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Conrod question

W

Wesdunns70t5m

New member
Joined
Oct 4, 2016
Location
Jacksonville, NC
So Monday my motor started knocking, Tuesday it officially crapped the bed. The conrod bearing on the crank end let go, letting the piston slap around in the cylinder. It ended up popping the freeze plug, breaking the cylinder wall between cylinders 1, 2, and 3, and the piston separated from the conrod.

I?m now in a search for a new engine and have a lead, possibly two. My conrod in the victim cylinder appears to still be straight and possibly reusable. Of course I?m looking for a big rod motor, but if it comes down to getting a skinny rod motor, would the bigger rods swap right in place, or would something not be compatible? I?m not sure of wrist pin sizes, or the big end size of either big or small rods. Of course I?d have a machine shop check all 4 rods before proceeding. Thanks all in advanced
 
You don't want to be using that rod.

If you need a set of 13MM rods I have some I'd let go for the price of a cheap lunch on top of shipping.
 
yea don't reuse broke junk. if it spuna bearing and was hammering around in there, the big end probably isn't dimensionaly correct anymore and it'll just spin again in 100 miles or so.
 
My two current possible engine choices are a 93 NA motor, or an 89 turbo motor. Im now leaning towards the 89, and if that’s the case I’ll just need the rods, possibly. I’m still trying to find out if the rods will be a direct swap or not
 
Wesdunns70t5m said:
My two current possible engine choices are a 93 NA motor, or an 89 turbo motor. Im now leaning towards the 89, and if that?s the case I?ll just need the rods, possibly. I?m still trying to find out if the rods will be a direct swap or not
Click to expand...

The 93 NA block should have the squirters btw...

Check if the 89 is a mid or rear thrust bearing engine. Probably a rear but you never know...

The NA block should have been less stressed in its life. But you'll have to drill and tap the oil return in the block if you don't wan to weld a fitting in the oil pan.
 
Volvo changed things around on the B230 bottom end mid production, reverted back for the last part. I'm not really clear on when things changed, but I think engines 88 and up al lhave the same rod specs, some just had skinny rods, some thick. And they're all the same dimensions on big and little ends.

Over the years of blowing up redblocks, I bought two different 93+ squirter turbo motors and stripped them all the way down, using just the block, crank, oil pans. Both of them had 200K+ miles, so I wouldn't suggest anyone use the pistons, but the rods are fine.
 
Having the squirters would be nice, but it isn’t gonna be the deciding factor. The 89 motor has 110k miles so I am leaning towards that one. Plus I’d rather avoid having to drill the block or weld onto the pan. Is there any easy way to tell if it’s rear or mid thrust? The seller and engine are
Located up north, and Easter weekend he’ll be in the area and be bringing the motor with him
 
Not sure on the mid/rear thrust, but the squirter blocks are (usually) easy to identify because they have the round toothed timing belts on them. Some earlier engines might have squirters, and occasionally you hear about some rare round toothed motors that didn't have them, but perhaps after a couple of decades those are just the results of someone piecing something together, and it later on being found in a junkyard.
 
Wesdunns70t5m said:
Having the squirters would be nice, but it isn?t gonna be the deciding factor. The 89 motor has 110k miles so I am leaning towards that one. Plus I?d rather avoid having to drill the block or weld onto the pan. Is there any easy way to tell if it?s rear or mid thrust? The seller and engine are
Located up north, and Easter weekend he?ll be in the area and be bringing the motor with him
Click to expand...

I just checked and B230 blocks after 1987 should be rear thrusted so you're good with the 89.

The squirter blocks are usually quieter (less piston slap) and show less piston and ring wear. Is that 93 block bare or does it still have the crank/rods and pistons in?
 
The 93 is described as a long block, while the 89 is a short block. I’ve got the head off my blown motor so the head wouldn’t be much an issue. Moreover, the seller stated he wasn’t sure if the 89 was a big or skinny rod motor, so I’m assuming the rotating assembly is still pressnt
 
AFAIK the 89's were skinny rod motors, 90+ went to 13mm, and 93+ had squirters. With some minor differences seeming to exist.
 
JohnMc said:
AFAIK the 89's were skinny rod motors, 90+ went to 13mm, and 93+ had squirters. With some minor differences seeming to exist.
Click to expand...

That?s the impression I was under as well. Seeing as I recently installed a 19t in my car, I?m not too sure the NA compression ratio would like that much turbo too much for too long. I?m now leaning more towards the 89 motor, and grabbing a set of 13mm rods and swapping them in. Should be good to go at that point in time
 
Wesdunns70t5m said:
That?s the impression I was under as well. Seeing as I recently installed a 19t in my car, I?m not too sure the NA compression ratio would like that much turbo too much for too long. I?m now leaning more towards the 89 motor, and grabbing a set of 13mm rods and swapping them in. Should be good to go at that point in time
Click to expand...

Grab both motors and swap the turbo pistons into the 93 block?
 
^^

Basically, what culberro is suggesting.

Get the 93 engine and the rods/pistons from JohnMc. The squirter blocks don't wear out the parts anywhere near as fast as the earlier design did. I'd bet those pistons are in nice shape. That will fit your Turbobricks budget and should actually last awhile.
 
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