Check out my gallery and let me know what you think of my project. I'll get some better pics soon. Already installed all the part. Now if I could just get the holley carb adjusted right. I have tried and got it close but when I dump the clutch it bogs down pretty bad. I have to ride it to get a good start. Anyone have any tips? Holley Street Performance 390 with a Trans Dapt 1" Swirl Torque Spacer. Kevin.

 

Welcome to FTE from the Tennessee chapter. You will have much better luck posting your question in the correct forum for your trucks year and engine.

To try to answer your question, If it boggs upon dumping the clutch your mix is too lean, I think.

We'll see if we can get a mod to move this to the right forum...Good luck

 

Aw crap - LOOKIT-

There are a couple of manuals out, by Chiltons and Clymer that are dead on with Holley tuning. You want the specialised "HOLLEY CARBURETTOR" manuals for that - they have way cool tips that you would have never guessed because they were built with old hot-rod know how.

Fourteen bucks you'll be glad you spent!

STREETHEALER don't you even go there - THIS guy is one of OURS!

 

I will try to find a manual. I was just informed that the carb I bought was a vac. secondary carb so i am only running on two barrels so I now have to figure out how to make it work right. I have a friend at a shop that adjusted my carb a little and told me to put a screw in the linkage so when the front two open about 3/4 the way the back barrels start to open

 

You'll want to check the diaphram that opens the secondaries too - it might be bad. Check also for any restrictions in the lines to it - sometimes there are restrictors deliberately put in to slow the secondary opening for smog and economy reasons.

A well set up vac secondary will actually out perform a purely mechanical one.

 

Ok I will check. My friend says that I only have one vac line on dist. which is a vacuum advance? and it hooks into carb but doesn't control the secondaries.he says I need a dual vac dist.? does this sound right?

 

I'd run a straight vac to a carb port - but you need a manual to give you the right ones

Better yet - go from a vacuum tee on the manifold. (should be near the back). That will be straight vacuum.

Check where the secondary dashpot is pulling vac from.


You want manifold plenum absolute pressure. (which is still a vacuum)

 

Ok Grey wolf you confused me???????? I have two holes in the offy intake man. which I plugged off. One hole in the carb spacer with I plugged off. One vac fitting on the dist. which goes to carb. three fittings on carb. One which was the one from the dist. One for PCV valve and the third fitting on the carb I have no clue what it is for. I am in a whole other world when it comes to the vacuum of a vehicle. All I know is that if it leaks it doesnt run right LOL
Like I have said before this is my first build. It was my father's truck
Kev

 

Wolfe, didn't mean to step on toes, I know he is ours. I didn't think I could answer his question apropiately is the reason I said what I said.

Now back to the question, did you get him on the right track with the bogging issue? I've been gone for several days. I will help if I can Good luck.

 

I'd run a straight piece of vac line from the distributor to the carb spacer - it will read exactly what vac is under the carb butterfly valve! THAT should give you the crispest distrib response to load changes.

Also take a clean piece of vac line, put it on the distributor connection and suck on it, then cover the end with your tongue.

If the distributor vacuum dashpot is good, it should hold vacuum. If it doesn't - replace that weak S.O.B. !

(The dashpot - not the whole distributor)


Alternately you can get a vacuum pump with a guage, but it will either hold a small vacuum or it won't. See what I mean?

Most older engines that run like dogcrap have bad vacuum advances and are running on pure mechanical advance. Which sucks badly, take that to the bank.

*What happens is that people compensate for the bad dashpot by adjusting their timing, not realising that it's a dirt cheap part that is going bad. Vacuum advance allows the timing to radically change to compensate for increased engine loading.

When the engine loses vacuum, the advance causes the plugs to fire PAST top dead center, and the mechanical advantage runs the engine HARDER.

Under normal loads, the plugs fire BEFORE the piston reaches top dead center, to more completely burn the fuel/air charge.

Vac advances can cause the plugs to fire as much as 20 to 30 degrees AFTER top dead center... (depending on the setup)

Think in terms of crankshaft leverage.

 

Ok I will try what you said. Now will moving the vac line from the carb fitting for the dis. to the spacer affect the secondaries opening? I have a vac pump I will see if it holds a vacuum in the morning if it isn't raining.
Kevin

 

It will definitely sharpen performance. You should check the 'strib AND the secondary vac dashpots to see if they leak.

If the secondary vac dashpot leaks, it's a mystery solved!

Vac Secondaries usually have their own vacuum port in the carb itself - you might also shoot some gumout or berrymans B-12 down that port to make sure it is clear. Also make sure you have a good vac line on it, I'd go with a short length of new line and make sure it fits tight.

As we all know - vacuum lines turn crummy over time. Heat makes them harden, crack, and the ends fit loose so that they leak at the connections.

If you can - shoot a pic of the vac secondary linkage and post it here or in your user gallery. I can download it and do some graphic stuff to point out where you can tweak on it.

 

OK I posted some new pics in a gallery Greywolf. Let me know if you need any other pics I will be glad to post them.
Kevin

 

Can you get a shot of the whole carb?

It's a classic Holley dual quad, that's for sure! I can tell by the tube going between the front and rear float chambers.

You need that Holley Carb tech manual badly if you want to really get inside this thing and make it perfect.
It's published by Haynes, and is one of the few manuals they do that really is a nice piece of work. Cruise a few parts stores until you find it or have them special order you one. I think my buddy across the street glommed onto my copy - I should beat him with his own torque wrench until he coughs it back up!

 

ok i will try to get a pic of carb in the morning. here some of the info on the carb in case you want to look it up.

Street Performance
390 CFM Four Barrel
Part #: 0-8007
www.holley.com