GratefulTread
My 82 j10, running a 360, Edelbrock Performer manifold and a Holley 4160... started idleing rough, and mileage went to hell.
Took it to a reputable local shop, and they did a service on the carb, tech said the "power valve" was blown out and dumping gas into the carb. Also said it was a bitch to get it running smooth...but then it ran GREAT! Gas mileage beyond anything I'd imagined, good power (Great power!), girls smiling at me....you know, pro service. OK, money well spent.
Four or five weeks later it started again, now it won't idle, diesels, run fine with throttle, but black smoke if you gas it in neutral (runs a bit smoother out of gear, TF727).
Bad carb? I can get an Edelbrock Performer 1411, 750cfm, which looks to be overkill (oversized?) for this manifold, but it is new and a good price (cheaper than a 650, which is what E says is right for the manifold).
Will it work? Is there a better choice? Should I just feed this beast dollar bills...sorry, I digress.
The giant thing is wearing me down, can't fix it fast enough to get it just running.
Any ideas? Any buyers? Just kidding... :razz:
jeepsr4ever
Dieseling and black smoke...hmm. Sounds like timing..could be the power valve blew out again.
AMX69PHATTY
yeah, power valve again, did it ever backfire since it ran good ? a backfire can damage the power valve, unless it's a newer holley which are supposed to have power valve blowout protection. One thing good about Edelbrocks, they do NOT have a power valve that can get blown out. A 750 Eddy carb would be ok on a 360. They're basically vacuum secondary carbs and "self compensate" for engine size. The newer "Thunder Series" ( I think ) have adjustable secondary opening.
Goose
I agree sounds like the power valve again..
I would also agree that the Edel brock carbs are a great choice (I would use the 1406 600 or 650 cfm) but either would work well on the 360..
This power valve issue you are experiencing is one of the major flaws in the holley carb..and is probably the reason that more people get aggravated with them.. I thought they redesigned it so it couldnt blow the P/V any more..?
GratefulTread
Thanks for the input...
There was a bit of backfire, some popping out the exhaust on decel, but I don't remember any dramatic event through the carb. It seems likely I did have a timing issue.
I don't have a Holley rebuild manual, so I was a bit freaked out by the exploded view (last carb I rebuilt was German aircooled, like fixing a toilet plunger) but I found a good article on on of the hot rod mag websites that was about changing out the valve, so I gave it a shot. It looked to easy, and it was, but no change. The article mentions that they tested valves that were bad out of the box, seems a little unlikely; but if those things are that sensitive I think I am going to give the Edelbrock a try.
mike4089
if you have a 750 on there it might be to big...i had a 750 on my mildly built 360 and it was to big stepped down to a 650 and it was like night and day...best money ive spent on that motor so far was a new carb...
GratefulTread
Crud... :sa: just called and arranged the buy... #-o
That's sorta what I wanted to know...define "too big".
The price new-in-box is $200, way cheaper than I'd seen the 600/650's. Looked at the Edelbrock site, they say OK for 360, but not so much w/Performer intake. I figured it would just be overkill, not a downgrade... 🙁:
I'd really just like it to start, roll & run. I just can't seem to get there from here.
GratefulTread
I finally got through to Edelbrock, and they say the Performer 750 #1411 will not work with the Performer manifold; sluggish off the line and it will bog down when you hit the throttle, impossible to fix. They say that it will work with the Air Gap manifold, they recommend the Performer 600 #1405/6 for daily driver or the Thunder AVS 650 #1805/6 for best performance.
I was looking for the quick easy way, but that doesn't really seem like my style... :roll:
What model # is the Remanufactured Edelbrock here in the store? Any downside in putting the offroad kit in an occasional offroad only truck?
dbesade
GratefulTread wroteI finally got through to Edelbrock, and they say the Performer 750 #1411 will not work with the Performer manifold; sluggish off the line and it will bog down when you hit the throttle, impossible to fix. They say that it will work with the Air Gap manifold, they recommend the Performer 600 #1405/6 for daily driver or the Thunder AVS 650 #1805/6 for best performance.
I was looking for the quick easy way, but that doesn't really seem like my style... :roll:
What model # is the Remanufactured Edelbrock here in the store? Any downside in putting the offroad kit in an occasional offroad only truck?
I run a 1406 600CFM Performer on a Performer Intake on my 304.. runs a bit rich but runs well should be fine on a 360.
-Dave
1980_Cj7
Interesting. We're running an Edelbrock Performer 750 on a Performer intake on the 401. Now Edelbrock is saying it isn't good on that manifold??? Are they saying it is too big for the 360, or just not a good match with that intake?
jeepsr4ever
Thats just one tech opinion and was it based on a camshaft? I wouldnt hesitate to run a 600cfm on a 360 or a 750cfm on a 360 or 401 depending on the condition of the motor.
GratefulTread
He said too big for the manifold. He said it would lag off the line and under full throttle acceleration would sag to the point of stalling, and it couldn't be adjusted away. Something about the secondaries being counterbalanced...My carb theory understanding is not deep, but he was pretty convincing.
scrible88
I have a 750 edelbrock on an edelbrock performer intake and my motor is in for a rebuild right now, but before when it was completely stock and ran well the 750 with performer manifold was a great combo for the motor... tons of power... I don't know what their deal is saying it is too big for the 360 because it isn't at all based on my experience...
here's a video of my motor with the edelbrock 750 and performer intake before the oil pump decided to go south on me:
http://smg.photobucket.com/albums/v156/sandstormII/?action=view&current=burnout.flv
Goose
At the risk of getting in trouble with some of the guys around here.. There is a formula out there that calculates CFM based on cubic inches..etc but based on practical theory.. a 530 cfm carb will feed 350 cubic inches at 6500 rpm. some guys run bigger carbs and get away with it.. the truth is simple.
If you choose the correct CFM you can jet up to match fuel flow..
jeepsr4ever
Goose wroteAt the risk of getting in trouble with some of the guys around here.. There is a formula out there that calculates CFM based on cubic inches
Plus 30% is what major carb mfgs suggest
1980_Cj7
Goose, so what is the formula, or do you know where I can find it?
AMX69PHATTY
The problem is that the carb makers do not tell at what pressure drop thier CFM ratings are taken at, they all use different rating methods.
1980_Cj7
So they don't have an ".050 kinda deal" like the cam guys do so you can comparison shop, huh.
82Waggy
(CID/3456)*RPM = CFM @ Volumetric Efficiency of 100%
CID RPM VE=100% VE=95% VE=90% VE=85% VE=80% CID RPM
360 4500 469 445 422 398 375 360 4500
360 5000 521 495 469 443 417 360 5000
360 5500 573 544 516 487 458 360 5500
360 6000 625 594 563 531 500 360 5800
360 6500 677 643 609 576 542 360 6000
360 7000 729 693 656 620 583 360 6500
When in doubt, go smaller.
a440plus6
GratefulTread wroteI finally got through to Edelbrock, and they say the Performer 750 #1411 will not work with the Performer manifold; sluggish off the line and it will bog down when you hit the throttle, impossible to fix. They say that it will work with the Air Gap manifold, they recommend the Performer 600 #1405/6 for daily driver or the Thunder AVS 650 #1805/6 for best performance.
I was looking for the quick easy way, but that doesn't really seem like my style... :roll:
What model # is the Remanufactured Edelbrock here in the store? Any downside in putting the offroad kit in an occasional offroad only truck?
It will work fine if you fiddle with jets, springs and rod.
I'm not sure but I think you might have to lighten up the velocity flapper a little or just put on from a 625cfm carb in if you ar not used to tuning them.
