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Discussion Starter · #1 ·
What constitutes a small block in PRO STOCK N/A??
I mean lets say true Pontiac engine they never made a small block per say like Chevy, but you can build a small cid Pontiac.

Do the rules go by cid or manufactured development.

Thanks
Steve
 

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Discussion Starter · #3 ·
I don't think that question has ever been contimplated Steve... it's a good question though. I couldn't imagine what John could do with a 420 inch version of his engine....
Well we need to know then don't we??? Not just for John's sake.:p

BTW..Chris Your PM Mail Box is full tried to PM you earlier.;)
 

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a 420" Pontiac would have to weight the same as a sbc but you are limited to the edelbrock or wenzler head or anything under 477"??? You could not run a 420" motor or even a 440" Pontiac in that class with anything other then a 5-speed behind it because you would not be able to get to weight. Even if some long stretch of the imagination that you could get to weight, you would be something like 60% on the nose. Good luck making that work with a 10.5 tire.
 

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Discussion Starter · #9 ·
a 420" Pontiac would have to weight the same as a sbc but you are limited to the edelbrock or wenzler head or anything under 477"??? You could not run a 420" motor or even a 440" Pontiac in that class with anything other then a 5-speed behind it because you would not be able to get to weight. Even if some long stretch of the imagination that you could get to weight, you would be something like 60% on the nose. Good luck making that work with a 10.5 tire.
Ok so I gather your talking about Pontiac Eng CID per WT and HP made would not worth it because they weigh the same as a big inch motor which is way off of the SBC even if you got the small CID weight break from the rules. Then again you mention 60% nose, Is that true for all Big Blocks not just Pontiac???. Dosen't a jouncing momentum factor key in here for nose weight??? Are you not able to move some weight anywhere Lat, Long or +-vert(XYZ) on the chassis???
Also...
Wouldnt that depend on the car and how it is set up (XYZ) or which car style it was in??? How much diff is there from lets say the 69 bird and the 02 birds. Isn't there more weight to pull out of or transfer diff in the newer styles???

Just picking yer mellon.:rock:
 

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I am pretty sure that the NMCA Pro Stock late model BBC f-bodies can get down to around 3150 with all of the weigh out of them. I can get my car to around 3135 ish, no ballest and a 235lb driver. Keep in mind that a traditional Pontiac weighs around 100lbs or so heavier then a BBC. Additionally, I have an IA1 block in my car which is around 30-40lbs lighter then the IA2.
 

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Discussion Starter · #12 ·
I am pretty sure that the NMCA Pro Stock late model BBC f-bodies can get down to around 3150 with all of the weigh out of them. I can get my car to around 3135 ish, no ballest and a 235lb driver. Keep in mind that a traditional Pontiac weighs around 100lbs or so heavier then a BBC. Additionally, I have an IA1 block in my car which is around 30-40lbs lighter then the IA2.
Ain't that some thing John. So that would make you 70lbs heavier with the IA1 in regards too the BBC.
Now what is the weight break for a SBC or SBF??? And would "420 or 440cid" IA1 be considered as a "Small Block" to qualify for the small block weight break?
 

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a 400/420/440 pontiac would run at sb weights and then the pontiac weight break on top of that. The Tiger head is not legal on a sub 477" motor????? You would be stuck using the "E" head or Wenzler. Unfortunately the stock deck height on a Pontiac is in the neighborhood of 10.220". The "most" you can take off of an aftermarket block is .100. The BBC is 9.800 and can go to around 9.500 +/-. That is alot more block material for the Pontiac = weight. The lightest you will see a Pontiac crank is around 62lbs. There are sbc and sbf that are out there under 36lbs. The Tiger head with valves and springs (no shaft bars) weigh in at exactly 50lbs each.
 

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I am pretty sure that the NMCA Pro Stock late model BBC f-bodies can get down to around 3150 with all of the weigh out of them. I can get my car to around 3135 ish, no ballest and a 235lb driver. Keep in mind that a traditional Pontiac weighs around 100lbs or so heavier then a BBC. Additionally, I have an IA1 block in my car which is around 30-40lbs lighter then the IA2.
A Dart BBC block is about 280 lbs. at 4.50" bore. How can your Pontiac be "any" heavier than that? The Bowties and Merlins are about the same. The Dart race block is 303 lbs., bare, we weighed one. A factory four bolt block Chevy is 220 lbs. at a 4.25" bore. i read that the pontiac standard block comes in at around 640 lbs. complete. I'm assuming that is with cast iron heads so how could a Pontiac be any heavier that a standard BBC which tips the scales at 685 lbs. with iron heads? The small block is about 565 lbs., again with iron heads.
 

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An aftermarket Pontiac block that is not filled is approximately 100-140lbs heavier then a stock pontiac block. The IA1 block is around 30-40 pounds lighter then an IA2 block. The IA2 added material in the valley area, deck, front of block and has registered mains. When they registered the mains, they simply added material to the pan rail of the block and then machined down the starter pad. The 303lb block, is that a tall deck or standard height block?
 

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An aftermarket Pontiac block that is not filled is approximately 100-140lbs heavier then a stock pontiac block. The IA1 block is around 30-40 pounds lighter then an IA2 block. The IA2 added material in the valley area, deck, front of block and has registered mains. When they registered the mains, they simply added material to the pan rail of the block and then machined down the starter pad. The 303lb block, is that a tall deck or standard height block?
Dart's new race block, at a 10.2" deck height. They also make this block in several more deck heights, eg. 10.6" & 11.1" The Merlin Pro block is also over 300 lbs. but the Merlin II & III are in the neighborhood of 280 lbs. at 4.50" bores. They will bore out to 4.625" at which point the trim down to about 250 lbs., or a little less. My factory 4.25" four bolt main block is exactly 218 lbs., bare, with main & cam bearings.
 

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There isn't any tall deck block running in either pro stock or x/s. I would go as far to say that I dont think there is 1 bbc with over a 9.600" deck height in pro stock or a bore smaller then 4.625. That is why the BBC is lighter then the Pontiac in those classes. My block weighs 260lbs bare and I have one of the "light" ones. You would think that you dropped a nut if you tried to put in the back of a truck by yourself.
 
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