Howdy all, I am still digging through my new car trying to figure out what all I have on this thing. I noticed today that I definitely do not has Q-Jet on my 455. It is is Holley 4160 part # 3310-3. I looked it up and that is a 750cfm carb. Right now, I just want to get this thing running reliably for cruising around so no strip runs. Is this carb even worth keeping right now with the intent of putting a proper Q-Jet back on in the future? Or should I ditch immediately? Thanks!
I guess I should go ahead and add that when I stomp on it, it will kind of hiccup, then rev up, almost like it falls on it's face and then has to get back up again. I am taking it to a shop to get tuned up, but I want to make sure I am not beating a dead horse.
a 750 would be OK but, i would prefer a qjet myself. the hesitation sounds like it might be a vacuum secondary carb and needs a different spring but then again i donno. i would say its directly related to the secondaries. is it mech or vacuum?
It has vacuum secondaries. I was looking around the net and saw other people mention an improper secondaries spring. It definitely doesn't feel like it has as much oomph as it should. Granted, this is my first, but still, I figured I would have enough juice to smoke the tires at will. I think it might be running rich as well. Might as well have the shop to a rebuild. I kind of want a clean slate to work with and start learning from.
The 3310 in all it's various forms is probably THE most-used aftermarket carb on the planet. There is NO reason it can't be tuned to run well on your engine...providing the engine is in good condition. I'm not saying its the BEST carb for your application--just that it should work OK. WHAT intake manifold do you have, that a 3310 will bolt to? Adapter plate?
if you thinks running rich go down a couple jet sizes and while your at it make sure you use blue gaskets and get a power valve for it just in case. you shouldnt pay someone to rebuild a holley as easy as they are to work on. also. check your float level. it should be just level with the bottom of the plug. put a different spring in for the secondaries. you will have to experiment though. also if your stumped with a holley if you know Doc, hes a guy on the board. hes real smart and nice when it comes to holleys i would bet he would be willing to help thanks, Lonnie
thanks for the compliment Lonnie,,,,, First get the engine tuned up electrically and then start working on the carb.... most of the time when there is a driveability problem it is the electrical tune up, or lack thereof that is causing the problem.... yes, it is easy to work on a holley,,, lots of books on them,,, parts are easy to get,,, you cannot buy a better carb unless you go to Webbers....the secrete to making a holley perform is to set them up just exactly like holley says to do....and yes that carb is plenty big for what you want to do.... in fact one of the best running engines that i have is a 425 buick engine with a 600 cfm holley on it ,,, it runs strong....surprises a lot of people..... From what you describe,,,I would suspect either incorrect engine timing, weak ignition system or insufficent accellerator pump shot in the carb.....not likely to be a problem with the secondary spring... unless someone has changed it ....
Howdy again, thanks for all the help so far. The intake manifold is an Edelbrock Performer Buick 455. There is some sort of adapter/spacer plate between the carb and manifold. I have a Delco Remy HEI vacuum advance distributor, but I don't know what the timing is set at (still learning!). I tell you one thing that is driving me nuts about the electrical system is that I don't have a clue how to hook the hood tach up to an HEI distributor. Is it even possible? Should I set the timing to stock numbers, or do the performance timing setup? 462 what is special about the blue gaskets?
there is a wire that is specially for the tach it even says it on top of the cap... the blue gaskets are reusable for a few times when you have to take it apart to tune it.. and set it optimal without detonation..
Well I got the tach all hooked up (well not the backlight yet) and that was easy enough. Also had a local shop that does restorations do a good once over and set the timing and tune her up. She runs much better now. Now that I have a nice clean slate it is time to start having fun and start learning how to do all this stuff on my own. Oh, and as far as it tripping over itself, I think it was to some extent, but I also think that it was downshifting to 2nd and I was perceiving that the wrong way. It kicks down and hauls butt now. I am going to run a new braided fuel line from the fuel pump to the carb and ditch the rubber hose/plastic fuel filter that is on there now. The stock hard line only runs up to about the distributor, then it is hose the rest of the way. Doesn't seem like the best setup...
just make sure its the kind of hose rated for fuel injection and you will be fine. i would double clamp them though. good to know you got it running good. usually when you have a bog like that. if its fuel related.. if you keep the throttle held down when its bogging it will backfire when it goes lean. thats a good indication the carb needs a lookover. what "backlight" are you talking about?
There are small screws on the side of the carb that you turn in or out to adjust the carb.. The back screw/screws are the ones for the secondaries, adjust that one/those to adjust the bogging down problem. You may have to adjust the front one/ones also. If you are not sure as you said you brought it to someone, just ask him/her to show you or he/she may have allready done it for you when they got it running right for you. As far as the light for the tach, just tie that into your parking light wire. turn on your lights and it will come on. If you want it on all the time just tie it into a 12 volt hot wire or run a wire down to your fuse block and tie into a wire/fuse at the fuse box. Or tie it into the wire (brown if I remember right) that comes out from the box, that is a "when key is on wire". Small screw is under the vacuum port, in front of the choke stuff. there should be one on each side of carb front and back. (may not be on yours, mine is a 4781-5 and it has 4 screws, yours may just have two)
You're right. Hose on the pressure side of the fuel pump should be minimized, or eliminated if possible. I'd suggest getting another metal tube bent so that you don't need ANY hose from fuel pump to carb. Just like GM did.
So I really romped on it, starting at a bout 15 mph. Holy moly I think it's dialed in, or at least really close. It freakin hauls. Tires broke loose on the shift to second. I love this car more every time I drive it!
Alright, so perhaps she is not as dialed in as I thought. I still have the issue where if I mash the pedal all the way down, it 'skips a beat' and then revs up (See the video links for what I am talking about. It is kind of hard to hear, but if you watch them 2 or times times you can hear it. The first is while at 40 mph, the second is from a rolling start). It is a very short little hesitation, you can hear it go vrr--vrrrrrrrrooooom. If I roll the power in it does not hesitate, the power comes in nice and smooth. It can happen from a slow roll or stopped, but is most noticeable at around 40mph when you floor it. It also seems very anemic like it did before at WOT. Maybe that one time I broke the tires loose the road was a little slick. I'm not expecting a 10 second car here, but dang it should light the tires up from a stop or rolling start right? It does have posi... I am still unsure of the gear ratio. It starts immediately, idles smoothly, and cruises fine; it's only WOT that seems to give it problems. As for the electrical, it has new plugs, wires, and the shop replaced the guts of the HEI distributor and set the timing. I was looking at my carb today (remember I am totally new to this) and if I grab the secondaries linkage right underneath the quick change housing and try to move the linkage it does not move. Should it move by hand? Tomorrow I am going to try the twisty tie or paper clip test to see if they are opening. I have been reading a Holley book, and from what I've read and what doc mentioned, it looks like it could be an accelerator pump problem causing a slight lean condition immediately after applying WOT. If the secondaries aren't opening, I am going to be pretty ticked that the shop that did the tune up couldn't figure that out and I could. If they aren't opening, looks like a new quick change housing and a spring pack is in order. If they are opening, should I do a rebuild and go from there? <iframe src="http://www.youtube.com/embed/44uqjI9DvrE" allowfullscreen="" frameborder="0" height="349" width="425"></iframe> <iframe width="425" height="349" src="http://www.youtube.com/embed/of6eiFxxuzw" frameborder="0" allowfullscreen></iframe>
OK, first a couple of questions,,,,,, do you have exhaust heat into the intake manifold....? and what is the differential gear ratio...? You have to have heat to the intake to make the cat pee gas we have now days flash into a vapor so it will burn.. liquid gasoline will not burn.... There is 2 different kinds of carb ''bog'' ,,,, lean bog and rich bog..... lean bog is usually accompanied by backfire in the intake.... rich bog is like what your engine sounds like with no backfire.... actually you have more of a ''hesitation''.... also, I wondered what the engine would do if it had some real gasoline in it.... av. gas mabey....:laugh: Now all that said, if the rear end gear is really high , like 2.93 or so,,, that could be part or all of the problem... You see, pard, the car only sees the whole pkg... carb,cam, engine tune, gear ratio, weight, ect.... I picked up on something when I reread your original post... you did not build/set up that engine, someone else did and you bought the car after it was done.... a lot of guys will block off the exhaust heat to the intake, trying to get more power,, that is a drag strip only mod... it does not work out good on a street driven car.... The holley carb is as good as you can get without going to Webbers,,, take a clue from the factories,,,,, in the muscle car era when the factories really wanted to go fast , they went to holleys,,, all three of them... you cannot do better.... you might do as good , with something else , but I doubt it.... :Smarty: Lets look at the easy stuff first,,,, First, check with the former owner/mechanic to see if he blocked the intake heat risers... if he did, open them up again....you will see a big improvement... Then,, what is the power band of the cam???? if the engine is ''overcammed'' you have 2 choices either change the cam out , or install a shorter diff gear... something like a 3.42 or 3.73 or 3.89.... next, I would set the carb so that it got a big shot from the accellerator pump and the main jets were what holley recommends for that carb.... and while you are working on the carb, adjust all the linkages JUST LIKE HOLLEY SAYS TO DO....that is the speed secrete with holley carbs , set them up just like holley says... I am running the old holley 1050 cfm three barrel carb with the rio accelerator pump, brown cam and vacume secondaries.... it is crisp and snappy on my 410 cu. in. nailhead.... You can sort this out.....:Smarty: At what rpm does the engine ''pick up'' and start really pulling,,, is that consistant???? I have learned the ''overcam'' lesson the hard way... I put a 427 cam into my 332 ford engine and it would not run untill it reached 35 mph...:laugh:
Hi Doc, lots of good learnin goin on in here! I am not quite sure what you mean by the exhaust heat. It is a '70 motor from a riv or electra and has long tube headers so no emissions gear. I don't see anything going back into the manifold from the headers. The gear ratio is unknown I was going to check when replacing the fluid and well, we forgot to look at the ratio. It 'should' be the stock cam. There is nothing in the documentation that shows otherwise, and the car is fairly well documented. It is impossible to track down the original mechanic unfortunately because the guy who I bought it from didn't do anything to it. It was the owner previous to him and the work was done many years ago.
