AQ171C broken timing belt

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tompowers85

Petty Officer 2nd Class
Joined
Nov 28, 2004
Messages
125
My timing belt broke while on the water this weekend. I was running about 2500 rpm's. I have seen some posts saying it is a non-interference and some saying it is an interference engine. I can put a wrench on the drive shaft and it turns without hitting anything. I am going to order a belt but it will be a few weeks. Can I test for damage without a belt or opening the block? When I turn it with a wrench I do not hear anything hit and it does not stick at any point.
 
sqbtr

sqbtr

Senior Chief Petty Officer
Joined
Feb 23, 2010
Messages
716
Re: AQ171C broken timing belt

Set the crank 90* past TDC, remove the valve cover, now you can spin the cam's and check valve clearance.
 
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tompowers85

Petty Officer 2nd Class
Joined
Nov 28, 2004
Messages
125
Re: AQ171C broken timing belt

I spoke to my dad today and he told me the same thing, so I just finished doing that and everything was working great. He told me he had a timing belt break on an old Volkswagen and when he spun the cam it was popping and clicking. I was able to spin both cams without any issues everything moved up and down and nothing clicked or popped. When I had the engine rebuilt the new pistons had notches cutout of the top of the pistons that align with the valves. I should have replaced the timing belt then but the person that rebuilt the engine told me the belt looked good. I took it off after it broke and it is really dry rotted.
 
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Robj

Lieutenant
Joined
Mar 22, 2007
Messages
1,441
Re: AQ171C broken timing belt

You are not looking for binding but rather an excessive gap between the lifter and the cam which is an indication of a valve not closing cuz it is bent. Those are interference fit engines. You can also do a leak down test without the belt but you have to make sure that each piston is at TDC on the firing stroke, so you manually need to turn the cams and crank. A bit tricky but it can be done though. Remember 2 crank revelutions for each cam revelution and you should be able to figure it out from there. Good luck!!

Have a great day,

Rob.
 
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