I.E ratio for heavy nitrous 565

[Ed-vancedEngines]

The Original Poster (Corvette Guy) has out of the box BB3 heads. I would have him get those worked no matter how he will run them. They can be made to come alive but out of the box aren't so great.

Here we go again though, If he has them worked to have them worked to excell at how he is wanting to use them. I would not have only the exhaust ported if he were doing only nitrous with them. I also would not have the intake opened up to be hog wild for nitrous or for N/A. I hate huge ports.

Ed

[cboggs]

it probably would have made more power not using nitrous also. Yes?

No, .. ..

If the original poster plans on using NOS all the time, .. yes I would
make some adjustments to the exhaust port.
And that doesn't necessarily mean I'd build a port with a big flow bench
number either. I'd make adjustments to port shape & cross sectional area
based on the greater volume of gas to expel during the exhaust cycle.

Also as Ed points out they are "out of the box" heads and by no means ready
for use on any race engine, .. so they need to be ported regardless.
Really all this should be up to the porter he chooses and let
him design the head.

Curtis

[63 Nitrous Ratt Vette]

Wow, lots of great info....thanks, it has given me a lot to think about.

[Strange Magic]

It's basic and simple. Weather it's nitrous or non nitrous an efficiant engine will always make gains if the exhaust port happens to be restricting the flow and this absolutely has nothing to do with having nitrous or no nitrous.

If you took two back to back engines and ran them down the track and on the dyno and still had potential to increase the exhaust flow by additional porting, then by doing so it will show gains regardless as long as the port is restrictive and not maxed out for that engines potential.

I would have to say that the ports in general (intake and exhaust) should be a certain percentage larger for any additive that is induced into it since this additive displaces or replaces area/air volume, but this does not only pertain to an exhaust side only.

As BTR said, you do as much as you can do regardless of the weather you have a power adder or not.

[442]

Strange Magic wrote:

As BTR said, you do as much as you can do regardless of the weather you have a power adder or not.

This is actually what BTR wrote and it does not say that.
But it is not surprising you have chimed in to defend him. You two are very close friends correct?



Don't worry about making the exhaust side better. You will be fine the way it is. You don't need to worry about the exhaust port flow on a nitrous motor on any of these good flowing cylinder heads. It is controlled by the camshaft.
I am sure most people would disagree with my findings, but many follow everyone else like sheep and don't think for themselves or really think about what is really going on during each cycle.


This site is not about mindless sheep. It has many great minds with years of experience.


To dano73327:

BTR wrote: I got my information from the internet and books. I never raced or built a nitrous engine in my life. BTW just about any engine will pick up whether using nitrous or not from the described modification. I read that too.

Another fine quip! Why this tone?

And yet another……

BTR wrote: My opinion differs from you guys and most other people. If I didn't go fast with my customers stuff and my stuff, I would consider myself a jackoff.

Joe Mendelis wrote:

Have you ever built an engine and run pressure transducers in the heads? I have seen enormous gains on the exhaust side on an SB2 head that only picked up 7 cfm. 40hp and -2 degrees of ig. timing. How could that not make a big difference on a nitrous engine?

Why can gains be had with ig. timing on the exhaust side? And why wouldn't that help a nitrous engine? Do you want to run more timing?

What are you doing on your exhaust port? What is the valve size, venturi size, exit size, and valvejob. Maybe you arent seeing any gains because flow numbers look good. There's alot more to look at. Exhaust is very picky about certain things.



Curtis wrote: I've been reading this thread since it started, .. interesting to say
the least.

I've worked on NOS engines since the 80's and days of working at Sonny's
and the first 200 mph door car, .. . a better exhaust port has
ALWAYS made more power.

Would not a civil response to these gentleman lend to the conversation?

Please do us all a favor and keep these condescending remarks on the ROP site www.realoldspower.com

It is just that language which is used there that has filled that forum with discontent.

This forum is far too respectable to have such discourse.

[72Pete496]

Strange Magic wrote:

As BTR said, you do as much as you can do regardless of the weather you have a power adder or not.

This is actually what BTR wrote and it does not say that.
But it is not surprising you have chimed in to defend him. You two are very close friends correct?



Don't worry about making the exhaust side better. You will be fine the way it is. You don't need to worry about the exhaust port flow on a nitrous motor on any of these good flowing cylinder heads. It is controlled by the camshaft.
I am sure most people would disagree with my findings, but many follow everyone else like sheep and don't think for themselves or really think about what is really going on during each cycle.


This site is not about mindless sheep. It has many great minds with years of experience.


To dano73327:

BTR wrote: I got my information from the internet and books. I never raced or built a nitrous engine in my life. BTW just about any engine will pick up whether using nitrous or not from the described modification. I read that too.

Another fine quip! Why this tone?

And yet another……

BTR wrote: My opinion differs from you guys and most other people. If I didn't go fast with my customers stuff and my stuff, I would consider myself a jackoff.

Joe Mendelis wrote:

Have you ever built an engine and run pressure transducers in the heads? I have seen enormous gains on the exhaust side on an SB2 head that only picked up 7 cfm. 40hp and -2 degrees of ig. timing. How could that not make a big difference on a nitrous engine?

Why can gains be had with ig. timing on the exhaust side? And why wouldn't that help a nitrous engine? Do you want to run more timing?

What are you doing on your exhaust port? What is the valve size, venturi size, exit size, and valvejob. Maybe you arent seeing any gains because flow numbers look good. There's alot more to look at. Exhaust is very picky about certain things.



Curtis wrote: I've been reading this thread since it started, .. interesting to say
the least.

I've worked on NOS engines since the 80's and days of working at Sonny's
and the first 200 mph door car, .. . a better exhaust port has
ALWAYS made more power.

Would not a civil response to these gentleman lend to the conversation?

Please do us all a favor and keep these condescending remarks on the ROP site www.realoldspower.com

It is just that language which is used there that has filled that forum with discontent.

This forum is far too respectable to have such discourse.

Easy Frances, the boys from ROP are very knowledgeable. Even in a regular conversation with these guys you will get a tech tip, you just need to PAY ATTENTION. It was hard for me too, but after letting a builder do what he does best I have never been happier. I guess what Im saying is if you dont want someones advice dont take it.


Pete

[442]

Sir,

With all due respect, I am not talking about ROP being a bad site or whether those who post there are experts in their field. There are many who are! But.......Unlike this site, many posting go from inquiring minds asking questions or trying to find a simple understanding, to utter trash talking.

What I am talking about is carrying on adult conversations with constructive criticism and having due respect for our fellow man. Period....

76Pete496 wrote:

I guess what Im saying is if you dont want someones advice dont take it.

No.....If you don't want someones advice don't ask!!

This site is precious to those who can poise the questions to the "Knowledgeable" yet can be asked by the non-mechanically inclined and still get an answer that helps sort through the confusion.
Some folks have handicaps and/or tight budgets that might not allow them to push the limits but still wonder what the end results would bring them.

Many here support their families by their expertice. They are busy and may not have time to answer. It is of course the internet.

But I have learned a lifetime of information from the many who post here and don't wish to see it degraded.

[SWB]

It's basic and simple. Weather it's nitrous or non nitrous an efficiant engine will always make gains if the exhaust port happens to be restricting the flow and this absolutely has nothing to do with having nitrous or no nitrous.

If you took two back to back engines and ran them down the track and on the dyno and still had potential to increase the exhaust flow by additional porting, then by doing so it will show gains regardless as long as the port is restrictive and not maxed out for that engines potential.

I would have to say that the ports in general (intake and exhaust) should be a certain percentage larger for any additive that is induced into it since this additive displaces or replaces area/air volume, but this does not only pertain to an exhaust side only.

As BTR said, you do as much as you can do regardless of the weather you have a power adder or not.

Why do you want a "restrictive" exhaust? I don't understand this.

SWB

[hsutton]

I think Brodix has CNC programs that can help this particular head a great deal. It might be better to let Larry Meaux or one of the other excellent head porters here do some work on them. You'll undoubtedly get better results and can then turn the nitrous hit to a lower setting and save your engine undue stress. Porting should be able to get an extra 50-80 H.P. without killing your budget.

[Joe Mendelis]

No offense pete, but ROP looks like LS1 tech for Oldsmobile guys.

[63 Nitrous Ratt Vette]

I think Brodix has CNC programs that can help this particular head a great deal. It might be better to let Larry Meaux or one of the other excellent head porters here do some work on them. You'll undoubtedly get better results and can then turn the nitrous hit to a lower setting and save your engine undue stress. Porting should be able to get an extra 50-80 H.P. without killing your budget.

Harold, I sent the heads back to Brodix and just got off the phone with them. They are going to work them over a little and I will run them as I get them back. Like we have both pointed out the car is only certified to 7.50's and it went the 1/8 mile equivilent of a 7.99 in the 1/4 with a pump gas oval port 454 and a 36 jet. It "should" not be that difficult to get the car into the 7.4xx's with a dedicated nitrous 555.