Is the 25524140 casting block any different in strength than the 86-87 109 block? the 140 casting is from 85 rwd 3.8. This also has 20 bolt oil pan instead 14 like earlier years. Any better than the 290 casting from 83 3.8 block? Its same as 109 block except for rough casting in lifter valley area correct or not? Would the 140 casting be a good block to use on the 83 turbo buick is why asking?
block castings
- Thread starter buick83-T
- Start date
Hey there, okay I am beginning a TR project and have asked meny, many questions. As far as the blocks are concerned, in general, the 109 can take the most boost / abuse. Next would come the 4.1 (252 CID), and the rest of the 3.8 family comes in order of the yaer produced. Buick did many upgrades to the block as time marched on. So for your application, it would depend on what your planning. My set-up starts with a 4.1 and will have about 10-12 lbs of boost. Keep in mind that any engine will fail underboost if its not prepped for it. Post up somemore details and maybe these kind folks can steer you in the right direction.
Xamot said:
I disagree with the above. The 4.1 castings are the most prone to failure of them all. What upgrades did they do to the blocks? The main webbing is just about identical on all of them and that's where they fail. They are all the same alloy nodular cast iron. Crank flex loads the mains unevenly and increases the chance of failure as power is increased.
WarWagon
Caustic Cacophony
- Joined
- Mar 10, 2007
Listen to Bison!
I just found out this year about the 140 block being similar to a 109 but no clean lifter valley and it has a increased deck height over the 109 block and no drain back hole. So compression is even lower with those blocks, and just as weak as the other blocks save for the 109 but even it is weak too right lol.
To the OP: yes it would be alright to run in an '83 with drawthru mode turbo, that setup would probably not make enough steam and never hurt that block.
I'm running a stock long block 140 casting(except a double roller timing chain) in a blowthru configurarion and it's hanging in there just fine for now with high mileage.
I just found out this year about the 140 block being similar to a 109 but no clean lifter valley and it has a increased deck height over the 109 block and no drain back hole. So compression is even lower with those blocks, and just as weak as the other blocks save for the 109 but even it is weak too right lol.
To the OP: yes it would be alright to run in an '83 with drawthru mode turbo, that setup would probably not make enough steam and never hurt that block.
I'm running a stock long block 140 casting(except a double roller timing chain) in a blowthru configurarion and it's hanging in there just fine for now with high mileage.
turbonut85
Rarely used member
- Joined
- Apr 11, 2008
I agree with bison. As far as the 140 block is concerned, the deck height is higher than the 109, simply so a thicker composition head gasket could be used from the factory....compression would only be lower if the same thickness head gasket was used. All production v6 blocks will fail at some point....especially if detonated. The 109 can definitely take the most abuse, but any of the blocks will survive just fine if they are prepped correctly, and tuned properly. I would not shy away from the 140 block personally....just my .02
turbonut85
Rarely used member
- Joined
- Apr 11, 2008
4.1 main webbing failure.....to the extreme....(not because the block was weak...crank broke)
dr_frankenstein
Mad Scientist
- Joined
- Mar 17, 2008
I wouldnt concern one much with the heights of the deck, for a carb turbo motor that isnt going for max attack it should be neglegable. just choose proper gasket for either, composite for low deck, and steel shim for tall.
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