[DeTomaso] Crane cam 520341

[Kirby Schrader]

Actually, no...

The flat tappet solid lifter cam I was using was a Crower 15380 on the  
Pantera.
Lobe separation was 105 degrees.

Yes, I used power brakes. The vacuum line came off of the #2 cylinder  
of the IR intake manifold.
Never a problem with just that cylinder supplying vacuum.


On 17 Nov 2008, at 5:16 PM, Daniel C Jones wrote:

>> maybe with a vacuum reservoir tank?
>
> If not, there are always electric vacuum pumps.  I think Kirby ran
> a much larger solid cam with 105 LSA.  Kirby, did you run power
> brakes?
>
>> This cam has lsa of 106
>> 236/230 duration at 0.050"
>
> What is your compression ratio?  What sort of exhaust do you have?
> With 106 degrees LSA, you need a really efficient exhaust.  The
> mufflers in particular need to have very little backpressure.
>
>> I want the lumpy idle.
>
> Optimal LSA for your engine (assuming 4.03" bore by 3.5" stroke,
> 2.19" intake valve, compression between 9:1 and 11:1) is 107 degrees,
> the same as my dyno mule 351C.  For that engine, I picked a custom
> Reed hydraulic roller of the following specs:
>
> 228/232 @ 0.050" lift (280/284 @ 0.006), 0.588"/0.588" lift, 107 LSA
>
> If your mufflers aren't up to the task, I'd go with a 108 (or even
> a 109) LSA.  Crane will grind you the same cam on your choice of
> lobe centers, as will others like Bullet.  Another hydraulic flat
> tappet grind I know that has worked well with 4V heads and less
> than perfect mufflers was a custom Comp grind with specs:
>
> 226/234 @ 0.050" lift, 0.554"/0.574" lift, 109 LSA
>
> but be aware the Comp XE (and Lunati Voodoo) lobes are agressive and
> can be noisy (meaning they are likely wearing the seats more quickly).
>
>> but I think it's a fairly agressive lobe profile.
>
> Yes.  Recommended springs are 126 pounds on the seat and 337 pounds
> open.  Make sure to use a proper break in oil or the Comp additive
> and then use an oil high in ZDDP if you want the lobes and lifters
> to live.
>
>> I'm still deliberating on the intake. I'm thinking dual plane.
>
> We'll be testing both the Performer 4V and Blue Thunder dual planes
> on the flow bench and dyno.  I'd like to test the Ford aluminum dual
> plane too but so far have not been able to locate one.  Previous
> experience has shown they both will need work to balance the good
> and bad planes.  I won't be surprised if the RPM Air Gap 2V is better
> on the 4V heads for that reason but we'll see what the dyno says.
>
> Dan Jones
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