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Mazda Engine General \  Block Pitting.

Block Pitting.

Mazda Engine General Mazda Engine Mazda Tech
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replies 10
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tobot   +1y
Hello all,

I am new to this forum, and I hope I will be on here for a long time. Your advice in this situation may determine this.

I bought a 89 B2200 with a 91 EFI motor in it for $280. Needs some work. First on the list is the head gasket. The previous owner had it for 5 years. Said it always smoked on start up. It was blowing lots of smoke when I bought it. So i pulled the head. When I lifted it, the original gasket was all mangled up. The cylinder rings on the gasket were bent inward to the cylinder. I don't know how this happened.
Anyways. I just finished cleaning the block and noticed there is some pitting on the exhaust side right where the metal rings should be. I can't get a feeler gauge in there, but I'd guess almost 1/32" in some spots. It's pretty bad on one cylinder. The others not so much.

I'm working on my truck in a covered outdoor parking stall. I don't have the ability/tools to pull the motor. I'll probably be putting about $1000 into this truck to get it in safe running condition. I don't want to spend a whole lot on just the engine.

I've been doing some reading. Some people say to use an OEM gasket and copper gasket spray and it should be fine. Some say to use JB Weld also. Some say to never use JB Weld.

What do you guys suggest I do. I like doing the job right in most cases. But pulling the block is not an option for me.
Cusser   +1y


I rebuilt my engine (pretty much most but main bearings) three years ago, left the engine installed, $700 in parts and cylinder head machining. See thread link in the signature or in the Tech Write Up section.
tobot   +1y
To remove the pitting, I'd have to pull the block and send it to a machine shop.

If I can get this thing up and running, I probably will rebuild the engine in a few years. I love this little truck.
sincitylocal   +1y
Depending on how bad the pitting is, you can just run a hone for a while longer and see what happens.
You have to hone it to break the glaze anyway...
mazdatweaker_2   +1y
I would just use an OEM gasket and be done with that concern. The rings are where the oil smoke has probably come from so that might be more of an issue.
tobot   +1y


You make a good point. Maybe I should do the rings too. At this point it looks like I just pull the oil pan and undo the connecting rods, right?

Is it really better to use a OEM head gasket? Why?

Also, the PO told me the engine in here is a 91, but that doesn't sound right. It looks like EFI motors weren't introduced until 92. I can't find a list to match VIN numbers to year of production. I want to buy the right parts.
scotch   +1y
OEM or Fel-Pro head gaskets. The internet is littered with stories about cheaper brand head gaskets failing prematurely. We all like to try and keep things on a budget, but you don't want to do the head gasket over again because you saved $20 the first time around.

The B2200 came out with fuel injection in 1990. I don't think you will find any engine changes along the way. But if he said it was a 91 engine, then I would get parts for a 91.
mazdatweaker_2   +1y
From reading your posts it sounds like it started out as an '89 and a '91 short block was swapped in (under the head) and the engine is still carbureted. It seems like a lot of work to convert one of these trucks over to Fi, but who knows what the history is. That being said, since you have the head off there are a couple of things you can look at / for. There are supposed to be two dowel pins in the block to center the head gasket on the block. If either or both of the dowel pins are missing, that might be how the head gasket got mangled over time, because it would have been free to move around on the block deck. So maybe oil could have been being sucked in past the sealing rings. Can you post any pictures of the parts like the pistons or the block deck you are talking about?

As fas as your question as to getting a correct replacement part is concerned, I don't think there are any differences between the short blocks between the Fi and carbureted trucks, but if you have a concern about that, there is a spot on the right front corner of the block that carries a block stamp and you could take that number to a dealership and probably get whatever question you have answered.

You are right about doing the rings; it is just a matter of pushing the rods out through the top of the block and I would recommend doing that job while the head is off; otherwise I think you are going to see lots more smoke without doing that part of the rebuild. Make sure to mark the cylinders the rods come out of and rod direction. You could just throw a head gasket on it and hope that takes are of the oil burning but oil burning in these tractor engines is almost always due to worn out oil control rings.

Hope this helps.
tobot   +1y
The truck now has fuel injection. Could the head have just been swapped?

I took a couple pics. It was night time. I used a razor blade to show where the deck is pitted. The pic is of the worst spot. I'm debating finding something flat and sanding the deck. I have access to cast iron pieces, usually too large to fit in there though.

If I had to sand it down quite a bit, how important is it that i use a shim. I'm not interested in this being a performance vehicle but I want to take care of it. Would I have to use two head gaskets? One on either side of the shim?

Dang, I'll add photos shortly.
tobot   +1y
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