SBC combination critique

[NewbVetteGuy]

At this point, I'm going to assume "sometingwong" is trolling...

He-Who-Shall-No-Be-Named, mentioned on a 55/50/45 valve seat angle thread on YB, that he typically sees a 30-55 FPS airspeed increase on the port floor and secondary choke moving from a 45 to a 50 degree valve seat angle w supporting angles, and asked "what are you going to do with (about the increased FPS"? (I'm assuming he was talking about 23 deg SBC stuff as that's his bread and butter)

I'm curious what SHOULD be done with the extra port speed there, if that's the case. -Obviously open up the min CSA choke point up stream (like you bought a bigger head in the first place), but what about on the floor / around the SSR? (widen the port to slow down the air there?)

(I'm asking questions at / probably beyond my understanding here...)

Adam

[NewbVetteGuy]

How could there not be an increase in pressure concentration as that inclination angle increases????????

So you know enough to use big words like that but can't build a run-of-the-mill 350 in any of 500 magazines without help?

Something doesn't add up.

Are you saying that sumting is wong?
(couldn't resist; think he choose that username very intentionally...)

[Newold1]

There is something here a little funny! with the OP's questions and comebacks, Oh Well?

If "Sumtingwong" does not understand that in a 3 angle or 5 angle vale job of lets say 30/45/60/70/80 the 30 is a top cut above the standard 45 degree seating angle for the valve then he probably should not be designing, specing or building a 500HP SBC!

A 30 degree on the valve seating angle cut on a seat would be very unreliable and pretty quickly a disaster with some moderate spring pressure.

But I do like 50 degree seat angles and use them a lot.

[RevTheory]

I don't think that sumtingwong had any nefarious intentions nor do I believe that he who shall not be named gives two flyin' fuggs about ST, but I've been known to give credit where it isn't due and take things personally that weren't meant that way.

Thus is the way life goes when dealing with written words.

[GARY C]

At this point, I'm going to assume "sometingwong" is trolling...

He-Who-Shall-No-Be-Named, mentioned on a 55/50/45 valve seat angle thread on YB, that he typically sees a 30-55 FPS airspeed increase on the port floor and secondary choke moving from a 45 to a 50 degree valve seat angle w supporting angles, and asked "what are you going to do with (about the increased FPS"? (I'm assuming he was talking about 23 deg SBC stuff as that's his bread and butter)

I'm curious what SHOULD be done with the extra port speed there, if that's the case. -Obviously open up the min CSA choke point up stream (like you bought a bigger head in the first place), but what about on the floor / around the SSR? (widen the port to slow down the air there?)

(I'm asking questions at / probably beyond my understanding here...)

Adam

First I would want to know what happens on the dyno with that increased speed before I slow it down and then I would want to know what it does after I slow it down...

What you presented is how you would slow it down but without testing before and after there is no way to know what is better.

[GARY C]

So perhaps I will keep it simple with a three angle 45 degree 2.02 valve seat job and hope it comes close to meeting my goals....

I could be wrong, but I think the Dart Platinum heads already come with a 45 degree valve seat angle-based 5 angle valve job. -You planning on intentionally "downgrading" your heads with a new 3 angle valve job over the stock 5 angle valve job???

https://static.summitracing.com/global/ ... 20head.pdf
Stock intake valve job: 32, 45, 60, 70, 80
Exhaust: 37, 45, radius

Adam

Is it possible he didn't know this?

What do you do if a head comes with a 3 angle and you do a 5 angle and it losses flow every where?

[midnightbluS10]

How could there not be an increase in pressure concentration as that inclination angle increases????????

So you know enough to use big words like that but can't build a run-of-the-mill 350 in any of 500 magazines without help?

Something doesn't add up.

Can you provide a link to a 500 horse pump 350?

Nope. I don't read car mags, websites, nor sponsored articles religiously. And notice I said magazines. NOT websites. That includes the 50+ years of mags before the internet was invented.

You have the internet. You want links? Go find em lol. I'm not your personal servant.

[GARY C]

So you know enough to use big words like that but can't build a run-of-the-mill 350 in any of 500 magazines without help?

Something doesn't add up.

Can you provide a link to a 500 horse pump 350?

Nope. I don't read car mags, websites, nor sponsored articles religiously. And notice I said magazines. NOT websites. That includes the 50+ years of mags before the internet was invented.

You have the internet. You want links? Go find em lol. I'm not your personal servant.

How does any of this answer the question, further the conversation or in anyway add tech to a tech forum?

[77cruiser]

How could there not be an increase in pressure concentration as that inclination angle increases????????

So you know enough to use big words like that but can't build a run-of-the-mill 350 in any of 500 magazines without help?

Something doesn't add up.

Can you provide a link to a 500 horse pump 350?

https://www.youtube.com/watch?v=xt5SvAtCdlA

[Sumtingwong]

Thanks to all who've made contributions///////greatly appreciated, sorry to offend, I can assure their is no "trolling" on my part. Civility seems to be at a minimum these days.






The world we live in I presume. A lot of assumptions have been made about my intentions and base of knowledge although my ambitions were purely genuine I can assure you. I'll just continue to lurk and read Speedtalk in the distance. Thanks again.

Nathan Wong

[GARY C]

Thanks to all who've made contributions///////greatly appreciated, sorry to offend, I can assure their is no "trolling" on my part. Civility seems to be at a minimum these days.






The world we live in I presume. A lot of assumptions have been made about my intentions and base of knowledge although my ambitions were purely genuine I can assure you. I'll just continue to lurk and read Speedtalk in the distance. Thanks again.

Nathan Wong

Here is some cylinder head math to ponder if you haven't already seen it. It's not the end all but it is good info as to where you need to be.
Copy and past link to get you there, this forum has him locked out!
http://s peierracingheads.com/head-size-info.html

[rfoll]

Sumtingwong, You stated a plan to build a street/strip engine and along the way have 500 HP. If making good horsepower is a goal, why not start with a larger engine?. A 383 or 406 will be faster and ultimately more drivable. "500" is just a number, and a 500 HP 350 is going to be on the nasty side for street driving. High stall converters and low rear gears would be required. Build an engine to perform as you want and let the HP number fall where it may.

[lefty o]

Sumtingwong, You stated a plan to build a street/strip engine and along the way have 500 HP. If making good horsepower is a goal, why not start with a larger engine?. A 383 or 406 will be faster and ultimately more drivable. "500" is just a number, and a 500 HP 350 is going to be on the nasty side for street driving. High stall converters and low rear gears would be required. Build an engine to perform as you want and let the HP number fall where it may.

this is pretty accurate. its not that it cant be done, but life is easier with a few more cubes.

[Newold1]

I notice a lot of posters come in on a thread subject like this without starting at the beginning and reading the previous posts.

My first post #5 and a few others right behind me already made the recommendation to the OP to look at 383 or bigger cubes to achieve is goal in a milder operating street engine.

Try that if you can before you post and the subjects won't get so stale and have many of us sounding like parrots. Thanks

[lefty o]

I notice a lot of posters come in on a thread subject like this without starting at the beginning and reading the previous posts.

My first post #5 and a few others right behind me already made the recommendation to the OP to look at 383 or bigger cubes to achieve is goal in a milder operating street engine.

Try that if you can before you post and the subjects won't get so stale and have many of us sounding like parrots. Thanks

why dont you just tell everyone what they should post, should make it short and sweet!