Spring recomendations Dyno 04-03 cam

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If you're going to turn the 04-3 up (7000-7200) like most guys want to, then you had better have a real good flowing carb for it. Also, play with the ignition timing on the dyno. That set-up is very finicky on timing to make good power up on top.


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Brian Carlson
Carlson Racing Engines
Vector Cutz
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All depends on the rest of your set-up. Like I mentioned above, you have to have a great flowing carb if you're going to make usable power above 7000. Spring pressures are a bit tricky, and ignition timing is real particular with this set up (and varies from one engine to the next it seems.) 04-3 will definitely wind up higher than say a 96-3 if you set it up right.
 
All depends on the rest of your set-up. Like I mentioned above, you have to have a great flowing carb if you're going to make usable power above 7000. Spring pressures are a bit tricky, and ignition timing is real particular with this set up (and varies from one engine to the next it seems.) 04-3 will definitely wind up higher than say a 96-3 if you set it up right.
Id say that triple a we still have was up there on the bench. I cant remember much about engine set up. I was to busy keeping up with tires, chassis set up and driver moral. But I remember when he figured out the controlled valve float he was looking for. It's amazing what all can get accomplished with a highly consistent driver and a well oiled team. Man those were the days.
 
installed height 1.020 and 21 intake and 19 ext is a good starting spot for me.. when I was in the seat my own personal motor had one of the 1st 04-3s dyno produced.. thing was a monster.. but ran 26 degrees timing... never found another engine that would use that.. most were higher 29-30
 
installed height 1.020 and 21 intake and 19 ext is a good starting spot for me.. when I was in the seat my own personal motor had one of the 1st 04-3s dyno produced.. thing was a monster.. but ran 26 degrees timing... never found another engine that would use that.. most were higher 29-30

Soon as I get custody of that old Dover im gonna take it to Brian and have in look at the set up the old man was running, along with put her back in 2010 shape. Im very curious as to the difference in yours and his. Dang I wish I knew right now.
 
Allot of people say the 04-3 is for high rpm and maybe that's true if the set up and all the stars line up but I find it does it's best work in the mid range. After gearing for 7K+ I went back to 6800 real quick. Definitely agree it's a very finicky cam.
 
What Jimmy said is exactly what I've found. On most engines you can have 29-31* ignition timing, and another 26* to make it work. I've found no other cam where I've need to run less than 28* and get it to run like this, but occasionally, you find one that takes something out of the box to make work.
I recently got in an engine from another builder that I suspect was using this cam, or possibly his own close variation of it, and it had very low timing as well. It doesn't work on all 04-3 engines, but certainly more than a one off anomaly.
You can question it all you want, but when it runs out on the dyno AND on the track, you stop questioning and just believe. :)

I'm a little stiffer on IN pressures than Jimmy (generally) and softer, or the same, on the exhaust.
It also depends on if you're using a 1.485 - 1.500" spring or one of the WMS style HD springs. Installed pressure is one thing, but nose pressure @ max lift also figures in to where that valve starts to float and how much it controls it.
Once you get it right, you duplicate it in that block forever.
And no, there's no one size fits all on spring pressures either. Just tons of trial and error until you get it right.
 
Yep I think Jerry Dover had an article on how to get the right pressure for floating the intake using how hard the valve hit the head.. should just tick it..
I use the WMS heavy duty spring for the intake and standard dyno springs on the exhaust.. everyone is a bit different.

It's not magic but playing around with timing is always worth a look. I had more than a few engines like lower timing. Yes the 04-3 is best as a mid-range hog and still turn 68-6900 with ease..
 
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