Rebuilding Block and i see micro cracks need help v. PICS
 

Hey HT,

I bought a project hatch and ive been tearing down the d16z6 engine and i finally have it apart. I have it down to the bare block and I see these cracks. I'm not sure if they are cosmetic or structural.

This is my first time so i have no experience to be able to make any judgement. The symptoms of the engine before the tear down was spun rod bearing on cylinder #4, water in oil and over heating. When i removed the head the gasket seemed fine but maybe just a bad seal.

Unless these micro cracks are letting water into the block. The cracks dont propagate into the sleeves. This is underneath where the crank and oil pan are. Any help would be great if i either scrap the block or give it a shot and see what happens.

Re: Rebuilding Block and i see micro cracks need help v. PICS
 

They all look like that, they're just casting marks. Don't worry about it.

Re: Rebuilding Block and i see micro cracks need help v. PICS
 

Ok you dont think coolant is getting through those cracks in the crank case/ oil pan?

Re: Rebuilding Block and i see micro cracks need help v. PICS
 

No.

Re: Rebuilding Block and i see micro cracks need help v. PICS
 

Excellent im going to clean the block and start plastigauging main and rod bearings.

Re: Rebuilding Block and i see micro cracks need help v. PICS
 

Like was said previously, that is casting slag. It's those imperfections people will shot peen of their cast rods to help reduce hotspots. On the block it's not really an issue.

It's also that same slag that people port and polish headers to remove for smooth air flow in and out of the engine head.

It's not cracks, just excess aluminum material from the casting of the block.

Re: Rebuilding Block and i see micro cracks need help v. PICS
 

The main bearings are within spec, time to check the rod bearings. I have a question. I have eagle rods and vitara pistons (i know) my first build is budget. There is a lot of gap on both side of the piston where the rod meets the piston (the smaller bore of the rod). Like a half inch of travel on both sides. Its lateral gap. Is this normal? I didnt put together the pistons and rods.

Re: Rebuilding Block and i see micro cracks need help v. PICS
 

Yes, that's normal.

Re: Rebuilding Block and i see micro cracks need help v. PICS
 

Great thanks!

Re: Rebuilding Block and i see micro cracks need help v. PICS
 

I measured the rod bearings and they are within spec. However, there seems to be some end play on the rods. I can shake them back and forth (not up and down) and it makes some noise. I check the helms and with a feeler gauge im around the service limit.

Has anyone built a motor with a little rod end play or have any information regarding what i should or should not expect if i continue the build. This engines life time is not important just going through the learning curve.

Re: Rebuilding Block and i see micro cracks need help v. PICS
 

back and fourth in reference to what? What's making noise?

Re: Rebuilding Block and i see micro cracks need help v. PICS
 

Engine on stand upside down. The rod end cap is torqued down. If i wiggle the rod end cap left and right (twisting it) it has some play. Only one of the rods show this action. The noise is the rod end cap hitting the side of the rod journal.

There is however no up and down motion and the clearance with plastigauge is within spec.

Re: Rebuilding Block and i see micro cracks need help v. PICS
 

That's odd. The FSM doesn't say anything about that, but that rod might be out of round. Take it to a machine shop and have them measure it. If it is out of round, you'll have to replace all four - they're a balanced set.

Re: Rebuilding Block and i see micro cracks need help v. PICS
 

I found this in the helms. In the diagram its checking the gap on the sides. I have one that i can move side to side. Ill try over torqueing and see if that changes anything as an experiment.

Re: Rebuilding Block and i see micro cracks need help v. PICS
 

That's for lateral movement. You said "twisting". It shouldn't be able to twist when torqued down.

Re: Rebuilding Block and i see micro cracks need help v. PICS
 

In order for me to get it to move i have to twist it to wiggle. Maybe im just being overly cautious and some movement is acceptable.

Ill make a quick video tm to verify if its ok or not thanks guys.

Re: Rebuilding Block and i see micro cracks need help v. PICS
 

Hey guys this is what im experiencing. No rod movement up and down but twisting. This is torqued down. Im starting to think the girdle was warped and now the crank is out of round but the clearances are within range.
SHITTTY VIDEOOOOOOOOO

Re: Rebuilding Block and i see micro cracks need help v. PICS
 

Take the rods to a machine shop, have them measure the rods for roundness. It shouldn't be able to do that.