New Gen Holley. - Ford Forums - Mustang Forum, Ford Trucks, Ford Focus and Ford Cars

grey_esp · 02-13-2005, 18:51

When i bought my car it had a 650Sp VS new gen holley on it. But I have fitted a 600sq VS. the 600 was 2nd hand and Im having a dog of a time getting it to run properly, huge flat spot.
The 650 however ran really well and is almost brand new, the only reason I changed is becasue the gas didnt like the 650 much and it kept blowing power valves.

Has any body had much to do with these new gen things? any good? Im thinking about puting it back on when the 351 goes in as Im ditching the gas.

grey_esp · 02-16-2005, 16:51

Ok, I had a bit of a play with the old 600 last night, fitted a new cam to the throttle pump (bone or cream one). the Flat spot is heaps better, I can actually drive the thing now. But it is still there.

Any suggestions on how to get rid of it. Basically it idles really nice, but any rapid change in throttle possition causes it to cough, then it will catch up and off you go.
I have the adjuster screw on the throttle pump just loose so you can just move it without the pump moving. it seams to work better like this than it did when it was tight. I tried both settings on the new cam and this one works best (top hole). I screwed the idle mixture screws out an extra 1/4 turn didnt seem to make any difference.

The only other thing I noticed is when I took it for a drive it got pretty hot. Like too lean. From memory it has 60 and 64 jets in it.

XD408 · 02-16-2005, 18:33

hey grey esp I purchased a new generation holley from the Holley distributor in redcliffe a few years back now and they had alot of unhappy customers cause the new generation holleys were shit. I had a 750vac one on a mild 351, c4 and 9" XC GXL with the NG holley on it had this constant flat spot down low and just never ran right with it on I had it on chassis dyno where they tried to tune it and just couldnt get rid of the flat spot it put out 315rwhp with it on they put a 650DP on which got rid of the flat spot but it only put out 298rwhp. Everyone i spoke to and a few articles i read on them noone could get them to run properly all had flat spot problems.

grey_esp · 02-16-2005, 18:55

I didnt right that very clearly.
The 650 is the new gen and runs fine on petrol but played up when I had the gas fitted.
the 600 is the old skool holley and it is this carb that has the flat spot.

I have spoken to the Holley distributor in perth and he has informed me that they stopped making them about 5 years ago due to troubles with tuning. But he said some of them were fine and if you get a good one they are a good carb but the rest had problems with warping in the base plates and corrosion internally.

Im going to bolt the new gen on tonight and see how it goes.

Work Horse · 02-16-2005, 18:58

This site maybe of help with the older style Holley http://www.bob2000.com/carb.htm

Mike Gayner · 02-16-2005, 21:01

Accel pumps problems are pretty easy to diagnose - if it coughs, bogs or flat spots, it indicates a lean condition. If it accellerates smoothly but doesn't seem to be as quick as it should be, or blows black smoke, then it's rich. Yours sounds like a lean problem - try screwing the cam into the "2" position and if that doesn't help, try a cam with a sharper ramp up (sorry, I don't know about the colors).

grey_esp · 02-16-2005, 23:24

Yeah I have tried the other position already and this one is a lot less flat spotted, and has a far more radical cam than the one that was on there. Would jet sizes have anything to do with this?

pracy · 02-18-2005, 01:59

check your float levels
increase size of power value depending on ya vacume of course
i've just up'd size of sec jet to high 70's to fix a cough

my new gen sucks aswell!