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AQ130D/280 Cylinder head replacement

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Randel1

New member
I had a valve seat come loose and it damaged the head to the point that it is not repairable. I need to replace the head which are very hard to find. The part number listed for this head is 831656 and so far I haven't been able to find one that I have any confidence in buying. I understand that the same head is used on the B 18 or the B-20 automobile engines but I'm not sure which one is a direct fit or if there are any modifications necessary to adapt them to the marine block. Does anyone on the forum have any experience or knowledge in doing this part swap?
 
I know what you mean about finding one in decent shape. I went through 3 before finding one that wasn't cracked or had damage. As far as locating one, ebay and craigslist are good places to start. You could even do a reverse ad on craigslist (WTB). Might even try the classifieds on this forum.

The B18 heads have smaller valves and some had removeable seats. There are slight differences in the automotive heads. The fuel injected ones will work but you'll need to plug the fuel injector holes. I also recall a slight difference in the water line at the bottom of the thermostat chamber but not sure.

With any of these heads, check the valve seats carefully for cracks. It's not tough to remove the valves and buff the seats to check. If you buy one, might want to include the caveat that if it doesn't pass magnaflux testing of if the seats have any cracks that it's returnable. Another interesting tidbit is that the marine versions don't use removeable valve guides. No idea why but the replacements aren't listed for later model boat heads.

Good luck and let us know what you find.
 
There are a couple of heads listed on ebay. I have the same engine and replaced the head years ago. I got one at a junkyard off a b20 engine. Wish I remember which car it was. Probably getting real hard to find these days. There are a couple of places where the water pipes are different. The machine shop took care of modifying that for me. Another thing was different, the temperature sensor is on the front of the boat engine and at the rear of the car engine. Last summer the same thing happened to me valve seat gone, taking the head to a machine shop to see if it is repairable. Maybe need a new piston also. Good Luck on your fixit.
 
Thanks for the info and advise, I managed to find a head and had it rebuilt, I am currently waiting for some refurbish work to be completed on the exhaust manifold. With any luck at all I will have this old tub back on the water soon.
 
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