[Robert C.]

Originally Posted by GTO

Any more updates? Looking for a 'Kit' like this or crate motor if possible. ... Eric.

Eric,

We do kits and or crate motors. Please call for pricing. Ever combo is differant.

We will test this weekend on Sunday at MIR in Maryland, thats the plan, but that can change if we get rain.

[GTO]

Have sent an E-mail already. Just waiting for a reply. No rush, gotta marry off a daughter first. I'll be making a decition in August. Thanks, Eric.

[Gach]

Originally Posted by cfmcnc

Hi Jim,
Thanks! I can't release cam specs right now as we learned a lot about the cam over the past few weeks, I hope you understand. I have been meaning to take pictures of the heads but keep forgetting. I will try to take some of a finished set I have here before we ship them. The manifold is one of the first ones that were cast and I hacked on it to balance the runners so Frank could test it on the car. I don't have pictures of it. It's machined for a shear plate on top, so it's cut out real big at the carb pad and blended in. The manifold is UGLY! I used it as a prototype to correct the casting houses issues and had loaded it with epoxy around the outside of the plenum and never bothered to hide it. Interestingly, we dyno tested the final "as cast" manifold for one pull. It was matched to the full port window and has casting flash knocked off the plenum opening... that's it! It was within 10 h.p. and 5 ft. lbs. of Frank's prototype. All Pontiac is selling the manifolds now. So it's safe to say that the box stock manifold will support 1,050h.p. with a port match. No b.s. cheers, Johnny

This will be my next move..great to see a good combination all work out. Also no BS
track number to back it all up.

[GTO]

Got my reply. Very reasonable short block price! Will call for further details. Thanks for the quick reply. ... Eric.

[A Rare 70]

I normally don't respond to threads, just use them for an informational tool. But I felt the need to respond to this thread. My main question is on the HP numbers posted here. After a couple of years of working on it, I finally completed my IA II, Tiger Head 520 ci motor. I spent many hours on the phone with Frank and built it per his recommendations to achieve max HP with purchased parts (not well massaged over parts, heads, intake). I used an IA II block, Bryant Crank, Oliver Rods, JE 14.5:1 Pistons, Tiger Heads from All Pontiac (latest CNC version), Tiger Intake, worked 1250 Dominator, LSM Cam (about .833 Lift, 290 duration), and custom built headers (3 step). I was told that this combination should make around 900-925 HP. The dyno day finally arrived and I was quite shocked to see the HP number of only 830. After extensive conversation with my engine builder and dyno guy, they both thought that this was a very respectable HP number. The dyno guy then explains to me how easy it is to change these numbers, which I was well aware of. By him changing only 1 parameter (weather factor) by .1, my HP number jumped to 907! I thought that this was quite surprising. So long story short, is there standard numbers (like when flowing heads) to be used for certain factors on a dyno to get accurate comparisons between dynos and tuners? Why the significant difference on similar engines? Should the HP number be higher than 830 with the items listed above? Is 900-925 a more accurate number? Thanks for your input.

[455-4+1]

I am not even going to go into the correction factors, but ......................

HP and Torque number with out a related RPM value are next to useless in my opinion
It gives very little information on how and where those values are acheived

At least with RPM and either of the values you can work out the other at that RPM and the comparisons can be made. It may be such a simple thing as RPM in this case

I have caught out more than a few engine builders touting there HP numbers (not saying so in this case !!!) to bystanders by doing a few simple calcs on my cellphone while listening

ie There quoted engine makes xxxx HP at xxxx RPM, when qustioned the peak Torque value is devulged, after a frantic tap on the cell phone calc option we find out that Torque at the HP peak actually needs to be higher than the previous torque peak quoted ???

mmmmm, must have two torque peaks (happens sometimes but usually as a result of a dip in the curve ), but with one corresponding exactly with the HP peak or above ?

Suddenly said guru gets very aggitated as he is questioned about the twin peaks and all of a sudden needs to tend to something in his pit tent and storms off ??

Can you give us any more info such as RPM / TQ / HP values across the spread

(correction would help also if you have it)

[Gach]

Rare 70, Basicly your 70 hp off from what you where told it
would make. Not all dyno's are created equal just to many
factors involved. I agree with out knowing rpm... Were it made
peak torque or hp and a whole bunch of other thongs it's hard
to tell how real the hp numbers are. A dyno sheet would be great
that way one could see just what's going on.

[A Rare 70]

Attached please find the dyno sheet requested. I know all of the requested info is not listed, I need to contact my dyno guy and get some more of the information.

[BruceWilkie]

track numbers are more telling. The dyno sheet shows a fat power curve from 5400 to 7100. Generally when you get a wide curve like that you lose peak hp but gain avg power in your race rpm band. A cam revision could narrow the curve and raise the peak for a better number. Depending on weight and transmission gearing and convertor the narrower curve bigger number might or might not do any better at the track.

Now a few things to consider here as well. Your dyno sheets dont show the bsfc numbers and I dont know what the vacuum reading is relative to. That said, the difference in AFR on each side could be refined and your carb/manifold could be just not allowing enough air to actually flow to support higher hp. Here is a formula that Ford uses to determine airflow requirements to support a given hp. You will see that certain variables can change the airflow result quite a bit. Basic formula is 1.1 x (hp x bsfc x AFR) = lbs/hr airflow. the 1.1 represents an additional 10% over actual required thru flow but depending on other factors like manifold design cam etc you may need an even higher factor. Compression and combustion characteristics have a large influence over the bsfc number. Air temp barometer and humidity have great impact on how much air an engine needs to flow thru to support a given hp.You may have a manifold that shows no restriction to airflow relative to the heads yet due to runner length/plenum design/cam design/header design may be out of sync causing airflow-thru to be less than needed to support thenumber you are trying to obtain. Keep all this in mind and I'll give a few samples of airflow requirement to support hp. The bsfc factor really indicates the level of development of your package. Ultra high compression pro stock engines may see a bsfc of .37 while a daily driver may only be at a bsfc of .50-.52. I'll use .45 bsfc for the examples.

1.1 x (824 hp x .45bsfc x 12.6 afr) = 5139 lbs/hr airflow / 60 = 85.65 lbs/min = @1120cfm at 59 degrees dry air 29.9 barometer. At 85 degrees dry air 28.4 barometer the cfm = 1252 approx..

1.1 x(930 x .45 x 12.6) = 5800 lbs/hr = 96.67 lbs/min = 1263 cfm at 59 deg 29.9 and 1407 cfm at 85 degrees 28.4 barometer.

Without your actual bsfc numbers and uncorrected temps/barometer/humidity we cant determine what your dyno numbers are really telling us.

It does show us the basic powerband and that there is an air fuel ratio imbalance from one side to the other. 1250 cfm carb is rated that cfm at 1.5 in/hg or 20.3 in/h2o at .5 in/hg (6.8 in/h2o) that is only 721 cfm. However the above formula takes that into account. i think your carb size may be adequate to support 900 hp + but without other data It would be hard to say with certainty. 450 cfm heads could support up to 135% ve which would require approx 1450 cfm carb flow at 7100 rpm 100% ve typical formula says 1068 cfm. However what the carb flows on the engine vs a bench and all the criteria that determines how much is actually needed for size vs what its able to flow due to other factors need to be looked at.

[Gach]

I'll tell you what those are some Awesome dyno numbers
I'll take that 824 hp over 900 hp any day, I wouldn't
change anything. That is one of the flatest toque and hp
curve Ive seen.

You could take a motor that makes 900 hp and
peaks at 7100-7200, but doesn't make good adverage
hp and your motor would be much faster
and live allot longer. Trust me don't worry about
not making that exact hp number. you got one hell
of a motor there.

[Gach]

I just notice some thing.. Those dyno numbers are corrected
numbers which means your actualy making probably
well over 900 HP. See the C before torque and Hp
that stands for corrected hp. In other words it's not adjusted
for perfect condistions.

I also notice the cam lash is this a street motor?
What's it going in and what's the car weigh?

[BruceWilkie]

Originally Posted by Gach

I'll tell you what those are some Awesome dyno numbers
I'll take that 824 hp over 900 hp any day, I wouldn't
change anything. That is one of the flatest toque and hp
curve Ive seen.

You could take a motor that makes 900 hp and
peaks at 7100-7200, but doesn't make good adverage
hp"

(as I mentioned above)

"and your motor would be much faster
and live allot longer"

(likely if geared correctly).

"Trust me don't worry about
not making that exact hp number. you got one hell
of a motor there".

I agree especially if the numbers are NOT corrected. The track will tell !

I would try to balance the afr on both sides if anything.

[Daniel Barton]

Originally Posted by Gach

I just notice some thing.. Those dyno numbers are corrected
numbers which means your actualy making probably
well over 900 HP. See the C before torque and Hp
that stands for corrected hp. In other words it's not adjusted
for perfect condistions.

I also notice the cam lash is this a street motor?
What's it going in and what's the car weigh?

Lou, the C means it is corrected to some type of standard data... I dont know which correction factor is being used, standard or SAE but the actual raw data is typically less, rarely do we see the dyno correct down! It has to be a mine shaft day, like actual conditions below sea level. Many factors can skew dyno readings, room size, fan size, correction data(dry bulb, wet bulb, barometer), un-calibrated dyno, room temp, headers hitting test stand and some others. With that said I would find out what the correction factor being used is(standard and SAE are very different), standard is more popular but SAE is supposed to be more accurate. I would like to see the raw data as well as the current conditions. Without knowledge of different peoples dynoes it is hard to compare! With what you say that you have I would expect more in the 950HP range, but not all engine builders are created equal and that is possibly also a factor. EVERYTHING has got to be right inorder to make good power that will run quick and fast! There is many things to look at that can be the culprit here! I hope you get it figured out. Dan

[cfmcnc]

This engine has Tiger Race Ready pkg.peak intake flow around 420,port volume is just under 300cc, average cross section is 3.557.

[Gach]

Originally Posted by Daniel Barton

Lou, the C means it is corrected to some type of standard data... I dont know which correction factor is being used, standard or SAE but the actual raw data is typically less, rarely do we see the dyno correct down! It has to be a mine shaft day, like actual conditions below sea level. Many factors can skew dyno readings, room size, fan size, correction data(dry bulb, wet bulb, barometer), un-calibrated dyno, room temp, headers hitting test stand and some others. With that said I would find out what the correction factor being used is(standard and SAE are very different), standard is more popular but SAE is supposed to be more accurate. I would like to see the raw data as well as the current conditions. Without knowledge of different peoples dynoes it is hard to compare! With what you say that you have I would expect more in the 950HP range, but not all engine builders are created equal and that is possibly also a factor. EVERYTHING has got to be right in order to make good power that will run quick and fast! There is many things to look at that can be the culprit here! I hope you get it figured out. Dan

Yeah your right...( C ) stands for correct numbers...I realize that after looking at my dyno sheet..which has two columns one for corrected and uncorrected numbers. Thanks for correcting that.