aq131a #4 exhaust valve issue? cracked head?

[coronatrophy]

I searched and I can't find exactly what I'm looking for. It appears as if my aq131a has a crack in the cylinder head @ the #4 exhaust port. I'm seeing a few things about a vacuum problem with #4 causing water to enter the cylinder?

Can someone elaborate on the issue of #4 cylinder/exhaust valve on these engines?

I'm also seeing something about a modified riser for these engines? What is it and why?

Thanks.

 

[Don S]

Re: aq131a #4 exhaust valve issue? cracked head?

It appears as if my aq131a has a crack in the cylinder head @ the #4 exhaust port

What do you mean it appears? Does it have a crack or not?

Can someone elaborate on the issue of #4 cylinder/exhaust valve on these engines?

Have you asked the ones that made this claim that there is a problem? I haven't heard of one.

 

[sqbtr]

Re: aq131a #4 exhaust valve issue? cracked head?

Don't know about crack problems but I have seen erosion of #4 exhaust port.
Machine shops can be your best friends.

 

[coronatrophy]

Re: aq131a #4 exhaust valve issue? cracked head?

What do you mean it appears? Does it have a crack or not?


Have you asked the ones that made this claim that there is a problem? I haven't heard of one.

Always so helpful answering questions with questions arent you.

 

[coronatrophy]

Re: aq131a #4 exhaust valve issue? cracked head?

Don't know about crack problems but I have seen erosion of #4 exhaust port.
Machine shops can be your best friends.

Thank you. I believe erosion has lead to cracks around the exhaust port. Do you know if there is an issue with reverberation on the #4 cylinder? I'm guessing there must be something going on there as its not common for erosion on the other cylinders?

Thanks again.

 

[coronatrophy]

Re: aq131a #4 exhaust valve issue? cracked head?

What do you mean it appears? Does it have a crack or not?


Have you asked the ones that made this claim that there is a problem? I haven't heard of one.

Its not a "claim", its a fact. I dont get why you need to chime in on my thread if you have no useful information to offer! I just thought I would educate you a little.....here is what someone from another forum said about this KNOWN problem that you havent heard of.

Things to watch out for: Change the manifold every 3 years regardless. The design is not that great in that the riser is built into the manifold. It lets little bits of water dangerously close to the aluminum head and will corrode it which will result in a burned out exhaust valve in the head ( ususlly #4 cyl). Timing belt and tensioner bearing. Every season, re adjust the belt tension. It is not automatic as you would think. Easy though. Just loosen the nut on the bearing and the spring will tension it for you to the proper tension. Heat exchanger, oil cooler and raw water pump. Dissassemble and clean every other season or every 2 to 3 seasons. Keep it clean. Dirty, these will slowly increase your motors opperating temps and will slowly detinate your engine. I have seen these engines dead within 400 hours of operation because of this type of neglect. Do yourself a favor and buy the pertronix ignitor kit for that distributor. Keeping the points clean and tuned is a nightmare without one.