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Topic: RH chain tensioner modification (Read 4947 times) |
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Tobbe
Junior Member
4.1 litre 24v BOB
 
 
Posts: 93
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RH chain tensioner modification
« on: Feb 21st, 2005, 3:58pm » |
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As known a lot of 24v cosworths have problems with the RH chain tensioner. I am about to replace mine, and I was thinking about modifying the old one. My idea was to make a O-ring groove just right outside of the lube hole on the piston/plunger and test with an o-ring if it will make any differ, all though I haven't dissambled the old on yet so I don't really know what the problem(s) with it is, maybe it's a non-return valve failure on it. Perheps the best would be to make a new sleeve and a new plunger but harden it more. Since I've got the equipment to manufactor them it could be worth a try. It is really crap when they don't even last for 120000km.
//Tobbe
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Tobbe
Junior Member
4.1 litre 24v BOB
Posts: 93
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Re: RH chain tensioner modification
« Reply #1 on: Feb 22nd, 2005, 9:14pm » |
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Just a little update on the subject
I did replace the RH tensioner tonight, and as I suspected the sleeve and the plunger had excessive wear. I guess they are not hardened enough. The one-way valve works fine on it.
Going to make a cold start of the engine tomorrow (about -15c) and I am hoping the rattle will be gone.
//Tobbe
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Baz
Moderator
Senior Member
S Reg. 1998 24v Cosworth S2.9 COS (Deceased)
Posts: 4009
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Re: RH chain tensioner modification
« Reply #2 on: Feb 23rd, 2005, 8:07am » |
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-15c? Where are you Tobbe.....Antarctica?
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Tobbe
Junior Member
4.1 litre 24v BOB
Posts: 93
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Re: RH chain tensioner modification
« Reply #3 on: Feb 23rd, 2005, 10:08am » |
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Actually I am in the middle of Sweden by the coast, and it have been much warmer this winter then usuall. It's normally -25 or colder this time a year.
Anyway, I made a cold start up at -12 and there were still some chain rattle, not as much as before but it was there, next step i to replace LH tensioner.
//Tobbe
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Tobbe
Junior Member
4.1 litre 24v BOB
Posts: 93
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Re: RH chain tensioner modification
« Reply #4 on: Feb 23rd, 2005, 5:51pm » |
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Checked the hardiness of the plunger today, it's only
35-36 HRC. Going to manufactor a new sleeve and plunger and harden them to about 55-60HRC then there should be no problem with wear after a few thousands of miles. And a set of washers to compensate for the age of the tensioner spring are also to be manufactured.
If anyone got a LH tensioner dismounted and are willing to make a few measurments of it for me I would really appreciate it. I need the following measures:
Total length of the sleeve (removed from housing)
Total length of the plunger
I asume theese are the only measures that differ from the RH tensioner.
As thx I might be able to get you a set of both RH and LH side. (Sleeve+o-ring, plunger and washers). I.e if I get the hardening right.
//Tobbe
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Tobbe
Junior Member
4.1 litre 24v BOB
Posts: 93
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Re: RH chain tensioner modification
« Reply #5 on: Feb 23rd, 2005, 6:18pm » |
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In addition:
It was not possible to modify the rh tensioner with an O-ring groove and an o-ring,due to that there would not be enought of material left to ensure the plunger not to break into 2 pieces caused by fatique. On the modified ones the lube holes will be moved back a bit to increase the sealing area.
//Tobbe
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Tobbe
Junior Member
4.1 litre 24v BOB
Posts: 93
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Re: RH chain tensioner modification
« Reply #6 on: Feb 25th, 2005, 11:22am » |
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A little update:
Manufactured a few test peices in SS1672, going to harden them tonight with various temperatures. The sealingness (hope that word excists in english) between plunger and sleeve is much better then new original parts. Will get some pictures later on and test results of the hardiness and demolitiontests.
Still need the measuerments of the LH tensioner.. Maybe I just have to remove mine and use that one.
//Tobbe
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Scorpioen84
Full Member
Saloon 2.0 16v TC 140bhp -95
Posts: 404
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Re: RH chain tensioner modification
« Reply #7 on: Feb 25th, 2005, 1:26pm » |
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Tjenare Tobbe...
Bra at det er flere skandinaviere her...
Så mye rart me disse engelskmennene... Hehe...
Blir ensom som eneste Normann å Skandivavier her...
Håper du lykkes med prosjektet..
Måtte temperaturen vare... God helg.!
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....._____
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|_(O)____(O)_)_________
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Eddie
Full Member
Must try a different shampoo!
Posts: 495
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Re: RH chain tensioner modification
« Reply #8 on: Feb 25th, 2005, 4:32pm » |
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Hope your not talking about us! 
eddie
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low_tom
Full Member
mam the car goes up and down!
Posts: 167
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Re: RH chain tensioner modification
« Reply #9 on: Feb 25th, 2005, 6:25pm » |
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i think..
i thought i was the only scandanavian here,
with all these englishmen
now there are norge and scandananvians.
hope you like my project.
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Eddie
Full Member
Must try a different shampoo!
Posts: 495
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Re: RH chain tensioner modification
« Reply #10 on: Feb 26th, 2005, 5:29am » |
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Very amusing,I just noticed the addy at the top of this thread!
eddie
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Tobbe
Junior Member
4.1 litre 24v BOB
Posts: 93
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Re: RH chain tensioner modification
« Reply #11 on: Feb 26th, 2005, 6:37pm » |
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Did some hardening today, I think it was a success but I can't be sure I got 55HRC until I am back at work and can measure the surface hardiness, but I think it got really hard and I also need to make a demolition test. The measurements of the plunger and sleeve changed a bit, so the plunger has to be grinded to right size according to sleeve after hardening but that's no problem.
Test pieces.....
Theese pieces are just for hardening tests.
//Tobbe
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Tobbe
Junior Member
4.1 litre 24v BOB
Posts: 93
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Re: RH chain tensioner modification
« Reply #12 on: Feb 26th, 2005, 6:40pm » |
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Hmmm. It got big, to big, didn't it!?
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scorpio_man
Administrator
Ford Kuga awd
Posts: 5654
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Re: RH chain tensioner modification
« Reply #13 on: Feb 26th, 2005, 7:00pm » |
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hi there
just a bit!!!!!!!!! 
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Tobbe
Junior Member
4.1 litre 24v BOB
Posts: 93
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Re: RH chain tensioner modification
« Reply #14 on: Feb 27th, 2005, 10:00am » |
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There must be one that have one of theese but for the LH side in their garage:
I still need to know the length of the LH tensioners plunger and sleeve, I was hopeing to have one ready before the next weekend so I can try it on my cossie..
//Tobbe
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Tobbe
Junior Member
4.1 litre 24v BOB
Posts: 93
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Re: RH chain tensioner modification
« Reply #15 on: Feb 27th, 2005, 8:15pm » |
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Got some drawings of the RH plunger and sleeve.
If the surface treatment is a success, they will be manufactured tomorrow, at least the begining of it.
//Tobbe
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Tobbe
Junior Member
4.1 litre 24v BOB
Posts: 93
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Re: RH chain tensioner modification
« Reply #16 on: Feb 28th, 2005, 8:54pm » |
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Did test the surface hardiness today, it was a failure, only 28HRC, but I did find out what went wrong, I got SS2172 or 2143 instead of SS1672. Harden a new piece today in SS1672 and it seems to be hard enough. So tomorrow I will see the result when measure it and make a demolition test. Maybe I got a finnished RH tensioner plunger & sleeve that I can test by the end of this week.
If this little project is to no interrest for you cosworth owners, let me know. Got to wonder becuase there's no comments about it.
//Tobbe
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Paul B
Senior Member
'98 24V Ultima saloon
Posts: 2442
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Re: RH chain tensioner modification
« Reply #17 on: Feb 28th, 2005, 9:05pm » |
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I'm reading it all but I have to be honest, its completely over my head I'm afraid   
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Two hundred & seven horses and only one jockey!
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waders
Guest
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Re: RH chain tensioner modification
« Reply #18 on: Feb 28th, 2005, 9:08pm » |
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on Feb 28th, 2005, 8:54pm, Tobbe wrote:If this little project is to no interrest for you cosworth owners, let me know. Got to wonder becuase there's no comments about it.
//Tobbe |
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Tobbe, I don't have a Cossy but I'm still interested in your project keep posting
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SaveTheNight
Senior Member
I can resist anything ...except temptation !!
Posts: 1961
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Re: RH chain tensioner modification
« Reply #19 on: Feb 28th, 2005, 9:09pm » |
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sorry Tobbe .. well I for one am watching with interest .. just not sure whether the hardness has any relation to the problem .. as often a new tensioner does not cure the problem .. as you probably know , I too am working on the chain problem in general ..so i'm interested to see what result you get .. in our own research we tend to put at least 8-10k miles on before stripping down ..so it's a bit of a drawn out procedure ... regards ..... STN
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