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Re: Race Engine Challenge II

Posted: Wed Nov 01, 2017 4:10 pm
by CamKing
David Vizard wrote:
Wed Nov 01, 2017 11:16 am
The bottom line here Mike is not whether we should use a lift rule based on valve diameter,(although it seems like an easy way of doing it) but that we should pick a way to allow for a good working percentage so that whatever valve size is used no one will be penalized. In that respect we are both intent on achieving the same goal but are approaching this same target from significantly different directions.
My point is, if you go with a percentage of valve diameter for a max lift rule, you're penalizing the engine platforms with the smaller bores, twice. Say the CID limit was 427, the guy building a small block, that can't go over a 4.125" bore, is not going to be able to run as big of an intake valve, as the guy building a big block with a 4.300" bore. So, not only will he be handicapped by the smaller intake valve, you're now going to tell him, he can't run as much lift as the bigger bore engine.
All this would do, is give a huge advantage to the engine platforms that can fit a bigger bore and intake valve, and make the smaller bore engines non-competitive.

Re: Race Engine Challenge II

Posted: Wed Nov 01, 2017 4:19 pm
by ijames
CamKing wrote:
Wed Nov 01, 2017 4:10 pm
David Vizard wrote:
Wed Nov 01, 2017 11:16 am
The bottom line here Mike is not whether we should use a lift rule based on valve diameter,(although it seems like an easy way of doing it) but that we should pick a way to allow for a good working percentage so that whatever valve size is used no one will be penalized. In that respect we are both intent on achieving the same goal but are approaching this same target from significantly different directions.
My point is, if you go with a percentage of valve diameter for a max lift rule, you're penalizing the engine platforms with the smaller bores, twice. Say the CID limit was 427, the guy building a small block, that can't go over a 4.125" bore, is not going to be able to run as big of an intake valve, as the guy building a big block with a 4.300" bore. So, not only will he be handicapped by the smaller intake valve, you're now going to tell him, he can't run as much lift as the bigger bore engine.
All this would do, is give a huge advantage to the engine platforms that can fit a bigger bore and intake valve, and make the smaller bore engines non-competitive.
If you are trying to level the playing field, how about varying the max lift at the valve so that the curtain area at max lift is a constant? Big valves don't get to use as much lift as smaller valves but with the curtain area constant they should all have the same maximum flow, right? Just a thought.

Re: Race Engine Challenge II

Posted: Wed Nov 01, 2017 4:48 pm
by David Vizard
CamKing wrote:
Wed Nov 01, 2017 4:10 pm
David Vizard wrote:
Wed Nov 01, 2017 11:16 am
The bottom line here Mike is not whether we should use a lift rule based on valve diameter,(although it seems like an easy way of doing it) but that we should pick a way to allow for a good working percentage so that whatever valve size is used no one will be penalized. In that respect we are both intent on achieving the same goal but are approaching this same target from significantly different directions.
My point is, if you go with a percentage of valve diameter for a max lift rule, you're penalizing the engine platforms with the smaller bores, twice. Say the CID limit was 427, the guy building a small block, that can't go over a 4.125" bore, is not going to be able to run as big of an intake valve, as the guy building a big block with a 4.300" bore. So, not only will he be handicapped by the smaller intake valve, you're now going to tell him, he can't run as much lift as the bigger bore engine.
All this would do, is give a huge advantage to the engine platforms that can fit a bigger bore and intake valve, and make the smaller bore engines non-competitive.
Mikey,

I get the point you are trying to make but why would any engine builder worth their salt build a non-competitive combo?

As you may expect I have thoughts along the lines of a 4.185 bore SBC for a big bore, short stroke setup yielding about 380 inches.
I have done some very strong power producing 23 degree Chevy heads with as much as 2.180 intake valves (1.56 ex) that flowed 334 @ 0.800 and 339 @ 1.000 with 225 cc ports The figure that I liked best of these heads was the 192 cfm @ 250 lift – that’s a 78.5% flow efficiency and that does not come easy. That is the sort of flow at that lift you would expect to see with a 2.3 inch diameter valve as per a BBC.
But let’s look at the lift I could go to with a 35 or a 38% lift limit. At 35% the lift limit would be 763 thou and 823 for the 38% deal. Should I build this SB I fully intend, rules permitting, to use 0.800 net valve lift in spite of the fact that the strong point of my heads was the terrific low/mid lift flow.
But let’s look at a compromise that should satisfy your argument and mine simultaneously. Let us say than any combination with an intake valve less than say 2.05 can have as much lift as the builder deems necessary. But for anything over 2.05 the lift limit is 38% of the intake.

So would that work for you Mr. Cam King sir???
And BTW agreeing isn’t going to let you off lunch!!!!
DV

Re: Race Engine Challenge II

Posted: Wed Nov 01, 2017 5:07 pm
by MadBill
David Vizard wrote:
Wed Nov 01, 2017 4:48 pm
... Let us say than any combination with an intake valve less than say 2.05 can have as much lift as the builder deems necessary. But for anything over 2.05 the lift limit is 38% of the intake...
I dunno David. In your example wouldn't limiting the lift of a 2.180" valve to 0.828" be a lot like saying "no more than 18:1 CR."? :-k

Re: Race Engine Challenge II

Posted: Wed Nov 01, 2017 6:08 pm
by plovett
David Vizard wrote:
Wed Nov 01, 2017 11:22 am
plovett wrote:
Mon Oct 30, 2017 4:25 pm
Is Vee-Dizzie, David Vizard with a new login?


JMO,

paulie
Paulie,

I don't used a a screen name, I personally take full responsibility for what I write!!!

Although I have severe doubts as to it's accuracy I have heard it said that imitation is the sincerest form of flattery!!!
DV
My mistake. It just seemed like a weird coincidence. That and the colored text.

Re: Race Engine Challenge II

Posted: Wed Nov 01, 2017 6:12 pm
by David Vizard
MadBill wrote:
Wed Nov 01, 2017 5:07 pm
David Vizard wrote:
Wed Nov 01, 2017 4:48 pm
... Let us say than any combination with an intake valve less than say 2.05 can have as much lift as the builder deems necessary. But for anything over 2.05 the lift limit is 38% of the intake...
I dunno David. In your example wouldn't limiting the lift of a 2.180" valve to 0.828" be a lot like saying "no more than 18:1 CR."? :-k
Sure 828 lift is a big number but with a Ti valve, a really trick spring, rockers, lifters and push rods it is more than doable for street build peaking at 7300 rpm especially with one of Mikey's trick roller grinds. None the less the reason I went for 0.35 was because I thought it be a more reasonable figure.
DV

Re: Race Engine Challenge II

Posted: Wed Nov 01, 2017 6:15 pm
by David Vizard
plovett wrote:
Wed Nov 01, 2017 6:08 pm
David Vizard wrote:
Wed Nov 01, 2017 11:22 am
plovett wrote:
Mon Oct 30, 2017 4:25 pm
Is Vee-Dizzie, David Vizard with a new login?


JMO,

paulie
Paulie,

I don't used a a screen name, I personally take full responsibility for what I write!!!

Although I have severe doubts as to it's accuracy I have heard it said that imitation is the sincerest form of flattery!!!
DV
My mistake. It just seemed like a weird coincidence. That and the colored text.
No Paulie you are not on the hook for anything. But this guy might be good for some laughs though.

DV

Re: Race Engine Challenge II

Posted: Thu Nov 02, 2017 11:03 am
by CamKing
David Vizard wrote:
Wed Nov 01, 2017 4:48 pm
I get the point you are trying to make but why would any engine builder worth their salt build a non-competitive combo?
Some engine platforms can fit larger bores then other platforms.
Do we want a competition that draws the Chrysler specialist, 302 Ford specialist, LSx specialist, SB2 specialist, Pontiac Specialist, Holden Specialist, etc. ??
Or do we just want everyone building whichever engine they can get the bigger valve in, to take advantage of your lift rule?

Re: Race Engine Challenge II

Posted: Fri Nov 03, 2017 12:06 am
by Walter R. Malik
CamKing wrote:
Thu Nov 02, 2017 11:03 am
David Vizard wrote:
Wed Nov 01, 2017 4:48 pm
I get the point you are trying to make but why would any engine builder worth their salt build a non-competitive combo?
Some engine platforms can fit larger bores then other platforms.
Do we want a competition that draws the Chrysler specialist, 302 Ford specialist, LSx specialist, SB2 specialist, Pontiac Specialist, Holden Specialist, etc. ??
Or do we just want everyone building whichever engine they can get the bigger valve in, to take advantage of your lift rule?
I remember a few years ago that Mike Phillips finished last in the "Extreme Street" class of the Engine Masters Competition and he was a HERO to every Buick minded person on the planet because his big block Buick made over 800 horsepower and went over 8,000 RPM having an O.E.M. block, 3 1/4" main bearing, 1 3/4" diameter cam bearing and single 4 barrel carbed, wet sump, 468 all Buick engine.

I gotta admit ... THAT was cool to witness. =D>

Re: Race Engine Challenge II

Posted: Mon Nov 06, 2017 9:02 am
by David Vizard
Mikey,
your comment:-Or do we just want everyone building whichever engine they can get the bigger valve in, to take advantage of your lift rule?

Surely everyone would want to install the largest air-flow productive intake valve into whatever they are building. So If the largest effective valve is installed then there is no point in lifting it more than 38% of whatever the diameter of the valve is. This should mean a level playing field as far as valve lift is concerned - should it not?

DV

Re: Race Engine Challenge II

Posted: Mon Nov 06, 2017 9:33 am
by Walter R. Malik
David Vizard wrote:
Mon Nov 06, 2017 9:02 am

Surely everyone would want to install the largest air-flow productive intake valve into whatever they are building. So If the largest effective valve is installed then there is no point in lifting it more than 38% of whatever the diameter of the valve is. This should mean a level playing field as far as valve lift is concerned - should it not?

DV
Not really true ... Personally, I installed a larger intake valve and gained air flow into one of my past EMC engines ... and gained a little maximum torque and horsepower only to LOSE power everywhere below the RPM of that peak torque figure.
Just have a maximum valve lift figure here at "0" lash and they can use whatever valve size they want.

That was a change during testing that I wish I never made because it would now take installing 8 seats to go back. So, I left it that way.

Re: Race Engine Challenge II

Posted: Mon Nov 06, 2017 12:59 pm
by Vee-Dizzie
Walter R. Malik wrote:
Mon Nov 06, 2017 9:33 am
Not really true ... Personally, I installed a larger intake valve and gained air flow into one of my past EMC engines ... and gained a little maximum torque and horsepower only to LOSE power everywhere below the RPM of that peak torque figure.
Just have a maximum valve lift figure here at "0" lash and they can use whatever valve size they want
I agree.....UNLESS.....You were just holding a flow bench CFM contest. Does anyone have a link to this past years EMC's rule set?????????????

Re: Race Engine Challenge II

Posted: Mon Nov 06, 2017 1:16 pm
by CamKing
Walter R. Malik wrote:
Mon Nov 06, 2017 9:33 am
David Vizard wrote:
Mon Nov 06, 2017 9:02 am

Surely everyone would want to install the largest air-flow productive intake valve into whatever they are building. So If the largest effective valve is installed then there is no point in lifting it more than 38% of whatever the diameter of the valve is. This should mean a level playing field as far as valve lift is concerned - should it not?

DV
Not really true ... Personally, I installed a larger intake valve and gained air flow into one of my past EMC engines ... and gained a little maximum torque and horsepower only to LOSE power everywhere below the RPM of that peak torque figure.
Just have a maximum valve lift figure here at "0" lash and they can use whatever valve size they want.

That was a change during testing that I wish I never made because it would now take installing 8 seats to go back. So, I left it that way.
Exactly, with a gross valve lift rule, the engine builder can go with whatever valve size and port size he thinks will work best with that lift. DV can divide the max lift by .38 to get his valve size. Someone else can go bigger, and use less duration. Someone else can go smaller, and increase duration. It's all up to the engine builder to do what he/she thinks is best.

Re: Race Engine Challenge II

Posted: Mon Nov 06, 2017 1:28 pm
by GARY C
CamKing wrote:
Mon Nov 06, 2017 1:16 pm
Walter R. Malik wrote:
Mon Nov 06, 2017 9:33 am
David Vizard wrote:
Mon Nov 06, 2017 9:02 am

Surely everyone would want to install the largest air-flow productive intake valve into whatever they are building. So If the largest effective valve is installed then there is no point in lifting it more than 38% of whatever the diameter of the valve is. This should mean a level playing field as far as valve lift is concerned - should it not?

DV
Not really true ... Personally, I installed a larger intake valve and gained air flow into one of my past EMC engines ... and gained a little maximum torque and horsepower only to LOSE power everywhere below the RPM of that peak torque figure.
Just have a maximum valve lift figure here at "0" lash and they can use whatever valve size they want.

That was a change during testing that I wish I never made because it would now take installing 8 seats to go back. So, I left it that way.
Exactly, with a gross valve lift rule, the engine builder can go with whatever valve size and port size he thinks will work best with that lift. DV can divide the max lift by .38 to get his valve size. Someone else can go bigger, and use less duration. Someone else can go smaller, and increase duration. It's all up to the engine builder to do what he/she thinks is best.
For you guys that have been in EMC year after year what year/rule set did you find to be best?

It seems a lot of guy liked this years class that Creason won with the exception of flat tappet cam and possibly being able to use epoxy to fine tune the runner shape.

Re: Race Engine Challenge II

Posted: Mon Nov 06, 2017 7:44 pm
by Joe-71
EMC rules liked best: Specific fuel that allows builder to not have to worry about detonation, No timing belts, No vacuum pumps, No dry sump, Carburetion unlimited, No EFI unless class specific, Chassis headers, 12" maximum depth oil pan from crank centerline, cubic inch maximum parameters, replacement blocks, replacement heads, cast intakes. Joe-71