Chain tensioner questions
 

I know it's been discussed ad nauseam and I've read many of the threads piecing together info, apologies in advance for the rehash...

Helping with a friend's '78 3.0. We have the motor out working through all the usual refresher items. The attached pics show the current chain tensioners. The engine was built with webers and some flavor of high compression pistons but we have no details on what's in there, it's now going to an ITB/EFI setup. I figured since it didn't have the hydraulic tensioners installed we'd at least find collars once we opened the chain covers, someone with some knowledge tinkered on this in the past and I figured they would have done something to protect from tensioner issues. But the left tensioner has a 930 part number and the right one has a 901 part number - I'm assuming they would have had matching part numbers when it was new so not sure what the plan was here.

Some questions - the plungers on the tensioners have very little shaft exposed. I can move the idler arm a bit but the chains don't seem loose. I'm guessing these tensioners are in need of a rebuild at a minimum?

The million dollar question - should we just do the hydraulic upgrade? Lots of debate on this I know so not expecting an easy answer. From reading I do know that the wider idler arms are considered to be the best defense against any kind of tensioner failure so they'll be in the plan.

Appreciate feedback and inputs from the collective...



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I can only find those part numbers on ebay, not in the parts catalog or any distributor. Must be a tremendously superseded part.

And yes they do look awfully receded. If it were me and I already had the case open I would just put in the hydraulics. That said there may be some alternates I'm not aware of.

The tensioners are doing their job. Installing hydraulics will be the same as the chains are new, short and need to wear in..
The part numbers, regardless of age, are all built after 1981 because that’s when the factory narrowed the large end of the tensioner.
Bruce

Thanks for those comments - so judging by the lack of wear evident on the chains you’d judge this to be pretty fresh, and consequently the tensioners should be fairly compressed? We don’t have any history on the engine, just what we know from forensics

Is the spacer missing behind the left tensioner?

as John`s Eagle eye pointed out ..this one....
Ivanhttp://forums.pelicanparts.com/uploa...1630741004.JPG

Good eye, thanks for catching that. I just made sense of how the difference in the boss affects the fit of a 901 tensioner compared to a 930 tensioner. Curious that this engine has one of each, maybe one failed and they just swapped in what they had on hand. Annoying they left out the spacer, can’t imagine that helped the arm move properly.

Currently thinking we’ll do the carrera update but then have to decide what to do about the arms. The new arms sting mightily, I think about $750, but looks like Supertec may have a solution as well, waiting to hear back from them.

Open to suggestions, thanks for the support!

Attachment 10579
Attachment 10580

I got a set of Henry's arms for my 2.7 build and they're very nice and much more reasonable price than the factory arms.

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you don't really need to up date to hydraulic tensioners...even those go bad lately more often than before..Just set you Z1 on front pulley ,leave spark plugs in and if you do not have the tool for compressing the tensioner get one, so it will be easier to replace it while you put the spacer in.Your chains look pretty new,basically somebody replace the left side with newer type a did not put the spacer in..

Ivan
the tool
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Z1 on #1 to clarify. Cam will sit there as you swap the tensioner, unless you try to turn the cam or crank.

Thanks all for the great inputs. Keep going back and forth on the carrera tensioners, response just depends on who you ask.

But if we agree that the wide tensioner arms work better because they don’t bind, and in turn improve life of the tensioner itself then I’d be in the market for a second 930 model tensioner. And a single tensioner is a significant way toward the cost for the full carrera kit.

As an aside, the spacer I find says it’s only compatible with tensioner 930.105.053.00. But this tensioner is 930.105.501.00.

Do the spacers indeed work for all 930 tensioners? Ie all same width?

Thanks John, that’s what I figured. Just got done adjusting the valves so it’s currently back to Z1 with #1 at TDC

... as i said your tensioner on the right side is an older version the left is new version therefore you need the spacer....there is only one type of spacer...get the one form our host for 4,75 ..that is all you need..
https://www.pelicanparts.com/More_Info/93010551300.htm?pn=930-105-513-00-M105&SVSVSI=0794&DID=12478

Ivan

Yes, thanks, I saw that. My question was just if this is the only size spacer, which it sounds like it is. The info say it only works with a specific tensioner that doesn’t match the part number on mine. I’ll give it a shot though

My two sons and I each have motors that suffered chain tensioner issues, one 2.4 and a couple of 3.0's. We "fixed" each of them with the Carrera kits, adding the pressure fed tensioners. At least we thought we did... In the end, after fighting this on all three, we all bit the bullet and bought the double bushing idler arms. This was over ten years ago, and none of us have had a problem since. Problem solved in all three motors. I know the one side isn't cheap, but a lot of guys will tell you if you put the double bushing idlers in, you won't even need the pressure fed tensioners. Since we all started with those, we all have both, but I think if it were one or the other in the future I would start with the idler arms.

i got used replacement ones with the wider boss from a newer car for a very reasonable price.

Thanks Jeff, that’s great info


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In all the restoration work we did, there was a requirement to use regular tensioners. We always used late idler arms and rebuilt tensioners or re-bled new ones. When confronted with tight tensioners I would use all brown ramps to relax the chain a little.

Shoutout to Henry at Supertec for the help getting the parts I needed to sort this out. Got two of his modified tensioner arms and a rebuilt turbo tensioner. Got everything installed this afternoon, ready to press on with the xfaktory efi kit we’re doing on this car

Thanks Henry, appreciate the help!

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