Street Avenger 670cfm - Team Camaro Tech
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post #1 of 29 (permalink) Old Oct 11th, 09, 04:44 PM Thread Starter
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Jeff
 
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Street Avenger 670cfm

http://www.holley.com/data/Products/...199R8219-2.pdf

I am going to get the secondary spring kit so I can play around and see which one responds best. On the second page on that link, there is a chart that shows approximate RPMS for a given spring and it appears that as cubic inches go down, the RPMS go up. Given that I have a 327, I can assume that the RPMS will be higher than the ones listed for the 350. However, what does higher gearing do to it... anything? I have a 2.73 final drive and I have an M20 wide ratio (2.52 1st).

I know, the gearing is not exactly set up for high performance, yet... But, how does that react with the secondary spring? Should I use a slightly stiffer spring because I have a higher final drive or a more compliant spring? The street avenger came with the plain spring installed and I have swapped that out for the yellow spring just yesterday. It seems like it accelerates earlier, as expected, but perhaps it's a little too early because I get a backfire sometimes when it's around 1.5k RPMS and I smoothly mash the gas pedal.

According to the Holley tech videos, that backfire indicates that I possibly need a bigger squirter. I'm not sure what came with the 670 street avenger as far as squirter size, so I will go check that out and get a bigger one 3 sizes above it...
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post #2 of 29 (permalink) Old Oct 14th, 09, 01:37 AM Thread Starter
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Jeff
 
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Re: Street Avenger 670cfm

Really? No input from the Holley experts?
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post #3 of 29 (permalink) Old Oct 14th, 09, 05:05 AM
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Scott
 
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Re: Street Avenger 670cfm

I can only tell you what I had to do with my 670 Avenger on my 327. Off idle stumble. First I corrected all timing issues following John Hinckley's advice. Then I bumped up the jets. Problems solved. Your motor may tell you something different. As will every motor.
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post #4 of 29 (permalink) Old Oct 14th, 09, 05:41 AM
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Scott
 
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Re: Street Avenger 670cfm

I had to to do primary jets & larger squirter to get rid of the lean off idle problem. I'd fix that first, then play with the springs if you still are not happy. With your gearing, I would not think making the secondaries open sooner would be a good thing.
Scott

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post #5 of 29 (permalink) Old Oct 14th, 09, 09:37 AM Thread Starter
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Jeff
 
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Re: Street Avenger 670cfm

Would a backfire occur in a rich condition or only in a lean condition? I swapped the silver spring back in and it hardly pops at all, except when cold. A couple other comments: I watched the carb tuning videos on Holleys site. I learned that the power valve should be half of the idle vacuum. The 670 SA comes with a 65 but I'm only pulling 9-10" of vacuum (can't get it any higher than that at my 800RPM idle speed), which indicates I should swap the 65 power valve out for a 45. I'm still new to Holleys so I don't know exactly what the power valve does except that they refer to it as the power enrichment system. Maybe I need to do that swap and/or jet up a little bit.

But first I need to get a grip on what's going on, so would an engine backfire occasionally under a rich condition or just in a lean off-idle condition?
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post #6 of 29 (permalink) Old Oct 14th, 09, 10:27 AM
 
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Re: Street Avenger 670cfm

Backfire=lean(or timing)
I don't follow holley's divide/2 rule
I subtract 2-3 from idle
That's some low vacuum-What cam & timing
The gearing is gonna make it tough if your cam is big enough to really cause such low vac.
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post #7 of 29 (permalink) Old Oct 14th, 09, 10:50 AM Thread Starter
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Jeff
 
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Re: Street Avenger 670cfm

It's the Edelbrock 7102 - part of the top-end kit I got from them. Here are the specs from their site:

Duration at 0.006" Lift: Intake: 308 Exhaust: 318
Duration at 0.050" Lift: Intake: 234 Exhaust: 244
Lift at Cam: Intake: 0.325" Exhaust: 0.340"
Lift at Valve: Intake: 0.488" Exhaust: 0.510"
Timing at 0.050" lift: Open Close
Intake: 10 BTDC 44 ABDC
Exhaust: 59 BBDC 5 ATDC
Centerlines: Lobe Separation - 112 Intake Centerline - 107

I currently have it at 16 initial, 36 total with vac advance plugged. At idle vac advance adds about 17-18. It is hooked up to full manifold vacuum.
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post #8 of 29 (permalink) Old Oct 14th, 09, 12:00 PM
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Levi
 
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Re: Street Avenger 670cfm

I think you need to put some bigger jets in there man. With that lift thats sort of a breather I'm not sure your getting enough fuel in there.

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post #9 of 29 (permalink) Old Oct 14th, 09, 12:45 PM Thread Starter
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Jeff
 
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Re: Street Avenger 670cfm

My headers are getting installed today and I'm sure that will change something somehow. I didn't want to do the cam break-in with new ceramic-coated headers. So, my stock manifolds have been on there up until now...

In any case, the 670 SA ships with a 65 primary and 68 secondary... Stock squirter is a 31. With my high rear-end gearing, that 31 squirter should be good enough right? If I changed the jets, what should I try? Jump two sizes (min. jump that Holley recommends) on both jets or do I need a bigger jump?
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post #10 of 29 (permalink) Old Oct 14th, 09, 01:26 PM
 
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Re: Street Avenger 670cfm

Thats alot of cam for a 327-I see no real issue with yor timing
What pump cam are you running now?
I've seen headers do some crazy things to motors-GOOD and BAD
In your case I think they may help.
I personaly start with pump cams before shooters.
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post #11 of 29 (permalink) Old Oct 14th, 09, 01:50 PM Thread Starter
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Jeff
 
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Re: Street Avenger 670cfm

Indeed, it's a lot of cam. But it's paired up nicely with Performer RPM aluminum heads (64cc chambers and 185cc) and an RPM Air Gap (dual plane of course) on the top end. As far as the pump cam goes, I'm not sure. I'll have to look when I go pick the car up this afternoon (hopefully). It's the stock 670 SA pump cam (black I think?) - probably running in hole 1. I can verify that later. If that's the case, what color and hole should I switch to, if at all? I imagine with the low rear-end gearing, I probably don't want a pump cam that squirts it out too much faster... right?
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post #12 of 29 (permalink) Old Oct 14th, 09, 02:07 PM
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Scott
 
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Re: Street Avenger 670cfm

What VA can is in there? Is it a VC-1810?
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post #13 of 29 (permalink) Old Oct 14th, 09, 02:11 PM Thread Starter
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Jeff
 
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Re: Street Avenger 670cfm

That's a good question. I'll also have to check that later. Where would it be marked/stamped?
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post #14 of 29 (permalink) Old Oct 14th, 09, 02:18 PM
 
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Re: Street Avenger 670cfm

pop the dist cap and the code will be visible on the frame of the vac can
I like the blue on hole 2 & green on hole 1 cams in the front.
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post #15 of 29 (permalink) Old Oct 15th, 09, 05:53 PM Thread Starter
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Jeff
 
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Re: Street Avenger 670cfm

I haven't had a chance to pop the distributor cap and look at the vac can. But, I did check the pump cam and it is an orange one installed in hole 2. According to Holley's graph, the orange and green look pretty similar - slightly different shape to the shot curve - at least on the graph...

http://www.holley.com/BrowseCatalogs...Holley&Page=65
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