, reduced chances of jumping a tooth, but you got other issues if that's possible with chain.

LOL.... yeah... with two chains you have 2X the force against the guides and tensioner.

There is twice the mass with 2 chains, so it takes more energy to move them, more torque applied to the crankshaft sprocket and therefore more parasitic power loss.

Gnarls.
1986 XtraCab SR5 22RE 5speed W56B, ~26,000 MI after break-in, DIM (Did It Myself) rebuilt engine - .020" over, engnbldr RV head, OS valves, 261C cam, DT Header. https://imgur.com/oACTHTR

Lewis Hein

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Re: changing a timing chain
« Reply #18 on: Oct 18, 2018, 07:34:54 AM »
Hey guys, I think there have been a couple misunderstandings here and I wanted to help set the record straight for the benefit of future readers. No offense to anyone I hope because I know I've said plenty of stuff in my time that later turned out to be wrong and the world was a better place because others corrected me.

...With 2 chains there is twice the chance of a failure.
For the record, I am pretty sure those are not 2 chains, but rather 1 with two rows. Also, following your logic, suppose we have two properly made steel cables built with strands of the same size, one with twice as many strands as the other. Is it fair to say that the second has twice the chance of failure as the first? (this is leaving out a biig can of worms about manufacturing defects. Bottom lìne is that both 1 and 2 row seem to be pretty stout with a low failure rate for the chain itself)

LOL.... yeah... with two chains you have 2X the force against the guides and tensioner.

Actually I think the tensioning force is applied to the chain by the hydraulic doohickey that runs on oil pressure, irrespective of the number of rows in the timing chain. Even if  there were twice as much tension in the chain it also has at least 1.5 times the surface area contacting guides and tensioner. If there is a special high-force chain tensioning doohickey on the DRTC engines, somebody please correct me on this.

There is twice the mass with 2 chains, so it takes more energy to move them, more torque applied to the crankshaft sprocket and therefore more parasitic power loss.

The parasitic power losses, I believe, are quite real. However, Force=mass x acceleration. With the engine at constant RPM linear acceleration of the chain is zero, thus the mass of the chain is irrelevant. Extra energy spent accelerating the chain as the engine is revved is recovered (minus friction of course) during deceleration of the engine. Thus pretty much all parasitic losses from the DRTC are due to friction.

That's my physics-based opinion. IF you want to argue with me, I only listen to physics-based arguments :gap:

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Re: changing a timing chain
« Reply #19 on: Oct 18, 2018, 07:40:58 AM »
Hey Lewis....

Great!  I'm just trying to stir up a little "tech talk" since it's been rather scarce here lately!!  :gap:

Gnarls.  :disturbed:
1986 XtraCab SR5 22RE 5speed W56B, ~26,000 MI after break-in, DIM (Did It Myself) rebuilt engine - .020" over, engnbldr RV head, OS valves, 261C cam, DT Header. https://imgur.com/oACTHTR

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Re: changing a timing chain
« Reply #20 on: Oct 18, 2018, 07:45:14 AM »
....
 I am pretty sure those are not 2 chains, but rather 1 with two rows.

Yes sir... that is a fact!!

Gnarls
1986 XtraCab SR5 22RE 5speed W56B, ~26,000 MI after break-in, DIM (Did It Myself) rebuilt engine - .020" over, engnbldr RV head, OS valves, 261C cam, DT Header. https://imgur.com/oACTHTR

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Re: changing a timing chain
« Reply #21 on: Oct 19, 2018, 07:13:12 AM »

That's my physics-based opinion. IF you want to argue with me, I only listen to physics-based arguments :gap:

Lewis, Lewis, Lewis....  :smack:

Physics-based argument....  :willynilly:

Assume the mass of a single row chain is X.  Assume the mass of a duel row chain is 2X.

Using Newton's 2nd Law of Motion.....  would the [F]orce value be greater for the duel chain?

If the Force is greater, would it take more energy to move the duel chain?

Since the engine RPM is NOT constant, energy (power) that is required to move the chain is greater with a duel row chain.... thus the parasitic loss is greater.

Assuming the duel row chain creates more friction, if we add the friction.... we add more parasitic loss.  :gap:

Gnarls.  :thumbs:
1986 XtraCab SR5 22RE 5speed W56B, ~26,000 MI after break-in, DIM (Did It Myself) rebuilt engine - .020" over, engnbldr RV head, OS valves, 261C cam, DT Header. https://imgur.com/oACTHTR

Pat

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Re: changing a timing chain
« Reply #22 on: Oct 19, 2018, 08:31:29 AM »
I feel the need to reply to share another view point..  The single row chain does indeed stretch at a much faster rate then the double row chain.

#1 The guides breaking is a issue but the steel backed guides are only masking the real problem of the chain itself stretching or the tensioner block wearing allowing more movement in the chain.  Theoretically the chain guides should see next to no use until one of the previously stated things happen and the guides are a secondary protection measure to protect the timing cover while the tensioner pumps up. 

#2  the biggest reason for the Toyota going to a single row chain IMO is cost.  So lets say toyota saved $10 on every 22r/22re they produced by running the single chain.  That would be millions of $dollars$ in saving/profit for Toyota.  (the single row chain will get the 22r/re out of warranty)It is a simple business decision.  Add that cut$ with the hundreds of other adjustments in manufacturing they made it makes for a profitable business.

#3  The double row chain also with it's greater surface area will wear the tensioner block at a much slower rate thus allowing the chain to stay tighter longer.  As well as there being the obvious benefits of less chain stretch. 

#4   You can find many 20r's that have 200k+ miles on the original chain with no timing chain wear issues.  You will never find that with a single row set up. let alone making it to 100k miles(again it is not the guides) that in itself makes it extremely obvious the benefits of the double row timing chain set up.   Again less stretch in chain and less wear on the tensioner block due to the great surface area of chain riding on block.

#5,  the parasitic loss (all be it real)of the dual row chain is negligible at best.  I would love to see a engine dyno graph back top back with a single row chain vs the double on the same motor.
« Last Edit: Oct 19, 2018, 08:53:29 AM by Pat »
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Re: changing a timing chain
« Reply #23 on: Oct 19, 2018, 09:07:19 AM »
I feel the need to reply to share another view point..  T

Hi Pat,

While I respect your opinion and experiences, I have a different perspective and experience with 3 of the Toyota trucks I’ve owned since 1986.

If your profile is correct your age is 15.  So you have a vast amount of experience with Toyota early 20s and 22s!  How many timing chain R&Rs have to done?  Have you ever measured the worn out chains and compared their “stetch” to the new one?

First, I completely disagree with your statement that the cause of failure “again it is not the guides“.  The most common reason the timing system fails is due to the plastic chain guides.  Improper lubrication will contribute to roller chain elongation, due to excessive wear.

Your statement about “stretch” perhaps is not accurate.  The word “stretch” is often used in describing timing chain failure.  How about elongation?  Actually the chain does have some stretch, but is not permanent.  It happens when the chain is under sudden load force, like at start up, heavy acceleration, or higher than normal loads.

The elongation in roller chains happens to a greater amount when the chain has slack or not tensioned.  The rate of elongation is primary due to wear.  So, when the driver’s side plastic guide breaks at the bolt holes it allows the chain to go slack and that’s when the wear factor goes up and causes the elongation and wear.  Do you know what percentage of elongation is typical for a roller chain application, like that in a 22R engine, before it becomes considered worn out?

Do you have any facts to back up your statement that the reason Toyota discontinued the dual chain design after 1984 is because of cost cutting?

So based upon your reasoning, we should see an increase in timing chain failures in 22s from 1985 because of the single chain design.  Do you have any data to substantiate that assumption?

How many tensioners have you seen from a high mileage 20R compared to the tensioners you’ve seen from a high mileage 22R/REs?

The chain guides are NOT  “a secondary protection measure to protect the timing cover while the tensioner pumps up.”  The guides are the PRIMARY protection.  The tensioner provides plenty of tension on the chain without the oil pressure, and you would know this if you have ever installed a timing chain kit.  The oil pressure to the tensioner is simply to maintain adequate pressure to the block during RPM acceleration and deceleration.
   
That’s just my opinion – it may be worthless.

Gnarls.

« Last Edit: Oct 19, 2018, 09:14:07 AM by Gnarly4X »
1986 XtraCab SR5 22RE 5speed W56B, ~26,000 MI after break-in, DIM (Did It Myself) rebuilt engine - .020" over, engnbldr RV head, OS valves, 261C cam, DT Header. https://imgur.com/oACTHTR

Pat

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Re: changing a timing chain
« Reply #24 on: Oct 19, 2018, 09:11:52 AM »
Quote Gnarly4x
"Hi Pat,

While I respect your opinion and experiences, I have a different perspective and experience with 3 of the Toyota trucks I’ve owned since 1986.

If your profile is correct your age is 15.  So you have a vast amount of experience with Toyota early 20s and 22s!  How many timing chain R&Rs have to done?  Have you ever measured the worn out chains and compared their “stetch” to the new one?

First, I completely disagree with your statement that the cause of failure “again it is not the guides“.  The most common reason the timing system fails is due to the plastic chain guides.  Improper lubrication will contribute to roller chain elongation, due to excessive wear.

Your statement about “stretch” perhaps is not accurate.  The word “stretch” is often used in describing timing chain failure.  How about elongation?  Actually the chain does have some stretch, but is not permanent.  It happens when the chain is under sudden load force, like at start up, heavy acceleration, or higher than normal loads.

The elongation in roller chains happens to a greater amount when the chain has slack or not tensioned.  The rate of elongation is primary due to wear.  So, when the driver’s side plastic guide breaks at the bolt holes it allows the chain to go slack and that’s when the wear factor goes up and causes the elongation and wear.  Do you know what percentage of elongation is typical for a roller chain application, like that in a 22R engine, before it becomes considered worn out?

Do you have any facts to back up your statement that the reason Toyota discontinued the dual chain design after 1984 is because of cost cutting?

So based upon your reasoning, we should see an increase in timing chain failures in 22s from 1985 because of the single chain design.  Do you have any data to substantiate that assumption?

How many tensioners have you seen from a high mileage 20R compared to the tensioners you’ve seen from a high mileage 22R/REs?

The chain guides are NOT  “a secondary protection measure to protect the timing cover while the tensioner pumps up.”  The guides are the PRIMARY protection.  The tensioner provides plenty of tension on the chain without the oil pressure, and you would know this if you have ever installed a timing chain kit.  The oil pressure to the tensioner is simply to maintain adequate pressure to the block during RPM acceleration and deceleration.
   
That’s just my opinion – it may be worthless."  Quote Gnarly4x





I have been a member on this board since 2002 as you can see below my name.  I have personally measured no less than 25 to 30 of the timing chains I have replaced for myself and customers. I have owned no less than 40 toyota 20r 22r, and 22re equipped vehicles over the Last 30 years.

I speak from experience and stand by everything I wrote from that experience and disagree with most of your opinions. I won't be justifying or proving any statements as I feel no need to continue with the debate.  People can take my opinion and do with it as they want.  There is no need for semantics with terminology and everything I wrote is perfectly clear with reason behind each statement.    Everyone has their opinion
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« Last Edit: Oct 19, 2018, 09:54:39 AM by Pat »
Oroville CA, 80 miles north of Sacramento

Gnarly4X

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Re: changing a timing chain
« Reply #25 on: Oct 19, 2018, 10:00:34 AM »
Hey Pat,

Well... you got me on experience for sure!!

I know at least one well respected Toyota engine builder that agrees with your statements...

The dual row chains will go longer before failure.  And, any power loss because of the dual row chain is neglegable.   The guides don’t really have a main factor in timing chain failure, it is primarily due to the chain “stretch” and the tensioner gets weaker over time.

Just going by my very limited experience, I believe the driver’s side plastic guide is a defective design and if it didn’t fracture at the top bolt hole, allowing the chain to slap against the timing cover, the amount of elongation I have measured in the ones I've replaced is not enough to cause a failure.   I'll stand by MY experience.

If a single row chain goes 120K miles and a dual row goes 220K miles, I believe at 120K miles on my 22RE, I’m doing a head job at the very least, so at that point, I’m doing a t-chain job as well.

But… again that just my experience.

So single row vs dual row basically comes down to spending the extra $300+ for a dual row conversion from the single row, in a 22.

The next time I have to replace my timing chain, I’ll have to consider installing a dual row kit, so I can try it myself.  :gap:

Gnarls. :spin:


1986 XtraCab SR5 22RE 5speed W56B, ~26,000 MI after break-in, DIM (Did It Myself) rebuilt engine - .020" over, engnbldr RV head, OS valves, 261C cam, DT Header. https://imgur.com/oACTHTR

Pat

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Re: changing a timing chain
« Reply #26 on: Oct 19, 2018, 10:04:49 AM »
That double row kit that LCE sells IMO is actually really one of their only bargins when you consider what you are getting.  If you bought a single row kit, bought a new cover, water pump, oil pump, drive spline and what not all of a sudden it is a looking pretty good.  Have a good one  :)
Oroville CA, 80 miles north of Sacramento

Lewis Hein

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Re: changing a timing chain
« Reply #27 on: Oct 19, 2018, 10:33:56 AM »
...
Assume the mass of a single row chain is X.  Assume the mass of a duel row chain is 2X.

Using Newton's 2nd Law of Motion.....  would the [F]orce value be greater for the duel chain?

If the Force is greater, would it take more energy to move the duel chain?

Since the engine RPM is NOT constant, energy (power) that is required to move the chain is greater with a duel row chain.... thus the parasitic loss is greater.
Remember that the linear acceleration of the chain is zero at constant RPM (which can be a lot of driving time or not, depending on what you're doing). A heavier chain will store more energy under increasing RPM and release it under decreasing RPM. With zero effect on the energy put out by the engine and therefore zero parasitic loss due to the mass of the chain.

Assuming the duel row chain creates more friction, if we add the friction.... we add more parasitic loss.  :gap:

There was never, to my knowledge, any debate about that.  :thumbs:

Lewis Hein

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Re: changing a timing chain
« Reply #28 on: Oct 19, 2018, 10:41:15 AM »
Ok, I've said my say as clearly as I know how. It is my intention to offend no-one, but also to correct statements made in error for the benefit of future readers. I hope I have done both, and realize that my further participation in this discussion of parasitic loss due to timing chains will not further either goal.

Happy wrenching 'n' talking everyone, keep the good info coming!

EASYRYDERDANGER

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Re: changing a timing chain
« Reply #29 on: Oct 19, 2018, 09:18:41 PM »
The rotating mass of a dual row timing chain adds more torque, the smaller mass of the single row adds more hp.  This was proven by NASA.

 
 
 
 
 

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