What have I done?? Good, OK, or Bad??

racprops

Well-Known Member
And time and time I have seen personally that IF I can stand the slow speeds cars can get from 25 to 32MPG at 1500 to 1900RPMs.

This would be 45 to 49MPH in the Van and is 49 to 50MPH in my 03 Ford Explorer, and was 65MPH in a 2000 Mercury Grand marques, and 60MPH in my 03 Ford Crown Vic.

Rich
 
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racprops

Well-Known Member
OK I am able to admit I screwed up.

Got the facts.

A .020 gauge will reduce lift by .05%, at .025 Gauge will reduce Lift by .06%

This will also do the same percentages to Duration.

And seat to seat duration may drop about the same percentage.

The good news is the cam is strong by its self.

I will rerun the Rhoads lifter number again.

And another myth just got popped as well.

Australia uses the imperial gallon, SO that 30/35MPG in US gallons is 29MPG, or a gain of around 5MPG.

So my idea of the double over drive is one of my best shots.

Rich
 

T-Test

solid fixture here in the forum
You are now to far Into the build to just keep it simple.
My OLD head hurts just thinking about doing another engine build just for milage and towing.
I no longer think about the price of gas as if I can't afford it, I stay home. Sometimes I may not go anywhere for 2 weeks at a time.;):like:
 

Indycars

Administrator
Staff member
OK I am able to admit I screwed up.

Got the facts.

A .020 gauge will reduce lift by .05%, at .025 Gauge will reduce Lift by .06%
I could feel your frustration with me, but I figured at some point it would become clear to you. We all get so focused some times that we can't see the big picture. It's happened to everyone of us !

Australia uses the imperial gallon,
Why are you worried about Australia and their units of measure ?

This will also do the same percentages to Duration. I will rerun the Rhoads lifter number again.
Just remember that for your assumptions to be correct the lift curve would have to be a straight line, which it is not. So long as you understand that they are just approximation at best, then you will be OK.
 

racprops

Well-Known Member
You are now to far Into the build to just keep it simple.
My OLD head hurts just thinking about doing another engine build just for milage and towing.
I no longer think about the price of gas as if I can't afford it, I stay home. Sometimes I may not go anywhere for 2 weeks at a time.;):like:

I heard that some here are done such.

My God so much is happening NOW as I am near installing her.

But it is all good and for the better.

Would really like to either rear any posts on your forewords and results.

Rich
 

racprops

Well-Known Member
I could feel your frustration with me, but I figured at some point it would become clear to you. We all get so focused some times that we can't see the big picture. It's happened to everyone of us !


Why are you worried about Australia and their units of measure ?


Just remember that for your assumptions to be correct the lift curve would have to be a straight line, which it is not. So long as you understand that they are just approximation at best, then you will be OK.
NOT with you, with me as I could not figure out want the back of my mind was trying to tell me.

"Why are you worried about Australia and their units of measure ?"

Because for nearly 30 years I believed the Camaro's lean burn cruse could give 10MPG, seems it is only 5MPG....which is still a fair improvement.

And yes I know this is just a program, and that real world performance will not be quite the same, for one thing these programs are run with Wide Open Throttle, I do not plan on driving that way.

But these charts do tell an important story, where the torque and HP peaks calculate to be.

And other that some fine detail the torque peak is nearly where I planed it to be.

Now if only we both could come up with the same charts and numbers.

And if only YOUR program could be set for TBI heads and TPI intake, I would feel really better with your charts than mine.

I kind of find that lack of those settings inconceivable....

Rich

PS I am not sure what your saying here"Just remember that for your assumptions to be correct the lift curve would have to be a straight line, which it is not. So long as you understand that they are just approximation at best, then you will be OK."

"your assumptions to be correct the lift curve would have to be a straight line, which it is not." Please exsplain this father...
 

Indycars

Administrator
Staff member
And if only YOUR program could be set for TBI heads
If you can provide the flow vs lift numbers I can use that to be more accurate. Dynomation is not about using stock heads, but about aftermarket high performance heads that provide flow numbers at a pressure drop of 28 inch of H2O.

"your assumptions to be correct the lift curve would have to be a straight line, which it is not." Please exsplain this father...
For tonight, I will have to ask you a question, tomorrow I will try to explain further

Why did the lifter acceleration rate (Also called "Cam Ramp Rate") change in post #40, starting reading just below the first graph. If it was so simple as taking a percentage then the rate would not have changed from 2.37 to 2.78. Why do racing camshafts have higher rates? You could improve your gas mileage if your lifter acceleration rate was 5.5, so why not go there with a custom camshaft ?

Something to think about.
 

racprops

Well-Known Member
"If you can provide the flow vs lift numbers I can use that to be more accurate. Dynomation is not about using stock heads, but about aftermarket high performance heads that provide flow numbers at a pressure drop of 28 inch of H2O."

I have no idea what they are??

"Why did the lifter acceleration rate (Also called "Cam Ramp Rate") change in post #40, starting reading just below the first graph. If it was so simple as taking a percentage then the rate would not have changed from 2.37 to 2.78. Why do racing camshafts have higher rates? You could improve your gas mileage if your lifter acceleration rate was 5.5, so why not go there with a custom camshaft ?"

Not sure what the first part is about...

"You could improve your gas mileage if your lifter acceleration rate was 5.5, so why not go there with a custom camshaft ?"

I did not find any kind of cam other that factory and Hot Rod. Factory always were lame and hot rod was always power and higher RPM rated.

Even the so called RV cams always moved the torque and power curves up the RPM range. Given those two chooses I WAS going to run a Caddy low RPM cam....until I found roller cams, Rhords roller lifters and fed by a miscalculation believed I could have my cake and eat it too. Low RPM Torque and a more full cam and HP above 3K.

It still does it but it is more the cam than the lifters.

But if I at last got all the settings correct, the lifters are giving me 387 (+51) Ftpds @2k and 2K is the peak, and 200HP from 3k to 4k and 175HP at 4500 and drops to about 140 at 5K.

How numbers are closer.

Rich
 

racprops

Well-Known Member
Case in point.

Back in the late 90s when I was building a OLDS403 I wanted a Cam I could degree, mainly because back then with the early days of smog control there were rumors that you could not tell if a factory cam was advanced, straight up or retarded.

I was thinking I wanted to advance it, but advancing a unknown cam was not a good idea.

I shopped EVERY cam maker. The factory specs said the 403’s torque peak was 2000RPMs, I had some of the factory specs....THERE was no new stock cam to be found, the Mildest one was made by Crane cam, it ONLY moved the torque curve a few hundreds of RPMs up. It was I believe a RV cam…

BUT when I tried to order it they were out of stock, discontinued. The replacement, the improved model moved the peak even higher.

I call the company up and one of the old guys said, he would check the dead old stock and call back if he found any. An hour later he called and he had dug up the last two, and I bought both of them.

I still have the second one.

Rich
 

racprops

Well-Known Member
Here is every spec I have on this engine:

383 Specs:

Engine:

1990 SBC OE Roller Block - 30 over bore 4.030

Cylinder volume: 783.95 Total volume 382.7CI

Not decked (check by machine shop to be straight) but supposed to be .010" piston-to-deck clearance

Machined 400 crank with 5.565" 400 rods Stoke 3.750

Older KB hyper D-dish pistons (M9890-30) -I couldn't find this piston but they look identical to the KB102-030, so I'm guessing -18cc dish. Set Bought 2/12/2004

The piston top, combustion chamber, and intake and exhaust valve have all been Ceramic thermal barrier coated.

64cc (I think actually 65.3cc) Swirl port heads #14102193 1.94" / 1.5" valves

A felpro gasket that came in a rebuild kit with a 0.045" compressed thickness

Lifters: Rhodes Roller VMax lifters

Cam is from Oregon Camshaft #806 roller cam:
Adv duration: 265/270 @.006 206/213 @ 0.050": lift: 431"/428", LSA: 114, ICL: 110
9.25:1 static CR

Cam timing at .050 Intake open .7BTDC close 33ABDC 45 BBDC Exhaust open 45 BBDC and Closes at -12 ATDC this is by the spec sheet.

Below these is a hand written note: -18 1/2 Degree overlap @.050. Cam lobe lift is listed as .275 intake and .285 Exhaust. Lobe center line: Intake 110 and exhaust 118.

Then there is another set of numbers lobe Diameter intake 1.542 over 1.267 and Exhaust1.529/1.244.

1.5 ratio roller-tipped rockers Lift by 1.5 = .413/.428

Cam in DYNO listed as Stock Street/economy. Lifter Acceleration rate 2.30

I am not sure if some of these numbers were from John or the program its self:

See attached picture:

Running Rhoads V-Max roller lifters at .05% reduction so at low rpms she will be:

Dur. 196/202 Lift 393/407 Seat to seat dur. 251.5/256.5 lobe sep. 114

Degreed it very carefully even bough peg timing bushings to get it dead on spec.

TPI intake stock Reported by DYNO2003: Induction: 668.0 CFM @ 1.50

Stock cast iron exhaust manifolds I am considering headers…
 

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Indycars

Administrator
Staff member
Sorry it's been over 40 years since I've had a math class and I can't think of a good way to explain what I'm thinking about the straight line vs the curved line concept. If I try to graph it, it doesn't work out, so maybe I'm all wet on this one.
 

racprops

Well-Known Member
Perhaps if you don't mind, run your program using all the data I posted (as needed) and lets see what come up.
 

Indycars

Administrator
Staff member
What is the correct lift per the cam spec, is it .431 or .413 ? You have used both above.
 

racprops

Well-Known Member
Wonder what everyone thinks of this: From Don Terrill's Speed Talk thread https://www.speed-talk.com/forum/viewtopic.php?f=1&t=852

"GM owners found using larger throttle openings at lower RPMs trades improved fuel economy for increased main bearing wear. For fifty years, the SBC pulling a three-speed tranny at 2500+ RPMs never had main bearing issues. When the lockup/overdrive came along and computer controls allowed pulling near-WOT at 1900 RPMs, the main bearing problems began."

So I now think a high volume and pressure oil pump is called for....and higher oil pressure should pump up my Rhoards Lifters sooner...

Rich
 

racprops

Well-Known Member
As for DYNO SIMS I keep comparing these two:
 

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racprops

Well-Known Member
I did a little Photo Shop and got this,
 

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racprops

Well-Known Member
And put the two together I really hope your is the correct one...
 

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Grumpy

The Grumpy Grease Monkey mechanical engineer.
Staff member


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