Pictures showing a 420a block from an eclipse and second photo from a 2000's neon. Think the added support in the passages are any benefit at all?

It depends on how far down in the block they go, if its just up in the top its not going to do much.

How many 420a motors before this change saw headgasket issues? I could see them adding webbing right up top to help guard against deformity when at the point of highest static compression, but if it doesnt run all the way down then peak cylinder pressure would still wreak the most havoc.
if the webbing does run all the way down, what has that done in terms of coolant passage changes for flow paths or creating areas for coolant to remain mostly motionless?

Then again, the motor wasnt designed for boost, was it?

many questions, no simple answers

That will definitely help with deck stiffness.

Are we sure the deck hasn't been milled a little more on the top block pic? It's also got high-comp pistons, which makes me wonder if it wasn't cut down some for more effect, though it does seem that would be a lot of deck height cut out.

Ill agree the extra webbing will increase deck stiffness though, even the small amount.

ThunderChild said:

Are we sure the deck hasn't been milled a little more on the top block pic? It's also got high-comp pistons, which makes me wonder if it wasn't cut down some for more effect, though it does seem that would be a lot of deck height cut out.

Ill agree the extra webbing will increase deck stiffness though, even the small amount.

Click to expand...

Nah, thats how all the eclipse motors are (in the top pic). The stock motor that I pulled out before my bottom picture, looks just like the top one. Just not as clean