This thread is primarily for opinions/experience. A buddy of mine is putting together an ls/vtec (cracked a sleeve in his b18c) and had the option of going with either the B16 head or the GSR. We ended up deciding upon the PR3 because with the pistons he has the CR would be a little too high for his purposes with the P72.

however, this choice sprung a debate amongst my friends and I. low port vs. high port? why did honda decide to use the PR3 for its R motors? etc.

Discuss

 

https://honda-tech.com/zerothread?id=2130245 no?

damnit 2 post left!!

 

bah i figured there was an information thread.. was more just trying to get a fun little thread going.

good link though, thanks. i didn't bother searching b/c i've already got my setup hammered down -- just boredom because i have a day off work and nothing to do. lol

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Sean EH2 &raquo;</TD></TR><TR><TD CLASS="quote">however, this choice sprung a debate amongst my friends and I. low port vs. high port? why did honda decide to use the PR3 for its R motors? etc.
</TD></TR></TABLE>

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Sean EH2 &raquo;</TD></TR><TR><TD CLASS="quote">bah i figured there was an information thread.. was more just trying to get a fun little thread going.</TD></TR></TABLE>

It sounds like you wanted information judging by the first quote. Then you say you just want a "fun little thread".

Please dont create "fun little threads" in a tech forum because you are "bored" and have "nothing to do".

 

They're basically the same..
Case in point a gsr head will provide higher compression, which is why i went with a gsr head, and got rid of my itr head.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by IntegraType-R &raquo;</TD></TR><TR><TD CLASS="quote">They're basically the same...</TD></TR></TABLE>

Couldn't be more wrong.

 

the gsr head has better combustion chambers with flat quench pads. its less likley to detonate with higher compression,and i assume i would promote better flame travel. like cc said the castings are better quality than the b16's,though if your gonna get a QUALITY p&p then thats out the window
i would not buy or trade a head for .3 of compression

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Aquafina &raquo;</TD></TR><TR><TD CLASS="quote">

Couldn't be more wrong.</TD></TR></TABLE>
When your talking about flow wise, they almost flow practically the same.. Aside from the few things that are visiable to the eye

gsr head is different than the type r and b16 head.


b16/type r = same cast different internals

gsr = different cast

gsr intake manifold isnt crap, its crap if you dont have the right ecu. gsr manifold can easily have the secondaries removed and gutted since it comes apart in the middle.

gsr head has square combustion chambers bumping compression slightly over the other 2. i personaly went with the gsr head because i believe it will yield more power down the road with the same mods as on a b16 head.

B16/type r: Open Pocket Combustion chamber

GSR: Quench area Pocket Combustion chamber

Now if we were flat out talking about differences, i named some, i figured this was another thread talking about the gsr head vs the b16 head with flow.

 

flow is about the only area where they are similar. What most people never tell you (either because they don't know or understand, or they simply choose not to say) is that head flow is not a direct indication of how much power will be made, it is simply an indication of "potential" for how much power can be made with the right setup.

4g hatch started to hit on some of the lesser known differences between the two heads that can contribute to one head making better power than the other, even at identical flow rates. Flow is only one part of a combination equation to making power. Most people seem to forget this. Compression is another but again, not a sole predictor of how much power can be made.

 

velocity, port entry angle, etc.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Combustion Contraption &raquo;</TD></TR><TR><TD CLASS="quote">

It sounds like you wanted information judging by the first quote. Then you say you just want a "fun little thread".

Please dont create "fun little threads" in a tech forum because you are "bored" and have "nothing to do".</TD></TR></TABLE>

By fun little thread I meant conversation concerning the differences in the two heads, and what different people thought. Everyone has a different opinion on which head is better, that "tech forum" conversation is "fun" to me. sorry, forgot which site i was on for a second. figured we're into cars for fun in the first place. that's the way it was when i got into this, guess things have changed.

So the P72 is proven to be safer with high compression or is that theory?

like aquafina and 00red, power is not in flow -- correct? Aquafina hinted at this, power is in volume and velocity. just becuase a head flows a lot doesn't mean it will necessarily make power, because the air/fuel mixture loses velocity.

so the most important difference to those in the engine-building world would be the quench pad?

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Sean EH2 &raquo;</TD></TR><TR><TD CLASS="quote">

By fun little thread I meant conversation concerning the differences in the two heads, and what different people thought. Everyone has a different opinion on which head is better, that "tech forum" conversation is "fun" to me. sorry, forgot which site i was on for a second. figured we're into cars for fun in the first place. that's the way it was when i got into this, guess things have changed.

So the P72 is proven to be safer with high compression or is that theory?

like aquafina and 00red, power is not in flow -- correct? Aquafina hinted at this, power is in volume and velocity. just becuase a head flows a lot doesn't mean it will necessarily make power, because the air/fuel mixture loses velocity.

so the most important difference to those in the engine-building world would be the quench pad?</TD></TR></TABLE> You really need to read all the posts again. You have not learned much. I will give you a break, flow, compression, burn pattern, etc. explain the BHP you will get. WITHOUT flowing your intake manifold and system, with the head , head flow numbers mean nothing. Well, there is braging rights, just not engine application functions.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by DonF &raquo;</TD></TR><TR><TD CLASS="quote"> You really need to read all the posts again. You have not learned much. I will give you a break, flow, compression, burn pattern, etc. explain the BHP you will get. WITHOUT flowing your intake manifold and system, with the head , head flow numbers mean nothing. Well, there is braging rights, just not engine application functions. </TD></TR></TABLE>

explain further.. i thought that's what i said -- that head flow has little to do with power. or that just a head flowing a lot of air doesn't necessarily mean more power.

thanks though.. flow, compression, burn pattern.. what else goes into the "equation"?

 

Velocity and where the flow ocurs, compared to the cams will tell you where the power band is. Just picking numbers, a Bhead that flows 330CFM will suck at velocity, but on a B16-18 make great BHP @ 12-13,000 rpm. If you can find cams. Figure out what you want and the application, then go foward.

 

velocity or runner cc'ing never seems to be discussed near as much here as it is in any of the V-8 forums. the same rules do apply though. perhaps it's because our choices are more limited. not to get off track but are the aftermarket heads like the pro action honda castings being used by anyone? i do have to thank you guys for confirming my hunch about the p72 casting and the quench pads being better than the pr3 open chamber. fast swirl is always a good thing.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by DonF &raquo;</TD></TR><TR><TD CLASS="quote">Velocity and where the flow ocurs, compared to the cams will tell you where the power band is. Just picking numbers, a Bhead that flows 330CFM will suck at velocity, but on a B16-18 make great BHP @ 12-13,000 rpm. If you can find cams. Figure out what you want and the application, then go foward.</TD></TR></TABLE>

okay cool, much like a set of monster cams will suck under 10 grand or the way a 4" exhaust works on a heavily boosted car but kills power on a naturally aspirated one due to a lack of delta pressure (there's velocity again).

what do you mean by where the flow occurs? i'm sorry for the seemingly newb questions, i'm just trying to educate myself (and anyone else perusing the thread) on head tech.

 

sort of. runner cc size impacts velocity. there is a TON of good information on this printed about V-8 cylinder heads. it all applies to honda as well since a 4 cycle engine is basically a 4 cycle engine. runner size is generally used as a tool with cubic inches, cam and rpm. i have found almost zero information when it comes to honda engines and this very thing. in simple terms if you had a 2.0L engine at 6000rpm with cam X one could measure how much air the engine was moving. or at least guess. trying different runner sizes if it were possible could extract horsepower by finding the balance between air speed in the smaller runner and maximum cfm in the larger runner. with some of the aftermarket heads now being made this could become a consideration since it stands to reason that the p72 and pr3 heads while great with 110 cubic inches and 8500rpm will be a little small with 120 cubic inches and 10,000 rpm. increasing runner size can be a way to bring the falling top end back up. in short, the small runners stall and power will fall off. like i said, TONS of good info on v-8's look up some of the articles on cam, engine size and cylinder heads cc's and you can see what happens. if good information exists on this subject in honda land i have not been able to find it. For example, the vette in my sig has a 357 cubic inch engine. 354whp@6050rpm. the runner size on the cylinder head intake is 180ccs and flows 262cfm@.500 lift. if i were to use a 230cc intake runner, even though it may flow 300+ cfm, the car would almost certainly NOT be faster because air speed would slow down greatly at the valve. the cylinder fill would slow down and that 300+cfm head would get handled by the smaller 180cc runner. now if we moved the engine size up to over 400 cubic inches or the rpm level of the 357ci up to 8000 or so the 230cc head would really start to shine since more airspeed would be created by either condition.


Modified by idrivesideways at 12:25 AM 9/14/2008

 

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Hotori Hanso &raquo;</TD></TR><TR><TD CLASS="quote"> </TD></TR></TABLE>

this thread was already dead, yoooou just had to bring it back