To Edelbrock or not to Edelbrock?

[Boomyal]

Here is my dilemma; whether to have Holley rebuild my 450 cfm 4160 4 bbl for about 335$ + shipping or to just buy a 600 cfm Edelbrock 1409 4 bbl for 299$ + shipping?

On one hand it seems like a no brainer but here are my concerns.

a) Edelbrock makes a 500 cfm automotive 4bbl that they claim is suitable for sbc's, sbf's and possibly some of the bigger V-6's.

b) by default that would make a 600 cfm too big for the same range of engines.

c) if you employ any of the 'carb sizing' formulas, small block motors always come up with a sizing requirement way under 600 cfm.

d) another issue is progressive linked secondary actuation vs vacumm initiated actuation. The Holley is vacumm and the Edelbrock is mechanical. It has been my understanding that vacuum actuated secondaries were more economical the mechanicals

What are your thoughts on the subject?

 

[mkast]

Re: To Edelbrock or not to Edelbrock?

This is a no brainer.
Stay away from an auto carb with mechanical secondaries.

 

[Boomyal]

Re: To Edelbrock or not to Edelbrock?

This is a no brainer.
Stay away from an auto carb with mechanical secondaries.

I was not contemplating an auto carb, mkast. I only brought it up to show that, all though, Edelbrock makes both a 500 cfm and a 600 cfm in the auto carb, they only make the 600 cfm in the Marine carb.

Whereas, for the auto, they show the 500 for small blocks, they expect the 600 cfm to span all the engines.

In either case, marine or auto, all the Edelbrocks have the mechanical secondaries.

 

[John_S]

Re: To Edelbrock or not to Edelbrock?

The Edelbrock 1409 & 1410, and the Merc Webers have linked secondary butterflies, but the secodaries have an air door above them. The air door is counter-weighted. Engine vacuum opens the air door to allow flow through the secondaries. ie the they are vacuum secondary carbs, same as a q-jet (spring air door). As far as I know, all general marine production motors w/4brls had vacuum secondaires.

Merc had 4.3, 5.0, and 5.7s w/600/625 Webers. 5.7 and BB had Weber 750's. Back when the Q-jet were available, the 750 cfm could be found on a 4.3 through BB. A vacuum secondary can be tuned to much smaller engines.

From a pricing standpoint, once you add a tuning kit to the edelbrock, it will be more.

 

[Scaaty]

Re: To Edelbrock or not to Edelbrock?

I dunno on the Holley, but I tossed my (on a VP 350) Q-Junk in the water, put the EB 600cfm from Summit (think its free ship) on, and aint looked back since. Sell the Holley on Ebay. 600cfm probably just right for a boat rpm range, as come'on, Edelbrock's been doing this speed stuff for how long now? They know more than we do. Do it.

 

[Boomyal]

Re: To Edelbrock or not to Edelbrock?

The Edelbrock 1409 & 1410, and the Merc Webers have linked secondary butterflies, but the secodaries have an air door above them. The air door is counter-weighted. Engine vacuum opens the air door to allow flow through the secondaries. ie the they are vacuum secondary carbs, same as a q-jet (spring air door). As far as I know, all general marine production motors w/4brls had vacuum secondaires.

Merc had 4.3, 5.0, and 5.7s w/600/625 Webers. 5.7 and BB had Weber 750's. Back when the Q-jet were available, the 750 cfm could be found on a 4.3 through BB. A vacuum secondary can be tuned to much smaller engines.

From a pricing standpoint, once you add a tuning kit to the edelbrock, it will be more.

So John, what you are saying is that in the absense of engine vacuum, you can open the throttle, engaging the secondary linkage but the butterflies actually do not open?

Secondly, re the 'tuning kit'. How would you know which one to get or is it a universal kit.

On one hand I'd like to stick with the Holley because that is what I have on my other boat. On the other, I don't make a good carb mechanic so I don't know what difference it would make.

Yeah, I could throw the Holley on Ebay and recoup some of the cost of going to the Edelbrock.

So far, it seems one is for Holley and one is for Edelbrock? What a way to make a decision, huh?8)

 

[newport dave]

Re: To Edelbrock or not to Edelbrock?

I have had good results with several installs of the Edelbrock 1409 on small block applications. The 1410 (750 cfm/big block) I don't recommend. I would stick with the holley for those applications.

Dave

 

[John_S]

Re: To Edelbrock or not to Edelbrock?

So John, what you are saying is that in the absense of engine vacuum, you can open the throttle, engaging the secondary linkage but the butterflies actually do not open?

The secodary butterflies will open. They are mechanically linked to the primaries. The secodaries start to open when the primaries are around 1/2- 3/4 open. Just because the butterflies are open, doesn't mean there is any significant flow through them. The air door controls that, and a certain amount of engine vacuum is needed to open them. If you look at a picture of a 1409 looking down from the top of the secondaries, the plate you see is the air door. It looks similiar to the choke plate on the primaries.


Secondly, re the 'tuning kit'. How would you know which one to get or is it a universal kit.

I am not sure what engine you have, but edelbrock sells a specific kit for the pre-vortec 4.3L along with a general tuning kit. If you have a SBC, the tuning out of the box might be close enough.


On one hand I'd like to stick with the Holley because that is what I have on my other boat. On the other, I don't make a good carb mechanic so I don't know what difference it would make.
Yeah, I could throw the Holley on Ebay and recoup some of the cost of going to the Edelbrock.
So far, it seems one is for Holley and one is for Edelbrock? What a way to make a decision, huh?

Actually, I didn't vote. Just tried to give you the info to do your own voting.

Unless your current engine is cfm restricted, you will not get any performance increase. All carbs need TLC. Edelbrock/Webers are relativey easy to tune/adj. Holley is favored by the race crowds and have allot of adj parts available. Q-jets get most of the bad press, but probably because they are more complicated.

 

[Boomyal]

Re: To Edelbrock or not to Edelbrock?

Unless your current engine is cfm restricted, you will not get any performance increase. .

I do think that my 302 is cfm restricted. It has a weenie little goofy Merc? 2 bbl on it.(250-300? cfm) How much it is restricted, I can only go by the sizing charts. That is why I thought that 600 cfm might be a bit excessive. However, even though Holley makes the 450 cfm Marine, both Holley and Edelbrock claim that their 600's are suitable for Small Block marine use.

One other thing that I don't like about the Edelbrock is the goofy position of the fuel inlet.

 

[Fishermark]

Re: To Edelbrock or not to Edelbrock?

I don't make a good carb mechanic

That puts us both "in the same boat" so-to-speak.

Having said that, most Edelbrocks seem to run perfect right out of the box with no "tweeking" required. My "vote" would be the Edelbrock.

 

[Tail_Gunner]

Re: To Edelbrock or not to Edelbrock?

If it was a car Boom the vacum would be more user freindly. It's pretty simple the mechanical is setup for more of the drag type aka you can set them up to open the second you hit it.

Dunno my self, the mechanical migh be pretty cool, you could set it up to open just above you cruising speed, that migh provide better econ, the vacum you do not have that flexability. The 600 is the limit though anything more would just choke it out. New is usally far better than rebuilt id get the new one......Your gonna need it...8)

 

[Boomyal]

Re: To Edelbrock or not to Edelbrock?

TG. I have a little clarification on these Edelbrock 'mechanical' secondaries now. The secondary butterflies are hard linked to the primary throttle shaft. As you open the throttle, the secondary butterflies progressively (I think) begin to open. That part might be adjustable or it might not be.

The real key is that there are 'air doors' above the secondary butterflies. With everything at rest, when you look down the secondary throats, you cannot see the butterflies. What you see are the 'air doors'.

Also, on the bench, you could open the throttle shaft all the way, and hence the secondary butterflies, but you cannot see them when you peer down the secondary throttle bores. All you will see are the 'air doors'.

The air doors are counter weighted. It takes air flow (draw) to begin to open them. I assume if the secondary butterflies open progressively, the two work in concert. But even if the Secondaries are not progressive and open all at once, you need a certain air flow to open the air doors and they will do so progressively as the air flow increases.

So to me, they sound like it functions similar to vacuum operated secondaries without the diaphrams and linkage.

They sound like they would be more progressive and therefore more economical than a pure mechanical linked setup.

Whew?

 

[Bondo]

Re: To Edelbrock or not to Edelbrock?

I vote for the Eldebrock/ Carter Clone too.....

Go to the Eldebrock site,+ look around,...
Somewhere there, there's a link to a Service Manual for these Carbs,....
Reading it makes these carbs Real Simple.....

The Kit I bought years ago is the Federal Mogel Carter Strip Kit, pt# 10-201..... It was about $30. back then...
Edlebrock has the Same kit, probably with a different # though.... Last I looked it was up to near $50.....
With that Kit,... You can make 1 of these carbs feed a limp 4.3l, or a Fire Breathing 383........

I ain't gonna point out All the reasons I like these Carter Clones,.....
'cept,..... The 1 piece Body(can't leak, no gaskets),+ Ease of Tuning is Enough for Me..........

 

[180shabah]

Re: To Edelbrock or not to Edelbrock?

Don't forget there are no blown powervalves on the edelbrocks

 

[jimmbo]

Re: To Edelbrock or not to Edelbrock?

a 350 @ 5000rpm will use:

350cu.in./2 times 5000 rpm divided by 1728cuin/cuft equals 506 cfm @100% VE At 80% VE 405 cfm

So... the 450 cfm carb is plenty big for a 350 in engine running 5000 rpm.

Holley also makes some large 2bbl carbs for marine use. the 500 cfm when flowrated like the 4bbls flows about 360 cfm which makes it perfect for engines in the 302 - 305 range.
A carb can flow more than what it is rated at, but the pressure drop increases.

Holley mechanical secondary(double pumper) carbs are not the way to go on most boats, a drag boat maybe, but not a recreation boat. By allowing way too much carb area at low speed it will just cause the main metering circut to stop flowing and require huge amounts of accellerator pump to carry the engine untill the airflow is great enough for the mains to flow again.

 

[Tail_Gunner]

Re: To Edelbrock or not to Edelbrock?

:}

 

[Boomyal]

Re: To Edelbrock or not to Edelbrock?

Well look at this way a 350 @ 5000rpm will use:

350cu.in./2 times 5000 rpm divided by 1728cuin/cuft equals 506 cfm @100% VE At 80% VE 405 cfm

So... the 450 cfm carb is plenty big for a 350 in engine running 5000 rpm.

There inlies a good part of my dilemma jimmbo. Even when I run my relatively HiPo 5.0 ltr on the program, it comes out less than 600 cfm. However, that engine seems to be served well by the Holley 600 cfm unit.

My current case is with a dead stock Merc 188 Ford 302. Methinks that this engine would not have the same appetite as the HiPo 5 ltr in my other boat.

I do know however, that the current 2 bbl does not do it justice.

 

[jimmbo]

Re: To Edelbrock or not to Edelbrock?

Hook a vaccumn gauge to the intake and run the boat. If you are pulling more than 3 inches of vaccumn at WOT then you know the carb is too small. If it was a 4bbl then 1 1/2 inches would be the spec.

 

[jimmbo]

Re: To Edelbrock or not to Edelbrock?

I run a holley 2bbl 500 cfm on my 2002 350 vp. It was pulling 5 1/2 inches of vaccumn at WOT. I have put a Holley 650 spreadbore on and did gain 5 mph. I had a fuel leak so I put the 2bbl back on.

 

[Tail_Gunner]

Re: To Edelbrock or not to Edelbrock?


THe kit you need to mod the 600 is a 1485 kit,