I've never been able to get this original 4777 Holley DP 650 on the 396 to idle right or eliminate the off-idle dead spot. Now with the Comp XS282S cam, Proform mainbody, and E85, it's just downright intolerable. I've messed with air bleeds (it's 2-corner idle, the original secondary idle air bleeds with the Proform MB were for 4-corner - things improved mightily when that was discovered and rectified), throttle body adjustments, air bleed changes, cleaning up idle slots, ad-nauseum, I just can't get it right. It idles better off of the secondaries than the primaries, regardless of adjustment. The primary side-to-side adjustment is never equal turns out. It dies constantly on me when RPMs go down to idle. Rather than try to drill out idle restrictors or mess with it in any other way, I'm just going with the Proform 67165C billet metering blocks. 4-corner idle. Not sure if the idle restrictors are the replaceable type in that set, but it can't be worse than what I've been going through. Should be here by Thursday, enough time for me to get them installed and sorted out before the next race on Friday.

I would have hooked the cars exhaust pipe to a 4 gas analyzer and seen what was going on at idle. More timing at idle probably would have helped with the 2 corner idle system as well. Locally only my buddies shop still has the 1980s 4 gas analyzer in his shop, makes it very quick and easy to dial in a carb using that old school technology.

That would probably be true. If I was going to try to drill passages, I wouldn't start without it. And, perhaps I'll do that when I do get the new blocks.

The 750 VS I had before this idled without any issues whatsoever. The 650 DP from the very first time it was installed gave me fits. There is a slight possibility the throttle body is to blame, but just looking at it, I don't think so. If the metering blocks don't fix it, then that may be the next step.

Did you ever get ahold of Gene or Quick Fuel about the E85 metering blocks? passages are definately different. Here is the instruction per QF's E85 conversion kit..kind long so I'll nutshell it for the important stuff which may or may not be relevant to anything you have done to date or will do:

Metering blocks come with .043 idle feed restrictions

Four emulsion bleeds in the serpentine slot are pre calibrated, these pre-calibrated emulsion bleeds as as follows from top to bottom .028, blank, .028, blank. This emulsion pattern is a performacnce proven combination and works for most applications where carb size is correct for engine


The pwr valve channel restrictions are sized to .076". These holes are immediately behind the PV 1" hex head The purpose of these restrictions is to add supplemental fuel to the main well during WOT operation or when engine load drops the manifold vacuum below the calibrated value of power valve

CAUTION: Do not make drastic emulsion size changes as you can significantly alter the air/fuel ratio and could cause engine damage. It is highly recommended that when experimenting with emulsion calibration you consult one of the many books available on carburator modification and use one or more devices that monitors A/F ratio throughout the operating rpm range.

Special note: E*% fuel requires 25-30% more fuel than gasoline. This requires increasing the flow in all areas of the carburator. We recommend you use larger needle and seat (at least 130") and a needle material stainless steel versus viton. Your main jets should be 8-10 jet numbers higher than your original gasoline calibration. The final jet number could be larger if there are upstream restrictions such as booster thru hole is smaller than optimum. A 10 jet number increase is usally a safe starting point then jet for best performance from that basline.

END QUOTES


HERE are the parts from Quick Fuel and the P/N's for reference that I ordered for the conversion kit

Again, all Quick Fuel part numbers:

Qty: Part number
(1)- 34-106 Metering block conversion kit (2 metering blocks/whistle vents/gaskets...and gasket are a bit different than the standard 4150 HP gaskets)

(2)- 5-12 Pump disharge nozzle screw, hollow stainless steel

(2)- 35-13 GFLT 30cc Accelerator pump diaphram

(2)- 18-11 .150 alcohol S/S needle and seat

(2)- 21-35 Accelerator pump nozzle

I did order QF 2.5 high flow power valves as well, but I dont have the P/N on those.

Hope some of that helps, but I think the biggest thing is getting a sniffer of some sort to help figure this out since it all seems to be a crap shoot tuning on the track for a S/S car.

No, I never got a hold of them. But, that info should help with the new blocks.

The problem isn't E85, it's the Holley stuff. I couldn't get it right with gasoline, either.

Yeah, that's not a good boat to be in either, I've been on that end and tried to help a fw buddies with that problem too and it's like beating your head against a wall sometimes...i did a simple rebuild for the neighbor on a 650DP that's been on the shelf for years uncovered...and you can just about imagine how bad that thing was internally. I got it to run, but it was not 100% no matter what we tried, but like I told him for a carb in the shape his was, about the only fix was sending it out to a carb shop for a 110% disassembly/cleansing with higher power stuff than I had, or buy a new one...it was bad as I've ever seen one, and I did'nt make any promises.

good luck, hopefully the new metering blocks will be the cure. I'm still up in the air about orering a E85 specific carb for chits and giggles. Was talking to a buddy this afternoon that runs a low 10 sec BBC with a dom (been running it for a few yrs) and he sent his carb into pro systems. He said lasts weekend when he bolted it on they completely smoothed out the normal chugity chugity associated with bigger cams and bigger motors and compared it to his suburban he drives as far as streetablity goes, so I'm hoping if I send my carb in or have one built it will tame the nasty motor woes I'm used to at low rpm street driving, my 388 was very docile, but still unsmooth below 2500 rpm, this new 427 sbc is very choppy, but that may be the E85 at work too since it's more volital than gasoline and I'm just not used to it.

I talked to a fellow racer buddy this past Friday about his 468/Dominator/10.1-sec-at-5800' Monte. He sent his carb to a shop in Indiana and says it was a bolt-on and he's using less fuel per run and it's just as quick and more consistent. So, I know that would be helpful, but his was $400 with no parts like metering blocks. Since 4-corner idle was one of my goals, I'm sure I'd have to pay at least that much or more. So, I'll just suffer along with general information and self-tuning for the time being.

IHI, I may be slow, but I don't recall you posting the part numbers before. Not all available from Summit, haven't checked other sources.

I haven't noticed any issue to date with Viton needle/seat. Wonder how important that is. If the local speed shop has SS, I'll get them, otherwise stick with Viton. You are making a lot more power than I am, so I'm not sure how important .130" is. Doesn't seem to be starving. Guess I'll look into it.

I did step down from a 6.5 (stock 650DP) PV to 3.5. That helped more than I expected. Also removed the secondary jet extensions - I'm not fast enough to need them, and they seemed to contribute to the braking idle starvation - although I'm not 100% convinced about that.

I'm going to look for some precision drill bits. I was clearing out old car magazines a couple of weeks ago and came across a Chevy High Performance issue from 2006 about fine tuning carbs, and they included info about drilling out idle feed restrictions and the like. A little lacking in detail like pictures and schematics - (they were working with a Speed Demon carb, IIRC). They did use exhaust gas analysis, though.

All Im running for needle and seat are the stock ones right now too, and likewise, no issues. Dyno guy said I would'nt want the SS N&S street driving since it just beats the seat to death opening and shutting all the time as opposed to a track only car, so I guess it's a toss up. Do you go with a SS and take the chance of it beating the the seat and flooding stuff out, do you try the titanium N&S and see if it's better/worse than SS, or do you just order the viton .130 N&S and realize at some point they need to be swapped out....all a guessing game IMO and there's too much info back and forth with guys saying this wont work, and this will work, and vice versa...I think it's still too new, and not enough folks running it/experimenting with it for a standard to appeal to the masses.

I cant remember if I posted it above, but we actually made more power with less timing with both race gas and E85...both made the most pwr at 32* I thought for sure based off what I've read guys liked to ramp up the timing with alcohol or E85, but after seeing it plain and day with mine, and what the dyno guy says he sees all the time, I guess lower was the way to go. But since your in such thin air to begin with, I imagine your timed higher at basseline than what we are in the plains area...but either way, just more food for thought.

I'm too nervious about drilling hard parts since you cant put material back. That's why I would love to get on a chasis dyno with a sniffer and try the conversion kit to see what it does since i have no desire to pull the engine in this thing...too much work with the tight tolerances LOL!! so until I get near a chaasis dyno I'm going to leave mine as is unless it gives me fits.

It's hard to imagine the needle "banging" into the seat due to street flow. The rubber-tipped needles first started appearing in the 70's (from my recollection), and conditions were probably a lot rougher when they came out. I don't imagine my drive-to-the-track street driving is that much more severe than the track itself.

The local shop usually carries steel needle/seats, but was out when I went at noon today. Said they'd have them by noon tomorrow.

Precision drills they only had in sets, from BG. Of course, the above dimensions cross over the two sets, about $100 for the two of them. I think I'll just take the metering blocks to the local carb shop if I need to go that far. . .

According to UPS, "Your package is on time with a scheduled delivery date of 06/01/2007."

I hope they're just being conservative, and it'll actually get here tomorrow.

The local speed shop got in some Holley .130" steel needle/seats for me today as well. Will install when the metering blocks arrive.

I think this was the right move (even if a little expensive).

Idle feed restrictions are .033" with .039" in the box (may be necessary with 850 CFM, they say). PV channel restrictions are .063" with .055" in the box (may be necessary for 750 CFM, they say).

Emulsion holes are pre-drilled, size not stated; to change you drill out and put in screw-in. I assume blanks would be available. Instructions say to start with .028" if you do change them.

So, change the idle feeds to .039", run the rest as-is for now, and we'll see how it goes.

One of the vent channels was broken in the box. Not sure how important that is, guess I'll mount it with the hole up and ask for a new one when I get new restrictors.

(Instructions say to contact Quick Fuel for service and calibration parts. Are Quick Fuel and Proform related???)

Stock/original metering block numbers for Holley 4777 (old ones, anyway, not models built in the last 10-15 years):

list 4777: 6501 primary, 6497 secondary
list 4777-1: 8392 primary, 6497 secondary
list 4777-2: 8539 primary, 6497 secondary

Check your old metering block numbers against the list number of your carb. Wouldn't be the first carb that had the wrong set of metering blocks screwed to the main body by a previous owner.

If she's a -3 or newer carb, just call Holley's tech line and they can X-reference the metering blocks for you.

Holleys? Don't know nothin' 'bout fixing no Holleys. I only do QJets. Far as you know.

It was a -7, actually. The Holley website has some weird #'s for the MB's. I'll post the #'s in a bit. I got it from the original buyer who went from 350 to 454. He removed the choke parts and jetted, PV, and the like, but didn't change metering blocks (I think).

I think it was just plain poor quality. What I had to do to the throttle body secondary idle slots is testimony to that.

Okay, the # stamped on the primary metering block is 11170 with a 5 below it. The secondary is 11166 with a 3 below it.

The changes:
Before:
Jets: 89/97
PV: 3.5
Idle air bleeds: 65/31
Needle/seat: Standard Viton
Holley metering blocks

Now:
Jets: 84/96 (smaller primary based on larger PV restrictors)
PV: 4.5 (found one, idle vacuum is 9"; Couldn't find it the other night)
Idle air bleeds: 71/69 (didn't have 4 of either)
Needle/seat: .130" steel
Proform metering blocks

Same:
Squirters: .037" (what I've always run with E85 based on original calculations)
Fuel bowls (Holley)
Throttle plate (Holley)

First blush, idle still isn't quite right. But, at least I can get it to idle and stay running. Off-idle is very crisp. I didn't take it out, (got a complaint from a neighbor @ 9:45 p.m. - they were apologetic for complaining, but gotta maintain good neighbor relations so shut it down).

Need to play with the primary accel pump adjust (looser now for some reason), and going to try smaller idle air bleeds in the primary - or maybe 67 in all 4 corners, and see what that does. Might also pull the throttle plate off and see if there's something I missed there.

Only thing that hasn't been changed are the float bowls and throttle plate. So: 650 CFM DP 4777, $200 (in 2003); Proform main body, $100 (in 2003); Proform metering blocks, $130. Plus misc., $50. Total $480 vs. $736.95 Quick Fuel E85 750 DP. Guess if I need to get the $150 throttle plate that still leaves me slightly ahead (depending upon how much the restrictors are going to run me).

67 air bleeds in the primary idle helped a bunch.

Main issue now is there isn't enough vacuum at idle to advance the ignition. The Pro Billet instructions say to used ported vacuum, but the Proform main body isn't drilled for ported vacuum. So, that's probably going to be an issue (unless I get bold and drill the passage myself).

The 37 squirters are probably too big as well. I'll save that for the next round.

what timing curve are you running? I would try advancing the initial to see if it cleans up the idle a bit, then dial back the vacuum advance to keep the engine from pinging. I run my timing locked out now and it runs 10x's better than when I had 14 initial.

I'm running the blue bushing, approximately 21 degrees mechanical. At 44 total mechanical, that's a little over 22 initial.

I was thinking I might just disconnect the vacuum advance out at the track and adjust the idle accordingly. But, more initial wouldn't be a good idea when the vacuum advance is still on.

I'm contacting Proform's tech department to see what they have to say.

sorry I am a little late on this, but you asked a couple days if Proform and Quick Fuel (QFT) are related. yes and no. Quick Fuel designed the Proform main bodies I believe they also designed the metering block and E85 conversion blocks. You can send yours to them to be rebuilt and test calibrated for under $200. Marty Brown is the one I talked to there (great guy) It is him and another guy there anyway they both worked at Holley for around 20 + years apiece so he would be of great help. I had a couple rebuilt a while back almost perfect out of the box. I am having mine rebuilt in a couple weeks by them and I am having it rebuilt with new bolts and having it changed from the green dichromate finish to the shiny finish and all new non stick gaskets also changing to downleg boosters (might even be the price to go to annular I don't remember because I asked them about both) and they quoted me $210 I think. they run it to check for leaks and functionability prior to shipping it out.

Just watch your back on having them convert carb to E85. I called the first week i was checking all the big carb make over guys and QF told me 2-3 weeks turn around and $400 to convert my 950HP to run E85. I decided to go with them and called back to get shipping info and anything else they needed from me as far as car and set-up, and when he told me the price I had to laugh and say no thanks. $600 plus shipping both ways, so basically I was in the range of just buying their already converted/calibrated 750 E85 carb....that is less cfm than I need for my engine and drag racing and more than I wanted to spend...$400, not a problem, $600....thanks but no thanks. Just my experience with them, not taking away any of their knowledge and ability to work over a carb, but I had 3 items on this engine where I was quoted one price one day and something out of the ball park when I got ready to purchase one week or less from inital contact, so I just automatically file them in the do not call file and move on.

I'm not at all inclined to send my carb off to anyone at this point, but just whatever bolt-on/recalibration that I can do myself.

There's a local carb outfit that is advertising E85 conversions, so if the carb needs "professional help", I'd be inclined to go to them. I know a few racers that are sponsored by them, and obviously have gone to them for carb work (although no E85 jobs to the best of my knowledge).

Did I mention that I ran my best-ever at-altitude MPH Friday night?