NA8 Timing Belt Change Progress Report .. and some questions

Old Dude · Postby **Old Dude** » Wed May 30, 2012 12:51 am

The seal looks flush with the surround and that is fine

Cheers
Dale

snshami · Postby **snshami** » Wed May 30, 2012 1:46 am

Thanks Dale.

Next step (tomorrow) I will reinstall the black plate under the camsprockets, the cam sprockets themselves and the crank and key and boss with the timing belt. I can't believe in my car the timing belt is only accessible by removing the crank bolt.

I have to remember not to put the crank sprocket on without also putting on the cam belt otherwise it will be coming right off again.

snshami · Postby **snshami** » Thu May 31, 2012 1:36 am

Hi, I have finally got the timing belt over the pulley. Haven't tightened the crank bolt or the torqued the two pulleys but here is an image of the marks on the cam sprockets. The crank sprocket is at the TDC position.

Below that is what it looked like before I took the old belt off. I also have not turned the crank two revolutions so things might change but these marks look good to go. I have followed the the lower markings on the sprocket face along the tooth and it lines up on both sprockets. I'll tighten the the crank up tomorrow. I am planning on using loctite and want to be able to take it off again easily if there is any problem

NEW BELT:

AND

THE OLD BELT:

An update also on the bolts for the crank pulley. I ended up getting them from Pick-a-Part. I looked among the Mazda and related cars and found that the old 90s Ford Festiva crank pulley has identical bolts (it makes sense since its a Mazda engine).

Mr Morlock · Postby **Mr Morlock** » Thu May 31, 2012 3:23 pm

there is no tension on the new belt. You have to check it tensioned and a common thing to do is count the belt ridges. I would think the best bet is tension the belt as described in manual(s) and rotate the engine and recheck. I am supposing tdc on firing stroke is also evident by the position of the cam lobes.

snshami · Postby **snshami** » Thu May 31, 2012 4:07 pm

The belt ridges are the same (19). The tension across the top of the belt is actually tighter than it was on the old belt. The old belt had a lot of slop in it. All down both sides it is now in tension but I do have to turn it to rotations of the crank. If all goes well I should be on the home straight.

snshami · Postby **snshami** » Fri Jun 01, 2012 2:37 am

In case anyone is following this thread, I will finish the story in my garage section

http://mx5cartalk.com/forum/viewtopic.php?f=57&t=46765&p=667143#p667143

snshami · Postby **snshami** » Fri Jun 01, 2012 11:07 pm

In case anyone is wondering, everything went back together very easily and the car started first time. Its a bit of an anticlimax. No leaks of any sort to report. I drove it for about twenty minutes and then let it idle for half an hour just to make sure.

JBT · Postby **JBT** » Sat Jun 02, 2012 6:30 am

Well done

Great result.

Varjak · Postby **Varjak** » Sat Jun 02, 2012 1:46 pm

Congratulations snshami! What a marathon!

snshami · Postby **snshami** » Sat Jun 02, 2012 2:04 pm

Varjak wrote:Congratulations snshami! What a marathon!

Thanks. If you are interested in reading some more about it I have tried to put it all in one place in my Garage Section
http://mx5cartalk.com/forum/viewtopic.php?f=57&t=46765&p=667143#p667143