Custom cam ?

[nightdiver]

Hey guys do you know where to find some really serious info about camshaft design ?
I want to make one that will work with my combo, the 422 looks kinda small

 

[jwaller]

Re: Custom cam ?

Hey guys do you know where to find some really serious info about camshaft design ?
I want to make one that will work with my combo, the 422 looks kinda small

use the 430 then. thats what I have

 

[nightdiver]

I was thinking of a cam with 276 intake 280 exhaust 112* lobe sep. and .51 & .53 lift
I do the exhaust bigger cause my exh. ports are 55% of the intake, so i need something better.
The 276/280 can change to 280/285 for the 6000 range
What do you think ?
The 430 is nice but with some more balanced heads,intake vs exhaust
I also need at least 500 rpm

 

[BigAl...]

when you say 276/280 do you mean advertised or .050 duration? either way I think you'll need a wider lobe seperation, I think that much duration with that little lobe seperation angle will yeild you to much overlap.

BigAl...

 

[nightdiver]

Yeah advertised duration it is. so the overlap wouldnt be that much

 

[BigAl...]

that's still gonna be a bunch of overlap, we'll only know exactly how much overlap when you receive the cam specs from the manufacture. what turbine wheel and housing are you using? very important.

BigAl...

 

[nightdiver]

The wheel is 71mm. T Qtrim is 68
The turbine size differs from the garrett nrs cause the turbo is a kkk :roll:
Its around .80 to.85 compared to garrett

 

[BigAl...]

well if the exh wheel you're using is actually bigger than a Q wheel then that wheel if pretty big and would allow you some margin for error on the overlap but I still would not use a cam with more than say 30* of overlap.

just my .02 worth, spend it as you wish!

BigAl...

 

[nightdiver]

I think youre right...we need overlap but just a little bit
A 116* would make things better but we know that this would pull the power higher, not to mention the fucked up idle
What Hoover has for a cam ? he shifts at 8000 right ?

 

[nightdiver]

did some calculations
The 412 has 39* overlap
the 422 has 45*
the 430 has 60*
a 430 with 114* LSA would have 52*
In the 430 there is duration with less LSA than the 422 to keep the torque lower
Bigger duration/overlap takes us in a higher rpm band
Now the question is how much more power will we get from a cam with a power band like Crowers 3350 ? 280* 288* 108*
Crowers 3350 is nice with 68*overlap and a power band up to 6200
Waller how do you find the 430 ? with what tc stall speed ?

 

[jwaller]

did some calculations
Waller how do you find the 430 ? with what tc stall speed ?

I like the 430 so far. it doesnt begin to make power until to rpm's come up though. has to be above 3k. I stall around 3900. and thats enough to get my 76 goin just fine. but it does pull much harder and higher than the 412 ever did.

430 is a harder cam to tune though. less vacume and more touchy in the vac areas.

 

[nightdiver]

I sold a jimmy 2 turbo(8 turbine) to a 2000cc 16V opel guy.
Spooled at 3500 and full boost was at 3800. When he changed the cams to 285* the boost came at 4500 ...propably because of the overlap.
You cant see the tach from 4500 to 7500, its 1 sec away(first&second gear)
I mean we lost 1000rpm with the bigger cam ...now with a crower style cam would our spool raise at 5000 rpm ?