stage1 compared to stage 2

[tom j]

What are pro's and con's over the other besides cubic inches .

 

[750H.P.V6]

The block castings are the same so there is no difference in displacement for the same casting. The 25500012 is a 3.8 liter and the 25500016 is a 4.1 liter. Stage I's come with 2 bolt cast iron main caps, Stage II's have 4 bolt center main caps that are steel. Later versions of the Stage II Off center blocks had 3 steel main caps then all 4 steel main caps depending on vintage. Stage II's have a different oiling system and come drilled for 14 bolt heads. Stage I's can be drilled for 14 head bolts but originally have only 8 head bolt holes per side.

Neal

What are pro's and con's over the other besides cubic inches .

 

[norbs]

Stage 1's usually crack between the two frost plugs for some reason, not sure why. Sometimes making it impossible to repair.

 

[750H.P.V6]

I've seen that happen in both Stage I's and II's. 3.8's are the worst for it. Personally I won't build a 3.8 liter Stage block. That's just me.

Neal

Stage 1's usually crack between the two frost plugs for some reason, not sure why. Sometimes making it impossible to repair.

 

[GNFOOS]

I have a q what is the diferance beetween 3.8 and 4.1 is it the bore? gnfoosball

 

[750H.P.V6]

The bore size is what accounts for the difference in displacement. The 2 block castings are different. The 4.1 liter block has siameese cylinder bores which actually adds to the structural integrity of the block. Standard bore on a 3.8 block is 3.800" a 4.1 block is 3.965".

Neal

I have a q what is the diferance beetween 3.8 and 4.1 is it the bore? gnfoosball

 

[PaCemkr86]

nice thread good info

 

[49-blues]

Neal- could you explain alittle more about the siamesse bores-what are the physical appearance differences? is it how they are cast?

 

[Mac in SD]

Neal- could you explain alittle more about the siamesse bores-what are the physical appearance differences? is it how they are cast?

On siamese bores, there are no water passages between adjacent cylinders. On non-siamese, the cylinders are surrounded all the way around by water. It's how they're casted.

 

[49-blues]

thanks- i would think that having coolant around the cylinders would help in the combustion process.