Johnny Blaze

iTrader: (15)

Does anyone have the stock specs for an L98 cam? I know the duration is 207-213, but what is the IVO, IVC, EVO, EVC, specs? Such as you would use to plug into desktop dyno?
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Thanks.

poncho@home

here is a screen shot of the cam specs

AJ_92RS

Or you could just go to https://www.thirdgen.org/newdesign/tech/techdb.shtml and see all the cam data you could ever want.

Johnny Blaze

iTrader: (15)

Ponco@home, I tried plugging that into Desktop dyno, but it won't let me put in - numbers. What gives??


Oh,
I looked at that page first. It does not list the opening or closing times, just lift , duration, and lobe sepatation.

AJ_92RS

You can't enter the IVO, IVC, EVO, EVC number anyway. All you can enter is the LCA, IC, duration (either seat-to-seat or .050") and the lift at the valve.

Enter everything that's in those specs, then use the LCA as the IC -4*. That's the average amount of advance on a SBC cam.

You can enter 116* like poncho has, but there's no guarantee the cam you'll install will have the same IC unless you check it (aka degree the cam).

Johnny Blaze

iTrader: (15)

I have Dyno2000. You must enter those specs on it.

AJ_92RS

So do I, and you don't have to. All I have to do is enter the specs I mentioned and it automatically calculates the timing events.

On the toolbar on the top there's a small ICON that looks like a cam. Click on it and you can enter the specs I mentioned. Then the work is done for you.

If your toolbar isn't showing then click on "Tools" then "Cam Math..."

If you want the toolbar to show, click on "View" then "Toolbar"

AJ_92RS

Here's a pic of it. It says "Cam Math" with the little red line pointing to it.

AJ_92RS

Did you get it figured out Johnny?

Johnny Blaze

iTrader: (15)

When I go to cam math, I get the screen posted previously, however, it will not allow me to post a negative time.

AJ_92RS

If you're talking about the -12.5 under IVO, Poncho didn't enter it, the calculator calculated that.

Make sure you have the "Cam Specs @" set to ".050-Lift" when you enter the other specs like duration, lift, LCA, IC, etc.

IVO (BTDC) -12.5* means the intake valve doesn't start to open until 12.5* ATDC, which is why it's expressed as a negative number BTDC. But that's where it is at .050" of lift which is why it's expressed as a negative number.

If you had the "seat-to-seat" specs, and were to enter them that way, that probably wouldn't come out to be a negative number.

I'm not trying to sound critical, but maybe you should break the "guy rules" and actually read the instructions that came with DD2000. Or maybe buy some books that tell you what those cam specs mean.

Johnny Blaze

iTrader: (15)

I know what the cam specs mean. I am having a problem with entering the numbers, not cam knowledge. With the specs entered the same as in the post, and I click on 'apply', it states
" a valid IVO value is required"

AJ_92RS

As I said, I wasn't trying to sound critical.

Start with a cam from the main menu, the change the specs of it.