bambbrose

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?

1991civicsi

Either block will suit your needs, if you are concerned about the metal particles heve them hot tanked.

TorganFM

I'd use a smaller turbo if that's all you'll ever want. Mitsu t25 shooting for 200whp will be a bit more low end friendly, but do what you want, that's just what I would do.

bambbrose

how about the different girdles. Does one offer any strength advantage over the other?

ryan89crx

only problem is that power is seriously lacking up top. i managed 12psi by 3300 on my .42/.48, definitely not slow spool by any means

bambbrose

I'm certain the 42/48 t3 is the turbo I want to use. Ease of compatible parts and rebuilds being one reason. Also I won't have to worry about pushing the turbo too hard with my goals. I've done rhb5/dsm t25/saab t25 setups already and I'm looking for a bit more punch on the top end.


So does anybody have any idea on the girdles or is it not really important?

I would assume steel is stronger, 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?

1991civicsi

The Z6 girdle (alum) is more than sufficient. There are Z6 setups w/over 400hp on stock sleeves (and girdles).

A6 block had steel girdles - earlier model years.

bambbrose

Ok. I think I'm going to go with the aluminum one then. Simply because its cleaner and going to be more than strong enough.

If anything, at least its saving weight lol. Probably about 4 lb difference between the two girdles actually.



I also have a question about the journals. They are cleaned up already in those pictures, but there is a small amount of darkness that won't clean off. There are no scrapes and I can't catch my fingernail on them in any way.

Do you think they need to be micropolished somehow or just left alone?

1991civicsi

If they arent scored then you should be fine. What do I know?

jwbetley

You should bring both blocks to a machine shop and have them measure the bore on each. Most machine shops will do this for free. While your there, ask for advice on the girdle. Noone here is going to chose which block/ girdle you should use without physically examining your parts.

While you are there, have your crank polished and block honed. You will be in for less than $100-$150 and will have a much better engine.