Econodrag...I was wondering what pistons you are using? I am in the market for a new set of forged pistons to get me in around 9.5:1 compression. Just wondering which ones you are using and where you got them.

thanks
CHRIS

 

 

I don't use forged pistons. I use Hypereutectic pistons from Federal Mogal. I think they are sealed power H304p.....I think. Anyways I picked these pistons up through Car Quest Auto Parts. They were around $200.00 with the rings.

 

>Now guys. No need to be rude and so inconsiderate. My
>roomate/friend/mechanic is very knowledgeable in alot of
>areas. He is ASE certified and has worked at a Chevrolet
>dealership for quite a while doing heavy motor work and the
>like.
Well I believe we found problem 1. LOL JK

>He may have decribed the carb thing to me in one way
>and I took it another. He was talking about how the doors
>were mechanical on the bottem. But we didnt talk about the
>rest of it. He told me that the secondaries take in only
>what the motor needs. As in the air demand of the motor.

That is the exact defintition of a vac secondary carb.


Scotty

 

>Well I believe we found problem 1. LOL JK

Although he may work at a Chevy dealership he has worked on anything from a Acura to a Volvo and everything in between (domestic AND import).

>>He may have decribed the carb thing to me in one way
>>and I took it another. He was talking about how the doors
>>were mechanical on the bottem. But we didnt talk about the
>>rest of it. He told me that the secondaries take in only
>>what the motor needs. As in the air demand of the motor.
>
>That is the exact defintition of a vac secondary carb.

Just wondering who's defintion you are using? Yours? Edelbrocks? Holleys?

Too bad the Edelbrocks dont have that POS vacumm secondary diaphram to worry about huh? hmmmm Oh and those Power Valves were are SWEET design too! heh ;-)

By the way I took apart the Edel 1407 last night and I could find NO parts consistent with a vacumn type carb. It is all mechanical. The bottem plate moves with the linkage and the top flap moves with the air demand of the motor. There is nothing that controls it upon vacumn unless you are calling the air that the motor needs vacumn. Which could be what we are stumbling on here.

Looks like I am going to have to start a new club for you guys called HLA which stands for Holley Lovers Anonymous! heheh

lata guys
CHRIS

 

>By the way I took apart the Edel 1407 last night and I could
>find NO parts consistent with a vacumn type carb. It is all
>mechanical. The bottem plate moves with the linkage and the
>top flap moves with the air demand of the motor. There is
>nothing that controls it upon vacumn unless you are calling
>the air that the motor needs vacumn. Which could be what we
>are stumbling on here.

EXACTLY! The air velocity valve senses airflow (ie vacuum sucks the valve open).

BTW, Edelbrock calls it the mechanical secondary air velocity valve.

I'm not partial to either one, the Holley works great on my CJ and the Carter works great on my truck. Different strokes for different folks. Now lets talk about the Q-jet. ;-)

Barry

 

>BTW, Edelbrock calls it the mechanical secondary air
>velocity valve.

Actually it is called "mechanical secondary air sensing valve". I have also heard it called a "transition valve".

Thing remains as you just proved in your post that it is a mechanical secondary carb with an air flap to make going from the primarys to the secondaries more smooth than without. You can also take the "flap" out entirely and the secondaries will still come in. Weird how that works...hmmm

Q-jet is even worse than a Holley and that is bad enough.

As long as you get your fuel pressure right when using an Edelbrock carb everything will work perfectly. 5.5psi is the max that you can run unless you like to pop and crack going down the road. But maybe you do since y'all like Holley's so much ;-) hehehe

But like you said different strokes for different folks.

later
CHRIS

 

I've tried to keep my mouth shut but enough is enough. Nobody other than you is trying to turn this into a "Holley vs. Ebok" debate. We have just been trying to explain to you that your ebok is a vacuum secondary. Spare us your ignorant postulating and pick up some technical manuals so you can increase your knowledge on the subject of how carbs work. Even Dino chimed in to clarify this for you and he's one of the most knowledgable on here. I'm probably ruffling feathers, but I'm still just trying to help you. No, I won't argue this with you, because we are correct and you and your friend are simply wrong. It up to you whether or not you choose to learn from this or remain in the dark. Good luck.

 

>I've tried to keep my mouth shut but enough is enough.
>Nobody other than you is trying to turn this into a "Holley
>vs. Ebok" debate. We have just been trying to explain to
>you that your ebok is a vacuum secondary. Spare us your
>ignorant postulating and pick up some technical manuals so
>you can increase your knowledge on the subject of how carbs
>work. Even Dino chimed in to clarify this for you and he's
>one of the most knowledgable on here. I'm probably ruffling
>feathers, but I'm still just trying to help you. No, I
>won't argue this with you, because we are correct and you
>and your friend are simply wrong. It up to you whether or
>not you choose to learn from this or remain in the dark.
>Good luck.

All of this really doesnt matter. Besides you guys hijacking my thread and turning this into "You know everything and I dont know jack" thread is pitiful. I was just wondering what cams you guys were running. What worked for ya and what didnt.

One thing you guys arent understanding is in the end. I am going to use whatever carb that I feel like using. It is simple as that. This is just one of those things that happens with high-performance parts. Some people swear by one part(s) and some think they are total crap. I am sure you have ran into this alot. It is a normal human thing in this field.

Also...Get your head out of the books and do some real hands on learning. Learn alot more that way.

Lastly. I will ask you again to prove yourself on how this carb is a vacumn secondary carb. Just prove it. Cite your sources, etc etc. That is all I ask.

thanks
CHRIS

 

>Lastly. I will ask you again to prove yourself on how this
>carb is a vacumn secondary carb. Just prove it. Cite your
>sources, etc etc. That is all I ask.


Chris, I was hoping to get some good cam info out of this thread too.

As far as sources, in the book "Carter Carburetors" by Dave Emanuel, SA Design on page 43, look at the paragraphs titled Vacuum Secondary Actuation. It says "In order to correlate the degree of secondary throttle opening to actual engine requirements, carburetor manufacturers use one of several forms of venturi-vacuum activation. The method used commonly by Carter is a counterweighted or spring-loaded air valve....the concept is designed to precisely tailor carburetor air-flow capacity to engine requirements rather than providing too much too soon as can be the case with mechanical secondary opening.

The following paragraph titled Air Valve Secondaries says "In the air valve controlled secondary, as employed by Carter, manifold vacuum and air veolcity (rather than venturi vacuum) are the primary factors that control secondary activation.

I've tried removing the air valve on mine and all I get is a big bog off the line.

Anyway, there's one reference. Yes, it may have a mechanical link to the secondaries but it's not a mechanical secondary in the classic sense.

Maybe we can get this thread back on track.

Barry

 

If you would read our original responses to your post you will see that you were given the requested cam information. I won't dignify your other inane comments with a reply. Barry may have helped you a little in that department. I would suggest a search in this forum however, as the cam topic has been brought up many, many times and there are many threads on this topic you would find helpfull if you choose to. Good luck.

 

I'm glad this thing is starting to get back on track "kind of". If we are going to talk carburetors start a new thread that way others can learn. One thing that isn't going to go is carburetor bashing. Even the quadrajet has its strong point. This thread needs to be about "cam selection for a 390".

 

Nicely put Sean....... Also the cam that one person uses may not work in another case nless the 2 engines are identical, not close but identical.. If I would have listened to every one when it came to cam selection includine dyno and drag strip programs. I may not be able to turn the numbers that I turn with the "UGLY TRUCK". Some times you just have to experiment. I'll leave it at that.

 

Seems the thread has already gone to CRAP. I have found the cam that I am going to use I think hehe

Crane PowerMax cam:
461 peak ft/lbs averaging 450 ft/lbs from 1500-4200 rpm
383 peak hp

not too bad, by the way the numbers are from my tooling around with desktop dyno.

thanks guys. Maybe we can start this thing over sometime.

CHRIS