Actually running a old school cam in a LT1 is not that hard. Using a non Vented opti timing cover helps since the plug you have to make to cover that bad boy up is much smaller that a vented cover. Throw a good timing pointer on the cover to boot. With the proper measurements you can machine the cover so you can run a cam button on the front of the cam and that makes it drop like in like a '87+ roller block. Only thing is the opti has to go bye bye, which is not that bad.

The rest of that combo sounds good. I still think that a drag race only NA LT1 should have AFR RR's and a 2926 Super Vic on it. That's a 700hp motor if it's done right.

Bret

 

These Valve covers are center bolt. Tanner has the same ones. Joe Overton did the cam for me, and I haven't even fired the car up since the changes. This car wont see the street that much. More geared for the track now.

Neal

 

Those are the plans after next summer. AFR RR's and a super Victor. I just need to find a good porter. I want the most out of this combo. I don't know what else I could do. Once I fire this car up I will post the vid. I'd like to here it idle aswell. Once it's started which should be in a couple weeks, I'm off to the dyno and then straight to the track. I race at 5,400 feet altitude. I'm hoping for high tens. Who know's what it would run at sea-level?

Neal

 

When moving to some AFR 227s how much do I need to be concerned about the head's 60/40 valve spacing? I currently have JE Nitrous Ready pistons for AFRs in my motor with pretty substantial valve pockets, but I have no idea if the 227s valve spacing will cause any problems. How substantial of a change is the valve spacing and do they clear most pistons?

Dave

 

Most pistons will work with a 60/40 split easy.

Bret

 

Belvedere is a Polish rye vodka and is probably my favorite of that variety. For the potatoe (<~Dan Quayle joke) varieties, I'd have to go with Columbus. Can't say I've really tried that great an assortment of potato vodkas though.

If you'd like to send some samples my way I surely wouldn't refuse them though.

WRT fisticuffs... well let's get right to some more of that.

LR
I always love these little talks we have. I end up answering all your questions and you answer none of mine.

First of all, since you don't know... there is a mathematical model for just about everything. Then there are some things that are better evaluated empirically. If you'll go back a page you'll see an empirical formula for doing what you're saying can't be done. Not my formula, but one from an aeronautical engineer and avid r&d guru.

If that's not enough for you, there are formulas in CF Taylors books for calculating air speed through ports and one that specifically calculates what Taylor refers to as a Mach Index. Taylor's book is almost 40 years old now and people still use his formulas. I have some more recent papers that show modified versions of the formula that incorporate dynamic effects of inertia and the like but the root formula is still in there. Must be a good one.

And how can you presume to know what Bettes does and does not know? I'm to assume you and Bettes sit down from time to time and have intimate discusions regarding engine design? You pass some of your ideas his way, he passes some of his your way in hopes of some approval.... that sort of thing??

Please...

No one ever said you could calcualte Mach directly from VE. High VE is the product of three key things..... one is Mach and the other two are the dynamic factors that make up the tuning part of the intake and exhaust. High VE is however a good sign that these three are somewhat optimal and I'd venture to say that any port that only reaches a Mach of ~.4 as your original post suggested (your numbers have grown since that 1st reply) would also show poor VE numbers.

Good luck on your quest of knowledge...... whoops, forgot... you've already arrived! My hat goes off to you.

-Mindgame

 

Hi Mindgame

I have performance trends engine analyzer pro. The SB2.2 sample given has 115.9 VE at 6800. The mach listed at 6800 is .311 BUT I think that is calculated at the valve AND SB2.2 heads are not 23*.

Engine sims are interesting but not gospel. I tend to think along your point of view so the numbers were a suprise to me!

 

I guess I should pick up EA Pro and see what it's all about some time. Truth is, I don't know much other than the fact that it's relatively inexpensive.
My guess is the software's real forte lies in identifying trends vs accuracy in regards to system dynamics. You'd need a bit more $ to get that level of accuracy and of course that always passes on to the consumer.

I'm curious as to the output though... .311 @ 6800rpm
Was 6800rpm the torque peak (highest VE)? Also, does the SB2.2 example allow changes within the cylinder port min. cross section area or does it just use a generic "SB2.2 head" as a variable?

I'm also wondering if those could be average port numbers vs peak?

Either way, if there's an absence of minimum port area input, I'd take those results with a huge grain of salt and maybe a touch of castor oil. What you really want is an accurate port model but that's probably asking for too much. I'd like to see the look on the face of one of the design engineers at Brodix etc. when you call asking for a port model of one of their heads. "Yeah, just send me the iges file please.".

-Mindgame

 

Following is excerpted from EA Pro handbook, nearly verbatim:

The basis for Mach # calculation in EA Pro is a 1979 SAE paper (790484) by ***utani and Watanabe called "An Analysis of the Volumetric Efficiency Characteristics of 4-Stroke Cycle Engines Using the Mean Inlet Mach Number". This was an extension of the Mach Index characteristic first identified in the 1940s by (surprise!) C.F. Taylor and co-workers from MIT. The Internal Combustion Engine in Theory and Practice 1985 MIT Press.

These papers state that an engine's air flow potential per cycle (VE) depends on its average intake flow coefficient, intake valve flow area, cylinder size, speed of sound in air and RPM. These five items are combined into one value called the Mach Index, called Mach # by EA Pro. In simple terms Mach # relates the average velocity of the intake charge past the valve to the speed of sound.

EA Pro does not use Mach # in its calculations, but reports it only for information.

There's more, if we want to go there.

(Had to laugh. The author of the SAE paper has a name starting with Fu that the PC naughty-word filter doesn't like. It doesn't even have a "c" in it. )

The potato vodka is Chopin. Yep, Belvedere is the rye vodka. If you stop by we can taste them, 'Game.

 

Let's see
Peak torque within 200 rpm
Uses avg. dia which can be adjusted
MIM-- mean inlet mach not used for calc but included for information

DEMO with some locked features can be downloaded and run
user manual can be downloaded Page #88 discusses MIM

Yea> as in the above post by OS

 

MIM = mean inlet mach

That's where the difference lies, the MEAN vs. the PEAK MACH.

Bret

 

And how can you presume to know what Bettes does and does not know? I'm to assume you and Bettes sit down from time to time and have intimate discusions regarding engine design? You pass some of your ideas his way, he passes some of his your way in hopes of some approval.... that sort of thing??

---------------------------------------------------
MG,
Are we building airplanes now?????

Yes, I know Harold Bettis well enough to talk to him from time to time with an air problem.Maybe you could share some of your theories with him.Hey you might even learn something.
You know us from LA are way back in the woods.I may have rode the truck for a while,but I didn't just fall off of it like some.
I have the same formulas,and a lot of this stuff is hand's on not formula's and you need to "know" instead of figuring.All that figuring without being able to apply it ain't a bit of good,you can get LOST in the number's.You can also out engineer yourself and according to you I will NEVER be guilt of that.Wheeeew,Am I glad.
Yea EAP will tell you a lot,and it ain't cheep.Well,with your money,$500.00 ain't nothing.
That's what I use,It does a lot of the work for me.Ya know redneck's can't figure worth a crap.

It's ok to say you guessed on the MACH number's on your engine.

 

I take it you have no idea who I was talking about back there do ya?

First of all, Harold's last name is Bettes... no "i" in there. Secondly, a [space] goes after every comma and period. Makes everything easier to read when it doesn't run together.

For your information, "My theories" are not at all my own. They are the theories of people who did all the research a looong time ago. I'm not into reinventing the wheel.

A little latitude here...
Me... I now develop encryption software, firewalls and other security applications to protect this countries secrets. I work as a special projects manager to that end. On top of that I use to work as a consultant to various engineering firms with programmers who developed applications for various things, so it's fair in saying that I know a little about engineering and quite a lot about computer programming and security, my real forte if you will.

Don't have anything figured out with engines but I do know where to look for the answers and I'll take Taylor, Vizard, etc., over EA Pro any day of the week when I want to actually understand what is going on inside an engine. There are some great IC engine simulator books out there if you can handle the math.

Well of course, I thought that went without saying.

Tell me about it.

You just never know about some people. On top of all this computer stuff I went to school for I use to do a fair bit of racing. Some of which was on a pretty serious competition level.

3 times in Super Gas top 5 standings, 1 1st place points finish
6 1st place wins in Quick-16 event, 2 times as runner up
2 1st place standings in Street Eliminator
1 1st place finish in Top Dragster

And I owned a TS car with one of only a handful of Sonny Leonard mountain motor small-blocks that I sold when my father passed away.

Now I just race the cheap stuff and build an occasional engine but I turn all my own wrenches and always have. So I guess I qualify as your hands-on guy with enough college math to get into the tech stuff too. Shoot me.

No, unless you're calling Chuck Riddick a liar.

I don't have to guess, I've seen the data on my heads. They were flowed at three different depressions.... ~40, 60 and at better than 100. The numbers were converted to 28" for reference sake but PRED does quite a bit of high-end port development and I know for a fact that Chuck flows heads in excess of 100" H2O all the time. Not to mention, they have some really nice simulation software that uses actual port models for swirl and airflow analysis. I simply asked about peak Mach out of curiosity and the reply I got was that they would be in that (.55) range if not a little higher.

So again, I'm just relaying information... not theorizing.

-Mindgame

 

Impresive resume,don't need to know your life history.

I have done some racing myself,but don't brag about it to fortify my position.This includer dirt sprint cars, drag racing,and boat engines.
I mostly wrench.I have wrenched the fastest 4.6 Ford door slammer on the planet and built a 632"Ford that will/has run 5.2's in the 1/8 mile on motor and 10" tires.There have been a "few" more than that,and they can and do win.My customer's seem satisfied and that's what count's and for some reason they make HP.Lucky I guess.
I'm not calling anybody a liar.But your .5-.55 Mach number is all on paper.Your intake velocity was not measured on a dyno.Somewhere in the "neighborhood" is a large place and still a guess.

 

hate to butt in here, with all the fun going on, but since MG was correcting LR on his grammar, i just figured i would point this out!

there are 2 spaces after every period...

just picking!