Posted By: GTX MATT
750 Edelbrock Problems - 05/05/09 06:07 PM
A buddy of mine bought a '68 Road Runner restored about a year ago. Its all factory and the 383 is supposed to be rebuilt to factory specs, the one incorrect thing on it is the original Carter AVS has been replaced with the 750 Edelbrock, I guess its the Thunder Series?
Anyway my buddy, Steve, is a pretty sharp tuner. Hes owned many cars over the years and they've all been pretty much stock but he spent hours tuning all of them and got them to really fly. This car is just a dog. It will get moving, and it could be worse, but it feels like its got a 383 2 barrel really. He can't figure out this engine out, mostly the Edelbrock carb and thinks its the problem. I mentioned to him that theres alot of complaints about them and told him Id see if I could find anything out.
Any tips for getting these things to work? Are they basically just junk, or can the problems be fixed with some work? He doesn't have money for a new carb, so hes trying to fix what he has.
Posted By: Mr.Yuck
Re: 750 Edelbrock Problems - 05/05/09 06:37 PM
choke horn sucking shut? throttle adjusted so it's wide open? I'm not a fan of those carbs but it should work fine on a stock 383.
Posted By: lewtot184
Re: 750 Edelbrock Problems - 05/05/09 06:53 PM
some of the oem type replacement pistons are around 8:1 compression with 88cc heads and .039 head gaskets. going from 10:1 to 8:1 will kill a bunch of torque off. from looking at the 750 edelbrock specs they seem to be calibrated fairly rich. i'd also look at the advance curve also, especially if the compression is down.
Posted By: JohnRR
Re: 750 Edelbrock Problems - 05/05/09 07:48 PM
First the 750 Ebrock is a performer series carb , the thunder series is only 650 and 800 , the 750 has issues tell your buddy to get a Holley.
Quote:
some of the oem type replacement pistons are around 8:1 compression with 88cc heads and .039 head gaskets. going from 10:1 to 8:1 will kill a bunch of torque off. from looking at the 750 edelbrock specs they seem to be calibrated fairly rich. i'd also look at the advance curve also, especially if the compression is down.
As far as the 383 goes there was NEVER a real 10.0 engine out of the factroy in 68/69, the compression is actually more like 9.3 at best and going to 8.0 would make it worse .
Posted By: Anonymous
Re: 750 Edelbrock Problems - 05/05/09 07:59 PM
TOO MUCH fuel pressure and you have trouble with Edelbrock carbs--They say nothing over 5 1/2 lbs any everybody thinks of the old Holley 7 lb rule--They can't handle the extra pressure--causes all kinds of trouble--best place to start before you dig into the carb
Posted By: deansrr
Re: 750 Edelbrock Problems - 05/05/09 10:49 PM
call their tech line - 800-416-8628 they are very helpful
Posted By: Anonymous
Re: 750 Edelbrock Problems - 05/06/09 12:22 AM
The 750 Eddy blows, pick another carb.
Posted By: Simonic
Re: 750 Edelbrock Problems - 05/06/09 04:49 PM
The 750 is not an easy carb to tune for a big block,however the thunder avs carbs are much better,as for the fuel pressure i totally agree 4-5 psi is plenty,any more and you can see the fuel being forced into the carb at tickover......
Posted By: SomeCarGuy
Re: 750 Edelbrock Problems - 05/06/09 07:30 PM
The 750 Eddy does have issues but I have my 383 running good with one. I still may switch to a factory AVS, but right now the Eddy is working great.
I do have the 1411 version with electric choke and I think it is a bit leaner and I have a HSD intake and headers so maybe that is making the calibration work out.
I run an Eddy fuel pump that is 6 PSI internal regulated. I read enough posts on problems with pumps so I saved up and paid out the [Edited by Moparts - Keep it clean] for it.
The other Eddy carbs are suppose to be good but the 750 has always given people fits.
Posted By: moper
Re: 750 Edelbrock Problems - 05/06/09 07:37 PM
Matt,
If you want to post a bit more detail about the engine (cam, intake, etc) I can help you with it. Like any carb, they all need tuning to be right. If someone bolts on a carb of any manufacturer and it's perfect out of the box, the owner doesn't know what really good is. If he needs it, worse comes to worse have him swing up to the farm. I'm finally HOME.
