Something Went Wrong! Very Wrong!

[twstdv6]

Motor had previously been rebuilt, I ended up wiping some main bearings pretty good. I will rebuilding it myself this time around. Upon taking it apart, I noticed the piston's had some scratches on them right above the pins, like some with scratches on both sides & some with one side. Diamond Piston's faced Correctly, but my question is were the 2 Dot Rods put in right? They are as follows upon breakdown:

1. Rear
2. Front
3. Rear
4. Front
5. Rear
6. Front

If this is correct, What may have caused the pistons to scratch against? By the way the motor had 4k+ miles, was running 18-20lbs of boost

 

[gossamer]

The rod orientation looks correct. You will sometimes see scratches on the thrust side of the piston (the side of the piston facing down) depending on miles, abuse, etc.

 

[twstdv6]

Okay! I went and talked to the builder, The scratched are from the pins being pressed in he said. That is good news, but the bad is that I broke my motor in with Mobile 1 Synthetic, the new cam was wiped, and he said that's probably what took out the main bearings, or just a number of other things. The motor was strong and just seemed to lose power over the month's and I could not get boost over 20lbs. The cam was wiped and the exhaust valve wasn't doing something he said, and my piston's top's were black within 2 day's. Had a rough up n down idle, no power. Learning new things about these car's everyday. Back to drop off block, crank to the machine shop and order some new parts and hope not to make the same mistake twice.

 

[87 WE2]

Spend the money and get a roller cam, or if you use another flat tappet, make sure you use valvoline vr1 racing oil it has a higher level of zinc in the oil that will protect the cams lobes during breakin and load. Or use regular oil and pick up a bottle of ZDDP to add to the oil, I use the valvoline VR1 and the ZDDP additive also. Can never have too much of a good thing.

Do a search on zinc, or zddp and read up.