Compression vs Horsepower

Crossroads said:

I prefer to stay with Honda engine builders and tuners. It amazing who you can talk to on Honda-Tech.

Click to expand...

So do you think there is nothing to learn from a v8? Why exactly is their bigger air pump different than your smaller air pump? I would tend to believe people that build pro stock motors (the pinnacle of naturally aspirated) over some guys on ht.

Crossroads said:

Seriously, hit the All-Motor forum over there and start asking those guys what they think of high compression in anything other than a race engine. They'll all tell you to run less than 12:1 and get a quality port and polish...for a street engine.

Click to expand...

So why again is the magical number 12:1. What happens at 12.5:1 that was so different? What if I build my a6 to 11.9:1? Am I safe to run on pump gas?

In the world of internet forums, there are those that do and those that listen to people that haven't done.

I heard the same thing about stock fuel lines in a foxbody cannot support more than 450rwhp. I saw them support 800rwhp on a twin t3/t4 352" windsor. I heard that the stock TFI distributor cannot run past 7000 or support 600fwhp. I saw a car make over 900 to the tires (On 93 octane!) with a 363 and a precision 88mm turbo and a FAST xfi. Just recently someone told me that ported stock mustang heads (E7TE) cannot flow enough to make power past 4600 rpm, regardless of what was done to them. I built a very budget 347 that made 300rwhp from 4700 to 5800 and 360rwtq off idle with only $2800.

The point is this: if it is within reason, and is mathematically sound, then why does someone's brother's cousin say it cannot be done?

Crossroads said:

Rage Racing/Whitfield Tuning
Church's Tuning
RLZ Engineering
Rocket Motorsport
Don Flores
etc.

Click to expand...

id like to add to this too..
those name/companies have to deal with costumers that tend to be more on the careless side , so i can understand a conservative compression coming from their advice, they have to deal with potential costumers with the HT typical attitude " i want power, all the compression and cheap gas, and no tuning or a bit of tuning only "

and add to that, over at HT i see many daily driven builds thats way above 12.5:1 compression , so its either they didnt listen? or theyr doing sumthing that those noted peepz dont know.. highly unlikely right?

to add to that, ive bin around B-series peepz locally.. eversince i got into honda's and almost all builds are above 12.5:1 comps, then and now, from running old "SUPER DUPER" pistons to the newer Endyn Rollerwaves,
all above 12.5:1 comp, and the old builds are still running up to now..

yes they are all B-series examples.. but since those names are notable for their B-series work.. then i see this example fit too..

thats my .02

not trying to stirr up anything hehe

88cr-rex said:

So do you think there is nothing to learn from a v8? Why exactly is their bigger air pump different than your smaller air pump? I would tend to believe people that build pro stock motors (the pinnacle of naturally aspirated) over some guys on ht.

Click to expand...

Yeah, Don Flores, JDogg from Rocket Motorsports, Chris Whitfield from Rage Racing, Earl Laskey (R.I.P.), ect. are just random dudes on the internet without any practical experience. Those guys sucks.

I learned a lot about engines from V8s. Then I moved to Hondas, started talking to the guys who've devoted their lives to them, and learned that these are different monsters. I'm going to repeat something I've said before, why don't you go talk to some professional head porters if you want a greater understanding.

88cr-rex said:

So why again is the magical number 12:1. What happens at 12.5:1 that was so different? What if I build my a6 to 11.9:1? Am I safe to run on pump gas?

Click to expand...

I don't remember saying anywhere that it wasn't safe. I said you'd make the same power with lower compression because you wouldn't have to pull as much timing. And since I think your next statement was total bullshit, you should try understanding what you read before you mouth off.

88cr-rex said:

In the world of internet forums, there are those that do and those that listen to people that haven't done.

I heard the same thing about stock fuel lines in a foxbody cannot support more than 450rwhp. I saw them support 800rwhp on a twin t3/t4 352" windsor. I heard that the stock TFI distributor cannot run past 7000 or support 600fwhp. I saw a car make over 900 to the tires (On 93 octane!) with a 363 and a precision 88mm turbo and a FAST xfi. Just recently someone told me that ported stock mustang heads (E7TE) cannot flow enough to make power past 4600 rpm, regardless of what was done to them. I built a very budget 347 that made 300rwhp from 4700 to 5800 and 360rwtq off idle with only $2800.

The point is this: if it is within reason, and is mathematically sound, then why does someone's brother's cousin say it cannot be done?

Click to expand...

Reading comprehension, the ability to understand what you read.

Not once did I say it wouldn't work. Not once. You jumped way off the deep end there junior.

edit:
I have a question. What is it with you guys and opinions that go against your popular D-Series grain? Jesus fucking Christ guys, there are actually people outside of this forum who know what they're talking about. Believe it or not. In fact, there are even people who do this for a living and win professional race after professional race with the engines they build and/or tune. Some even have their own dynos. But what the fuck do they know, they post on Honda-Tech right? Completely forget the fact that the guys I'm talking about, not your average user, have forgotten more about engine building than most of us have learned.

Crossroads said:

Those guys sucks.

Click to expand...

Crossroads said:

I'm going to repeat something I've said before, why don't you go talk to some professional head porters if you want a greater understanding.

Click to expand...

Hmm . . . okay.
Let's see, I work at a 3 man shop where all we build are mustangs (please flame). The guy who owns the place ports cylinder heads for Brad Brand (700" Outlaw 10.5 car which has gone a best of 6.79 @ 209), Tim Matherly (4.6 2v NMRA/FFW Real Street, been a best of 9.1x @ 141), and numerous local guys. His personal car went a 6.0 ( 1 / 8 ) at 114 on the motor. Plan is to run faster than 5.39, which is what the old car went.

So maybe I don't know anything because it isn't a honda. Or maybe its because my first porting at a honda head only went 227 I and 200 E.

So not only that but I have known Barry at Proline Race Engines for a couple of years now and he does measly heads for Tim Lynch's Outlaw 10.5 (best of 6.66 @ 215) and numerous other race cars given they build a ton of motors and Steve Petty tunes in-house.

Crossroads said:

Not once did I say it wouldn't work. Not once. You jumped way off the deep end there junior.

Click to expand...

No, here is the issue you have had. You imply that since someone online said it couldn't be done, it can't. And here is the major problem, you never once said that these people knew your exact combo and therefore made a blanket statement on the internet. [email protected] was exactly right, a lot of inexperience people read/sift through honda-tech and if someone on there said to run 12:1 on pump gas with no tuning or research, they would be getting phone calls from kids saying they blew their motors up.

So do whatever you want, run 11.9:1. After last time, I am over arguing on here so I just try to mess with my ebay/junkyard junk and post the results.

Crossroads said:

edit:
Jesus fucking Christ guys, there are actually people outside of this forum who know what they're talking about. Believe it or not.

Click to expand...

The compression vs VE thread left a lot of holes:
The rule of all rules is #1. This is the key to understanding compression.

1. If static is already near the detonation limit for the fuel being used, further increases in the static compression may hurt engine output and/or reliability.

With a typical n/a motor, the VE is often not much more than 87-89% (for a bolt-on motor) maybe slightly more for a well-built (heads/cam etc). These types can almost always gain from compression being that the motor cannot fill every last space of its cylinder given that the VE is under 100%. Compression allows an underachieving motor to use its incoming intake charge to the fullest extent. When you are above 100% VE is when reducing combustion chamber size is a bad idea. It is true that you reduce VE when you decrease combustion chamber size because total swept volume is less that it was before.

So, as stated before, without knowing #1, you have no perspective. You have rumors that increasing compression all the time is a good thing and its also a bad thing. The point is, you have to know what your motor is doing now to have any idea of how it will respond.

static vs. dynamic......lets add a bumpstick to mess everything up.....

or do you start with the cam then figure compression?????

LSA between intake and exhaust events, centerline.......blah blah blah.....

Just the surface is being scratched....

Lets see, 740 Dart Iron block, Big Chief heads, 14:1 compression, dual 1150 Dom's, Wilson intake, 3 stages of nitrous for 1000 shot......yep, I'm clueless

6.82 @ 213 only using 2 stages (600 hp) of nitrous in a old Pro Stock chassis (early 90's).....90-92 Trans Am skin.....

just air pumps.....

First, I'm not a kid. You jackholes assume too much and make yourselves look fucking stupid in the process. The reason why I quote articles is because I know how closed minded this community is. You don't believe anything that anyone says that goes against what you believe. You don't even have the reading comprehension skills to understand what I said. The only thing you all seem to be able to read is "uh...duh...it um, won't work" which isn't even remotely close to what I'm saying.

Why does NASCAR only run 12.5:1 with huge cams and still get 800hp? End of discussion and my involvment in your bullshit community. I'm going to talk to people who are actually knowledgable beyond the mechanical phase of engine building instead of people who have their heads up one person's ass. I feel less intelligent for having even posted on this forum. Flame away, asshats.