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Timing belt idler and tensioner questions for franken motor...


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Between school, and not really needing to wrench much due to my current subie that's been extraordinarily reliable, I'm returning after quite a long break from the board...

 

What I'm working with:

1999 legacy brighton, with 350k+ miles.  Originally had ej22, rebuilt engine when I got it about 4 years ago.  My memory is foggy on some of the details, but when I rebuilt it I found that parts were pretty hard to find and expensive relative to that of the ej25, and knew someone that had the bottom end from an old ej25.  So we put the ej25 block in with the ej22 heads, intake, etc, everything dropped right in and has been a fantastic engine since.  SOHC ej25, CR is modest, or even slightly less than the original ej22, lots of fun to drive and when everything is good it'll range between 28-32 mpg on the highway.

 

Except...

Here I am about 70k later doing the timing belts and other fun stuff(I couldn't remember if it was a 65k belt or 105k, and front crank has been leaking for some time now) and I'm having issues getting the right parts, partially due to me being a dumba** and not doing the right kind of research before hand and not writing down what I used years ago.  Turned out to be a good thing I'm doing it now, old belt has several cracks forming and 2 of the idlers bearings had more play than I would have liked.  I'm already more $$ into it than I want to be, I have 2 questions:

 

1) What is the importance of the style idler pulls used? I will attach a photo, but one of the old idlers has a lip that sticks up on the back of it, on the DOHC motors I notice that none of the idlers have this but the SOHC motors have one.  Is it important that I replace the old idler with one of the same style? or would it be fine with an idler that is different(see picture below, the new parts from the kit I have line the top, next to the old parts along the bottom row).

 

2) The tensioner pulley I bought I thought was mostly identical, but once installed I noticed that it could potentially rub on the drive sprocket on the crankshaft, where as the old one has slightly more clearance. After inspection, the only difference between the old and new one I could find is that there is more meat on the part of the pulley where the piston from the tensioner presses against(should be obvious in the picture). I feel like there maybe should be a spacer or washer that goes between the idler and the block and this would provide enough clearance, but I don't remember one being there when I took the old one off, and doesn't quite make sense if the old one clears without anything like that. I'm not really sure what to do other than go back and find one that better matches the old one--which means either waiting another day(was supposed to be in sacramento yesterday) or forking over more $$.

 

What do you guys think?

post-12410-0-05523300-1408048259_thumb.jpg

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I feel like there maybe should be a spacer or washer that goes between

the idler and the block and this would provide enough clearance, but I

don't remember one being there when I took the old one off, and doesn't

quite make sense if the old one clears without anything like that.

there is a sleeve with a flat washer type shoulder that fits in the bolt hole from the back side.

it is not unusual for the new bolt or sleeve to not be exactly right.

but i guess it depends on where you bought it and who made it.

look around for the sleeve.

 

the rest of the idlers look fine.

install them.

Edited by johnceggleston
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Yeah, new idler came with new sleeve, bolt and sleeve on both are identical.  With new idler and new tensioner, it fits very tightly, if I were to pull the grenade pin out it probably wouldn't move much. I guess I'm just uncomfortable with the very tight fit and tiny amount of clearance.

 

Does it matter that none of the new idlers have the flange on the back, like the old one(see bottom right, one with the orange seals on the bearings)? 

 

I'm probably being overly anal, but I have no idea if this is an interference engine in its configuration, absolutely do not want to risk being 1000 miles away and experience a destroyed valve train...

 

Also, I don't think its relevant, but just in case, car has a manual transmission.

 

 

Update: Okay, so I definitely was worrying too much about it.  Stopped by and talked to the awesome guys at Superior Import Repair and they got me set straight.  The tensioner pulleys are identical part numbers, and difference is in the casting, machined dimensions are close enough to work fine, though I'd take it back and get something that looked closer to the original part but I'm stuck with this one and it should work.  They also told me the flanged idler is just a newer design, and the older cars used both idlers w/o flanges and that the bearings are actually better in the older design.  Gonna go put everything together and call it a day...  :drunk:

Edited by scrap487
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