Timing belt issues...

[Caz Marciniak]

I have an 86 Subaru GL, 1.8L. The timing belt recently snapped on it (I
brought this up before) and my mechanic friend is trying to help me fix
it (I'm a novie, as stated before, as well. )

However, he hasn't worked that often on Japanese cars. So, his question
is that if the timing belt snaps, will the piston hit the valves?

 

[Caz Marciniak]

Basically, what I forgot to add, was will there be valve damage if the
belt snaps.

Yeah, that's it.

Thanks, y'all. You guys have been great.

 

[Kurt Krueger]

I have an 86 Subaru GL, 1.8L. The timing belt recently snapped on it (I
brought this up before) and my mechanic friend is trying to help me fix
it (I'm a novie, as stated before, as well. )

However, he hasn't worked that often on Japanese cars. So, his question
is that if the timing belt snaps, will the piston hit the valves?

Depends. The Gates Rubber company has an exhaustive list of vehicles,
time belt change interval and whether they are interference engines.
Sorry, I don't have a link for you.

BTW, most Subaru's are non-interference. Virtually all the older ones
are non-interference. The only one I know for sure that is inteference is
the 2002 WRX. And even in that case the piston doesn't hit the valves,
the valves hit each other.

 

[Eric Cartman]

Depends. The Gates Rubber company has an exhaustive list of vehicles,
time belt change interval and whether they are interference engines.
Sorry, I don't have a link for you.

BTW, most Subaru's are non-interference. Virtually all the older ones
are non-interference. The only one I know for sure that is inteference is
the 2002 WRX. And even in that case the piston doesn't hit the valves,
the valves hit each other.

the valves hit each other.......

WHATS WRONG WITH THIS STATEMENT........

 

[BD]

WHATS WRONG WITH THIS STATEMENT........

I didn't know valves could move that far...

 

[Carl 1 Lucky Texan]

I didn't know valves could move that far...

While I do not have an exhaustive amount of data memorized, in the case
of the OP, she may be OK. Most older soobs, SOHC, are non-interference.
Most newer soobs are interference, either piston/valve, and/or
valve/valve. Even installing the belt on a soob DOHC engine can be
tricky as the cams may try to rotate and cause valve clash. It's the
penta-roof design and the angle of valve intrusion that CAN, if you're
unlucky, lead to valve clash, even if the piston is untouched.

I'd ask at www.ultimatesubaru.net for the int. versus non-int. question,
and for general info on what to watch for changing the belt(s) on that
engine. also, a decent on-line place for parts is
www.subarugenuineparts.com the contact there is jamie, she's good and
also races soobies!

good luck

Carl

 

[johninKY]

You didn't damage anything on this engine. Timing mark for the belts is
located on the flywheel. Use the center line. After the first belt is
installed, rotate the engine one full revolution before installing the
second belt. Don't use the ignition timing marks on the flywheel. Not a
bad idea to replace the oil pump gasket and camshaft seals at the same
time.

 

[nobody]

I didn't know valves could move that far...

I don't know what the head actually looks like, but I *can* visualize
ways that the valves could hit each other or hook under(? trying to
describe the head of one being snagged under the other. Only thing is
that this could only happen in a DOHC engine. I'm just theorizing, mind
you....

 

[Carl 1 Lucky Texan]

I don't know what the head actually looks like, but I *can* visualize
ways that the valves could hit each other or hook under(? trying to
describe the head of one being snagged under the other. Only thing is
that this could only happen in a DOHC engine. I'm just theorizing, mind
you....

sorry for the length of this post - might help someone searching in the
future though. the following is from this link;
http://endwrench.com/main.php?smPID=PHP::article_detail.php&&RECID=360
Unfortunately, you can’t make an accurate estimate
of the job until you find out whether or not the engine is
of the interference variety. If it is, the repair may have to
include pulling the heads for the installation of some
new valves.
Unlike most other Asian engines, Subaru 1.8L and 2.2L
engines are freewheeling — no bent valves if the belt should
break. We consider this good engineering practice and
the mark of a company that really believes in giving its
customers solid, long-lasting products. Of course, even
though there won’t be catastrophic internal engine damage,
the car will stop dead, perhaps stranding a family in an awkward
situation, so replacement at the proper interval is still
very important.
Meanwhile, it was impossible to accomplish the freewheeling
feature given the crowded combustion chamber of
the 2.5L boxer and still achieve maximum performance and
efficiency. So that motor is indeed “a hitter,” as we technicians
put it.
But there’s more to the story. On the 16-valve DOHC
version, if the cams are out of synch there’s a good chance
the intake and exhaust valves will collide with each other,
perhaps bending them. So, turn those sprockets with as little
force as possible, and if you feel anything touch, go back the
other way.
Which brings us to an interesting question: Just because
it’s supposed to be a hitter, did it actually hit? And, if so,
did this collision do any valve damage? As one exceptional
independent Subaru service specialist tells The End Wrench,
“I know you’re supposed to immediately do a disassembly
and inspection if a 2.5L snaps a belt. But you won’t do any
damage if you remove the spark plugs, rotate the crank
carefully so that all the pistons are at half-mast, then do a
cylinder leak-down test. That’ll tell you if any valves are
bent. Sometimes you luck out and the crankshaft stops
spinning before any damage is done. That would be good
news to the customer.<<<<<

Carl