working my fingers to the bone

[Rodney Bullock]

i have been working on my street rod here lately. I have new heads, headers, roller rockers, intake. The car runs 80 % better however the carb stumbles if you are running 40 mph and step into it. I don't know what's wrong. I adjusted the float, side air mixture screws. There are no leaks around the intake or carb. I think I will send the carb back.

[Niel Hoback]

Late timing?

[greg g]

Typically street rods are over carbureted. I see its a holley do you know what the CFM is? What size is the engine?

It might be the secondaries opening to soon. Or could be the air cleaner is not flowing enough air. Have you pulled the plugs tosee what they can tell you. Is your vacuum advance working?

[Rodney Bullock]

Hey guy's, timing is 24 total degree. no ping. the carb is a 600 cfm and I have an adjustable vac. advance. The plugs are clean, white tip clean. No gas smell on them. They are burning even. I think something is wrong with the "flow" of the carb. At part thottle then to full the carb stumbles. Pulling out in drive the car burns rubber right into second gear and beyond. Nothing wrong there however rolling along let your foot off the gas, then give it gas and the car stumbles then catches. I have had this problem before a long time ago. I just don't remember what I did to fix it. I think it involved a power valve replacement. This is a new carb It should not have this problem.

[maurice wade]

Yep, sounds like a power valve, easy fix!

[Joe Flanagan]

Rodney, for what it's worth, my daily driver showed the very same symptoms and it was a vacuum line going to my vacuum advance. Worth checking and it's an easy fix if that's it.

[Rodney Bullock]

Shel, my wife likes the color also what is it about Purple that makes the ladies just love it:)

Hey Joe, I just talked to some of the guy's and they said the same thing. When I did a tune up on the car I changed the vacum advance to the kind that uses the allen wrench for adjustment. It might be closed so tomorrow I am going over and open it up, I will also check for a vacum leak at the base gasket.

Wade, this is the new Holley carbs with the "blow proof power vavle" right I will believe that when I see it. those Holley carbs always had a problem with the power valve I have a box of them and don't know if they are blown or not. I use to just change them whenever the thing acted up.

[Rodney Bullock]

I got it right this morning, adjusted the vac. advance. I turned it out three turns and now it's like lighting.

[Young Ed]

Whats the rod in the background?

[BobT-47P15]

Fiberglass Ford, I'd say.

[Don Coatney]

I got it right this morning, adjusted the vac. advance. I turned it out three turns and now it's like lighting.

So Rodney.... You wanna race me;)

[Rodney Bullock]

So Rodney.... You wanna race me;)

Don, I know when to fold them and walk away.

I can't wait until you make your way back over this side. we can go to the cruz spot in my Rod and burn a little rubber. Scare some old people you know have some fun!

[Rodney Bullock]

Fiberglass Ford, I'd say.

1934 ford from street beast. tune port motor lots of goodies. It's the owner's car. He and I have been working on cars for 25 years. since my car came in there he has been very motivated to finish his car.

[Don Coatney]

Rodney;

You need to be thinkin about the pilgrimage to Oregone this summer. I am making plans

[Greenbomb]

Hmmm...Old people scaring other old people. That DOES sound like fun! Nyuk! Nyuk!

[maine48ply]

Rodney....where did you get your adjustable vacuum advance? I need to replace mine. The only one I've found so far is on the Bernbaum site for $69.95. There's one on ebay right now thats OE for $9.98, no bids yet. I have a '48 special deluxe.

[james curl]

If you have your old one, Terrell Machine in DeLeon, Texas can rebuild yours. Beware, mother MoPar used three different distributors and they all take a different vacuum advance. You will need the part number from your distributor before buying one from Andy or anyone else. Terrell Machine can be found in the link section of the home page. He has rebuilt two different vacuum advances for me. If I remember right it is around $75.00 but you have the right advance.

[Rodney Bullock]

When it comes to adjustable vac. advance for GM H.E.I systems I got mine from Summit racing. They sell the whole kit. It is refered as a 'tune up kit'. If you are using an HEI distributer that advance is for you.

[blueskies]

Nice looking '40 Rodney... My dad has one with a blown small block, air-ride, etc. Fun cars-

Pete

[claybill]

RODNEY....i am having similar problem but not as severe..at 50 mph it hesitates when i accelerate quickly. but soon catches..

does it sound like a vac adv as well....ANYBODY

RODNEY.....WHAT ENGINE ARE YOU USING? i have the exact carb in mine,

1978 dodge 360.

i am also running a hot cam, unfortunately, so it is hard to get any kind of idle. AND THE CAM doesnt comeon til 65 mph..so 99% of my driving is 'lumpy'. bought it that way.....

Also...what size tires..front and rear??

[martybose]

I'm curious why everyone is talking about the vacuum advance, as my experience is that a hesitation like this is almost always related to the accelerator pump setting. It could be that the pump shot isn't big enough, causing a momentary lean condition until the air flow catches up.

Marty

[Rodney Bullock]

Hi everyone, I went back to holley this time as I have been using Edelbrock carbs for the last 3 motors I installed on my V8 cars. I was about to send the carb back when I went over to the shop and did a little test. 1st, it is always good to check your float level on these Hi perf. carb when you have a problem out the box. Shipping is hard on them. It is also true that the accelerater pump sometimes does not have a large enough squirt. That can be adjusted with the nut at the level.

My problem was at the vac.advance. The mechanic test drove the car and said it had a hesitation. That vac advance when it is adjustable can swing those weights to come in sooner and give you a great hole shot. using an allen wrench small enough to go in the opening can change the smoothness of the hi performance excellaration. If you have an adjustable vac. advance.

Bill, if your cam does not come in until you hit 65 miles mph then it's your secondaries that need to open up. Do you rememeber that sound that those qad 4 bbls use to make are you hearing that sound? when you hit it at 55 -60 mph? There is a nut and a screw on the air horn housing that can be adjusted. Go to the holley website and you will fine instructions on how to do this on that new 600cfm carb.

[Rodney Bullock]

Bill, you may not have this but all cams have a cam card. On this car it gives you the cam lift and it's duration. The duration is important because it determins if you need a stall converter or not. I think for a small block mopar and this can easily be looked up. The area where a converter is nessasary is about 280 duration, 268 is good 272 is border line for a regular torque converter. I know with mopar and I only have experience with big blocks, when you buy a cam they ask you if you have an automatic trans and converter or 4 speed trans. The duraion has to be pretty high for it to come in at 65 mph. Normally cams come in at 2,500 rpm to 3,000 and you get a stall converter to come in at about the same time. At 65 miles an hour you have to be at about 4,000 rpm unless you have a very tall gear. On od trans they drop the rpm's some however a cam comes in long before that.

Edited February 17, 2010 by Rodney Bullock

[Rodney Bullock]

The motor I am running in the street rod is a 1969 350 small block. It has not been bored. It has summit racing heads, with large intake valves 2.02 ans 194 exhasut valves. It has three angle valve job with 1.5 roller rockers. I have headers (shortblockhuggers) with a Wein intake. It breathe very well

Bill listen to this motor. It has a cam however there is no lope. I could not tell you why.

[claybill]

for sure it is a TALL GEARING. as my mechanic said, the cam is set for a stickshift high rev..etc......AND he thinks the acc.pump needs to be set up to stop the hesitation.

this car is SOOOO new to me in mechanics and driving that i am just not savvy to it all. I am getting great help from my mechanic friend.

----------------------------------------------------------------

my car was fitted with an auto, '79 dodge with a 2.71. too tall.

if it was a 3.71 it would be just right i think.

in my case i bought the car as is, from a middle owner who did not know what was used.....we had to count,measure, take apart, put together, re-jet etc etc..adj shift rods..etc

the rear end came from a '79 dodge aspen wagon..so it is.

(i have one of those vac that uses the allen wrench)

by the way....i have extremely low vacuum at idle, and only fair vac throughout.....attributed to....the cam?

the auto squeels off the line, and gives a loud chirp as the auto shifts into 2nd..

i have a lot to learn about this rig, but it FEELS RIGHT.

bill