Timing belt reinstall - Another PK tensioner over extended?
05-28-2016, 06:00 PM
#46
Inventor
Rennlist Member
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How about redesign the bracket so the TD is 2 mm closer to the lever? Then if it's too tight to get the belt on have instructions to elongate the holes and move it back. It's better to have to move in that direction then to drill, push up and depend on friction to keep it at minimum spec.
Not sure it would help you though as it would be a few months before it would be available.
05-28-2016, 06:10 PM
#47
Nordschleife Master
Unless you machine off part of the current bracket to be able to have a ledge there. Otherwise any lip present will move the tensioner out too far.
My solution is to use my TIG welder and well a stainless pad onto the bottom of the lever (where the tensioner rod touches) then machine it flat after welding. This requires removal of the bushing first of course.
05-28-2016, 06:15 PM
#48
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Sounds like you are doing this but for other's benefit:
Extension should be checked after spinning the engine with the starter to settle the belt, then waiting a few minutes (more when cold).
Hot readings will be smaller than cold. (Usually about 2mm from dead cold to hot.)
The Audi system is dynamic. It will not show a true reading by hand cranking.
Extension should be checked after spinning the engine with the starter to settle the belt, then waiting a few minutes (more when cold).
Hot readings will be smaller than cold. (Usually about 2mm from dead cold to hot.)
The Audi system is dynamic. It will not show a true reading by hand cranking.
The first Portensioner that I tried was on an engine I was assembling.
I had a terrible time trying to figure out how and where to set the cam timing because of the "floppy" Audi tensioner....the cam timing jumps all over the place.
I asked you how to do this, at the time and you replied with the same verbage as above....that the Audi tensioner was dynamic and really didn't get tight until it was running.
Obviously, pretty tough to dial in the cam timing on a running engine....and pretty tough to crank over an engine with a starter while on the engine stand.
How about some clues on how to dial in the cam timing when the engine is on a stand, being turned by hand.....
Last edited by GregBBRD; 05-28-2016 at 06:40 PM.
05-28-2016, 06:36 PM
#49
Nordschleife Master
That said. I am more a fan of adjusting the camshaft timing when the engine is hot to balance the compression numbers bank to bank. Or with two AFR gauges, one per bank.
05-28-2016, 06:37 PM
#50
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how do you figure offset studs wouldn't reduce strength?
Unless you machine off part of the current bracket to be able to have a ledge there. Otherwise any lip present will move the tensioner out too far.
My solution is to use my TIG welder and well a stainless pad onto the bottom of the lever (where the tensioner rod touches) then machine it flat after welding. This requires removal of the bushing first of course.
Unless you machine off part of the current bracket to be able to have a ledge there. Otherwise any lip present will move the tensioner out too far.
My solution is to use my TIG welder and well a stainless pad onto the bottom of the lever (where the tensioner rod touches) then machine it flat after welding. This requires removal of the bushing first of course.
Cosmo.....lI'd suggest sending me the early water pump, machine it to fit the later engine, and use the stock tensioner.....be over this nonsense and abuse.
If the pump is a new Laso or Porsche pump, and it has just been bolted on....I can send you (Cosmo) a pump already modified and you can send me yours back.
05-28-2016, 06:55 PM
#51
Rennlist Member
I think that would work. Might be too complicated if not available off the shelf.
Dave
05-28-2016, 07:23 PM
#52
Nordschleife Master
If one is concerned about welding a piece on. Add a piece of stainless steel in whatever thickness you want and get an industrial adhesive. They make a great deal of adhesives which you will never get off without a grinder. I preferred the welder myself as I know the bond is there.
05-28-2016, 08:09 PM
#53
Inventor
Rennlist Member
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Oh joy. What could go possibly go wrong (real or imagined) with Greg doing a PKT installation?
Do you have a receipt of purchase for a PKT for your personal 928? Can't really help you much if not, you understand.
If you are installing a used one that is not a PKT-B, I recommend you source a hardware update kit.
Either way, download all of the newest manuals. Even though, in my regrettable dealings with you, you have demonstrated that you don't read or listen (or often comprehend) them.
Either by dial indicator or using the PK32V'r I found that the timing cannot repeatably set or reset unless the engine has been spun with the starter to settle the belt.
Set the cams in the middle of the slots. After the engine is installed use a PK32V'r and PKBumpstick.
If the belt is new, after 1000 miles you will want to check the timing again. If you use the tips in the PK32V'r manual the seasoned measurement will likely be close enough for most folks (±1°).
If you are installing a used one that is not a PKT-B, I recommend you source a hardware update kit.
Either way, download all of the newest manuals. Even though, in my regrettable dealings with you, you have demonstrated that you don't read or listen (or often comprehend) them.
Set the cams in the middle of the slots. After the engine is installed use a PK32V'r and PKBumpstick.
If the belt is new, after 1000 miles you will want to check the timing again. If you use the tips in the PK32V'r manual the seasoned measurement will likely be close enough for most folks (±1°).
05-28-2016, 08:28 PM
#54
Captain Obvious
Super User
Super User
Just thinking about it with my logic, PKT is the most valuable upgrade for engines with custom cams, stiffer valve springs, and intentionally shaved heads. It's not at all clear what tension the stock tensioner should be set after those modifications that change the belt tension side tension and therefore the required slack side tension, and what the impact of those changes will be on the required service intervals. The stock tensioner will probably be ok with those modifications, but who knows?
Because I think that the PKT system is most valuable for systems with a lot of modifications, then I think the kit should have clear instructions about how to modify the system to match alternative geometries of modified engines. This would add value to the kit when installed to (expensively) modified engines.
Because I think that the PKT system is most valuable for systems with a lot of modifications, then I think the kit should have clear instructions about how to modify the system to match alternative geometries of modified engines. This would add value to the kit when installed to (expensively) modified engines.
05-28-2016, 08:39 PM
#55
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The area being welded is a very small area. I tested on a used lever I had from a VW VR6 (same part). It welded up like regular old steel. I cannot see a failure occuring from this addition of material. I also smacked the test piece with a large hammer a bunch. No fractures, or issues showed up.
If one is concerned about welding a piece on. Add a piece of stainless steel in whatever thickness you want and get an industrial adhesive. They make a great deal of adhesives which you will never get off without a grinder. I preferred the welder myself as I know the bond is there.
If one is concerned about welding a piece on. Add a piece of stainless steel in whatever thickness you want and get an industrial adhesive. They make a great deal of adhesives which you will never get off without a grinder. I preferred the welder myself as I know the bond is there.
I just looked at one of those fulcrums. Appears to be cast, not forged.
I'll Rockwell it and see if it appears to be anything special.
05-28-2016, 11:45 PM
#56
Rennlist Member
Thread Starter
Cosmo.....lI'd suggest sending me the early water pump, machine it to fit the later engine, and use the stock tensioner.....be over this nonsense and abuse.
If the pump is a new Laso or Porsche pump, and it has just been bolted on....I can send you (Cosmo) a pump already modified and you can send me yours back.
If the pump is a new Laso or Porsche pump, and it has just been bolted on....I can send you (Cosmo) a pump already modified and you can send me yours back.
I have the car back together and running using Ken's method to elongate the holes and clamp it to make it go into spec. I will watch it closely. So much for set it and forget it.
05-29-2016, 12:09 PM
#57
Rennlist Member
Anyone know how common it is to have to elongate those holes? I didn't have to...and I know my extension was within spec but I don't remember exactly what it was (dammit why didn't I record that?). I always assumed that was a rare case involving custom engine work (and I think Ken implied that as well). I wonder if that (frequency of this being needed) has increased over time?
05-29-2016, 12:32 PM
#58
Rennlist
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Thanks for the offer Greg, I have Ed's Guardian pump I believe it was made from an oem Porsche casting. Could end up going that route you never know!
I have the car back together and running using Ken's method to elongate the holes and clamp it to make it go into spec. I will watch it closely. So much for set it and forget it.
I have the car back together and running using Ken's method to elongate the holes and clamp it to make it go into spec. I will watch it closely. So much for set it and forget it.
Every time my mind even wanders to thinking about this as a solution, I find myself standing still, just shaking my head.
I literally can't believe anyone with any mechanical knowledge would even suggest this as a solution.
Three 6mm bolts in sloppy holes....not short bolts, but bolts that are long and leveraged are all that keeps you from a very expensive pile of junk.
Good luck is seriously all I can come up with.....
05-29-2016, 01:01 PM
#59
Rennlist Member
And yet, we have ONE documented failure due to PKT (Hai's problem is still undiagnosed IMO) and that was a broken bolt...I don't recall anyone saying that that one had elongated the holes due to over-extension, but I don't really know. So if the risk is as great as implied here, we'd see far more failures. HOWEVER...that's where my previous question becomes important. How rare is this scenario?
05-29-2016, 01:07 PM
#60
Rennlist Member
Thread Starter
My brain is so overwhelmed by this solution, I literally have nothing to say. It's like my brain convulsed and just refuses to even consider this approach as a viable solution....to anything.
Every time my mind even wanders to thinking about this as a solution, I find myself standing still, just shaking my head.
I literally can't believe anyone with any mechanical knowledge would even suggest this as a solution.
Three 6mm bolts in sloppy holes....not short bolts, but bolts that are long and leveraged are all that keeps you from a very expensive pile of junk.
Good luck is seriously all I can come up with.....
Every time my mind even wanders to thinking about this as a solution, I find myself standing still, just shaking my head.
I literally can't believe anyone with any mechanical knowledge would even suggest this as a solution.
Three 6mm bolts in sloppy holes....not short bolts, but bolts that are long and leveraged are all that keeps you from a very expensive pile of junk.
Good luck is seriously all I can come up with.....
Personally I think the tensioner bracket should be redesigned so installs a bit on the tight side, then if a longer stroke is required drill it to loosen it. Would be a safer option.