B2000 Engine rebuild

OK, so I am rebuilding the motor in my 86B2000 (stock 2.0). So far I have a new head, webber carb, pace setter header (ceramic coated). Got rid of all of the emissions bs. Had it bored 20 over, new pistons and rings, ground the crank, etc. and was about ready to assemble the block when one of the con rod studs snapped while torqueing it. That put me in a position of not trusting the other rods.

This is where I am at: I am going to replace the rods, but I am not building a race motor. I want reliability and at the same time why not reduce the weight with a better aftermarket? I do not want to dump a ton of money into items that are of no use if I am mainly building a stronger than stock motor, but with reliability in mind.

Should I buy new or reman rods? Should I have the whole bottom end balanced while I am at it? Is there a benefit?

What about the head, it is brand new with no EGR hole. Is there anything else I should do to the head before installing it? Any special tricks that I don't know about?

Also, tell me any experience any of you may have had rebuilding these motors and what you did as well as the performance gain (given what it is)

Thanks sooooo much!!

Wow......never had one of the rod bolts snap before. What was the torque setting that you were tightening it to?

Since you're doing the Weber carb, you don't need any EGR.

Amazing about snapping a stud on a connecting rod using a torque wrench !

I've had them stretch before......but not on a Mazda......it was on a Pontiac motor......had to buy new bolts.

The rod bolts should come to torque rather quickly, if you seem to keep tightening the nut and it's not getting tight quickly, then the bolt is likely stretching on you.

The rod bolts can be replaced by themselves. So that just leaves the question as to how tight you may have overtightened them to, unless the bolt was in the receiver crooked. I think correct torque for them is 45 ft-lbs. And as low out put as these motors put out, I don't think there is any benefit to balacing the bottom end.

My .02 worth.

I was torqueing to 50ftlbs, which I now know is too much by 8 or 9 lbs. Got those torque specs from another forum. But I was no where close to that when it just started stretching the bolt and not getting tighter. I also think my torque wrench may not be as precise as I thought.

Anyway, I am still wondering if there is anything else I should do to this motor, while it is apart, to increase performance and reliability. I know that the EGR is gone, was part of my goal. But is there any head work that I should do? It is a brand new head, so should it be ported at all? I have seen people build up welds to keep oil for the cam, is that a common problem?

Just trying to get the things done that you all have had experience with before I put this sumbitch back together!!

Thanks again for all of your help!

The 8 valve head is really not worth doing anything to......in my opinion. Sure you could port it and do all kinds of trick things to it, but you'll still have an engine with less than 100 horsepower, so I wouldn't waste my time.

NOW, that being said, if your going to use the vehicle as a TRUCK.....like it was intended to be, then that little 85 hp engine will trudge right along for many of miles and never complain.........but if you want a street truck with some get-up-and-go......then I would look into other engine options, OR, try and get a 12 valve head (and intake & other associated stuff) that was put on these engines in a rear-wheel drive setup, and then you would gain a noticeable hp improvement........but those parts are kinda hard to come by since the US never imported any of those vehicles that those parts came in! Like the Bongo.....

Just thought I would throw a few pics of the rebuild.

Almost finished. Runs great, just working out the little bugs...

Looks very nice in there! Congrats on the build!