I;m trying to figure out if the stock 3.4 cam is a more aggresive design than my crane 2030. This 2030 cam has:
.423/.423 lift

204/214 duration

109 lobe sep

 

Duration at .050" is
i=204*
e=216*

Valve lift is .427"/.454"
Lobe is 107
Your cam has lopey idle
Designed for a stick car, I'll bet.
BUT, the stock 3.4 addresses the issue of a weak exhaust by INCREASING the exhaust number for lift.
Your cam is a "single pattern" cam.

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Chat Soon,
KED85
Karl
1985 Firebird 2.8 to 3.4 swap project for Smog Happy LA, CA

 

hmmm, the lobe sep looks to low for my car. I had a federal mogul cam with about .460 lift and 108 lobe sep. The cars computer was thrown off by it.

 

Can anyone help? I'm not super great with cams and what happens with lobe separations to cause a computer to go "wacky".

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Chat Soon,
KED85
Karl
1985 Firebird 2.8 to 3.4 swap project for Smog Happy LA, CA

 

I will take a stab at it, but i really do not know that much about cams.

The computer was thrown off as ya over cammed the car without addressing the comp program. A lopey idle from my understanding is caused by a over lap in intake and exhaust valves being open at the same time. Altho not much time is seen. The lope is litterally the gasses escaping thru the headers or exhuast manifolds - also goes into the intake side which adds spent gasses into the new charge - thats alot of the reason they are for high rpm use - better clearing of the cylinders at higher rpm. A way to trick the car is to get a custom chip made for your type of setup. They take the car and put it on a dyno to tune the chip for the car. At two seperate rpm levels, one high and one low. I know of guys running well into the .600 lift WITH computer but again it takes a special program to do it.

I would say you would be fine with the 3.4L cam. It takes advantage of the exhaust side - thats what ya need right now. The other thing you can do is put 1.5 roller rockers on your intake side and 1.52's on your exhaust side to make it breathe abit more. MORE exhuast out = more fresh intake in = more power. Running a deul pattern cam would be a better solution as well.

 

In addition to whats been said here's some information on my website on all the basics of how a cam works and whats involved on deciding what type of cam to use. Hope this helps:

http://users.spec.net/home/emxjc/cam_shaft_power.html

Here's also a list of streetable cams for computer driven vehicles:

http://users.spec.net/home/emxjc/cam.html

KED85, How did you manage to get the 3.4L cam specs? Do you know the GM part #?

 

I open up the GM Performance parts book

12363220 (cam), includes lifters.

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Chat Soon,
KED85
Karl
1985 Firebird 2.8 to 3.4 swap project for Smog Happy LA, CA

 

KED I could be mistaken but I don't think this is the same cam used in 93,94,95 Camaros. According to GM, the 3.4L package was intended to be used for upgrades to Chevy S-10s with 2.8s so I recall from the performance book that it was not 50 state legal at the time or something to that effect. The GM peformace mentions it is not legal in CA. and I believe the reason being is because of this cam that is intended for high torque in the low RPM ranges (107 centerline) the ECM will not like the low vacuum. What car did your 3.4L come from?

 

1995, the last year for the installed 3.4.
Later that same MODEL YEAR, installed were the 3.8s.
Honest, I only picked up what is stated in the 1998 edition of the Perf. Parts Book.
And it's the same specs for the 3.4 engine conversion.
GM DIDN'T WANT TO SPEND THE MONEY ON THE COVERSION CARB CERTIFICATION PACKAGE. They didn't need to, AS MOST VEHICLES IN CA ARE TURNED OVER OR CRUSHED when the engine wears out.

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Chat Soon,
KED85
Karl
1985 Firebird 2.8 to 3.4 swap project for Smog Happy LA, CA

 

Apples and Oranges. What I am trying to point out is that the 3.4L cam that was used in the 93-95 Camaro is NOT the same cam used for the 3.4L upgrade. I believe the lobe centerline is 117 for the Camaro engines. Since you passed Emissions in Cal, wasn't the engine you used for you Bird from a Camaro?

 

Yes it was.
About the ONLY other thing I can think of/ offer is for one to get a Chiltons or something like that, to show the cam specs for this 3.4 supplied engine in the cars.

I only have those resources I've offered.
My Chiltons goes up to the 1992 F body model. I got that Chiltons for free.
My Helms is the 1985 book for my Firebird.
I have a Chiltons for my Blazer, too and a 1992 & 1998 Performance parts book.


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Chat Soon,
KED85
Karl
1985 Firebird 2.8 to 3.4 swap project for Smog Happy LA, CA