94 Z28 coupe

[Bent77]

The LT4 is a good cam. @6872 was asking me about it the other day, so I used it for my example
The fact it was one of the original offering for this application is neat

Look at the specs, and you'll notice it is almost verbatim what some of the early LS and lots of the Aftermarket cams are near identical


If I swap I'd use the 8071 just because I have the stick already

 

[tRustyK5]

Already having it definitely makes the decision easier.

 

[Bent77]

So in this application, this change to just lift maths out to adding ~10 HP,
This is the same HP gain as changing to 1.6 rockers in the lift change, which as shown on the dyno is very close.


In the actual LT4 cars, they are rated at 330hp, 55 higher than the LT1.
These are all 1.6 rocker, putting it at .525 lift (that brings it in line with the LS style cam lifts that are based off of it)
They also have a different intake and heads, which consists of the raised runner. these two alone make up about 20 of those HP numbers
This puts us seeing the cam actually gain about 35, of which ~25 comes from the change in the timing events

 

[Bent77]

Already having it definitely makes the decision easier.

Easy there, just talking theory at this point....

 

[76zimmer]

Seeing those flow numbers, I wish I knew what my double humps flowed.

 

[Bent77]

So in this application, this change to just lift maths out to adding ~10 HP,
This is the same HP gain as changing to 1.6 rockers in the lift change, which as shown on the dyno is very close.


In the actual LT4 cars, they are rated at 330hp, 55 higher than the LT1.
These are all 1.6 rocker, putting it at .525 lift (that brings it in line with the LS style cam lifts that are based off of it)
They also have a different intake and heads, which consists of the raised runner. these two alone make up about 20 of those HP numbers
This puts us seeing the cam actually gain about 35, of which ~25 comes from the change in the timing events

Interesting derivation to consider:

In the zz3 and zz4 engines (original source for the 8071 cam) they were rated at 345 and 355 respectively
running those engines in comparable weight cars, we figured they made 360 and 370 (no accesories)
ZZ3 was 10.1:1
ZZ4 was 9.76:1
Slight change in the head
Both engines heads were based off the L98

The LT1 head is based off of the L98, and was the first heart shaped chamber GM made
LT1 is 10.5:1
No accessories, they make about 360 with headers (using the 202/207 cam)

 

[Bent77]

Seeing those flow numbers, I wish I knew what my double humps flowed.

You and I went through this at one point based off your MPH (which is great for a street car), but I don't remember writing it down
I do however have airflow files of similarly prepped 461s that we had

Believe 230 range is in the ball park

 

[Bent77]

 

[76zimmer]

I like his documentation of changes

 

[tRustyK5]

Holdener is a testing beast...

 

[Fastereddie]

You still tinkering with this?

 

[Bent77]

Haven't done much to it since last summer.
Fixing the MAF made it a lot better
Needed a new battery and starter
Sanded the clear coat off one fender and attempted the shake and shoot it with marginal success
I have a 3.73 ring gear for it, I've already written the tune/gear charts for it
AC still works

Just drive it to church on Sundays. Think I've put a whopping 5-600 miles on it

 

[fastazz81]

You should go to church more often if that’s all you’re driving it.

 

[Fastereddie]

You should go to church more often if that’s all you’re driving it.

The garage is a church!

 

[Bent77]

.

 

[ktmoutfront]

Turning it into a fishing boat?

 

[Bent77]

Yes!

 

[Bent77]

No fish there, river was defective.
Drove to the next town and picked up a gun instead

 

[6872xtc]

No fish there, river was defective.
Drove to the next town and picked up a gun instead

I hope that you weren't trying to use the Camaro for trolling the river..

 

[Bent77]

Maybe I’m lost. I’m a long way from home

Got 25.5 getting here. Some of that spent over the speed limit…