I have two d16a6 blocks to use for my rebuild. I'm just building it for mild boost, about 6-8psi, using a .42/.48 t3. Basically I just want to do an OEM rebuild using arp studs to make it a bit stronger. Goals are around 200whp.


Here are the two blocks I have. I am only concerned with the bare blocks here, not with cranks or anything else

The first one has a steel and aluminum girdle. It did have a spun rod bearing but I'm not using the crank. I am worried there may be shavings in the oil passages but not sure how I'd clean those out.

Here is how its journals look, notice the steel caps on the girdle:





The second block has an entirely aluminum girdle. It just had a blown headgasket so no chance of shavings anywhere, but I'm wondering if there is a strength advantage to the steel girdle over the aluminum one.

Here is how its journals look:





Is there a strength advantage either way with the girdle differences? How about the journals, which one looks best to you guys? Also is there a risk of shavings being everywhere inside on the one that spun a rod bearing?

 

Why not just have them hot tanked? I mean it is kinda cheap insurance to ensure EVERYTHING is clean of small stuff you may not even see.

 

I plan on having the one I choose hot tanked, decked, and inspected. I'm just trying to decide which one to use.

 

I would assume the steal.... I am in for more answers

 

I would assume steel as well, but I am curious if the coefficient of expansion makes a difference (the upper half being aluminum and the lower being steel vs both being aluminum).

Also the series numbers on the block are 4 million for the all aluminum, and 2 million for the half/half one. I always thought the numbers were related to casting date, which would indicate the steel is the older version.

Anybody with knowledge on this subject?

 

got a few more answers on another forum.

Looks like the aluminum one is indeed the later model, and is the same as the one used in the d16z6.

I decided it's probably the best choice as it is cleaner, and hasn't had a bearing spun in it. Plus its about 4lbs lighter.

Another question.
Based on the pictures, do you think I should have the journals micropolished? Or should I just start to measure and assemble?