Simulated cam grind for 3500 motor

[SappySE107]

I was asked for the best grind to put on a 3500 cam for a 2500-5500 powerband. I simulated all of the cams with the stock specs and came up with the 1393 grind on the store.

206/206 260/260 .533/.533 110 LSA 106 ICL

Attached are the simulated dyno results

[SappySE107]

Ported Manifolds as well

Here are the ported 3500 manifolds on a 3500 motor, both stock cam and 1393 grind.

[gectek]

can u do the same with the 1312 and the 1393 on a stock 3400 and a 3400 with ported UIM/LIM

[SappySE107]

I dont have the ported 3400 manifolds in my program yet. The 1312 cam wasn't nearly as strong as the 1393 on the 3500 engine. I have a small list of the cams that helped the 2500-5500 overall,even if it hurt the bottom for a lot of top in that range.

[gectek]

well i have the gearing for bottom, and i want a good idle though, and im using the ls6 springs with this on my head, and i want to make sure i dont get too much lift and have to worry about coil bind.

the LSA and Dur show to be good on both of those for idle and not much overlap, so they arent hideous with idle, but i want good lift and flow, but keep the idle as smooth as i can

[gectek]

also im not going above 6k at all, so there is no need for the outrageous top end if i cant use it all...i may have 3.91 gears in my 4t45, so ill need something to help top end, but make use of the gearing for bottom...im looking for about both, i know that isnt possible, but i will sacrifice lift and dur for a good idle and some descent 2kto5k

[Superdave]

Ben can you run that sym with my cam and your ported flow numbers?

i'd like to see how close DD2K is to your program.

cam card: http://www.3500z.com/3500/Cam-Valvetrain/camcard.jpg

here is the graph i got from dd2K



right about 300HP/300TQ

Thanks

[gectek]

r u really gonna crank it to about 7k?

[SappySE107]

Im porting now but if you want 3500 specs, sure. What valves? My street porting for 3500 heads using stock valves doesn't gain much flow at all. Its more for quality without opening it up to keep the velocity.

Ill have to sim it when im finished with this head.

[Superdave]

r u really gonna crank it to about 7k?

I plan on setting the rev limiter to 6750, the rods are the weak link.. everything else is more than capable of 7K RPM.

Im porting now but if you want 3500 specs, sure. What valves? My street porting for 3500 heads using stock valves doesn't gain much flow at all. Its more for quality without opening it up to keep the velocity.

Ill have to sim it when im finished with this head.

I gasket matched mine, fixed the casting flaws and a few transitions. Also did some small work to the combustion chambers. i'd call that more of a "race porting". I spent most of the time on the exhaust side.. they're purdy It's too bad i never got them flowbenched

[torq455]

That's pretty sweet for n/a Dave!! I used to hope for that with 10lbs of boost!

[Joseph Upson]

I plan on setting the rev limiter to 6750, the rods are the weak link.. everything else is more than capable of 7K RPM.

The 3500 rods are a different and later design than the 3400 rods, forged powder metal vs. forged steel, what makes them comparatively weak? I'm curious because more often than not a lot of assumptions are being made without any real proof for support. Both engines have the same fuel shut off point 6K rpm yet the 3500 has the greater reciprocating mass.

The northstar V8 has rods made of the same material as the 3500 rods, same stroke and 1mm less on the bore with a 6750 rpm fuel shut off, so is it really the rods or the valve train that's the weak point.

The LS6 has powder metal rods no forging with a fuel shut off of 6600 rpm.

Here is what I just found after a little searching:

" In fact, the powder metal rods in the garden variety 3800 V-6 of your wife's Impala are stronger than the old Chevy "pink" rods. And as for the rods in the new Corvette's LS2 or LS7 engine, well, those much-respected forged steel pink rods are downright brittle in comparison" From this article:

http://www.superchevy.com/technical/engines_drivetrain/shortblock/1510sc_howards/

They're not making rods for GM but they made a very significant comparison as well as suggest that the powder metal process produces a stronger product than the traditional approach, and it appears the product maybe denser as well.

I don't know for sure, but I have planned for a 7K redline along with a valvetrain upgrade since my cam is already ground for 6500.

[Superdave]

The 3500 rods are a different and later design than the 3400 rods, forged powder metal vs. forged steel, what makes them comparatively weak? I'm curious because more often than not a lot of assumptions are being made without any real proof for support. Both engines have the same fuel shut off point 6K rpm yet the 3500 has the greater reciprocating mass.

The northstar V8 has rods made of the same material as the 3500 rods, same stroke and 1mm less on the bore with a 6750 rpm fuel shut off, so is it really the rods or the valve train that's the weak point.

The LS6 has powder metal rods no forging with a fuel shut off of 6600 rpm.

Here is what I just found after a little searching:

" In fact, the powder metal rods in the garden variety 3800 V-6 of your wife's Impala are stronger than the old Chevy "pink" rods. And as for the rods in the new Corvette's LS2 or LS7 engine, well, those much-respected forged steel pink rods are downright brittle in comparison" From this article:

http://www.superchevy.com/technical/engines_drivetrain/shortblock/1510sc_howards/

They're not making rods for GM but they made a very significant comparison as well as suggest that the powder metal process produces a stronger product than the traditional approach, and it appears the product maybe denser as well.

I don't know for sure, but I have planned for a 7K redline along with a valvetrain upgrade since my cam is already ground for 6500.

Interresting, i didn't realize that they were still "Forged". My LSx buddies always said that the powdered rods are the weakest link in the LSx engines and that guys pushing more than 6500 RPM were prone to snapping them.


If this is the case then i won't worry about going to 7K+.

Thanks!

[Joseph Upson]

The LSx rods failing over 6500 rpm must be considerably over since the fuel shut off is 6600 and they're probably running the engines to the extreme quite frequently and who knows what else. I did mention that the LS rods were not listed as being forged, only powder metal. That was from a 2005 GM spec sheet.

Whether GM purposely left the "forged" label off I don't know, the 3.6 DOHC rods are sinterforged and in the article I thought I saw sinterforged powder metal so is GM leaving the sinterforged label off the 3500 rods? Who knows, it looks like they are playing on words.

[torq455]

umm, FYI, the LS7 rods are titanium. yes the powered metal are stronger than the "pink" rods. the pink rods were ran to 6500 back then, so why couldn't you run a stronger rod at a higher rpm in a similar engine?