Mopar 440 racers - time to legalize that shortblock!

[Lynn A McCarty]

Originally Posted by SStockDart

This entire conversation affects our car. However, it seems that everyone is making a bigger deal out of it than it really is. Their is no difference in using the low deck block than using a decked tall block except the main bearings and distributor. Unless NHRA starts measuring crank CL to the deck (for everyone!!!) Expect to see decked 440 blocks. So, the end result is it will cost us more money to change our engines and add about 20 pounds to the front of the car. I don't understand NHRA's logic, except that it will cost us more money to get the same result in a combination that hasn't run within a tenth of a second of the SS/FA record, set by a Chevy.

With all due respect, this simply isnt true. One of the "natural" advantages of a 455 Pontiac is that it has a 6 5/8 rod 10.200 deck. This allows a 455 Pontiac to have a piston with a 1.500 compression height. With a single ring motor we have short piston skirts allowing a piston to be 380 grams without the pin. I now have a pin that goes about 53 gms. This makes a complete piston with two rings pretty freaking light. (one of our only true advantages) Our stroke is 4.223.

What if you have on the contrary a 3.75 stroke motor like a 440 or a Hemi with a 10.750 deck? This is a terrible disadvantage. It makes your piston like an air compressor. I measured Rick Allison's SS/AA piston about 20 years ago and it weighed over 1000 gms. Of course he didnt have a killer light set, but if you add 1/2 the additional stroke (4.223 - 3.75 = 0.473 then 1/2 = 0.2365 inches), then you add the difference between the Pontiac's 10.200 and the Mopars 10.750......that is another 0.550.

So you get a piston that is at least 0.550 plus 0.2365 or 0.7865 shorter. Not only does this take weight out of the piston it takes weight out of the crank to balance. We always used 0.300 compression height as worth a tenth. Maybe with piston technology it isnt that much, but it isnt zero. If you want to read some good info go to Wiseco's website about piston technology and power. It is a good read.

http://www.wiseco.com/TechTips.aspx click on "forged piston technology 101"

We have been talking to Wiseco about their strutted piston. We can get a compression height of 1 inch with this new strutted piston design with a single ring motor no problem. Pontiac has a block 9.200 deck. With our shorter stroke 9.200's we can get a 3.75 stroked 400 motor pretty killer. Like I said, if NHRA wants to go there we are going to have some weird looking motors out there. Like I said, I have no problem with the BBMopar guys getting it, but we should get it too. 400 Chevy guys would have a killer short block.

Rocket block's posts I agree have been excellent! Rocket, you dont know the 1/2 of it, the truth would shock you to the core!

Lynn

[RocketBlock]

Originally Posted by Lynn A McCarty

With all due respect, this simply isnt true. One of the "natural" advantages of a 455 Pontiac is that it has a 6 5/8 rod 10.200 deck. This allows a 455 Pontiac to have a piston with a 1.500 compression height. With a single ring motor we have short piston skirts allowing a piston to be 380 grams without the pin. I now have a pin that goes about 53 gms. This makes a complete piston with two rings pretty freaking light. (one of our only true advantages) Our stroke is 4.223.

What if you have on the contrary a 3.75 stroke motor like a 440 or a Hemi with a 10.750 deck? This is a terrible disadvantage. It makes your piston like an air compressor. I measured Rick Allison's SS/AA piston about 20 years ago and it weighed over 1000 gms. Of course he didnt have a killer light set, but if you add 1/2 the additional stroke (4.223 - 3.75 = 0.473 then 1/2 = 0.2365 inches), then you add the difference between the Pontiac's 10.200 and the Mopars 10.750......that is another 0.550.

So you get a piston that is at least 0.550 plus 0.2365 or 0.7865 shorter. Not only does this take weight out of the piston it takes weight out of the crank to balance. We always used 0.300 compression height as worth a tenth. Maybe with piston technology it isnt that much, but it isnt zero. If you want to read some good info go to Wiseco's website about piston technology and power. It is a good read.

http://www.wiseco.com/TechTips.aspx click on "forged piston technology 101"

We have been talking to Wiseco about their strutted piston. We can get a compression height of 1 inch with this new strutted piston design with a single ring motor no problem. Pontiac has a block 9.200 deck. With our shorter stroke 9.200's we can get a 3.75 stroked 400 motor pretty killer. Like I said, if NHRA wants to go there we are going to have some weird looking motors out there. Like I said, I have no problem with the BBMopar guys getting it, but we should get it too. 400 Chevy guys would have a killer short block.

Rocket block's posts I agree have been excellent! Rocket, you dont know the 1/2 of it, the truth would shock you to the core!

Lynn

It's just that the first half is reason enough. Speaking of ring count on a SS engine, an inherent advantage to a short deck, long rod engine (which is what this 440/400 is all about) is the wrist pin is moved up an extreme amount. That allows a very short piston design as I mentioned earlier. Maybe everybody doesn't know what is good about a short piston with a high pin besides weight. This design allows the piston more stability as the piston is at top dead center and maybe more importantly rock over towards bottom. An engine built to the rules may require two compression rings, an engine built against the rules may only need one compression ring which offers even less weight and less frictional loss. True, many in SS only use one ring but there may be compromises. Those compromises may be negated with a long rod motor. A short deck / long rod engine also has a piston that shows more dwell time at TDC, enhancing the burn rate for more complete combustion. And I agree with you, the crank can get a lot lighter because of the piston weight reduction.
Could you just mill a RB family block to obtain the same advantages? Probably. But I don't think there is enough material there and you would probably have a problem with head gaskets and warping the decks.

[Lynn A McCarty]

Originally Posted by RocketBlock

Could you just mill a RB family block to obtain the same advantages? Probably. But I don't think there is enough material there and you would probably have a problem with head gaskets and warping the decks.

No it screws up the water hole in the front. So, I was told certain "Hemi" teams were allowed to go into the foundry and massage the foundry cores. This allowed the after market blocks to be altered to less than 1 inch if they wanted with plenty of meat on the top. When that kind of bull**** is allowed, we are all done for.......well now that you mention it.....who else is doing it? We shouldnt just pick on the Mopar guys!!!!!!!!!!!!!!

The short deck block issue is a serious one, and no one is paying attention. My opinion is that it takes away from the original engine design. If they are going to allow this, then why dont I alter Pontiac heads to fit a 400 Small Block?

Lynn

[SSDiv6]

Originally Posted by Lynn A McCarty

No it screws up the water hole in the front. So, I was told certain "Hemi" teams were allowed to go into the foundry and massage the foundry cores.

Lynn

It does not affect the water pump mounts. If this was the case, then the 383/400 engine would have the same problem. The camshaft bore C/L to crankshaft C/L is the same for both the RB and B blocks and they share the same timing sets. When the RB block was created, they just added material to the deck height in the same fashion that there are different deck heights for the Chevy big block engine: there is a standard deck and tall deck. Was the 1959/1960 383 block with the 3.75 stroke cast with an RB or B block deck height? It appears they are rare and hard to find. Therefore, if the 1959/1960, 383 block was cast with the B block deck height, has an OEM 3.75 stroke, what would preclude its use in SS class as a 440 engine?

[Paul Precht]

The Golden Lion 383 is a raised block. It is physically identical to a 440, just a very small bore and a different crank flange to fit the cast iron torqueflites.

[Lynn A McCarty]

Originally Posted by SSDiv6

It does not affect the water pump mounts. If this was the case, then the 383/400 engine would have the same problem. The camshaft bore C/L to crankshaft C/L is the same for both the RB and B blocks and they share the same timing sets. When the RB block was created, they just added material to the deck height in the same fashion that there are different deck heights for the Chevy big block engine: there is a standard deck and tall deck. Was the 1959/1960 383 block with the 3.75 stroke cast with an RB or B block deck height? It appears they are rare and hard to find. Therefore, if the 1959/1960, 383 block was cast with the B block deck height, has an OEM 3.75 stroke, what would preclude its use in SS class as a 440 engine?

SSDiv6,

We have two separate issues here:

1.) Blocks with "cross breeding" from a 383 engine "family" for use in a 440 to get an extremely light rotating group.
2.) Blocks being altered completely different than what is approved as a Hemi replacement block by NHRA for a Hemi. The approved RB block has about 0.600 on the deck total. So what 0.400 at the most? If you go below that the water hole doesnt allow water to the cylinder heads. So any Hemi with anything lower than about 10.300 isnt using the NHRA approved block. If I am wrong about this please inform me.

If you are cutting down the approved block on deck a couple hundred thousandths that is one thing. If you are altering sand molds or substituting alternate unapproved castings.....that is something completely different. Just like was stated here previously, there is no way you can cut an RB block even close to 10.00 deck. In either case grossly illegal for Super Stock.

The 440 guys have a much easier way to go. However, cross breeding as stated in the rule book is prohibited.

If we let this happen, it is a slippery slope. We will have a Pontiac with RA-IV heads that looks like a 289 Ford, and a "G" string intake wide enough barely to fit the Q-jet.

The real question is where does NHRA draw the line? It cannot be Mopar guys get it and no one else does. I am respectful of the Mopar guys doing this for power, but we gotta be able to do the same. Otherwise if they want a big motor and a very light piston with a big stroke with a 10.200 deck, they need to build a Pontiac.

Lynn

[Jack McCarthy]

travis miller has drawn the line a few times... it was erased by gracia repeatedly !!!

jack mccarthy

and if larry hill says 483 cid ill bet he's right !!

[RocketBlock]

As soon as NHRA approves the short deck non-production 440 you will want to find one of these 400 blocks listed as it is the strongest B/RB block available with increased support to the crankshaft. And since you have taken over .125" (more if using spacers) from the crankshaft you will need all the support you can get. http://www.440source.com/blockinfo.htm

[Max'd Out]

Originally Posted by Jack McCarthy

travis miller has drawn the line a few times... it was erased by gracia repeatedly !!!

jack mccarthy

and if larry hill says 483 cid ill bet he's right !!

Jack, Don't overload Gracia's brain. He has all the work he can do running interference for a certain upstate New York Max Wedge racer who cheats his a** off. He even had A&A cast him illegal manifolds. I believe his initials are J.S.