increasing power of a naturally aspirated engine

[hightower99]

What are the 8 stages?

ok starting right after ignition:
In place of classic exaust phase:
-Exhaust Blowdown
-Exhaust Return
In place of classic intake phase:
-Intake Overlap
-Intake Suction
-Intake Charging
After both intake and exhaust valves are closed there is a:
-Compression phase
Then in place of Ignition or power stroke there is:
-Pre-power burning phase
-Power Production stroke

there you have it the true 8 phases of the otto cycle!

[hightower99]

Have you had all these parts checked individually??

nope I only checked after the port treatment because I myself was skeptic after that I only tested it after I was finished...

[hightower99]

So no one else is going to talk or discuss this highly debatable subject???

and I thought I was talking with pros!

[fpv_gtho]

I dont think people believe you after you listed what's been modified on the engine.

[hightower99]

I dont think people believe you after you listed what's been modified on the engine.

why not?
and why would that stop people from discussing it with me?

[magracer]

I think people here are not interested in an empty discussion. Some of us already expressed doubt, so it's probably time for you to do some kind of "egg nog test". i.e. do you have dyno run printouts? show them! Can you explain us in detail the miracle of obtaining supercharging power gains with just some epoxy"? Photos would be cool. However extendend and technical it might be, try to explain the theory. We all know venturi effect but to obtain supersonic speeds with it... hmmm...

BTW, these is the south korean scientist I was talking about...

http://news.bbc.co.uk/1/hi/world/asi...ic/4554422.stm

An this is the norwegan one...

http://en.wikinews.org/wiki/Norwegia...ings_in_Lancet

So, I guess the ball is on your court... remember, hard facts instead of "this gains with this mods". I for one will not discuss this subject further until you provide some further detail and proof.

[johnnynumfiv]

Also adding onto magracer, can you explain your sig and how do you have what sounds like unlimited access to a dyno?

[LotusLocost]

The high velocity porting is no new thing:http://www.mototuneusa.com/
This "motoman" has done it some years... but he must be dumb or maybe this is something else..
He only gain some 3 to 5 hp on the motorbike engiens

I really want to believe you hightower99.. So pleas, give us some pics and dyno sheets...

[hightower99]

The high velocity porting is no new thing:http://www.mototuneusa.com/
This "motoman" has done it some years... but he must be dumb or maybe this is something else..
He only gain some 3 to 5 hp on the motorbike engiens

I really want to believe you hightower99.. So pleas, give us some pics and dyno sheets...

you are referring in fact to the man I learned from!!!
I am working on getting some pics of a dyno run before and after port treatment and some pics of what I did (I need to find some old pictures cause I ain't tearing the motor apart again!)

and about gains: he says that he can get about 10hp or even slightly more out of an already powerfull motorcycle engine so lets take an example:

he says he can get about 10hp from a bike that makes 100hp to begin with so a good 10% increase in power

I claim to have achieved a 47hp increase on a motor that made about 150hp so alittle over 30%

the difference: He performed the treatment on a 750cc motorcycle engine (Highly tuned from the factory)
and I started with a 3.8L ford V6 (Crap from the factory) I think that you will see that a 20% difference in the relative gains is attributable to the difference in the base tune of the engines

His base engine made over 133HP/L
mine made about 40HP/L
There is a 70% difference there!!!

also I don't have unlimited access to a dyno but I do have access when I need it, what gave you the impression that I did?

[LotusLocost]

you are referring in fact to the man I learned from!!!
I am working on getting some pics of a dyno run before and after port treatment and some pics of what I did (I need to find some old pictures cause I ain't tearing the motor apart again!)

and about gains: he says that he can get about 10hp or even slightly more out of an already powerfull motorcycle engine so lets take an example:

he says he can get about 10hp from a bike that makes 100hp to begin with so a good 10% increase in power

I claim to have achieved a 47hp increase on a motor that made about 150hp so alittle over 30%

the difference: He performed the treatment on a 750cc motorcycle engine (Highly tuned from the factory)
and I started with a 3.8L ford V6 (Crap from the factory) I think that you will see that a 20% difference in the relative gains is attributable to the difference in the base tune of the engines

His base engine made over 133HP/L
mine made about 40HP/L
There is a 70% difference there!!!

also I don't have unlimited access to a dyno but I do have access when I need it, what gave you the impression that I did?

I see your point there, but I`m a non-believer until the contrary is proved Looking forward to the pics

[h00t_h00t]

also I don't have unlimited access to a dyno but I do have access when I need it, what gave you the impression that I did?

That IS unlimited access.

[hightower99]

That IS unlimited access.

no it isn't I can't use it untill after the work day is over but before they lock it up (So I only have between 8pm and 10pm) and I don't run it I have friends that do it for me. (of course I get to put the cars through the paces once in a while)
it doesn't cost me anything and i could in principle use it about 3 maybe 4 times a week.

still not unlimited!

[Matra et Alpine]

Interesting but the points missing in the porting discussions is the impact in the rest of the power curve. All this was done in Ford and BL blocks in the UK in the 60s and we got some seriously increased power at the peak point of the rev range and some almost unusable cars in the end result. Vizard himself had said that 90% of what they believed to be true back then about getting power OUT of the engines proved to be false solutions as they didnt' actually return a faster car.

Have you bench checked any of these engines to see the overall results ?
I suspect you'll find significant low end losses where turbulence in the flow can actual;y be your friend in ensuring the fuel/air mix stays optimally vapourised till ignition. It's why the variable valve timing and lift became the norm for road usage in managing to meet the opposing needs of low rev usability and high power.

Dyno checking low revs is fraught with inaccuracies Needs the bench

When the designer intends major overlap the engine is often then referred to as either using the Atkinsons or more normally Miller Cycle. Otto didnt' really include overlap in his considerations the other two did. Another auto-trivia from the pen

[hightower99]

Interesting but the points missing in the porting discussions is the impact in the rest of the power curve. All this was done in Ford and BL blocks in the UK in the 60s and we got some seriously increased power at the peak point of the rev range and some almost unusable cars in the end result. Vizard himself had said that 90% of what they believed to be true back then about getting power OUT of the engines proved to be false solutions as they didnt' actually return a faster car.

I am not quite sure if you are talking about eigther making the ports bigger or smaller? However I did give a rough description of how the power curves changed on my engine after treatment. and I wouldn't say 90% was wrong more like 40% of what they thought!

Have you bench checked any of these engines to see the overall results ?
I suspect you'll find significant low end losses where turbulence in the flow can actual;y be your friend in ensuring the fuel/air mix stays optimally vapourised till ignition. It's why the variable valve timing and lift became the norm for road usage in managing to meet the opposing needs of low rev usability and high power.

What engines should I have checked? I checked my own on a flow bench if that is what you mean but that did not give an accurate account of what was happening in the engine. You are very correct when you talk about turbulence being your friend, and thus I have not polished my ports I have in fact made them rougher! (In a certain pattern much like rifeling the flow will not decrease but the turbulence will!) this helps to keep the fuel in the air at low speeds and helps the engine swallow the air at higher speeds.

Dyno checking low revs is fraught with inaccuracies Needs the bench

In my experiance a well set up Dyno will be far more accurate then a flow bench unless you are talking about something else???

When the designer intends major overlap the engine is often then referred to as either using the Atkinsons or more normally Miller Cycle. Otto didnt' really include overlap in his considerations the other two did. Another auto-trivia from the pen

if you are referring to one of the 8 phases I mentioned called Intake Overlap then you misunderstood the meaning. Intake Overlap is the very short time where the exaust is closing and the intake is opening. Almost every Otto cycle engine has this phase! and it has nothing to do with the miller or atkinson cycles! This phase is pretty important when it comes to getting the most out of your engine!

[c2xejk]

the 3.8L V6 started at 152hp peak and 210 ft.lbs.torque peak pretty low for the capacity.

the choke point was reduced to 4/5 the diameter of the valve opening

So what was the starting diameter of the port?