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I will be starting my motor build soon. I have two blocks to choose from, a 1995 and a 2001. Would there be any advantages to running one over the other? Is the '95 block located PCV much better than the vave cover PCV location? I won't be using the stock '95 air/oil seperator. Any weight differances? I'll be putting both blocks on a scale later once completly taken apart, but if anyone knows if one is lighter off hand.

I also know the main bearing notches are different.



^^^ '95 with vent tubes located in the middle of the block.



^^^ 2001 block without PCV bosses or vent holes.

http://www.babcox.com/editorial/ar/eb80234.htm

you already mentioned the #1 drawback to using the 95 block. The PCV setup was phased out because of emissions and other apparent issues like sucking in oil....

And the new design doesn't suck oil? I can see the point tho. If there was a seperate chamber in the block, like the pushrod inline type engines have in the lifter area then it would have worked great. But if you still need a catch can, I'd opt for the newer block.
Edit: unless you wanted an oil return line for some reason...

darrell cox also mentioned during my build that the newer blocks use a higher silica content. less brittle and better with heat. apparently allows for a better mating b/w the aluminum head and iron block. not sure that it makes a difference, but it did factor into darrell using the new block for my build.
brad

SGT BRAD wrote:darrell cox also mentioned during my build that the newer blocks use a higher silica content. less brittle and better with heat. apparently allows for a better mating b/w the aluminum head and iron block. not sure that it makes a difference, but it did factor into darrell using the new block for my build.
brad

that's because of non-similar metals causing corrosion

occasional demons wrote: And the new design doesn't suck oil?

None at all . Well, they do, but it's not block-related. The valve cover is your only enemy with sucking oil with the 2000+ engines. Swap it for a 1996-1999 valve cover and you're golden. I've got over 40k miles on my 2003 with a 1997 valve cover. Now I can take exit ramps like an animal (or any other corners) and not have to worry about a drop of oil ending up in the intake.

Definitely go with the 2001 block.

jonnymopar wrote:

occasional demons wrote: And the new design doesn't suck oil?

None at all . Well, they do, but it's not block-related. The valve cover is your only enemy with sucking oil with the 2000+ engines. Swap it for a 1996-1999 valve cover and you're golden. I've got over 40k miles on my 2003 with a 1997 valve cover. Now I can take exit ramps like an animal (or any other corners) and not have to worry about a drop of oil ending up in the intake.

Definitely go with the 2001 block.

I have a first gen valve cover too however, i do have oil in my intake manifold still (magnume intake).

If there isn't oil in your intake you're not taking corners hard enough

I guess the main question I've still got is will evacuating the crankcase gases directly from the crankcase be more effective than pulling the gases through the oil drain back passages and out the head? I'll be using a pan evac simular to what SGT BRAD is using on his stroker.

Seems to me that pulling the gases directly from crankcase would be most effective. ?

fixitmattman wrote:If there isn't oil in your intake you're not taking corners hard enough

The way the first gen valve cover is designed, its not supposed to.

Update: I weight both blocks bare. Both cylinder blocks came in at 74lbs, both bedplates came in at 25lbs... 99lbs total. No weight differance.

kevo wrote:The way the first gen valve cover is designed, its not supposed to.

The oil is hot enough it comes out out of the crankcse/rocker cover as vapor, then it cools on the way to the intake, condensing back to liquid, hense the oil in the intake. There isn't a valve cover made that will keep oil vapors from passing, unless it has a way to cool them before exit. A well designed catch can system will do a pretty good job tho.

arnt 95 cams more aggressive?

Fuzzyneon wrote:arnt 95 cams more aggressive?

yes, but they are talking about the block, not the head.

Yeah i realized that after i posted d'oh