Custom Ground Cams

[Lyle's GTP]

I'm in.

Lyle

[34T]

that's TWO; eight to go.

what specs do you think you would be after, Lyle; the GM ones or W41?
remember that the W41 would be entirely experimental and the cam grinder won't take any responsibiity if it doesn't work out that great......

[sspeedstreet]

I'd be in for the GM spec. The lift on the W41 seems a little hairy for my taste.

[5SpdGTP-91]

I'm In

[Gemmer]

I have no idea how close to real life DD is, Im assuming its optimistic in its math...as Im sure there are alot of variables in the mathamatics behind engines that it doesn't take into account.

I would prefer w41, or something simular, since the power curve was (according to DD) better than "official GM" over the entire curve...I just dont know if I trust the .410 lift

Aaron: yea, I toyed around with a few setups that netted waay nicer peak HP, they all took place where you wanted power, in the 6-8kish range. I didnt save any specs so Ide have to toy around more...I dunno how many of them would be possible on a regrind, and how well they would work for you since these are based off stock, not the higher CFM intake you want to build

[Gemmer]

hmm, I punched in w41 with .370 lift (like official GM) and its still better by about 1-5 hp untill 7k rpm where it breaks even...at about 8k (where most of us wont ever go) the trend switches and the "official" specs are about 1-5 hp better

I also put them both at .410 lift, and got the exact same results...just both curves being around 3-6 hp higher

we know by the 94' specs we can at least go .373 safely

Anyone else wanna double check? Ill play around a little more...

[Gemmer]

I give up...been trying all night to make any specs better than w41, and anything that comes out to be a significant difference is either too aggressive (not enough bottem) or prolly too risky or unable to be reground (I think)

Im leaving this task for someone else

34T: You can technically insert stock specs from any engine and create a simulation, and It doesnt take too long to put in #s, but I assume it would take some degree of tweaking to get the simulated dyno numbers close to stock.

Im using the very nice stock 3.4 DOHC specs and flow files sappy created for DD, which come in right at 210HP...im not sure if they are closer to pre or post 94, but I def dont think they are 96 specs...the hp curves seem close enough to real world DOHC dynos ive seen for something like this.

Ill install photoshop later today and post some fun charts for those interested in the simulations

[sspeedstreet]

Gemmer, thanks for your time on this. Your numbers are really helping me decide on this project.

Neil

[Lyle's GTP]

Could someone post the graphs showing the "GM official" and the "W41" and the "94'" DD results. Whats the problem with 410 lift. Are we concerned about interferance? Because as long as I'm not breakin' belts I don't really care.

Oh, I'm kinda leaning towards W41.

Lyle

[Gemmer]

Ill post them tonight.

Lyle, we are afraid there wont be enough clearance in the cam banks

[Gemmer]

What else you nigz wanna see?

[Gemmer]

...............@3000RPM...........@5000RPM........ ...@7000RPM

W41............102ish................213ish....... ............252ish

Official...........95ish...............207ish..... ..............245ish

Stock............121ish..............206ish....... ............190ish

[RacerX11]

Try running the stock profile with the 13 degree exhaust retard trick and see what it gives.

Marty

[sspeedstreet]

Now if we could figure out a long-short runner intake to go with it . . .

[Lyle's GTP]

So, it looks like 260 HP @ 6500 RPM. Nice. Doesn't anyone have the specs to determine if the cam banks can handle the lift.

Lyle