Top Dead Center - why?

[frag]

I don't mean to talk down to you, but you only see a thumbnail because that is what it is. As for the rest of what you said, maybe the problem is that you are not willing to listen what others are telling you. Quoting from Haynes or Chilton's means nothing in my book, on any given day, I can find errors with either book.

 

These are my last words in the post, flame away.

 

Arrogant and beside the point as always in this thread. Adios!

[cookie]

I have only put one timing belt on a Subie if I recall, and that was so long ago I have forgotten the details.

I did it in New Zealand and the only instructions I had were the marks on the belt and good advice given to me by a friendly auto parts guy and a couple of mechanics waiting in line.

I sort of wondered why a Subie had the pistons down when everything else I have worked on usually timed to TDC on the compression stroke.

To think that if the pistons are down if you rotate the cam your valves should be safe. Good idea, and it would take some planning to get it to work that way!

[frag]

Frag,

 

My replies had nothing to do with the TDC argument. It is not relavant to the question asked. Question was.

Question was awnsered.

When replaceing a SUBARU timing belt TDC is irrelavant.

 

There is a reason why Subaru did what they did. Any Subaru repair info that you read, be it a FSM or info published in The End Wrench, will tell you, and provide you with pictures of which timing marks are meant to be used when replacing the timing belt. They are not the marks that line up when #1 is at top dead center. That is FACT and not my opinion. Other sources, i.e. Haynse and Chilton, and any others you have read that say to set #1 at TDC when replacing a SUBARU timing belt are wrong simply because that is not the way that SUBARU desinged it to be done. SUBARU engines were designed so that when the proper timing marks are lined up when replacing the timing belt all pistons will be midway down the cylinder. So............ if the cams need to be rotated there will be no chance of valve to pistion contact.

It would seem that you were questioning where the pistions are when the proper marks are alignend. There are two sets of marks so I can understand the missunderstanding there. But for a first timers doing there first timing belt it could be critical for them to have the proper marks aligned to avoid unwanted and expensive engine damage. This is why I do not post my opinion in responses to technical questions. If someone is asking a question about replacing there timing belt, they need facts not opinions.

 

Finally, I did not mean to talk down to anyone, and if it seemed that way I apologize.

 

Wawalker, I think I can now see you as someone I would like to keep talking with... Dont run away!

I will not answer your post completely (points in you post I agree with, others...) today for lack of time and cause I think I did my day's work here already:burnout:

Before I leave i would like you to understand that i followed Haynes and Motor Magazine recommendations when I replaced my belt and that it made my placement of the belt easy. Is that not ALSO a FACT someone asking for info here should know ?

I had mucho problemos with the cam seals but that's another story.

See you next time.

[WAWalker]

Before I leave i would like you to understand that i followed Haynes and Motor Magazine recommendations when I replaced my belt and that it made my placement of the belt easy. Is that not ALSO a FACT someone asking for info here should know ?

 

In fact it did work for you.

 

OK, I just read the Chilton manual.

Step 2. Position the No. 1 Piston to TDC of its compression stroke.

Step 5. Align the camshaft sprockets so each sprocket notch aligns with the cam cover notches. Align the crankshaft sprocket top tooth notch, located at the rear of the tooth, with the notch on the crank angle sensor boss.

 

So step 5 is the proper proceedure for lining up the timing marks.

Step 2 however is busy work.

 

Good discussion is always welcome.

[tcspeer]

When I done my belt by the Haynes manuel I brought # 1 to T.D.C. then when I took the covers off, the directions I remember then said to rotate the engine with belt on to line the mark, so I guess that then put the pistons in the middle. I had no trouble the first time going slow by the book, but the next time I tried to do it by memory and I used the wrong mark on the crank spocket. Lucky for me the engine was already shot or I would have surley ruined it.

 

 

I think to figure out how many times that engine would have to rotate to line every thing back up would require the use of that pie number I heard the teachers say we would need after we got in the real world. To bad I dont remember that one.

[frag]

I can provide pictures.

 

OK, I get it. You got me on that one.

I really must have too much faith on what professionnals can do. I'll learn...