Hello everyone
I know this site is full of HQ people. Emailed Doug at HQ he said the 575 could be used @10:1.
Just wondering about which one of the two cams would give me the most low & mid grunt. I live in ohio, we do have 93 fuel. I'm worried that it may not be availible when I ride out of state. thx for your feedback. Bob

 

If I believe correctly the 575 is the new chain version of the 0039. With an 03 you'd want the 0039 gear cam

 

I believe the 0039 Little more tq 575 little more hp I believe I read that the 0039 has like 4 more ft lbs and the 575 has like 4 more hp on average, there is a lot of info on this on the H.Q. techline you can get to it from the web site and its free. Phil M I believe had the 0039 in his 98" he can probably give you some insite to this as well. His dyno sheet from the 98" was impresive.

 

thanks asuperheat & dawg
the 575 is another cam from HQ they use it in there 10.5:1 kits. It has 4 more degrees duration. offered chain or gear. Just like the 0039 dawg thx Bob

 

I run an S&S 585 gear drive set in my 107" and I have buckets of torque from as low as 2500rpm and i'm all in by 2800rpm. Great cam for torque at all rpm ranges and runs fine on 91 otane whic is mostly what we have around here.

 

Bob:

If Doug said the 575 will work in the 10:1 motor I'd go with that.

The 0039 is suggested for the 10:1 motor because its cam timing builds slightly more cylinder pressure than the 575, so that cam induced cylinder pressure increase offsets the somewhat the difference between the 10:1and 10.5:1 compression.

Frankly, unless you have an extremely sensitive butt dyno, (and I don't), I doubt you would notice the difference between the two.

 

Really, the biggest difference is that the 0039 hasbeen around forwhile and the becuse of that there is a lot ofhistory and data behind it. The 575has not been around as long but is really gaining in popularity. AsIunderstandit, the 575 is a better choice than the 0039 as compression gets above 10.5:1.I builtmy 98" motor@ 10:1 basedpast experience with other motors at 10.5:1. While Doug assured me at the time, that there was no issue running his stuff at 10.5:1 (properly tuned, of course), I was gun shy and wanted to stick w/10:1. For that reason, we chose the 0039. Since that build, I have only done one other HQ build w/0039's. All the rest have used 575's. Additionally, all but mine have been 10.5:1 builds. The main thing I learned from my build was to "listen to Doug".

The 0039 & 575 are different grinds on the intake lobe. Both are available for 99~06 motors, but the 0039 is NOT available for 07 & later motors.

Does that help at all?

 

If tuned right it should not ping. I ran 10 1/2 to1 also on 91 octane with no pinging and NO COMPRESSION releases.

 

I live in the NE corner of Oh. I have a 06 Ultra with a 95" HQ 10.1 0039 cam build. I'm happy with it, pulls real strong on the bottom end. I don't have a good dyno sheet to show, but then to me thats pretty much all they are good for. I let my dad take it for a ride and he was pretty supprised at how quick it is. I don't think you would go wrong with either cam. If Doug says the 575 will work I would trust him and roll with it.