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importance of and improving power curve

General engine tech -- Drag Racing to Circle Track

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Frankshaft
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Re: importance of and improving power curve

Post by Frankshaft » Thu Oct 18, 2018 12:26 pm

CGT wrote:
Thu Oct 18, 2018 12:23 pm
randy331 wrote:
Wed Oct 17, 2018 10:22 pm
CGT wrote:
Mon Sep 10, 2018 8:56 am
What do you think about trying more lift? That could possibly be better everywhere in that rpm range....
This,... from the guy who said not to change things in the valve trian cause it seems happy now ??? :lol:
Lift is on the table for change for next year. :D

Randy
Lift could possibly calm the valvetrain even more.....depending on how you go about getting it..
Or exaggerate an issue that you may have.

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Re: importance of and improving power curve

Post by CGT » Thu Oct 18, 2018 12:32 pm

Frankshaft wrote:
Thu Oct 18, 2018 12:26 pm
CGT wrote:
Thu Oct 18, 2018 12:23 pm
randy331 wrote:
Wed Oct 17, 2018 10:22 pm


This,... from the guy who said not to change things in the valve trian cause it seems happy now ??? :lol:
Lift is on the table for change for next year. :D

Randy
Lift could possibly calm the valvetrain even more.....depending on how you go about getting it..
Or exaggerate an issue that you may have.
True...lol
"Never let your hobby ride you. Work while you work and play while you play"

"Hobbies are a contradiction; they take work and turn it into leisure, and take leisure and turn it into work."

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Re: importance of and improving power curve

Post by Frankshaft » Thu Oct 18, 2018 12:37 pm

CGT wrote:
Thu Oct 18, 2018 12:32 pm
Frankshaft wrote:
Thu Oct 18, 2018 12:26 pm
CGT wrote:
Thu Oct 18, 2018 12:23 pm

Lift could possibly calm the valvetrain even more.....depending on how you go about getting it..
Or exaggerate an issue that you may have.
True...lol
How big of pushrods are in it? The last engine I did, that spread port BBC that was ignored in a BBC thread, that actually exists, was over shadowed by a mini Cooper, go figure. Anyhow, It was absolutely mind boggling how much 7/16 .165 wall pushrods were flexing in that thing before, especially on the eggsghaust side. Smith Bros. told me they are WAY overkill. Ahh, not!! It definitely helped it go up in rpm and carry the power farther. The bigger pushrods that is. Used 1/2 .200 wall.

CGT
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Re: importance of and improving power curve

Post by CGT » Thu Oct 18, 2018 12:53 pm

Frankshaft wrote:
Thu Oct 18, 2018 12:37 pm
CGT wrote:
Thu Oct 18, 2018 12:32 pm
Frankshaft wrote:
Thu Oct 18, 2018 12:26 pm


Or exaggerate an issue that you may have.
True...lol
How big of pushrods are in it? The last engine I did, that spread port BBC that was ignored in a BBC thread, that actually exists, was over shadowed by a mini Cooper, go figure. Anyhow, It was absolutely mind boggling how much 7/16 .165 wall pushrods were flexing in that thing before, especially on the eggsghaust side. Smith Bros. told me they are WAY overkill. Ahh, not!! It definitely helped it go up in rpm and carry the power farther. The bigger pushrods that is. Used 1/2 .200 wall.
Double taper or straight?
"Never let your hobby ride you. Work while you work and play while you play"

"Hobbies are a contradiction; they take work and turn it into leisure, and take leisure and turn it into work."

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Re: importance of and improving power curve

Post by randy331 » Thu Oct 18, 2018 7:06 pm

Frankshaft wrote:
Thu Oct 18, 2018 12:37 pm

How big of pushrods are in it? The last engine I did, that spread port BBC that was ignored in a BBC thread, that actually exists, was over shadowed by a mini Cooper, go figure. Anyhow, It was absolutely mind boggling how much 7/16 .165 wall pushrods were flexing in that thing before, especially on the eggsghaust side. Smith Bros. told me they are WAY overkill. Ahh, not!! It definitely helped it go up in rpm and carry the power farther. The bigger pushrods that is. Used 1/2 .200 wall.
Pushrods are Trend 3/8 x .145" wall. Not room for more diameter on the intake and keep the width in the port it has now.
Could fit larger on the ex.

It has pac 1325 springs on it with 1.7 in rocker and 1.6 ex rocker.
It's in the 260 on the seat 750-760 open pressure.
More intake lift would require a different spring.

Randy

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Re: importance of and improving power curve

Post by zums » Thu Oct 18, 2018 8:48 pm

Frankshaft wrote:
Thu Oct 18, 2018 12:20 pm
randy331 wrote:
Wed Oct 17, 2018 10:22 pm
CGT wrote:
Mon Sep 10, 2018 8:56 am
What do you think about trying more lift? That could possibly be better everywhere in that rpm range....
This,... from the guy who said not to change things in the valve trian cause it seems happy now ??? :lol:
Lift is on the table for change for next year. :D

Randy
How about a 30 degree radius intake seat? For big low lift flowz. And some major port bias? I think that would crank the port energy thru the roof.
Lol, and 94% throats , that will beef up the low end, so your in the woods if it can use that carb size at its lowest rpm, cant simulate that on the dyno, any witness marks on the pistons or port sides {pushrod {{inflection"" "lol
Tom

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Re: importance of and improving power curve

Post by randy331 » Thu Oct 18, 2018 9:11 pm

Frankshaft wrote:
Thu Oct 18, 2018 12:20 pm
How about a 30 degree radius intake seat? For big low lift flowz. And some major port bias? I think that would crank the port energy thru the roof.

Hummm, well I was thinkin going to 55* seats on the ex, maybe steeper than the current 50* on the intake, rolling the heads over a bit more to get comp up over 15-1, a much bigger carb (already have that) some bigger custom headers, switching the ex valves out to titanium and trying either a little faster ex lobe or higher ex rocker ratio and some induction tract work. Kinda ran outta time on the induction tract and it wasn't just like I wanted. I got a couple spider intakes here for 18* heads. Was thinkin about getting one of them to fit and try it.

But,... if 30* seats and bias ports and big low lift flowZ works better,...……. I'm all in :^o

Randy
Last edited by randy331 on Thu Oct 18, 2018 9:20 pm, edited 1 time in total.

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Re: importance of and improving power curve

Post by randy331 » Thu Oct 18, 2018 9:19 pm

zums wrote:
Thu Oct 18, 2018 8:48 pm
so your in the woods if it can use that carb size at its lowest rpm, cant simulate that on the dyno,
Yes currently in the woods on that,... but I think it will work.
I can simulate the big carb on the dyno to some extent.
The Stuska will sweep down too. We could bring it up to 8000 rpm or so and sweep it backwards down to 4000 rpm or so.

Kinda like to take it to the dyno with the current small headers and pull it out to 9000 rpm just to get a power number there to go along with the current gear.

Randy

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Re: importance of and improving power curve

Post by randy331 » Thu Oct 18, 2018 9:38 pm

n2xlr8n wrote:
Fri Aug 31, 2018 8:36 am
That is one of the finest sounds in the world.

Nice job. Your son has to be thrilled with the family results.
We are all happy with the results considering it's our first year at a serious try at pulling.
And it is a cool sound for sure.

The classes with spark plugs are the best. LOl

Randy

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Re: importance of and improving power curve

Post by CGT » Fri Oct 19, 2018 8:38 am

randy331 wrote:
Thu Oct 18, 2018 9:11 pm
bigger custom headers, switching the ex valves out to titanium and trying either a little faster ex lobe or higher ex rocker ratio

"The better the Exh port works overall and especially in the .050" to .300" lift range the smaller the Exh lobe you will need to make power!!!!

Compression ratio / cylinder pressure are big factors that can help a under performing Exh port to work as needed during the blow down cycle, that being getting a good size chunk of the spent gasses out of the motor even before the piston starts its way up the Bore on the Exh stroke!"

randy331 wrote:
Thu Oct 18, 2018 9:11 pm
if 30* seats and bias ports and big low lift flowZ works better

" Use the stock exit size more efficiently. The ssr needed bias and reshaping."

IM OUT!!!!!
MOO3.jpg
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"Never let your hobby ride you. Work while you work and play while you play"

"Hobbies are a contradiction; they take work and turn it into leisure, and take leisure and turn it into work."

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Re: importance of and improving power curve

Post by CGT » Fri Oct 19, 2018 11:57 am

randy331 wrote:
Thu Oct 18, 2018 9:11 pm
Frankshaft wrote:
Thu Oct 18, 2018 12:20 pm
How about a 30 degree radius intake seat? For big low lift flowz. And some major port bias? I think that would crank the port energy thru the roof.

Hummm, well I was thinkin going to 55* seats on the ex, maybe steeper than the current 50* on the intake, rolling the heads over a bit more to get comp up over 15-1, a much bigger carb (already have that) some bigger custom headers, switching the ex valves out to titanium and trying either a little faster ex lobe or higher ex rocker ratio and some induction tract work. Kinda ran outta time on the induction tract and it wasn't just like I wanted. I got a couple spider intakes here for 18* heads. Was thinkin about getting one of them to fit and try it.

But,... if 30* seats and bias ports and big low lift flowZ works better,...……. I'm all in :^o

Randy
Interesting, whats your thought behind speeding up the exhaust valve, rpm I would guess? Weren't you considering switching over to the 14 degree heads? The headers and the carb seem to be no brainers. Which 18° manifolds do you have? I would want to look at the condition of the current seats, after going through those extreme conditions before going to a steeper VJ.
"Never let your hobby ride you. Work while you work and play while you play"

"Hobbies are a contradiction; they take work and turn it into leisure, and take leisure and turn it into work."

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Re: importance of and improving power curve

Post by Carnut1 » Fri Oct 19, 2018 2:29 pm

CGT wrote:
Fri Oct 19, 2018 8:38 am
randy331 wrote:
Thu Oct 18, 2018 9:11 pm
bigger custom headers, switching the ex valves out to titanium and trying either a little faster ex lobe or higher ex rocker ratio

"The better the Exh port works overall and especially in the .050" to .300" lift range the smaller the Exh lobe you will need to make power!!!!

Compression ratio / cylinder pressure are big factors that can help a under performing Exh port to work as needed during the blow down cycle, that being getting a good size chunk of the spent gasses out of the motor even before the piston starts its way up the Bore on the Exh stroke!"

randy331 wrote:
Thu Oct 18, 2018 9:11 pm
if 30* seats and bias ports and big low lift flowZ works better

" Use the stock exit size more efficiently. The ssr needed bias and reshaping."

IM OUT!!!!!

MOO3.jpg
I will bite, how would you improve it vs. my method?
Servedio Cylinder Head Development
631-816-4911
9:00am - 9:00pm EST

CGT
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Re: importance of and improving power curve

Post by CGT » Fri Oct 19, 2018 2:42 pm

Carnut1 wrote:
Fri Oct 19, 2018 2:29 pm
CGT wrote:
Fri Oct 19, 2018 8:38 am
randy331 wrote:
Thu Oct 18, 2018 9:11 pm
bigger custom headers, switching the ex valves out to titanium and trying either a little faster ex lobe or higher ex rocker ratio

"The better the Exh port works overall and especially in the .050" to .300" lift range the smaller the Exh lobe you will need to make power!!!!

Compression ratio / cylinder pressure are big factors that can help a under performing Exh port to work as needed during the blow down cycle, that being getting a good size chunk of the spent gasses out of the motor even before the piston starts its way up the Bore on the Exh stroke!"

randy331 wrote:
Thu Oct 18, 2018 9:11 pm
if 30* seats and bias ports and big low lift flowZ works better

" Use the stock exit size more efficiently. The ssr needed bias and reshaping."

IM OUT!!!!!

MOO3.jpg
I will bite, how would you improve it vs. my method?
Improve what? Exhaust flow?
"Never let your hobby ride you. Work while you work and play while you play"

"Hobbies are a contradiction; they take work and turn it into leisure, and take leisure and turn it into work."

Carnut1
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Re: importance of and improving power curve

Post by Carnut1 » Fri Oct 19, 2018 2:46 pm

CGT wrote:
Fri Oct 19, 2018 2:42 pm
Carnut1 wrote:
Fri Oct 19, 2018 2:29 pm
CGT wrote:
Fri Oct 19, 2018 8:38 am



"The better the Exh port works overall and especially in the .050" to .300" lift range the smaller the Exh lobe you will need to make power!!!!

Compression ratio / cylinder pressure are big factors that can help a under performing Exh port to work as needed during the blow down cycle, that being getting a good size chunk of the spent gasses out of the motor even before the piston starts its way up the Bore on the Exh stroke!"





" Use the stock exit size more efficiently. The ssr needed bias and reshaping."

IM OUT!!!!!

MOO3.jpg
I will bite, how would you improve it vs. my method?
Improve what? Exhaust flow?
Sure
Servedio Cylinder Head Development
631-816-4911
9:00am - 9:00pm EST

CGT
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Re: importance of and improving power curve

Post by CGT » Fri Oct 19, 2018 2:58 pm

Carnut1 wrote:
Fri Oct 19, 2018 2:46 pm
CGT wrote:
Fri Oct 19, 2018 2:42 pm
Carnut1 wrote:
Fri Oct 19, 2018 2:29 pm

I will bite, how would you improve it vs. my method?
Improve what? Exhaust flow?
Sure
Just so happens I am building a LS3 right now. A real engine, that runs and everything( soley for testing purposes)....something that you should actually do(build an engine) My exhaust port will get very little work, at least initially. Valve job, and maybe throat taken out some and blended in. And then I will put it on an engine and run it!!!!! If my 378 inch LS makes 700hp NA? How much would it make with your magic port that will never run?

Try using the power of skepticism once and awhile, it can be an effective learning tool. Do some real testing, learn how an engine works first before trying to tell people what will cause what within one, when you have no idea. Walk away from that flow bench for awhile, you may find some extra money from electricity savings to play with real motors and establish some ideas of your own.
Last edited by CGT on Fri Oct 19, 2018 3:45 pm, edited 1 time in total.
"Never let your hobby ride you. Work while you work and play while you play"

"Hobbies are a contradiction; they take work and turn it into leisure, and take leisure and turn it into work."

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