Engine too! More problems.

[oino]

I have the floats down low as they can go. I set them when I had it apart.

I'll get a regulator today and a pressure guage. See what happends after that.

Being that I need on today and money isn't on my side.
Can I get away with this. Spectre / Chrome fuel pressure regulator
and Spectre / 1 in. 0 to 15 PSI fuel pressure gauge

Oh and I'm using a cheap fuel pump too.
Mr. Gasket / 4 to 7 PSI 35 GPH electric fuel pump

If you guys think a better fuel pump and regulator would solve the problem.
maybe I should get this. Holley Performance / 110 GPH blue logo electric fuel pump

 

[putz]

That should work fine the most important thing is the gauge to tell the whole story.

 

[Screaming Metal]

Yea, Putz is right. everything should be fine, just get a cheap little inline regulator, put it in before the carb. Since your on a shoestring budget, get yourself a Tee, (About $1.50, 2 nipples, about the same, at a hardware store), plumb it in after the reg, and put in s small cheap guage. You can pick these up from a good industrial supply place for under $8. It ain't gonna be pretty, its gonna be small, no frills, go from 0 to about 20psi....thats all you need though. set the pressure at 2, should start and idle fine, right off the bat with the pump on.

I see that you have a 650 Holley. What model? Is it a single feed, Vaccuum secondary?. Make extremely sure also that on your accelerator pumps are backed off all the way on the carb too.....if your holding your pump open....thats not gonna help your situation.

RPM is right, one backfire....the power valve is history....Its a sad state of affairs, I have a 5 drawer toolchest that I carry with me, and all thats in it is power valves and jets, and a few assorted trackpacs....well, 2 drawers are powervalves, 1 Drawer is jets, next drawer is accelerator pumps, cams, and squirters, another is just metering plates. The top is full of gaskets and o'rings, 1- calibrated regulator with a fuel filter attached and a pressure guage plumbed in. And thats just the Holleys....DON'T EVEN get me started on the Dominators! Ha!

 

[oino]

K, I got a gauge on there. LOL 12 psi.

I'll go get a regulater after work.
Where should it go? Back by the fuel pump or up by the carb?

I'd want to by the cheap one because of my budget. But I'm worry about vibrations changing the dial.

 

[Mike]

Holleys have a real problem with power valves.

Not when ol' Mike goes through them, they don't.

Actually, the newer Holleys are OK in the power valve department. Someone in Bowling Green finally caught onto the trick of using a check ball in the power valve vacuum passage, like we had been doing for 30+ years.

Rules number one, number two, number three and number four when buying/installing parts - Check, check and check again. Just because the box says you've got a left-hand thread smoke-grinder doesn't mean a damn thing, until you have verified it. The one you have might be right-hand thread, with a fractured frammus bearing. I cannot stress this enough. I say it time and time again. I've seen standard engine bearings with factory markings clearing indicating they were for .010 cranks. They were not the wrong bearings in the box, these were bearings that had been marked incorrectly. And if someone had not taken the time to check, what would the result have been? I was checking clearances on a set of rod bearings for one of the race motors. In a bearing 0.842" wide, I measured .0007 taper in just one bearing. How much oil clearance was that bearing going to have? One, fairly well-known, Left Coast oil pan manufacturer sent me a dozen SBC pans a few years back. Four of them would not bolt onto a block, no matter how hard you tried. Thank Goodness we discovered that here in the shop and didn't sell one to a customer at quitting time on Friday night. I've seen stock, Delco HEI modules shoot craps at 3800 RPM, when the next two dozen would spin to 4500. How would you ever know that was your problem, if you did not check? Heck the module can't be causing it, I just replaced it. Uh-huh.

If you trust the 'other guy' to do his job properly, you're setting yourself up for a lot of unnecessary stress and heartache. Check everything. Absolutely everything. Are those oil pump cover bolts tight? Did you pull the oil pump cover to make sure everything was as it should be? Check everything. Repeatedly. With zero interruptions from anyone. And keep checking until you are satisfied everything is correct.

 

[oino]

Oh ya, forgot this. Got the numbers last night from the neck on my carb. 3310-2 I beleave.
Google searched it. Says it is a 750.
Thats going to be to much for my stock motor isn't it?

I'm thinking to fork out the money and change to:
Holley - Carburetor 259.00
Or
Edelbrock - Carburetor 299.00

 

[one finger john]

Oh ya, forgot this. Got the numbers last night from the neck on my carb. 3310-2 I beleave.
Google searched it. Says it is a 750.
Thats going to be to much for my stock motor isn't it?

I'm thinking to fork out the money and change to:
Holley - Carburetor 259.00
Or
Edelbrock - Carburetor 299.00

NO, NO, NO, do not spend any more money (except for a regulator right next to the carb). The 750 will be fine. Readjust the floats and get it running. Attend to the details and make it driveable to your next residence.
I'll help you lift it over the fence. Also put mufflers on it. Then you can run it longer without incurring the wrath of the neighbors.

John

P.S. Mike is right, the devil is in the details.

P.P.S. If you really want to spend the money, send it to me, I can use it.

 

[oino]

lol, ok ok.
I'll get the regulator after work and take it from there.

Are you sure the regulator should go near the carb. Not a lot of room there to put it in.

 

[Rick]

lol, ok ok.
I'll get the regulator after work and take it from there.

Are you sure the regulator should go near the carb. Not a lot of room there to put it in.

IMO 750 is WAY to much for a 350.Regulate all you want but the pumpers and your jets are going to dictate how much fuel you get.A regulator will tell the pumpers how much gas they will get but the jets will still let the same amount of fuel through.Fuel and air.

 

[oino]

IMO 750 is WAY to much for a 350.Regulate all you want but the pumpers and your jets are going to dictate how much fuel you get.A regulator will tell the pumpers how much gas they will get but the jets will still let the same amount of fuel through.Fuel and air.

Awww crap. What to do. what to do.

I've also been told. Sence I'm using a performer intake with the split in the middle that he CFM is split. And it get cut down more sence the rear barrels are opened by vacuum on that carb.

 

[oino]

Just got off the phone with TGs Performance Speed Shop.
They told me the 750 should be fine. If its still rich after I put in a regulater. The Jet it down.

 

[Screaming Metal]

Yea Mike, I know where your comin from on all that. Folks quality control is the pits anymore.

Anyway, oino, yes, 750 cfm is too much for the motor to use..., but as you were told, don't worry about that right now. put your regulator just ahead of you carb and after the fuel pump, since I can't see your layout. Set your float leve till it trickles outt the hole as told, then start it up and run it some. I mean just let it idle and all the way up to temp. You then should change your jets to keep from washing your rings out. Seriously, when you can afford it or can find a friend thT DEALS with car parts, have someone trade you a good used 625 or a 650 dual feed vacc secondary carb. Or sell that 750. But not right now if you can't afford it. Just rejet the thing.

If you ever build yourself a good street/strip engine for a full bodied car thats gonna run about 600 horses...the 750 would be the ticket. For a Hi performance BigBlock, yes, its the correct carb.

Just keep us aprised of whats going on and we'll try and help ya out.....

 

[Screaming Metal]

If I remember correctly, the 425 horse 427 Vette motors of the late 60's and early 70s had a 725cfm/750cfm carb like yours on it. Just to give you an idea. The 450 horse 454 had I believe a 850 on it, but you could also get both motors with dual quads also for even more power....

 

[oino]

ok, Got the budget regulator on there. Cheap ass thing. Set it to 5 1/2 psi and only does 3. But with that said it runs better. Float levels good. No back fire. But still rich.
Now I know what I need to fix it. I'm taking back that cheap ass regulator. Guess I'll just have to order a good one.

Jeting it would be cheaper.
I'm thinking maybe I should just save this carb. for when I build the motor up, and go get me a 600cfm carb. for this motor
I have the money. Its moving money. but I'm not moving till 7-1 anyway. I'll make the money back by then.

 

[Mike]

Whoa! Hold the phone. Go grab a glass of whatever, sit down and take a few deep breaths.

Yes, 3310 is getting close to being too big for what you're trying to do. But 3310 is a vacuum secondary carb, so it is going to work just fine. And I'll wager the price of the 600 CFM carb I am right. The secondary side on your 3310 will only open when air flow through the right venturi calls for it. Stop worrying about throwing more parts/money at it. We're not dealing with a 750 double-pumper (0-4779), so relax and put your wallet away. We can tune this combination to run just fine, but we need to start at square one. And no, the 180° intake makes absolutely no difference on the flow capacity of the carb. Actually, this intake is helping us out, so quit worry about that one, too. Leave the regulator right where it is, because we still do not know what is happening here.

Now, describe to me how you know the carb is too rich. I may have missed something here. Are you driving this thing, or just working on it at your shop? Without driving it, there is no way you would ever be able to tell if it is jetted too fat. The main jet will not flow until the throttle blades are open and pulling air through the boosters. What technique are you using to determine it is fat? Be as detailed as you can, as I think we're missing some details as we've come down the pike.

If this car is just sitting and idling and you think it is fat, then we have narrowed down the playing field. But I need to hear from you exactly what is happening. If the motor has a bunch of idling time on it (particularly with excessive fuel pressure), then you are never going to be able to read a plug. So tell me how you know it is too fat. You say it is not backfiring. Was it backfiring through the exhaust, or sneezing back through the carb? This is a very big difference.

 

[RPM]

Also keep in mind that the jets have nothing to do with how it idles. Screw the idle mixture screws all the way in the engine should die. If it does not then you have a internal carb leak some where. Power valve, gasket etc. And that 750 will be just fine on a 350 motor.

Didn't Chevy run that same carb on the 302 in the Z28 from the late 60s?

 

[Mike]

Also keep in mind that the jets have nothing to do with how it idles.

Exactly. If people take just a couple minutes to look at the circuitry in a Holley metering block, it's clear to see the jets at the bottom of the block. And where are the passages leading to the boosters? At the top. It requires air flowing through the boosters to create enough low pressure to actually flow the jets.

Ron, Holley could have saved thousands of people a lot of heartache if they would simply cast your reminder on the top of every float bowl.

People don't want to hook up the chokes on Holleys, so on a mildly-cool morning, the motor wants more fuel than it's getting. So a lean backfire occurs. Suddenly, the motor won't idle smoothly, so one of two things happens - 1. It's time to start changing jets (and none of the changes will work) or 2. That damn Holley is a piece of junk.

Or someone doesn't know how to set ignition timing or valve lash and they keep sneezing through the intake until the power valve diaphragm gets torched. When they finally learn the power valves are delicate and need to be shielded or the motor needs to be tuned correctly, they want to plug the power valve.

A carburetor is a very simple, pressure-differential device that meters fuel into the air stream passing through it. It has no brain, so it has no capacity to think. Which means it most certainly cannot out-think you!

 

[Screaming Metal]

Also keep in mind that the jets have nothing to do with how it idles. Screw the idle mixture screws all the way in the engine should die. If it does not then you have a internal carb leak some where. Power valve, gasket etc. And that 750 will be just fine on a 350 motor.

Didn't Chevy run that same carb on the 302 in the Z28 from the late 60s?

Yes, was close to that CFM if I remember correctly. On that Z motor, it flowed bigtime, big ports, big valves, headers and all. Plus it wasn't redlining at no 5000 either.

I know the carb will run on his car. and since its vacc. secondary, he probably won't hardly ever tilt the back two, I did tell him later on.
If he keeps it purely stock, your smaller primarys give you extremely crisp throttle response and pep. I KNOW that the IDLE circuit doesn't influence the Mains, but there is a TRANSITION circuit in there, too. And this could also malfunction.
Rejet the thing and get it moving to his new place, He doesn't have a car Trailer/ hauler like us, does he??? I could actually care less if he wants to run a 1050 Dom. or the big square predator...its his car. He needs to move it. I imagine he's goosing it some......a 750 should idle with that motor, if its loading up at idle, he's probably reving it a little to keep it running, RIGHT?????

I agree...needs tho thin it out at idle....

 

[one finger john]

O.K. a quick review.

1. Present electric pump was found to put out 12 lbs. of pressure at the carb. At the carb because you want the fuel pressure to be regulated as accurately as possible as close to the float needles and seats as possible.
2. 3 lbs. w/cheapo regulator. Was that measurement taken after the fuel regulator? Flow should be fuel tank, fuel pump (as close as possible to tank), fuel line to front of car, fuel filter, regulator (as close to needles and seats as possible), connecting fuel line from regulator to carb, and then carb. READJUST the floats to factory settings. 3 lbs. will let the car idle and be normally driven. I would not worry about hi rpm or extended Bonneville type operation right now.
3. Take back the cheap regulator, why? It works and it was cheap. Besides, I don't think the parts store will take back a used fuel item.
4. Take money from moving expenses to buy a carb? Momma won't be happy 'bout that. Better to have the T viewed as a positive thing rather than a money pit. That hasn't moved out of the back yard yet.
5. Here is your mantra. Timing - 10 to 12 * initial, disconnect vacuum advance, .040 feeler gauge clearance btwn primary butterfly and throttle bore wall, idle screws 1 1/2 turns out. Fresh gas in system, Start and adjust for 800 rpm idle in gear (block rear tires or have someone hold the brake down) Why 800 rpms in gear? No flameouts at traffic lights. Both embarrassing and dangerous to you, the driver.
6. Always make SMALL adjustments to timing and fuel mixture. One or two degrees for timing, 1/8 turn to idle mixture.

John

 

[oino]

Wow, So much information. Thank you!!!

ok let see if I can make this make sence. :hooray:

With the regulater on there. Idle is fine at 600 rpm. Timing mark at TDC. Sounds good now.
No black smoke. As I give it gas then its starts to get black smoke. Even get some sputtering sometimes. The more gas I give it the thicker the black smoke. Oh and scrach the no back fire. When I give it lots of gas slowly and release it fast or give it lots of gas fast and release it fast it back fires out the tail pipe, and/or the carb.

Returned the cheap regurlater last night, and got a Holley one. Came with a mounting bracket. Only $40 at pepboys.
I'll install it after work.

Oh, No I don't have a car trailer. Wasn't going to drive where I'm moving to anyways. Just going to get a Big uhaul and make a ramps.
Thats why I need to drive it. So I can drive into the truck. Also going to be towing my SUV behind the uhaul.