600 Eddy tuning

-
harvenator

harvenator

A fish called Wanda
Joined
Sep 22, 2008
Messages
333
Reaction score
50
Location
El Paso, TX
I have a new 600 cfm 1406 Edelbrock on my newly rebuilt 273. It has a D4B hi-rise, stock .030 over flat pistons, an electronic ignition and mild cam ( duration 240/240, .050 duration 212/212, lift .290, valve lift .435/.435, centerline .106/.114, lobe separation 110). My idle vacuum is 18" at 800 rpm. Fuel pressure 6 psi at idle, goes to 10 when goosed.
The car starts and idles fine. It seems to bog about 2500 rpm until around 3000 rpm and evens out.
I started out with a borrowed 635 Carter AFB which I rebuilt with the same issue. Figured that may have been too much carb and it might have been worn or had something else wrong with it. So I swallowed and bought the 600 brand new. Still had the bog, just not as bad.
I've tried replacing springs both ways (up & down) to no avail.
Thought someone out there might have already set one of these up for a 273 before and might be able to give me some insight as to what else I can try. Jets?? Metering rods?? I don't want to just start throwing money and parts at it.
Thanks,
Harv
 
Try adjusting the pumpshot for less?
 
I'll work on that Tues and post my results. I was thinking of trying the weakest springs and last hole down on accel. pump. Work springs up from there. If that doesn't do it, I need to look at the metering rods. That's why I'm looking for someone else that's experienced the same issue.
Harv
 
The springs are for part thottle accereration, when the pedal goes half way to the floor kind of thing.
Metering rods are for the mixture. If the car is running rich, change them to thicker ones.
A bog is a off the line issue concerning weak acceleration. To much pumpshot is a reason. If goin to the hole fatherest away from the carb doesn't help much or at all, a small pumpsot cluster should be used.
If you move the pumpshot arm closer to the carb, what happens or is it in the closest hole to the carb allready?
 
Started with the pump in the middle, moved it up, tried all the springs in the kit. Now I'm looking to move the pump down to the lowest hole and go through the springs again.
I don't see any black smoke on acceleration so I don't think I'm too rich. That's what's got me confused and I don't want to have to go through a few hundred $'s in jets and metering rods to get this right. That's why I'm hoping someone out there who has a 273 will chime in with what they did and the sucess they had.
The only thing I left out is that I'm running a dual exhaust, stock manifolds and a 4 speed.
 
harvenator said:
I have a new 600 cfm 1406 Edelbrock on my newly rebuilt 273. It has a D4B hi-rise, stock .030 over flat pistons, an electronic ignition and mild cam ( duration 240/240, .050 duration 212/212, lift .290, valve lift .435/.435, centerline .106/.114, lobe separation 110). My idle vacuum is 18" at 800 rpm. Fuel pressure 6 psi at idle, goes to 10 when goosed.
The car starts and idles fine. It seems to bog about 2500 rpm until around 3000 rpm and evens out.
I started out with a borrowed 635 Carter AFB which I rebuilt with the same issue. Figured that may have been too much carb and it might have been worn or had something else wrong with it. So I swallowed and bought the 600 brand new. Still had the bog, just not as bad.
I've tried replacing springs both ways (up & down) to no avail.
Thought someone out there might have already set one of these up for a 273 before and might be able to give me some insight as to what else I can try. Jets?? Metering rods?? I don't want to just start throwing money and parts at it.
Thanks,
Harv
Click to expand...

That fuel pressure jumping up to 10 is most likely your problem, you want the pressure to stay as steady as possible, even under hard throttle, carter carbs "do not" like alot of pressure, 5.5 is about all you want on those. Might want to install a reg.
 
Had a similar problem on the 273 in my valiant when i ran a 1406. Try changing the squirter size. the kit is only $25 & gives you several options. Using the smaller .024 size which provides a longer duration squirt worked for me. Here is kit info.
http://www.summitracing.com/parts/EDL-1475/

Oldschoolcuda
 
Don't have much experience tuning AFB's but sounds like a nice combo for a 273. toolmanmike
 
X2 toolman. Very nice specs. Have similar build to yours harvenator except mine has ported heads, port matched stock exhaust manifolds & port matched factory 65 4bbl intake manifold. Your setup should be fun with a 4 speed. Hope you can get your bog corrected.

Oldschoolcuda
 
Thanks for the comments guys. I hope I can get this sorted out also. I've put a lot of work into this little car and have more to do but want to get the mechanicals finished before moving on to other oarts of the project.
I'm going to try "oldschoolcuda" suggestion about the smaller accel. pump and go from there.
Anybody else with a 273 want to chime in, please feel free.
I had a 273 4spd in a '64 Barracuda from 70-73. It had a 780 dual feed Holley, fenderwell headers, Mallory ignition, 3.90 Ford rear end, weld on bars and a D4B hi rise. Ran like a raped ape. Traded in for a 73 ElCamino in Biloxi, MS. and went back the next day to buy it back -- it was gone.
This present car started as a /6 with factory 4-speed. Guess I'm trying to get back to my youth.
 
Guess I'm trying to get back to my youth.[/QUOTE]
Me too! Nothing wrong with that.
 
Carb spacer may help some. It did for me. That and I would try changing out the pump shot. What is your initial timing set at?
 
I already have a 3/8" insulator which seems to really help with hot start. Timing is 10 BTC set with a vacuum gauge. Seems to like it there for starting.
 
Well, I changed the squirter to the 024,and the metering rods to 073x42 with plain springs. It seems to help a little but I'm still getting the bog. Any one else have a suggestion?
 
Harv, the jet and rod kit is inexpensive and the jet pack clusters are cheap as well. Tuning a cxarb is a pain, even if you have done it a few times. But once your there, you'll be fine.

Make one change at a time.

You changed the squirter, did you move the rod in the lever around?

Engine timing can also have an effect.
 
Yes to both Rumblefish. I ordered a whole kit today and am going to really fatten the rods up and see what happens.
 
I too like Joe said would be looking at the fuel pressure, 10 is too high. That amount of pressure could easily force its way passed the needle and seat and dump too much fuel causing it to run way rich and bog down.
 
Got my kit today and changed to the 70x37 rod with not a lot of change. Then U tried jockeying the timing. Retarding the timing to about 5 after seemed to help some but the car is lazy. I started twisting the dist. to advance and Im probably 20 BTC and it runs better but doesn't sound right. Think I'm going to fatten up the jets and play with the timing a little more.
 
It seems we all run, or have run Edelbrock Carbs.

I run a worked 1406 on a Bigblock 400....no problem.

From the sounds of it......I would Go Back to Initial Box Stock.....then you need to move the Accelerator Pump Rod DOWN to the bottom hole...Disconnect the Vacuum Advance hose, and plug the port....crank the engine up...then set the idle at 900rpm..let it warm up until it is at normal operating temp (whatever your stat is)......Make sure your electric choke setting has the choke blade FULL OPEN at this time..Start with the Driver Bank and run the idle mixture screw all the way IN to CLOSED...it should stumble and possibly even Die...thats ok....Recrank it...back THAT Idle Mixture Screw out 1 Full turn from CLOSED......then Repeat it for the Passenger Bank.

I believe that any fuel pressure OVER 7 psi WILL cause fuel to push past the needle/float assembly, momentarily filling the float bowls excessively, overruning the primary circuit during transition to secondary, and the addition of your pump shot was not in the bottom hole from the getgo.

If you have dual exhaust, What is your exhuast pipe diameter?

I run a NOT Touched, box stock 1406 on a Roller Cam 360, and it revs like a Monster.....my BB 400 runs a bit lean up top, but it runs great too.

Good Luck


:wav:
 
Thanks Prine. A lot of people have commented on the fuel pressure but it bogs with the fuel line disconnected so I've discounted that theory. I'm running a 2" exhaust except for about 3 inches of exhaust pipe on both sides which is stock 11/2". Seems the muffler shop took the easy way out when the fabricated the exhaust. I'll be going back to them to rectify that but don't see that as being an issue as the stock single exhaust was 1 1/2" all the way.
I've done the initial pretty much the way you described it several times with the same result. That's why I'm trying different combinations and will now be looking at jets and timing. Seems as if you can put 3 different 1406's on the same motor and have different results. For as much money as I've spent on the carb, squirters, rods and the tuning kit, I could have had the old Carter dyno tuned.
 
Hi from Sweden

I have made the journey as you, rebuilding a 65’ 273 with Edelbrock 1406, D4B and electronic ignition. Also a new cam, but sharper than yours (don’t remember the spec here at work).
Just started it up, and so far so good, no problems, that surprise me.
If you are interested I can give you the cam spec tomorrow
 
Harv. Getting away from the carb here but what type of distributor do you have. Is the vacumn advance hooked up and have you checked initial and mechanical advance then total to include vacumn advance with a timing light and what rpm totals are occuring. Starting to sound like you may have a timing problem IMHO and you absolutely have to have your timing where you need it before tuning your carb. If it is a stock distributor they are famous for breaking springs & screwing with your mechanical advance. I'll shoot you some info. thru PM.

Oldschoolcuda
 
Good to hear someone else is building a 273. I'm interested to know how yours runs when you drive it. Mine idles beautifully. Just can't seem to get it to transition out of cruise mode. Changed my primaries to 101 with no noticeable difference. Friday I'm going to change the secondaries to 98's.
 
You must log in or register to reply here.
-

Back
Top