HIGHEST HP N/A Small blocks out there!!

[bob460]

The highest documented hp out there for N/A small blocks...............is URE still number 1....at 1,244hp?

Here is top 15

466” CU/Marcella SB Chevy 1,244 HP, 2.67 hp/ci (ROX)
400” BRE SB Mopar 1,200+ HP, 3 hp/ci
400” ELIO SB Ford 1,200 HP, 3 hp/ci
457” CU LSX 1,200 HP, 2.62 hp/ci (2x4, Mozez/Slick Rick)
450” CU/BK SB Ford 1,185 HP, 2.63 hp/ci
396” Grant SB Ford 1,175 HP, 2.97 hp/ci
400” BRE/Dart LS Next 1,169 HP, 2.92 hp/ci
400” BRE SB Chevy 1,163 HP, 2.91 hp/ci
450” CU SB Chevy 1,140 HP, 2.53 hp/ci (Splayed Valve)
440” BES LSX 1,116 HP, 2.54 hp/ci
442” CU/BK SB Chevy 1,108 HP, 2.51 hp/ci (SB2)
400” Patterson SB Chevy 1,100+ HP, 2.75 hp/ci
401” Weurtz Bros SB Ford 1,085 HP, 2.71 hp/ci (D3)
435” SAM LSX 1,064 HP, 2.45 hp/ci
450” BES SB Chevy 1,064 HP, 2.36 hp/ci (Wedge)

[Sparksalot]

That's a strange topic but go for it. The displacements for some of your candidates puts them well out of easily accomplished small block swept volume.

The 3 HP per cubic inch versions are stunning if true for two valve American iron on gasoline. Never happened NA.

There are reasons for that which you are unaware of. Study mechanical engineering to learn why.

[ClassAct]

That's a strange topic but go for it. The displacements for some of your candidates puts them well out of easily accomplished small block swept volume.

The 3 HP per cubic inch versions are stunning if true for two valve American iron on gasoline. Never happened NA.

There are reasons for that which you are unaware of. Study mechanical engineering to learn why.

IIRC that small block Chrysler is N/A. Pretty sure most of what’s on that list is N/A.

[lefty o]

That's a strange topic but go for it. The displacements for some of your candidates puts them well out of easily accomplished small block swept volume.

The 3 HP per cubic inch versions are stunning if true for two valve American iron on gasoline. Never happened NA.

There are reasons for that which you are unaware of. Study mechanical engineering to learn why.

actually not hard to get those cubic inches from small blocks any more.

[LSP]

That's a strange topic but go for it. The displacements for some of your candidates puts them well out of easily accomplished small block swept volume.

The 3 HP per cubic inch versions are stunning if true for two valve American iron on gasoline. Never happened NA.

There are reasons for that which you are unaware of. Study mechanical engineering to learn why.

You and some of the other brain surgeons on here need to build something, and show this list of those that actually have how inept they are, I'll wait.

[nhrastocker]

When looking at high horsepower N/A engines, you will find many in NHRA Comp Eliminator, Aussie Pro Stock class and some of the 10.5 tire classes.

[dannobee]

Aren't current pro stockers around 1470hp now on 500cid? 2.94hp/cu in. And there's a whole field of 'em out there.

[wwmtlineman]

How about the highest HP under 300 CI ?

[swampbuggy]

When an engine builder builds a naturally aspirated engine comprised of a block (any metal), crankshaft (any metal) , con-rods (any metal) , pistons (any ring package), cylinder heads (any) with 2 valves, valve train that includes lifters, pushrods, and rocker arms, any manifold or individual runner induction system carbs (or) fuel injection....oiling system, oil pan, cam drive system, ignition system, exhaust system all optional, hope i didn't miss anything important to making power?? When a person builds an engine which falls within the above parameters and is able to produce an honest 3 H.P. for every cubic inch, that person is in a very small/elite group of people. My .02 cents . BTW, i believe these types of Max. effort engines showcase the possibilities and prove what Bore/Stroke and total cubic inch combinations have the greatest potential, would like to see the build sheets on these engines LOL, Mark H.

[Steve.k]

This^!!

[frnkeore]

My observation regarding the above chart, if accurate, is that a 400 ci, V8 seems to be the sweet spot for a 2 valve engine. The 400 ci, EMC engines seem to have some sort of a advantage, too.

Are the 397, 400 Ford and Mopar inline valve engines?

I would also like to know the max, hp per ci for under 310 ci engines.

[digger]

what about with mass production OE block and heads? i.e. came from showroom on a truck/car

[nhrastocker]

Aren't current pro stockers around 1470hp now on 500cid? 2.94hp/cu in. And there's a whole field of 'em out there.

We are talking about small blocks...

[maxracesoftware]

by frnkeore » Sun Dec 20, 2020 1:45 pm
My observation regarding the above chart, if accurate, is that a 400 ci, V8 seems to be the sweet spot for a 2 valve engine.

in the above Chart most of the very best 400cid engines are in "State of the Art" Australian ProStock Cars ( Rules : up to 401cid Legal )
Naturally-Aspirated 2-Valve Heads + Oxygenated Race Gasolines = very close 3 HP/CID Ratio

[nhrastocker]

When an engine builder builds a naturally aspirated engine comprised of a block (any metal), crankshaft (any metal) , con-rods (any metal) , pistons (any ring package), cylinder heads (any) with 2 valves, valve train that includes lifters, pushrods, and rocker arms, any manifold or individual runner induction system carbs (or) fuel injection....oiling system, oil pan, cam drive system, ignition system, exhaust system all optional, hope i didn't miss anything important to making power?? When a person builds an engine which falls within the above parameters and is able to produce an honest 3 H.P. for every cubic inch, that person is in a very small/elite group of people. My .02 cents . BTW, i believe these types of Max. effort engines showcase the possibilities and prove what Bore/Stroke and total cubic inch combinations have the greatest potential, would like to see the build sheets on these engines LOL, Mark H.

To add to your statement, although many feel is not important, depending on the cylinder head in use, rod ratio does matter. However, many times you are limited physically, especially on short deck, short stroke engines such as those used in Comp Eliminator. In those cases, you have to decide what is optimal and compromise. One of the biggest considerations is the speed of the piston at different timing points.

Too many consider it just as a leverage angle that you can apply power to the crank, nevertheless, it is very important when filling the cylinder and making power. Therefore, you do not want a piston/rod/stroke combination that would overpower the flow capabilities of the cylinder head and you do not want the piston to be slower than what the cylinder head velocity can provide. That is the critical balance and it is more difficult with a smaller displacement engines like the NHRA Comp Eliminator classes because of the short deck heights. I will not run a piston with a big compression height and I try to come up with a cylinder bore and stroke combination I want for the specific rod ratio I want. That is the reason why you will see some weird connecting rod lengths and very short crankshaft strokes in Comp Eliminator engines. The shortest connecting rod I have seen was in a Chevy small block engine with the Aurora block that was used in the defunct Pro Stock Truck class; the connecting rod was around 5.02" length on a 7.95" deck height block.

...and no, build sheets are not shared...