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Discussion Starter · #1 ·
Hi guys.

I need to check a few things.

I purchased some advance engine software that can calculate the engines HP, without dyno tuning it. It will hopefully save me a lot of time and money, because I can try different mods and get a predicted dyno output in a couple of minutes. I can run hundreds of simulations in a day, which will take me months and heaps of money to do in real life.

I have a whole host of questions and wonder if anyone has some of the info I am looking for.

One of the question I would like to start with is the rocker arm ratio.

The software seems to indicate that most rocker arms are between 1.3 to 1.8.

If I measure the intake rockers I get a ratio of 1.12 and the exhaust is 1.17. Is this right???

I took the distance from the centre of the rocket shaft to the middle of the rocker "pad" where it runs on the cam, divided by the distance from the centre of the rocker shaft to the centre of the "pad" pressing against the valve.

Maybe I measured it incorrectly, so correct me if I am off the mark here.

Has anyone got the stock 660 cam specs?

I need intake and exhaust lift, duration, centreline, opening and closing degrees.

Then, do you have the same info on a stage 1 or stage 2 hotcams? I have a bit of the hotcams specs, but I am missing the opening and closing degrees. I contacted Hotcams for the info, and they where no help. They sent me the info on the web, which I had anyway.
 

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well a stock cam lobe height is 35.69-35.79 on the intake lobe and 36.50-36.60 on the exhaust lobe i got this info from my clymer manual hope it helps. measurements are in mm
 

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You’re right with the ratios on the rocker shafts. My measurements were very close. There is a lot of info in the workshop Manuel. I have it in PDF format if you want.
 

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Discussion Starter · #4 ·
Thanks guys, but I have the raptor manual and the info the software needs goes way beyond what the manual supplies. I would love to get the stock cam details and confirm more detailed specifications on the Hotcams, but so far it seems the software is spitting out the numbers and it is comparable to some engine specs I have.

For example, Coalshed got 65HP out of a 672cc, running hotcams stage 2 and 11:1 compression. Feeding that info into the software and I got around the same Peak HP numbers. I had to assume a lot of things which might still effect the predictions. Before using this software to do all kinds of test, I would like to make sure that a lot less assumptions are made.

PS, Chrisjan. I run the software as per your engines specifications, and it confirms the dyno result we got on your quad. The main cause are those intake and throttle bodies you run, and not so much the valve and port sizes, although they also have an effect, but to a minor extent.

Exhaust and intakes seem to be the HP killers here. The length and diameters of these parts are extremely important. Get it wrong, and you loose a serious amount of power. The software is even pointing out that the 39mm FCR's people love to use, is not a requirement to make the high numbers. It should be possible to make the number, even when running 33mm carbs and intakes. If the stock carb are capable of flowing the correct CFM is another debate, but if you can get a 33mm carb that can do the required flow, you have a very good combination.
 

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that software is cool and stuff but its a database and all databases require accurate inputs to get accurate outputs.

Regardless of what the software says, I've never seen stock carbs deliver more than 58HP, it might be possible to get more with a different 33mm carb, like say a TM33 which is Mukunis flat slide carb, but the stock carb design just won't get it done.
 

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hows the software coming along freez?
 

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What is the name of the program that you have?
 

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I would like to know this myself. I am interested in this software.
 

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Discussion Starter · #9 ·
The software is working fine. It is not an exact match to what we see on the dyno, but then again, there is no way to tell the software exactly how the 660 raptors intake ports work and their layout. The software can for example do calculations for a 3 valve intake head with 1 or 3 intake ports and runners, but the raptor uses 2 runners of different sizes for 3 intake valves, so you have to round things of and assume a few things.

Also for the software to be very accurate, you need flowbench results. I don't have that for the raptor head, so the software uses averages and port diameters.

the software gets close to the real findings, so it can help you run tests to see what will be different if you change the cam or intake or exhaust for example. Even if it is not perfectly accurate, it is a great help to test different things, and get the results within minutes, instead of spending hours making things, and testing it, only to find it’s been a waste of time.

The software I am using is called Engine Analyzer Pro 3.3 or 3.5.

You can download it for free, but it will only run for 10 days or so without activation.

Here is the link.

http://www.performancetrends.com/Engine_Analyzer_Pro_v3.3.htm
 

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Thanks Freez. I think I am going to download the demo and play around with it a little.
 
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