670 Street avenger ..good choice ??

[Brasil 10]

Hello...

 

I need some help...because I need to buy a new Carb for my Mach 1.....

 

 

first of all... this is my "combo"

 

 

351 W 0.030 over roller block

 

balanced within 1 gramm

 

ARP Main /Head BOLTS

 

zero deck hight

 

flat top pistons ( hypereuthetic with chrom moly rings ) CR ?? around 10: 1...?? I guess

 

204 / 214 @ 0.50 lift cam

 

60 cc heads from the 69 MAch 1 4v ported

 

Dual plane intake ( Buddy Bar )

 

LOngtube Headers 3 " collectors 2 1/2" tubes with Raptor mufflers

 

B&M torq Converter 2000 Stall

 

C 6 with shift Kit

 

3.00 : 1 Rear with trac loc 9 inch

 

235 60 15 tires

 

and now the million Dollar question.......

 

Is a 670 Holley Street Avenger a good choice for my SET UP ???

 

Thank you

 

Greetings from Germany

 

Juergen

Edited December 12, 2010 by Brasil
forgot the piston type....

[Brasil 10]

....no ideas ?

 

Greetings fromGermany

Juergen

[Rcodenewf 44]

Hello. With that compression I would have up'd the cam to something a tad hotter with a duration @.050 of 220 or so.

 

Nothing wrong with the 670 street avenger. Any that i've used have been fine right out the box as far as a 'plug and play' type of carb, but i've also discovered via using a wideband that they are definitely on the lean side.

 

Therefore i've had to remove the iabs (idle air bleeds) , hsab (hi speed air bleeds) and definitely IFR's (idle feed restrictions) and drill/tap them to make them adjustable.

 

This is certainly just my opinion....regards....John

[Brasil 10]

Hello John...

 

I know, that the cam is a little ... "small"... but perhaps I will resolve that "problem" next year... ( smile )...

You wrote about the iabs,hsab,ifrs.... do I have to modify all of these parts ??

and...how "LEAN" is this carb working ?? I had a 600 cfm Holley ( 80451 ) and a 600 cfm EDE ( 1406 ) on the car.... but those carbs where not satisfying me... so I am thinking about the 670 cfm Holley...

 

Greetings from Germany to Canada

Juergen

[Rcodenewf 44]

Greetings back at ya Juergen :

 

What I found after installing the 670 avenger was this:

 

While trying to set the idle mixture screws I noticed that i couldn't get a satisfactory idle with the screws 1 1/2 turns out and had to continue way out further.

 

The greatest improvement occured when i closed off the choke nearly complete and the engine smoothened and picked up in Rpm. This indicated the carb circuit was lean and upon checking i confirmed i had no vacuum leak issues.

 

I took the carb off and set the idle speed to show roughly the 'preferred' .020 of transition slot and eventually had to increase the idle feed restrictors to allow the mixture screws to be more sensitive and finally arrived at a 1 1/2 turn out adjustment.

 

Then i 'tuned' each circuit of the carb with a wideband 02 ( Innovate Motorsports)

 

There is no hard and fast rule that an engine should run at a certain A/F ratio. Camshaft design, compression, intake manifold, etc will dictate what fuel requirements the engine has.

 

I can't say, and maybe nobody can, that the 670 will perform exactly the way you want it. In my opinion rarely do you find a carb that is an 'out of the box' bolt on.

There are so many variables comprising an engines state of tune that each carb should theoretically be 'tuned ' to a given engine. Again, just my opinion.

 

Bolting them on and just driving is certainly possible and probably should work...but if you are looking for performance and having that engine/carb combo work to its' maximum potential then some tuning will be required.

 

Hope i haven't confused the issue.....regards...John

[Brasil 10]

Hello John...

the next days I will install my new 670 cfm Holley... I will keep you informed how the carb works...

Greetings from Duesseldorf / Germany

Juergen

[Rcodenewf 44]

I'll be watching for your post. Good luck...John

[Brasil 10]

Hi John ....

as soon as the snow is gone...I ll be on the road...(testride )..

 

Greetings From Germany

Juergen

[70Mach03 12]

I have the 670 CFM Avenger on my 351C-4V and think it's a good choice. I felt it was slightly on the lean side out of the box. I bought a hand full of jets and kept upping them till I was satisfied. Of course this was all based on the "old seat of pants butt-o-meter" dyno.

[Brasil 10]

Hello 70mach03....

 

did you change the primary and the secondary jets ? If yes...how much "steps " did you go up ?... Did you leave the Power Valve, and the other stuff as they came from the factory ?...

Greetings from Germany Juergen

[70Mach03 12]

Hello 70mach03....

 

did you change the primary and the secondary jets ? If yes...how much "steps " did you go up ?... Did you leave the Power Valve, and the other stuff as they came from the factory ?...

Greetings from Germany Juergen

 

 

Only changed the jets. I believe it came with something like .054's in the primaries and I ended up with something like .066 or .068. I upped the secondaries to like .070 or .072 or something close as it was about 5 years ago and I haven't touched them since. Your results will probably vary according to your mods but they do come much leaner now days. I had a 1970 428 SCJ many years ago and it came with .079 and .099 jets from the factory.

[Brasil 10]

Thank you !

 

I will buy a set of jets on Monday... so I have a lot of choices.. I will also start with the 66 / 70 combo I think..

 

Greetings Juergen

[70Mach03 12]

Thank you !

 

I will buy a set of jets on Monday... so I have a lot of choices.. I will also start with the 66 / 70 combo I think..

 

Greetings Juergen

 

 

Try it first. Your needs may be different. There are many variables on jets like weather and elevation. At least the Holley's are easy to swap out jets. Good luck and have patience. :cowboy: