Dart 180 cc alloy head as cast

[SpeierRacingHeads]

...THE BEST way to know where you stand is ask the operator, what conversion? And what would be killer on your dyno for power.

A few years back, a friend of mine bought a 358" SBC with a dyno sheet showing just over 600 HP. It had some decent parts in it, but nothing that could get it close to that number. I pointed out that the sheet was dated in late winter, so the 14% CF shown could only have have come from a dyno at the top of Pike's Peak...

EXACTLY, little tricks like that make a dyno not honest.

Or using a 3% friction on a engine that should have 6%..

[PRH]

Not sure why the engine contest is being mentioned? Is that to validate the other dyno?

The way I took it was simply that at the Engine contests, everyone uses the same dyno.
High or low...... it’s the same for all.

Not like comparing results gleaned from dynos from other parts of the country, where it’s possibly two different types of dynos being used, along with different room layouts, operator/tuner skill, elevations and corrections, etc.

[Elroy]

...THE BEST way to know where you stand is ask the operator, what conversion? And what would be killer on your dyno for power.

A few years back, a friend of mine bought a 358" SBC with a dyno sheet showing just over 600 HP. It had some decent parts in it, but nothing that could get it close to that number. I pointed out that the sheet was dated in late winter, so the 14% CF shown could only have have come from a dyno at the top of Pike's Peak...

EXACTLY, little tricks like that make a dyno not honest.

Or using a 3% friction on a engine that should have 6%..

would be interia factor on stuska if I remember correctly/ what factor was used on yours and how was it derived?//stuska has their share of problems but can be good but not the best in my opinion//don't see them being around very much longer//you don't have to pass a class to purchase a dyno just have to have the money.

[Elroy]

The way I took it was simply that at the Engine contests, everyone uses the same dyno.

Exactly ego's go to engine contest to test ideas and theory against one another not compare different dynos

[Elroy]

most of what I have seen to make a dyno read incorrectly whether higher or lower has been unintentional////then theyre is the intentional stuff

[BlitzA64]

I have a couple different engine combos that I dyno on the same unit. The only numbers I really care about is if I'm better or worse than my last run and I also look at uncorrected numbers to compare to my own weather station readings. I have beaten more than one guy with a supposed 15-20% more power than my sheet reads. Pipemax tends to give me close to real numbers to shoot for if I don't know but the real truth comes out when raced. Even in the 90* Summer Dog Days I never remember more than about 7% correction

[SpeierRacingHeads]

A few years back, a friend of mine bought a 358" SBC with a dyno sheet showing just over 600 HP. It had some decent parts in it, but nothing that could get it close to that number. I pointed out that the sheet was dated in late winter, so the 14% CF shown could only have have come from a dyno at the top of Pike's Peak...

EXACTLY, little tricks like that make a dyno not honest.

Or using a 3% friction on a engine that should have 6%..

would be interia factor on stuska if I remember correctly/ what factor was used on yours and how was it derived?//stuska has their share of problems but can be good but not the best in my opinion//don't see them being around very much longer//you don't have to pass a class to purchase a dyno just have to have the money.

4218 DA.. 70 degrees, 70 humidity, and 2400 alt.

Correction was 104.8%

[randy331]

i think the dyno conversation would be great
i have never been on a dyno so any information would be appreciated
as far as EMC- pretty good platform to make power in certain rpm parameters
debate all you guys want,i am happy for the discussion

Steve, do you know what brand of dyno you will be using ? That will help in suggestions on it's use.

A few things to do before your dyno day.

Find out what fuel size connections they use so you'll know what to have in your carb.
Find out if you need a starter or if the dyno has one built in.
Find out oil pressure fitting size and have that in your engine when you get there.
Find out if they use an oil temp probe in the oil drain plug, if so leave your oil out till your there.
Find out if you need your flywheel.
Find out if you will be able to use your headers and make sure you get whatever size adapters you need to get the ex hooked up.
Find out if you will need your own fuel or if they provide it.
Some dyno shops are much better than others at these things.
Bring an extra set spark plugs incase you drop one or break one somehow.
Make sure you have jets bigger and smaller than what's in the carb you will be using. Bleeds to if they are replaceable.
Bring your own timing light to compare to the one they have.
If you can, get a timing light set up on the timing marks that you can see from the dyno console. That way you can watch a few pulls to see if it's stable or moving around under load. ( I've seen some that did)

If your not too far away stop by and see the set up.

The more prepared the sooner you will be making useful pulls instead of chasing problems.


Randy

[Elroy]

4218 DA.. 70 degrees, 70 humidity, and 2400 alt.

Correction was 104.8%

I was speaking of inertia factor not CF//this is a number input based off of rotating mass of engine//necessary on a stuska dyno due to acceleration rate being variable//

[SpeierRacingHeads]

4218 DA.. 70 degrees, 70 humidity, and 2400 alt.

Correction was 104.8%

I was speaking of inertia factor not CF//this is a number input based off of rotating mass of engine//necessary on a stuska dyno due to acceleration rate being variable//

Stuska doesn't have a interia factor as a entered number. The dynos at EMC did however, which were DTS.

Which I might add that one year they left the same for all engines dyno'd.

[PRH]

Imo, for something like an engine contest, and using a dyno that has good control over the rate during a pull, I’d rather there not be any inertia correction.

[Elroy]

surprising how many people don't understand the machine they are using or own.

Stuska doesn't have a interia factor as a entered number.

Ok. dont take this as anything but constructive it just proves my point and shows there are many in the dark.///A stuska has to have an inertia factor entered or else its been hybridized, converted, has different acquisition...///or its no longer a stuska dyno////this is not to say that continually changing it for different platforms is required or necessary for development.///repeatability=internal development///
Its entirely possible the dyno owner has never touched its initial setting or knows of it////not uncommon//the problem comes from the this dyno reads low crowd///and like I say they all do read low just ask the owner of one If everyone was on top of the workings of their dyno/regional comparisons can become much more meaningful//I have witnessed very good consistency from one dyno to the next myself///but it takes knowing and staying on top of things along with having a dyno owner that doesn't have too much ego to admit he don't know why some things are the way they are///bottom line..a stuska dyno is extemely intertia factor dependent.

The dynos at EMC did however, which were DTS.

Last i looked dts was using a bit of inertia factor input into their correction math////very small component compared to stuska///small enough that at a dyno contest like enc i foresee there would be more inaccuracy and conflict amongst competitiors by changing it than if left alone///back to the point of a engine dyno contest////everyone dynos on the same dyno///everyone knows the rules going in///build an engine friendly to that small amount of inertia factor input..its very small///i would bet the teams that do well at those events know some things about how a dyno works////watch and listen to some videos on engines making pulls on dts, superflow, stuska///you can generally hear why a stuska needs inertia applied//almost my bedtime and i missed wheel of fortune

[SpeierRacingHeads]

surprising how many people don't understand the machine they are using or own.

Stuska doesn't have a interia factor as a entered number.

Ok. dont take this as anything but constructive it just proves my point and shows there are many in the dark.///A stuska has to have an inertia factor entered or else its been hybridized, converted, has different acquisition...///or its no longer a stuska dyno////this is not to say that continually changing it for different platforms is required or necessary for development.///repeatability=internal development///
Its entirely possible the dyno owner has never touched its initial setting or knows of it////not uncommon//the problem comes from the this dyno reads low crowd///and like I say they all do read low just ask the owner of one If everyone was on top of the workings of their dyno/regional comparisons can become much more meaningful//I have witnessed very good consistency from one dyno to the next myself///but it takes knowing and staying on top of things along with having a dyno owner that doesn't have too much ego to admit he don't know why some things are the way they are///bottom line..a stuska dyno is extemely intertia factor dependent.

The dynos at EMC did however, which were DTS.

Last i looked dts was using a bit of inertia factor input into their correction math////very small component compared to stuska///small enough that at a dyno contest like enc i foresee there would be more inaccuracy and conflict amongst competitiors by changing it than if left alone///back to the point of a engine dyno contest////everyone dynos on the same dyno///everyone knows the rules going in///build an engine friendly to that small amount of inertia factor input..its very small///i would bet the teams that do well at those events know some things about how a dyno works////watch and listen to some videos on engines making pulls on dts, superflow, stuska///you can generally hear why a stuska needs inertia applied//almost my bedtime and i missed wheel of fortune

Maybe I should have said I HAVE NEVER seen them enter it, but most use .26 for small block and .33 for big blocks. But that really depends on several things.

I don't own a dyno. If I did though you can guarantee I would know it like the back of my hand.

What is going on with a collar type system that uses a big aluminum hub that bolts to it and not the crank?

[randy331]

Sounds like Elroy has been around dynos some.

Randy

[steve cowan]

Randy,
appreciate the tips you posted,damn would not have thought of half of what you said but have taken notes.
the dyno is a Superflow but thats all i know,but gives me time to visit the guys shop.i know him from the track but i believe he has not had the dyno long and i dont know how much experience he really has.i am going to talk to my machine shop and see who they use.