5 replies to this topic

[LC-GTR-1969]

Gday all,

 

So I am building a new donk and would like a custom cam designed using modern software, and ground to spec, to suit the flow characteristics of my new head (JZED/ Holden 6)...

 

I know just about every cam grinder will sell me a 'custom' cam but I really want the specs calculated specifically for my setup as to get the most out of it. 

 

Has anyone here got any recommendations for a cam grinder who can and will do the above? 

 

Ive got Engine analyser Pro but I figure there are probably more accurate cam design software, not sure though.

 

I guess I just dont want an educated 'guess' at the cam specs- hell, I can do that.. 

 

Thoughts?

 

 

[TK383]

Put up your specs, head flow, valve sizing, port minimum cross sections, throat sizing.

Engine capacity, compression ratio, rod length.

Auto or manual (if auto, what stall speed), diff gears.

Induction - webers, efi, what choke size or butterfly size.

Fuel?

 

Requirements - rpm range, drag race/street/circuit/hillclimb?

 

Cam type - flat tappet or roller?

 

Any recommendation is going to be an educated guess, from my experience good engine builders tend to know what'll work better than cam grinders.....

I spec all the cams in my engines myself, sometimes in consultation with a cam grinder, I look at their master lobe profile list & figure out what I want, then tell them what to grind for me.

[LC-GTR-1969]

Put up your specs, head flow, valve sizing, port minimum cross sections, throat sizing.

Engine capacity, compression ratio, rod length.

Auto or manual (if auto, what stall speed), diff gears.

Induction - webers, efi, what choke size or butterfly size.

Fuel?

 

Requirements - rpm range, drag race/street/circuit/hillclimb?

 

Cam type - flat tappet or roller?

 

Any recommendation is going to be an educated guess, from my experience good engine builders tend to know what'll work better than cam grinders.....

I spec all the cams in my engines myself, sometimes in consultation with a cam grinder, I look at their master lobe profile list & figure out what I want, then tell them what to grind for me.

 

Thanks TK, I really appreciate your advice. I will post back with all the specifics ins a few weeks. 

 

At this stage I am just waiting on the JZED head to be delivered so I can get it flowed and CC the chambers etc.. Its due for delivery in about a week (hopefully), so I should have some hard data in the next few weeks. 

 

The new heads are CNC ported so if nothing else, the ports should flow more consistently but I just don't have flow data as yet. Joe has indicated the chamber size will likely be mid 40cc, like 45cc or therabouts, but ill need to check it myself to be exact. 

 

I get back soon. 

[TK383]

Joe gets them cast in small batches as required - it's quite a financial commitment for him so he needs to have them pretty much sold up front to be sure he'll cover costs.
He's not a big business, he's an enthusiast that does it for the love of Holden 6's.
Such is the case with many low volume made in aus products.
The very fact that jzed heads are available at all is something to be thankfull for.

[LC-GTR-1969]

Joe gets them cast in small batches as required - it's quite a financial commitment for him so he needs to have them pretty much sold up front to be sure he'll cover costs.
He's not a big business, he's an enthusiast that does it for the love of Holden 6's.
Such is the case with many low volume made in aus products.
The very fact that jzed heads are available at all is something to be thankfull for.

 

Agree mate. I bit the bullet and put my name down for a JZED as I can only imagine at a certain point in time, these will no longer be available. The 202 tragics are still around but unfortunately none of us are getting any younger and it is only a matter of time until parts and knowledge are very hard to come by for our old reds. 

 

I have had to be quite patient waiting for the head, but part of the issue is I think Joe tries to keep the costs of manufacture down, hence its not like there are 100s of places willing to cast, machine, port and prepare 20 custom heads for a price that makes it feasible for him. I can only imagine small scale things like this would be much, much easier in the US, where there is simply larger market opportunities as well as more options for casting and machining.