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Engine size vs. power by 85fieroguy
Started on: 09-20-2015 12:58 PM
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Last post by: dobey on 10-02-2015 10:03 PM
engine man
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Report this Post09-24-2015 09:29 PM Click Here to See the Profile for engine manClick Here to Email engine manSend a Private Message to engine manEdit/Delete MessageReply w/QuoteDirect Link to This Post
dobey you are right most engine wont use the full cfm of the head to make power but what i am saying if you want to make a certain hp engine the head has to flow a enough and of course there is a difference for forced induction and NA on how much a head must flow for that given HP . but you cant take a V8 head that flows 200 cfm and make 600 hp with out boost and i think i understand what you are saying is the engine only needs this many cfm to make 600 hp and the total air flow of the heads is more than that but for some reason it not the way it works maybe some one can explain why

[This message has been edited by engine man (edited 09-24-2015).]

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Report this Post09-24-2015 09:32 PM Click Here to See the Profile for dobeySend a Private Message to dobeyEdit/Delete MessageReply w/QuoteDirect Link to This Post
 
quote
Originally posted by Silvertown:
Pontiac "we build excitement"power supplied by chevy. But if you don't believe me then read this. Get off the island pontiacs dead the wars over
http://www.superchevy.com/h...block-chevy-history/


LOL. OK. So you read it in Super Chevy, so it must be true.

Can we get back on topic. And can you tell me what you mean a V8 in a Fiero is inefficient, or what is so bad about the transaxles?
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Report this Post09-24-2015 09:46 PM Click Here to See the Profile for dobeySend a Private Message to dobeyEdit/Delete MessageReply w/QuoteDirect Link to This Post
 
quote
Originally posted by engine man:
dobey you are right most engine wont use the full cfm of the head to make power but what i am saying if you want to make a certain hp engine the head has to flow a enough and of course there is a difference for forced induction and NA on how much a head must flow for that given HP . but you cant take a V8 head that flows 200 cfm and make 600 hp with out boost and i think i understand what you are saying is the engine only needs this many cfm to make 600 hp and the total air flow of the heads is more than that but for some reason it not the way it works maybe some one can explain why


Nah, I'm not saying you need so much CFM to make 600 HP. What I'm saying is, talking about just HP or just CFM is not useful. HP is a function of RPM and Torque. If you want to make X HP, then you need to know what RPM you want to make it at, and that you need to make Y lbs-ft of torque, at that RPM. And if you want the engine to be able to turn that RPM, you need to be able to flow that much CFM at that RPM, based on the average flow per intake stroke, for the duration and lift of the valve you're using. Then you also need to flow enough on the exhaust side, to get the waste out of the engine. From the power requirement, you can also calculate what cylinder pressure you'll need to make that power. From that, you can calculate what compression ratio you'd need, what the cam profile should be, etc…

If you want to make power, you need to know all this stuff, and not simply what the peak flow through the heads at an arbitrary lift, is. If the heads/intake/throttle body/air filter combination can't get you to that power level in N/A form, then you will have to see what you can modify to get you there. If you can't modify any of those to get you there, then maybe you'll need to go to forced induction to get there. You can calculate how much boost pressure you'll need, in order to get the cylinder pressure where it needs to be.

Yes, the one formula you posted can be used as a basic guiding value, but it alone won't get you anywhere near the end result.
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Report this Post09-24-2015 10:04 PM Click Here to See the Profile for engine manClick Here to Email engine manSend a Private Message to engine manEdit/Delete MessageReply w/QuoteDirect Link to This Post
that is true you need all that but what i was saying is you cant make more hp per cfm than the head can flow. in other words you cant have heads on a V8 that flow only 150 cfm and think you can make 600 hp NA it's not going to happen and sure you can make it do it if you put forced induction on it and shove enough boost at it. If this wasnt true then we could all just put a 4.9 Caddy engine in and boost it with a cam change

[This message has been edited by engine man (edited 09-24-2015).]

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Originally posted by dobey:


LOL. OK. So you read it in Super Chevy, so it must be true.

Can we get back on topic. And can you tell me what you mean a V8 in a Fiero is inefficient, or what is so bad about the transaxles?



Did you read it? I like the part where they said." Although it looks entirely different than the first 265 small-block, this engine is still designed with the 4.40-inch bore spacing." Don't get me wrong I love pontiacs. And as far as transaxles there just isn't any vendors supporting the swap to make it efficient. If it's for drag racing I just think your hamstring yourself with any of the transaxles availible. Your going to have so much torque. But maybe you can fab it up to make it work and sell it as a swap just make sure I can get one in a 282.

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Report this Post09-24-2015 10:15 PM Click Here to See the Profile for dobeySend a Private Message to dobeyEdit/Delete MessageReply w/QuoteDirect Link to This Post
To use the 600 HP number constantly being repeated, as an example:

Using the following formulas:

HP = TQ x RPM / 5252
BMEP = 150.8 x TQ / CID

If you want to make 600 HP, in a 6.2L engine, at the following RPM values, you need the stated torque, and BMEP, to get it. You'll also need the stated CFM at 85% VE, to keep the engine spinning at the RPM.

code:

RPM TQ BMEP CFM CFM/cyl
4000 787.8 315.96 372.0 46.5
5252 600.0 240.64 488.5 61.1
8000 393.9 157.98 744.0 93.0



Now, of course, at 85% VE, you may not be able to make the required BMEP to get you the 600 HP at the stated RPM. But even at 100% VE, you only use 108.8 CFM per cylinder, on an LS3. Depending on your valve timing, duration, and lift, though, you may need a head that flows 350-400 CFM, to be able to do that. All the bits need to fit together just right.
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quote
Originally posted by engine man:

that is true you need all that but what i was saying is you cant make more hp per cfm than the head can flow. in other words you cant have heads on a V8 that flow only 150 cfm and think you can make 600 hp NA it's not going to happen and sure you can make it do it if you put forced induction on it and shove enough boost at it. If this wasnt true then we could all just put a 4.9 Caddy engine in and boost it with a cam change



Big valves and long big runners its old school can you tell me something else.

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Report this Post09-24-2015 10:24 PM Click Here to See the Profile for engine manClick Here to Email engine manSend a Private Message to engine manEdit/Delete MessageReply w/QuoteDirect Link to This Post
yup evetry thing you have there is true but the cold hard fact is if you want to build a 600 hp V8 NA engine the heads must flow 300 cfm and you better be able to get every once of power out of the engine that you can . the formula you have kind looks like carb cfm sizing for a engine
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Report this Post09-24-2015 10:32 PM Click Here to See the Profile for engine manClick Here to Email engine manSend a Private Message to engine manEdit/Delete MessageReply w/QuoteDirect Link to This Post
if those long runners are as big as a straw it's not gonna make power i don't care how big the valve is . dobey don't take my word for it call you local race engine builder and ask them how many cfm a cylinder head intake port must flow to make 600 hp V8 engine

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Report this Post09-24-2015 10:35 PM Click Here to See the Profile for dobeySend a Private Message to dobeyEdit/Delete MessageReply w/QuoteDirect Link to This Post
 
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Originally posted by Silvertown:
Did you read it? I like the part where they said." Although it looks entirely different than the first 265 small-block, this engine is still designed with the 4.40-inch bore spacing." Don't get me wrong I love pontiacs. And as far as transaxles there just isn't any vendors supporting the swap to make it efficient. If it's for drag racing I just think your hamstring yourself with any of the transaxles availible. Your going to have so much torque. But maybe you can fab it up to make it work and sell it as a swap just make sure I can get one in a 282.


No, I didn't read it. I've read enough on the subject from plenty of other places. They, and plenty of others, make comments like that all the time, that lead people to false conclusions about the engine though. The LSx also has wedge heads, which are from the Pontiac. The Gen II LT1/4 had reverse flow cooling, also something Pontiac had in 1955 on their first V8. The bore spacing doesn't really mean much though in terms of relation to the original SBC, when nothing will interchange.

As for the transaxles, I disagree. Yes, it's not an easy swap. If you want an easy swap and to get an SBC or LSx in a Fiero, then use Archie's kit. It's a bit expensive, but it's the closest you're likely to get for a bolt-in kit with using a manual trans with an SBC or LSx, in a Fiero. The LS4 won't work with the 282 trans, because the starter for the LS4 mounts on the transmission side, and the slave on the 282 is in the way. An F23 is theoretically usable, with some hacking of the trans, and the F40 is definitely usable with hacking the bell housing. An NSX trans with the kit from WCF has also been used with an LS4.

I'm not going to sell any LS4+manual trans bolt-in swap kits. I'm not building my car to drag race. It won't have too much torque, and the gearing won't be too bad, despite it being a FWD transaxle. I'm building the swap that I am, because it's unique and challenging to me. Calling the thing that I'm building an LS4, or an SBC, is not at all accurate. The block, bare heads, and rear cover are the only parts from the original LS4 that will remain.
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quote
Originally posted by engine man:

if those long runners are as big as a straw it's not gonna make power i don't care how big the valve is . dobey don't take my word for it call you local race engine builder and ask them how many cfm a cylinder head intake port must flow to make 600 hp V8 engine

Did you miss the part where I said "long big runners"? Everything your saying is old school knowledge. Why are you passing it off as if you just found this out? What dobey is saying is the dynamics and numbers you only get from a dyno. You can't just throw a set of big flowing heads and expect big results.


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Originally posted by dobey:


No, I didn't read it. I've read enough on the subject from plenty of other places. They, and plenty of others, make comments like that all the time, that lead people to false conclusions about the engine though. The LSx also has wedge heads, which are from the Pontiac. The Gen II LT1/4 had reverse flow cooling, also something Pontiac had in 1955 on their first V8. The bore spacing doesn't really mean much though in terms of relation to the original SBC, when nothing will interchange.

As for the transaxles, I disagree. Yes, it's not an easy swap. If you want an easy swap and to get an SBC or LSx in a Fiero, then use Archie's kit. It's a bit expensive, but it's the closest you're likely to get for a bolt-in kit with using a manual trans with an SBC or LSx, in a Fiero. The LS4 won't work with the 282 trans, because the starter for the LS4 mounts on the transmission side, and the slave on the 282 is in the way. An F23 is theoretically usable, with some hacking of the trans, and the F40 is definitely usable with hacking the bell housing. An NSX trans with the kit from WCF has also been used with an LS4.

I'm not going to sell any LS4+manual trans bolt-in swap kits. I'm not building my car to drag race. It won't have too much torque, and the gearing won't be too bad, despite it being a FWD transaxle. I'm building the swap that I am, because it's unique and challenging to me. Calling the thing that I'm building an LS4, or an SBC, is not at all accurate. The block, bare heads, and rear cover are the only parts from the original LS4 that will remain.


Chevy used the best of all engines to build the 265. Ford flat head dimensions for size, Pontiac's heads and on and on. But to say just because they improved it with better coolant flow and the old parts won't interchange that it's not a small block chevy. The whole world knows this why don't you. And when you say LS4 which one are you talking about the big block or the small block. Because at one time the LS was for big blocks ie the ls6 which gave many a beatdown on its competition in 1970.
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Report this Post09-24-2015 11:03 PM Click Here to See the Profile for dobeySend a Private Message to dobeyEdit/Delete MessageReply w/QuoteDirect Link to This Post
 
quote
Originally posted by Silvertown:
Chevy used the best of all engines to build the 265. Ford flat head dimensions for size, Pontiac's heads and on and on. But to say just because they improved it with better coolant flow and the old parts won't interchange that it's not a small block chevy. The whole world knows this why don't you. And when you say LS4 which one are you talking about the big block or the small block. Because at one time the LS was for big blocks ie the ls6 which gave many a beatdown on its competition in 1970.


The 265 didn't have Pontiac heads on it. It had the crappy bathtub heads, the same as every SBC. Yes, the whole world knows it's not a SBC. When they go to the parts counter, they can't order a hose dingus for an SBC and expect it to fit an Gen II, or Gen III/IV engine.

Why are you being difficult to just to be difficult. If I was building a big block, I'd say a BBC. I'm building a Gen IV LS engine. You can't retrofit VVT onto a BBC or SBC. Only the Gen IV LSx engines (or the Gen V engines, but not interchangeable with Gen IV) can do VVT. The only people that use RPO codes for BBCs or SBCs are Corvette dorks talking to other Corvette dorks. Personally, I'm not going to futz around with 60 year old iron engines unless there's some amazingly special reason to do so (ie, some sort of sentimental value for some very old car that got passed down to me, but I'm not big on sentiment either), when I can spend less on a modern engine that is a whole lot more reliable, makes a lot more power, and doesn't rust or leak oil like crazy, with an assembled long block that comes in around 300 lbs.

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Originally posted by dobey:


The 265 didn't have Pontiac heads on it. It had the crappy bathtub heads, the same as every SBC. Yes, the whole world knows it's not a SBC. When they go to the parts counter, they can't order a hose dingus for an SBC and expect it to fit an Gen II, or Gen III/IV engine.

Why are you being difficult to just to be difficult. If I was building a big block, I'd say a BBC. I'm building a Gen IV LS engine. You can't retrofit VVT onto a BBC or SBC. Only the Gen IV LSx engines (or the Gen V engines, but not interchangeable with Gen IV) can do VVT. The only people that use RPO codes for BBCs or SBCs are Corvette dorks talking to other Corvette dorks. Personally, I'm not going to futz around with 60 year old iron engines unless there's some amazingly special reason to do so (ie, some sort of sentimental value for some very old car that got passed down to me, but I'm not big on sentiment either), when I can spend less on a modern engine that is a whole lot more reliable, makes a lot more power, and doesn't rust or leak oil like crazy, with an assembled long block that comes in around 300 lbs.


I thought ford guys were the worst but they ain't got nothing you. If you knew anything about auto motive history this would be a level playing field. But you believe what you want to believe. I don't care. That same reasoning is why those 3.8s are smoking v8 fieros. But if you raced pontiacs second place is last if ain't first just ask any ford fan.
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Report this Post09-25-2015 08:26 AM Click Here to See the Profile for engine manClick Here to Email engine manSend a Private Message to engine manEdit/Delete MessageReply w/QuoteDirect Link to This Post
sory silvertown i did miss that but just because i say the heads must flow do not mean that you dont have to look a flow velocity that is vary important to but you cant have a head that flows 200 cfm and make 600 hp no matter how much swirl the chamber has and velocity the port has and if i am wrong then pleas show me a book or article that says that you can have a head that has a intake port that flow 200 cfm and make 600 hp NA but the fact is in ever head porting book and article they are going to refer to the formula that i posted for cylinder head flow to hp and one last thing they dyno test and back all of this up with the results
thought i would add some thing now remember the flow numbers i am giving are on a flow bench at 28 inches of water not on the engine witch is not producing 28 inches of water rise for vacuum for each cylinder the flow bench is just a tool to check the flow at a given valve lift

[This message has been edited by engine man (edited 09-25-2015).]

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Report this Post09-25-2015 09:38 AM Click Here to See the Profile for dobeySend a Private Message to dobeyEdit/Delete MessageReply w/QuoteDirect Link to This Post
 
quote
Originally posted by Silvertown:
I thought ford guys were the worst but they ain't got nothing you. If you knew anything about auto motive history this would be a level playing field. But you believe what you want to believe. I don't care. That same reasoning is why those 3.8s are smoking v8 fieros. But if you raced pontiacs second place is last if ain't first just ask any ford fan.


Yep, winning the Quick 8/16/32, and Top Dragster fields at almost every race, and the overall championship, was clearly a loss. I'll remind the owner/driver how crappy that Pontiac was. I'll be sure to tell all the guys at Pontiac who ran the race programs that their engines were junk and they never won anything too. Since you seem to know everything, clearly you must be some god of engines that holds favor to Chevrolet, and therefore nothing can possibly be a better engine than an SBC.

If you knew anything about automotive history this wouldn't be an argument. The 265 did not have Pontiac's heads on it. Believe what you want to believe. Seems maybe you need to learn a little more about respect than automotive history though. If you're a Chevy fanboy and hate Pontiacs so much, why are you even here? Just to troll?
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Originally posted by engine man:

sory silvertown i did miss that but just because i say the heads must flow do not mean that you dont have to look a flow velocity that is vary important to but you cant have a head that flows 200 cfm and make 600 hp no matter how much swirl the chamber has and velocity the port has and if i am wrong then pleas show me a book or article that says that you can have a head that has a intake port that flow 200 cfm and make 600 hp NA but the fact is in ever head porting book and article they are going to refer to the formula that i posted for cylinder head flow to hp and one last thing they dyno test and back all of this up with the results
thought i would add some thing now remember the flow numbers i am giving are on a flow bench at 28 inches of water not on the engine witch is not producing 28 inches of water rise for vacuum for each cylinder the flow bench is just a tool to check the flow at a given valve lift



Im with you on all that. But its the dyno that tells you everything. I don't know why you guys are arguing this because you can buy heads that already have this work and testing done unless you work at this profession and diys. Without the right cam it's all water under the bridge.

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Originally posted by engine man:
sory silvertown i did miss that but just because i say the heads must flow do not mean that you dont have to look a flow velocity that is vary important to but you cant have a head that flows 200 cfm and make 600 hp no matter how much swirl the chamber has and velocity the port has and if i am wrong then pleas show me a book or article that says that you can have a head that has a intake port that flow 200 cfm and make 600 hp NA but the fact is in ever head porting book and article they are going to refer to the formula that i posted for cylinder head flow to hp and one last thing they dyno test and back all of this up with the results
thought i would add some thing now remember the flow numbers i am giving are on a flow bench at 28 inches of water not on the engine witch is not producing 28 inches of water rise for vacuum for each cylinder the flow bench is just a tool to check the flow at a given valve lift


Again, 28 inches of WC is not a huge amount of pressure. I don't know why you think it is. The difference in pressure between atmospheric, and the cylinder, is much higher than 28 in WC, on the intake stroke. 28 in WC is only 1.0 PSI difference in pressure across the bench orifice. The air is not being "sucked" into the cylinders. The air flows into the cylinder because the air pressure in the intake manifold, is higher than the pressure in the cylinder. As the stroke falls to the bottom of the cylinder, the volume increases, and as it fills, pressure increases, until the pressure of the air mass in the cylinder is equal to the pressure of the air mass outside the cylinder, or the intake valve closes, whichever happens first. You're getting too caught up in the numbers of 300 CFM peak flow and 28 in WC, on a flow bench, and seemingly not understanding what they actually mean.

Head flow doesn't make power. BMEP does. Head flow can help you achieve the BMEP necessary to make power, but not on its own. There is such a thing as having heads that are too big for an engine, just as you can have heads that don't flow enough. However, in almost all cases of production street engines, the heads flow more than the engine needs, already. Yes, even on the poor little 2.8. No, you're not going to make 600 HP N/A on a Fiero 2.8, even if you make billet heads that flow 400 CFM and use a sheet metal intake. The engine structure just wouldn't be capable of handling it.

As for making 600 HP N/A with less than 300 CFM peak flow measured in a head, sure it's possible. For the same reason that peak HP doesn't mean anything in real races. What matters, is area under the curve. You make up for flowing a higher CFM for a very short period, by flowing less CFM for a longer period. The same amount of air ends up in the cylinder either way. You need to select the right cam to match what the intake and exhaust systems can flow.
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i think we got stuck on this because the op original ? of engine size vs power and i was trying to point out you could have a huge engine and not make any power due to this and many other factors so the answer is it all depends on many factors of how much power a engine will make
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i am just say when you have the head on the flow bench it is measured at 28 inches and it has to flow a certain amount on the flow bench to make x amount of power and this is how you determine how much power you can make with the head on the engine in no way it means it is flowing that amount on the engine it just means that at this valve lift with this wiater rise the head will flow this much and the have based a hp formula off from that that will tell you what the peak amount of power would be
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Report this Post09-25-2015 10:44 AM Click Here to See the Profile for dobeySend a Private Message to dobeyEdit/Delete MessageReply w/QuoteDirect Link to This Post
 
quote
Originally posted by engine man:

i think we got stuck on this because the op original ? of engine size vs power and i was trying to point out you could have a huge engine and not make any power due to this and many other factors so the answer is it all depends on many factors of how much power a engine will make


Well, OP didn't clearly state what the question was really about anyway. Really, the physics don't change thoough. More displacement = more torque = more HP. Yes, you can intentionally screw that up by putting extremely inappropriate parts in a big engine, so that it can't make any power, but you'd have to try pretty hard to do that on purpose. You're not likely to build a 572 from catalog parts and end up with such a horrible combination. It's a little easier to screw up an engine in the 300-400 CID range though, as there is such a wide variety of parts available that don't necessarily perform so well. But if you're building with performance catalog parts, it's still kind of difficult to really screw it up unless you try. Worst case you'll spend a lot of money and get something average, instead of something that makes good power.

For me, statements like "you need heads that flow 300 CFM at 28 in WC on a flow bench, to be able to make 600 HP with a V8" is a vast oversimplification though, and doesn't really explain anything or help improve the discussion. Yes, the formula is there, and yes if you plug in the numbers, those are the numbers you get back, but it doesn't take into account all the factors there are in making power. You can flow less air and make that power, with the right combination, and you can flow more than that, and make significantly less power, with the wrong combination. I think the math is interesting, but you need to look at all the math, and not a single formula. But I'm an engineer, and the math is important to me, because I need it to create the software tools I need/want, to validate options in an engine build. Some math is useful as a guideline for how to proceed, but doesn't give you a full picture of what you need, such as the HP per peak head CFM formula. So, when I see these oversimplifications, I try to point out that there's a lot more math involved to be able to actually make that power, and just because you see 400 HP or 600 HP as a result of applying that formula to your heads, doesn't mean you're going to see that much power.
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i am not say you will make that much power i am saying that is the maximum power you could make with them IF you have every thing right in your engine so again i am not saying that you will make x amount of power just because a set of heads are bolted on i am saying it is about the maximum you can make with them if you get it all to work together perfectly meaning the right cam headers intake manifold injectors or carb timing fuel oiling system windage tray crank scraper ect ect. see you are looking at each cylinder in the engine as if it is pulling the same 28 inches WC as a flow bench but is not so the head flows less

[This message has been edited by engine man (edited 09-25-2015).]

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quote
Originally posted by dobey:


Yep, winning the Quick 8/16/32, and Top Dragster fields at almost every race, and the overall championship, was clearly a loss. I'll remind the owner/driver how crappy that Pontiac was. I'll be sure to tell all the guys at Pontiac who ran the race programs that their engines were junk and they never won anything too. Since you seem to know everything, clearly you must be some god of engines that holds favor to Chevrolet, and therefore nothing can possibly be a better engine than an SBC.

If you knew anything about automotive history this wouldn't be an argument. The 265 did not have Pontiac's heads on it. Believe what you want to believe. Seems maybe you need to learn a little more about respect than automotive history though. If you're a Chevy fanboy and hate Pontiacs so much, why are you even here? Just to troll?


Drag racing is like premature ej it's over before the fun even begins and the real driving begins. If you smart crack somebody don't have a hissy fit when they come back with the same. And if your a drag racer why are you on a fiero board.
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dobey with the engine the intake valve is not at full lift the whole time plus the vavle is opening and closing causing the air in the intake to start and stop plus the air changes direction due to other cylinders trying to get air in there cylinders where on the flow bench it is a constant air flow with a constant amount of vacuum with the valve opened to a specific hight so the port is seeing something totally different than on the engine
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quote
Originally posted by Silvertown:
Drag racing is like premature ej it's over before the fun even begins and the real driving begins. If you smart crack somebody don't have a hissy fit when they come back with the same. And if your a drag racer why are you on a fiero board.


If you got time to turn, you're not going fast enough.

Really. You come in here, brand new on the fourm for less than a month, make a bunch of childish remarks in some poor attempt to condescend and insult me, comment how bad you think Pontiacs are, and then try to play the victim when you get called out on it? And I'm the one having the hissy fit. Go and untwist your panties son.

I've been on here for 14 years, and I've been into Fieros for longer. Because I spent a large portion of my life, at the drag strip, doesn't mean I can't enjoy and respect other forms of motorsport too.

Now, back to the actual topic…
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quote
Originally posted by engine man:

dobey with the engine the intake valve is not at full lift the whole time plus the vavle is opening and closing causing the air in the intake to start and stop plus the air changes direction due to other cylinders trying to get air in there cylinders where on the flow bench it is a constant air flow with a constant amount of vacuum with the valve opened to a specific hight so the port is seeing something totally different than on the engine


Yes, exactly. That is what I've been saying all along. But the point you are arguing, is that this theoretical maximum value derived from a formula, can't be overcome. It can be overcome, but it's just very rare that it is in practice. It's also very rare that an engine produces the amount of HP derived from that formula as well. And like I said, depending on the cam profile, you can get the same amount of air into the engine with a head that flows less peak CFM, as one that flows more.

But this thread isn't about how much CFM you need to flow through the heads to make a certain amount of power (at least, I'm pretty sure it's not, since the topic is Engine size vs. power). The simplest answer to that is the classic cliche of no replacement for displacement. Cylinder volume and pressure give way to making more power. Increasing either or both will give you more power. You can decrease one and increase the other, to get the same or more power. That's how the practice of manufacturers downsizing to small 4 cylinder engines with turbos works. Chevy Cruze Eco manual for example makes about the same peak HP as the Fiero 2.8, but it's a 1.4L 4 cylinder. It makes less peak torque, but it provides almost all the available torque, over a very broad RPM range (1800-6500 or so). And it can get 50 MPG.

It's all in how you build and tune it. If you want to talk weight, it's possible to have a pushrod V8 that weighs less than a DOHC 4 cylinder turbo. It's just a matter of build and tune, to get what you want out of any car, especially the Fiero.
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quote
Originally posted by dobey:


If you got time to turn, you're not going fast enough.

Really. You come in here, brand new on the fourm for less than a month, make a bunch of childish remarks in some poor attempt to condescend and insult me, comment how bad you think Pontiacs are, and then try to play the victim when you get called out on it? And I'm the one having the hissy fit. Go and untwist your panties son.

I've been on here for 14 years, and I've been into Fieros for longer. Because I spent a large portion of my life, at the drag strip, doesn't mean I can't enjoy and respect other forms of motorsport too.

Now, back to the actual topic…


Did you own one when they were new? I guess that gives me 30 years in dealing with fieros. And whose engine is in the fiero? If pontiac had let chevrolet in on the project they wouldn't be the troubleshooting nightmare they are. Not for me but to someone who likes them and doesn't understand wiring and fuel injection it's a problem laid squarely at pontiacs feet. Thank god they had enough wisdom to put the l44 bowtie in it. And how can we stay on topic when you won't look at any of the evidence that refutes any of your claims.
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Cole's design borrowed the valve train design being used in the Pontiac V-8 for 1955. The stud mounted independent ball rocker arm designed was patented by Pontiac engineer Clayton Leach for Pontiac's new V-8 in 1948.[clarification needed] by forcing Pontiac division to share its valve train design in the new 1955 Chevrolet V-8
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quote
Originally posted by Silvertown:
Did you own one when they were new? I guess that gives me 30 years in dealing with fieros. And whose engine is in the fiero? If pontiac had let chevrolet in on the project they wouldn't be the troubleshooting nightmare they are. Not for me but to someone who likes them and doesn't understand wiring and fuel injection it's a problem laid squarely at pontiacs feet. Thank god they had enough wisdom to put the l44 bowtie in it. And how can we stay on topic when you won't look at any of the evidence that refutes any of your claims.


LOL. Seriously? OK hipster Fiero guy. I'm not the one ignoring evidence. Cut it with the troll crap already. This thread isn't about how much you hate Pontiac and love Chevrolet.
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quote
Originally posted by Silvertown:

Cole's design borrowed the valve train design being used in the Pontiac V-8 for 1955. The stud mounted independent ball rocker arm designed was patented by Pontiac engineer Clayton Leach for Pontiac's new V-8 in 1948.[clarification needed] by forcing Pontiac division to share its valve train design in the new 1955 Chevrolet V-8


Ball rocker arms is not heads.
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Originally posted by dobey:


Ball rocker arms is not heads.



Did you read the the part valve train design. You do know what that involves don't you? I'm beginning to suspect you've never even cracked open an engine in your life.

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quote
Originally posted by dobey:


LOL. Seriously? OK hipster Fiero guy. I'm not the one ignoring evidence. Cut it with the troll crap already. This thread isn't about how much you hate Pontiac and love Chevrolet.



At least mines not in my backyard on block waiting for the craigslist ad "fiero project"

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quote
Originally posted by Silvertown:
Did you read the the part valve train design. You do know what that involves don't you? I'm beginning to suspect you've never even cracked open an engine in your life.


Are you serious? Have you never cracked open an engine in your life? How about you stop grasping at the straws that aren't there, stop making attempts to condescend with such ad hominem attacks, and we get back on topic for the thread?
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dobey

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Originally posted by Silvertown:
At least mines not in my backyard on block waiting for the craigslist ad "fiero project"


Good for you I guess. Mine's not either. Whatever the hell you were trying to do with that lame attempt at condescending, yet again.
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quote
Originally posted by dobey:


Are you serious? Have you never cracked open an engine in your life? How about you stop grasping at the straws that aren't there, stop making attempts to condescend with such ad hominem attacks, and we get back on topic for the thread?



The op was size vs power? And my response was the sbc was the perfect balance of the two. This was not a rocket science question. Did you work for pontiac?
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Originally posted by dobey:


Good for you I guess. Mine's not either. Whatever the hell you were trying to do with that lame attempt at condescending, yet again.


You have to admit that was funny. I just saw an ad like that recently.
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quote
Originally posted by dobey:


Are you serious? Have you never cracked open an engine in your life? How about you stop grasping at the straws that aren't there, stop making attempts to condescend with such ad hominem attacks, and we get back on topic for the thread?


L84 327 fulie, toyota 22re are the only engines I've done.
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quote
Originally posted by dobey:

To use the 600 HP number constantly being repeated, as an example:

Using the following formulas:

HP = TQ x RPM / 5252
BMEP = 150.8 x TQ / CID

If you want to make 600 HP, in a 6.2L engine, at the following RPM values, you need the stated torque, and BMEP, to get it. You'll also need the stated CFM at 85% VE, to keep the engine spinning at the RPM.

code:

RPM TQ BMEP CFM CFM/cyl
4000 787.8 315.96 372.0 46.5
5252 600.0 240.64 488.5 61.1
8000 393.9 157.98 744.0 93.0



Now, of course, at 85% VE, you may not be able to make the required BMEP to get you the 600 HP at the stated RPM. But even at 100% VE, you only use 108.8 CFM per cylinder, on an LS3. Depending on your valve timing, duration, and lift, though, you may need a head that flows 350-400 CFM, to be able to do that. All the bits need to fit together just right.


can you tell me how this is going to give me 28 inches of wc rise if at 100 % VE at 8000 rpm it can only move 108.8 cfm on a head that flow 300 cfm with 28 inches of water rise the cylinder it falls short by 191.2 cfm to get it to show 28 inches of water rise so it is simple less suction less air flow thru the restriction / port this and the other factors i have pointed out so the flow bench and formula are not wrong so what this is say is you must be suck 300 cfm thru the port to get 28 inches of wc rise

[This message has been edited by engine man (edited 09-25-2015).]

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quote
Originally posted by Silvertown:
The op was size vs power? And my response was the sbc was the perfect balance of the two. This was not a rocket science question. Did you work for pontiac?


Not really:

 
quote
Originally posted by Silvertown:
You're spot on. The lsx 454 sbc will destroy a ram jet 502 that's why they make a 672? Ram jet now which brings us back to the displacement theory. But I read an article on a twin sc SBC that puts out over 2000hp. It all boils down to application. I would want as preference the sbc in corvettes and f body's and BBC in chevelle and trucks


 
quote
Originally posted by Silvertown:
Just check out this list there ain't no bb on it.
http://www.thesupercars.org...rld-–-top-10-list/


 
quote
Originally posted by Silvertown:
The fastest wheel driven gas powered single engine car is powered by a small block bowtie.


 
quote
Originally posted by Silvertown:
A hemi got nothing on this bad boy
http://hotrodenginetech.com...k-land-speed-record/


 
quote
Originally posted by Silvertown:
Those engines can't hold together that long. Youve been to bonneville? Live fast die hard is the creed out there. There was a 4 engine hemi that was faster than the sbc but that was years ago.


 
quote
Originally posted by Silvertown:
That's really the only thing about Hemis is the heads. Had a guy tell me I was wasting my money by putting larger valves in a 3.8 with a super charger. It's all about the flow of air into the intake valves and out the exhaust and whoever does it fastest wins. That's why Hemis dominated at the dragstrip and in nascar but not on the street for some peculiar reason.


And on and on. Really, you sound like a standard disrespectful salesman trying to shove a Chevy small block down everyone's throats. None of those statements were about how an SBC is the perfect balance between engine size and power. It's not the perfect balance. They're an OK engine that can be thrown together for cheap, and just tossed into the scrap heap when they break. All you've done in this thread is praise the crap out of SBCs, and basically attacked anyone who said anything that disagreed with your perception of the SBC's greatness. Then ironically you also stated how they'd be a total waste in a Fiero, because transaxles suck and it's not an efficient swap. So apparently they're not the perfect balance you claim they are, according to your own statements.

[This message has been edited by dobey (edited 09-25-2015).]

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quote
Originally posted by engine man:


can you tell me how this is going to give me 28 inches of wc rise if at 100 % VE at 8000 rpm it can only move 108.8 cfm on a head that flow 300 cfm with 28 inches of water rise the cylinder it falls short by 191.2 cfm to get it to show 28 inches of water rise so it is simple less suction less air flow thru the restriction / port this and the other factors i have pointed out so the flow bench and formula are not wrong



Do you do this for a living? Got your own shop? When you say 600hp are we talking wheel or crank.and what motor is this on?

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