I've seen A LOT of posts about making HP with a 318-So why is it so ???

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I guess it depends on how close to reality you’re looking for.
Off by 120ft/lbs and missing where the tq peak will occur by 2000rpm seems like it’s too far off to be of any real use to me.

I’ll try that 360 on my 20 year old version of DD and see what it says.

Some of you guys that have sims should plug the numbers in for that 360 and the 440-6 and see how close to reality the results are.

Edit- Okay........ here is what my 2000 vintage DD says.
It’s actually not all that far off.

82BDF494-8539-42A3-A503-8FBA20EB1F3D.jpeg


DC5E4D5B-FE85-4085-A1A2-6BC5D1A5EF45.jpeg
 
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PRH said:
I guess it depends on how close to reality you’re looking for.
Off by 120ft/lbs and missing where the tq peak will occur by 2000rpm seems like it’s too far off to be of any real use to me.

I’ll try that 360 on my 20 year old version of DD and see what it says.
Click to expand...
That would be interesting. I have an old version as well but no computer to run it on. I think it ran on Windows 95. LOl
 
PRH said:
Some of you guys that have sims should plug the numbers in for that 360
Click to expand...

Here ya go... with the exception that the heads are out OOTB Edelbrock heads (since I had those numbers already and disn't have to generate a new flow file).
DD 2003 (and illegal as well :realcrazy:). Everything else as per your example, including the valve events.

360_LC.JPG
 
I also ran the 440-6 through it..... it’s pretty close.
So, the DD2000 prediction vs reality for the 360 was...... it predicted both tq & hp higher than what the motor actually made.

The 440-6 is actually slightly better than what the DD predicts...... but pretty close.

And the next example is why I don’t really have any faith in what they spit out for numbers......
A very mild 505 with Ede heads.
It’s off 45hp...... and 80ft/lbs...... on the low side.
This program won’t give out good hp/tq if the head flow is low, or even low-ish...... relative to the size of the motor(which is most std port heads on a BB stroker).

360...DD is higher
440-6..... DD is close, but slightly lower
505....DD is 45hp & 80ft/lbs lower

I just modeled a mild 340 I did a while back....... it’s not way off...... DD shows 24ft/lbs and 10hp too high.

I’m not sure what’s going on with Toolmans DD where the TQ numbers are so high, and so low in the curve.
 
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Use to have the engine sim pro program. But the maker won't email me back with download link. :BangHead:
 
One more......
I had a 9.7:1 360 with 230cfm J heads on it, small solid cam, LD340, headers, 750 Holley on the dyno.
It absolutely crushed the 8:1 360 with the SM heads and XE268 cam(89hp more).

DD for this one has the TQ 17 too high, and the HP 36 too low, and peaking at a much lower rpm than it actually did(tq peak predicted 800rpm too low, hp predicted 1200rpm too low).
It also shows the tq will be 53 higher than the hp, when in reality they were within 2....... with the HP number slightly edging out the TQ.

The point being...... if you changed a bunch of entries into the program to make the results match what the motor actually made on the dyno...... it wouldn’t be a very accurate representation of what the real motor was.
So...... who knows what the modeled motor would really do on the dyno?

It’s just not consistently accurate enough for me to put any faith in it.......which is why I don’t base any decisions for planning a build on it.
 
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PRH said:
One more......
I had a 9.7:1 360 with 230cfm J heads on it, small solid cam, LD340, headers, 750 Holley on the dyno.
It absolutely crushed the 8:1 360 with the SM heads and XE268 cam.

DD for this one has the TQ 17 too high, and the HP 36 too low, and peaking at a much lower rpm than it actually did.

It’s just not consistently accurate enough for me to put any faith in it.......which is why I don’t base any decisions for planning a build on it.
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I am believing that the more I read. My stock 273 came out very close to the rated 235 horse. They probably used a stock 350 Chevy for a baseline and added from there. :lol:
 
I had done a cam swap on the dyno in an RPM headed 446.
What the real results of the cam swap were, was basically the opposite of what the DD predicted.
Said the new cam would make less...... but it made more.

I plugged the info for the low buck 1990 318 build into DD.
It’s showing 17 TQ too much, 15hp too little.
345tq/278hp....... so 67ft/lbs more than hp.
Reality was 35ft/lbs more than hp.
The DD is also showing the low end tq from 2000-3000 pretty optimistically compared to the actual numbers.
 
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PRH said:
i had done a cam swap on the dyno in an RPM headed 446.
What the real results of the cam swap were, was basically the opposite of what the DD predicted.
Said the new cam would make less...... but it made more.
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Ever use PipeMax? I never have, because I went to a Mac years and years ago, and Larry’s stuff doesn’t work with a Mac.

I suspect that is about the cheapest program with any accuracy there is. I know there are massively expensive programs out there, but man, they are really expensive. PipeMax isn’t that bad IIRC.
 
I haven’t, but it would be interesting to plug in some numbers and see what it says.

Here’s another big cube/smallish head comparo.......
572, 10.7:1, EZ-295 heads, solid roller, 266/272-110, .672/.645, single plane, 1.560 venturi 4150 carb.
DD shows 664tq/615hp
Real dyno shows 719tq/715hp

That’s 55ft/lbs and 100hp low.

If you were using the data from the DD to plan the build to make over 700hp....... and it’s showing you’re at 615hp...... how much stuff do you change to make the program spit out 700hp+?
That DD2000 program will steer you wrong for that type of build.
 
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Just purchased pipemax after some research. Will let you know shortly I can plug in some stuff. Wonder how the database is. Might have to take some time to build
 
PRH said:
I haven’t, but it would be interesting to plug in some numbers and see what it says.

Here’s another big cube/smallish head comparo.......
572, 10.7:1, EZ-295 heads, solid roller, 266/272-110, .672/.645, single plane, 1.560 venturi 4150 carb.
DD shows 664tq/615hp
Real dyno shows 719tq/715hp

That’s 55ft/lbs and 100hp low.

If you were using the data from the DD to plan the build to make over 700hp....... and it’s showing you’re at 615hp...... how much stuff do you change to make the program spit out 700hp+?
That DD2000 program will steer you wrong for that type of build.
Click to expand...

Way back when , I'm talking late 90's I was young and super gung ho about high performance NA builds, I purchased an early version of DD. I spent hours playing around with various parameters and marveled over the results. I had the "good" version that you could run a camshaft iteration and it would "try" all of the camshafts in the world and it took a couple of hours too before it would spit out the "best" cam. So as usually happens you start to hang out in like minded circles of people and another guy I came to know had the same version of DD. I had an idea to test its accuracy one night and got on the phone--yes an actual land line. I called him up and we both got on our computers-yes desktops and we ran the EXACT same builds and guess what?? We saw two DIFFERENT results! Over and over again we tried--sometimes they came up the same, others close and others again very different. It was that evening that I gave up on DD. I figured the tech just wasn't there yet. In the meantime I've amassed flowbench and dyno experience --as well as what I read and hear because I'm still "into" it and can extrapolate pretty close to what can be expected out of certain builds that are in my wheelhouse. So NO I do not use or own any dyno simulation programs. Do I have faith in them-yes I do. I have a FB friend that works for Tony Stewart and his entire role is dyno simulation and he has told me that it is within 3-4hp of real world results on a NASCAR engine. The software he uses costs a lil more than anything us common folks has access to. I'll stick to the real world but I'm lucky and have a real dyno and flowbench to build my database with. Then again I'm no UT. J.Rob
 
RAMM said:
If a license for Solidworks costs tens of thousands then I can imagine this would be the same. I'm just gonna guess 50K and up. J.Rob
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I thought a Solidworks licence was 10K to 15K. Guess I've been out of it for a while.
 
So far Pipemax is pretty good. A lot of parameters input data into. So in my opinion a lot of variables. Lacking in the cylinder head flow input as it only cares about max flow without a lift number...
 
Looking at the input screens for Toolman and Stixx sims...... they both have different cam info than what the motor used, and the specs I listed.
The cam used was a Comp XE268, part number 20-223-3.
Specs are:
268/[email protected]
224/[email protected]
.477/.480 lift
110lsa
Installed at 106

It’s still puzzling how Toolmans program is adding in the neighborhood of 100ft/lbs over the other DD programs.

How about posting a pic of the flow file?
Maybe there’s something off there.
 
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66fs said:
I thought a Solidworks licence was 10K to 15K. Guess I've been out of it for a while.
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I've been out of it for awhile as well--I'm sure Solidworks has come down over the years but back in 2008 it was over 15k CDN. J.Rob
 
cams...most would scoff at comps xe 256 and the Darling has always been the xe 268 ever since Dulchich built the 340.Lets compare the two...this is comps own Dyno using a 9:1 350 with Dart heads
That 256 is a much better street cam

xe256.JPG


xe268.JPG
 
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yes..the key is at and below 2000 rpm which you don't see much of.I have used the 268 and it definitely needed a converter in my warm 340...but to be fair i had 3.23's with a 25560 series tire.
 
ir3333 said:
cams...most would scoff at comps xe 256 and the Darling has always been the xe 268 ever since Dilchich built the 340.Lets compare the two...this is comps own Dyno using a 9:1 350 with Dart heads
That 256 is a much better street cam

View attachment 1715543251

View attachment 1715543252
Click to expand...


My guess would be the heads are a limiting factor there.

xe256 is more aggressive cam than stock 340, xe250 is about the same as a 340 cam with tighter lobe separation.
 
I gotta tell ya, that is a miss match.
To low of a gear with to tall of a tire and a no stall converter would have certainly killed it. Even with a converter, it still suffers some. 3.55’s and a 26 inch tire at a minimum will be OK. Not great, but OK.
 
i agree...3.23 were a poor fit for that cam.But to take advantage of it as you say 26 inch tires and 3.55.
i don't like 3.9's or 3.55's and think the best street gear is 3.23.
Now the quarter milers are gonna gasp at this, but in my last build i had the 204/ 214 broomstick!
It was very strong at any lo rpm, pulled great and i loved it with 3.23's and 26" tire.
I wonder how it would have been in the quarter mile?
 
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