[NPS Nova]

A good rule of thumb that we've come up with is about 7% of your displacement per point of compression. 548 x .07 = 38.36 hp.

Please explain as i've always used the general 20hp up to 13 to 1 and 15Hp after 13? Most here say maybe 20, yet your about double? I figured you'd found something the other don't have, care to expand on what is is?

38+Hp for going a point would be nice gains is this case.

 

[NPS Nova]

I can't explain it John. Besides, me and Chris are just a couple dumb hicks from TN. You don't believe a word we say. You're way smarter than us.

Scott, I never said anything about you guys being DUMB, a bunch of hick, or even not believing you (other than the weight of the 427 Impala). We just have different views on how to get a result. Things I've learned from hanging with Butch Kemp, IHRA P/S Konigshofers etc about engine and results lead me towards what my thought are. YOU and Chris don't seem to give others respect for saying there views......

But going back to this engine you posted and the 7% per point. Well the math is simple So take YOUR example 11.5-1 572 with 932Hp. CHANGE NOTHING other then pistons and bring it to 15.5-1, YOUR theory would mean the piston change can be 160.16Hp ALONE??? The man who's 572 is leaving a lot on the table with the 4 points???? A 572 with 1090+Hp would be pretty damn respectable!

Maybe your example, which is pretty impressive with ONLY .4 point change, indicates that it might be lacking in a given area, or rather better suited to the higher compression with cam/heads/intake combo???

I am honestly try to learn as your theory goes against what most say or have experienced and I'm trying to figure out if maybe MY info was wrong? No formula or theory is the absolute in this business, and with technology, things are always changing. I'm just trying to keep up with the times, and maybe learn as well.

 

[NPS Nova]

Looks like others are following this subject too:

http://www.chevelles.com/forums/13-...ums/13-performance/1000770-whats-half-point-compression-worth.html#post10085650

 

[NPS Nova]

Here you go again. YES I have some experience with these thing. NOT my stuff, but 3 engine I help with.

360 inline SB Ford. Torched a gasket, surfaced head, raised comp by .6, put back together, Same dyno, gained 11Hp, raised peak power 1 or 200 RPM. 886Hp before 897Hp after Konigshofer Racing Engines built

360 18 deg SB chevy. After we seen what the Ford above did, change to shinner gasket. It made a bit less, 7 Hp from the gasket change and 1/2 point. 911Hp and up to 918Hp. BES/Moroso built

3rd one will keep on the back burner. 750+ pumpgas SB Chevy. Built by Extreme in Ny.

I do know NOT own these motors, and neither do YOU. My crew chief does. I travel and crew on his N.A 10.5 car. So I would say since I was there during build, dyno and seen on-track performance, I have some experience as seeing results.

 

[NPS Nova]

A good rule of thumb that we've come up with is about 7% of your displacement per point of compression. 548 x .07 = 38.36 hp.

Scott, R E A D slowly seeing as you're, as YOU stated "a couple dumb hicks from TN", YOUR "GOOD RULE OF THUMB" you claim is 7% as you posted in the quoted post?

MOST on here are stating quote a bit less than that, myself included. NOW you have posted YOUR results in 1 particular case, then argue when someone states differently, but YOU "rule of thumb" is to be supported????

Do you not agree, that 7% increase PER POINT is rather generous for the masses as a "general rule of thumb" especially when others have posted some dramatically less results???? Weather it's the NASCAR engines, or the pulling 440 engine, they BOTH show dramatically less? AND you even posted that the A/F numbers are NOT right, but were to assume (and you what ASSUME stands for) are also right?????

Not trying to get into a pissing match, just wondering WHAT your doing so much better then those on here that has had different results. ER ALL HERE TO GATHER KNOWLEDGE.

 

[NPS Nova]

I agree with NPS nova 100%,

There is much more to an over simplified "formula" to estimate compression ratio power increase or decrease. There are many, many factors that will go into a "power increase" equation.
Camshaft timing, bore size, dome size (flame front), fuel used, 1 point CR increase (from 7:1 to 8:1, or 15:1 to 16:1). Many other factors that I have not listed also.
To simply come out with an over simplified equation - and the defend it? lol because you are a big time engine builder with lots of experience?
Calling NPS nova's response as BS, because he doesnt agree with you? You are the engine God now? Your theories are FACT? really? lets get back to reality.

Nothing against you or your shop - you have done some very impressive builds - but stop and think before calling anyones experiences or theories BS because they don't fall in line with your theories. Yes, your equation is a THEORY - not fact!

Thanks CANADA. It's more then that. Like I said, we have different ideas on engine things. This mostly stems from Team Chevelle when I was started questioning Scott and Chris about a couple thing. Scott wasn't too bad, but Chris just outright lied. Weather it was the 4600+, 427 '69 Impala, or the dyno where the oil pressure drops as RPM rises on dyno.

Scott is right in one part. I have NEVER built an engine and only changed compression! Again I personally think once you change compression the rest of combo could take advantage of more as well. I have 5 "good" friends and have learned plenty from them and their experiences while racing WITH them and helping them. I do call out people if I don't know or think there B?S or making a false statement. NOT to be a dick, but maybe learn something new.

Thought maybe Scott found something NEW that we have missed? So I asked, That's all!:-Daw

 

[NPS Nova]

Scott, no "personal agenda's" here.

Now I'm SURE you and Chris DO have one!!! Look back, I simple asked how "most" on here have stated and posted "around" 20Hp/point, yet I simply asked for you to expand on you rule-of-thumb? You did, BUT then BUT then turned it personal with the "your dumb hicks" and "not as smart as you" comments!!!!!

So i merely stated that if "most" of this industry on here see's about the returns that you do, maybe "something" in the engine liked the compression, or could have been lacking without it. YOU didn't build this engine either, you did heads and intake.

Scott, most here are pretty knowledgeable. IF they're not, they come on and get some education and hopefully some help to go in the right direction. So with that said, if say a mild enthusiast, has say a Vortec Pro, Pump Gas BBc motor that makes X amount of power, here might think/look into changing that combo from pumpgas to 15-1 and think he can pick up another 150Hp from that change alone.

Like Chris said in his OLD SCHOOL BBC 427 cam thread, he promised them 630 to 640HP, but it made 671Hp. Would it be better to aire on the low side of 15-20 per point as most have stated, then be over optimistic at 7% if engine size and not get the results!!

 

[NPS Nova]

keep in mind, your 7% "per cube" is different from a 7% over-all gain.

Just for shits and giggles lets assume the 548" in question makes 1.7hp per cube. that would put the power at 930 hp.

take the 38/930 = 4% increase

take the 930 x 2% = 19 hp. ( my questimate )

you stated that the 7% per cube you have seen is an "average" ... that means some have been higher and some have been lower. On AVERAGE there is far more gain bumping a 9.5:1 engine to 11.5 than there will be bumping an 11.5 to 13.5 or a 13.5 to 14.5. The returns are diminishing as the baseline compression increases

Your results my Vary

I never seen it that way as an "average" with some results higher and some lower? But 7% PER CUBE PER POINT of compression just seems a little generous?? IF YOU can get that, GREAT and congrads. But seems the general consensus is close to 15/20Hp per point.

 

[NPS Nova]

Look Scott, Canada ! is right. I respectfully asked you to expand on your generious 7% cube/point? My first post in this thread. YOUR the one that sarcastically came back with the crap at the bottom of the first page.

Seems anyone who disagrees with you, you get all uppitty.

 

[NPS Nova]

Get over yourself -if that's possible.

I think you need to take some classes on business etiquette and human decency.
You are doing yourself and Straub a huge injustice. I don't think I will buy my next set of lifters from Straub - or anything else for that matter. Straub doesnt come across like you do.
Its too bad your ego is so big you can't see the big picture.

YES you can get anything you need elsewhere, like I have found.

 

[NPS Nova]

He just posted the "number" knowing that it would be challenged so he could post up his "proof" and advertise his work.

It's actually nice to see the amount of response and data coming out in this thread.

Strange how this guy who did the heads and intake, not even the motor, is claiming the results that many others on here just don't seem to agree with unless there was an issue with the original set-up.

 

[NPS Nova]

Scott, as you say THIS IS NOT your engine! OUR NOT THERE and therefore you can't exactly say what was 100% due to hearsay on this 572. Add that to the fact you even said the AF are off, but you taking the rest of the numbers on the sheet as truth?

G code, even thought that chart came from a magizine artical, would you consider it as truth or accurate? It's seems to be a lot more in line with the general with what the industries general formula and what you have been saying.

 

[NPS Nova]

Scott, you do need medical help, seriously. You say I didn't contribute any technical data, we'll funny the 360 SB motors I mentioned and your quoted over there I guess is not technical, yet you went on to quote them.

I've posted various dyno sheets of my stuff, the recent ZL1 that you took acception to over there as there was an anonmally on 1 line, so you called it fake, yet you have a whole page of AF numbers off, and you call mine fake.

I started on this thread with a simple question to explain you rule of thumb that seems quite generous, and others have asked for other data of this and not just the 1 engine, yet nothing. But you come back as an ass, and funny others back me and you turn on them. He'll Canada 1 doesn't even like me!!!!

Over on Team Chevelle, I guess you can disprove what you to claim, or others back you and ban, like what happened to me. Seems you can fool those less educated, buck doesn't seem to be working here!! Not like there's anywhere near the talant or experience there, like there is here on YB.

So go have fun for a while, will come back after the ban and check you lies, like the what 4700lbs Impala??? just don't go passing of others work as your own, like this 572 that YOU did the head and intake work, and sent them out. NOT your build or motor, your heads and intake. Maybe that's why Davey had Vortex Pro do his motor this time!!!!?

 

[NPS Nova]

Scott, the only personal agenda I have with you two is, the way you try to solicit work and pull a muscle trying to Pat yourself on the back. Plus not thinking anyone else can do anything if it's against what you think? Remeber the 468 dyno sheet I posted from the shop I work with. You said it could happen, yet the heavy Chevelle run in the 9's with the observed 700hp the dyno says.

Double stands Mr Foxwell. And Chris, just just flat out lies! Telling me you guys only do 1 or 2 engines a year. And that 427 out the Impala would be $18,000 to run high 10's?????