348/409 intake and carburetor ?

[alshotride]

I have a 59 Chevy Convert. with a 348. At the moment I have a 3/2 set up on it but am thinking of trying a Edleabrock 650 AVS carb. I have a cast iron intake for it but I am not sure that it will work and am not sur what I need to do to make it work. Adaptor ?
I thought that maybe the secondary openings on the cast intake could be enlarged to accommodate the larger secondaries on the AVS without using an adaptor.
My motor is a mild build so I think the 650 AVS would be a good match for it. I love the 3/2 but just don't seem to be able to get it to idle right or consistently smooth. I thought the aluminium intake that was used on the 409 might work but have no info on that . Anyone have any info that may help :help

Thought I would finnish the description of the car. Has a 400 turbo trans.,Hurst on the floor, 411 posi. third member,MSD electronic dist., Power steering and brakes, factory AC. mild cam, punched about 60 over. Painted pearl white, custom interior but similar to stock. Just putting lake pipes with cutouts on it w/ continental kit. I have never had it on the road :dunno . Owned it for the past 15 years. THIS IS THE YEAR, my wife insist :takethat

[Mr.Jimmy]

The single 4 intake??? Its a spendy item these days.. Saw one a few weeks go for 600 on ebay. Do the adapater and the iorn intake if thats the way you want to go.

Have a good carb guy go through yours 3 deuces...You can get them to idle nice. There was suppose to be a guy that is in St. Louis that makes up his own from 2g's, makes alot of power and mileage out of them too. He advertises in the Goodguys Mag.

[w ogden]

Don't give up on the three carbs. Call Larry Fulton. He is an ace on rochesters and has built himself a very good business up in Great Falls Montana. Calls himself Automotion rochester Carb Service. A friend of mine has a tri power 348 and had all the usual problems. Had Larry set him up and the car idles like you would expect. Worth a try.....call Larry at 406-453-5395. Good luck. :)

[alshotride]

Don't give up on the three carbs. Call Larry Fulton. He is an ace on rochesters and has built himself a very good business up in Great Falls Montana. Calls himself Automotion rochester Carb Service. A friend of mine has a tri power 348 and had all the usual problems. Had Larry set him up and the car idles like you would expect. Worth a try.....call Larry at 406-453-5395. Good luck. :)
Thanks, I will call him

[Seon]

call Larry at 406-453-5395. Good luck.

What ever you do, don't ask him if his stuff are used :rolleyes: ? I called him last Monday inquiring about a three duce set up. He sounded irratated when I asked him if the manifolds were used or new. He got on his soap box about how all his stuff were new including the carbs because he just doesn't replace parts, he actually rebuilds the entire carb. Used bodies, new inners. He finally cooled down when I told him that I didn't know anything about him nor his product and that's why I called him to inquire....especially when he's selling his set-up at $2K a pop.

BTW we had a long chat afterwards. Nice enough guy, but don't ask if his stuff are used :D

[Mr.Jimmy]

I have a question....Does anyone make a 3 deuce intake for a 348-409 anymore??? How about those carbs other than Barry Grant?? Thats the going price right now for a 3 duece set up. A friend of mine payed 3500 for the correct set up for his 58 with the air cleaner....He put it on, and it purrs. Spend some money, get great stuff. Pay 200, put alot more into it.

[W Head]

Alshotride, A mistake that is sometimes made on the 3 duce set up is the fuel pump. The factory 2 barrel carbs needle and seat will not take a lot of pressure. If you have a pump other than stock, you may be over riding the needle and seat causing all three carbs to drip gas, causing the rough idle. these carbs will not take much over 3 1/2 to 4 PSI. I had this problem on my 59 El Camino 3-2s and a stock pump cured the rough idle and running rich fuel mixture.

W Head

59 El Camino 348 3-2s
59 Impala 409 2-4s

[fatride]

If you have progressive linkage dissconnect the front and rear linkage, make sure the end carbs are shut off all the way. Start the engine and see if this smooths the idle. Some times the progressive or stock linkage will bind between the front and rear carbs and keep one just cracked a bit, this would be equal to a vacuum leak as there is no idle circut in these carbs. Are you carbs original? The front and rear carbs should have no idle bleed screws! Another thing that will cause rough idle is dirt in the circut. With the engine running whack the throttle wide open, let the rpms build to around 4000 rpm, quickly place your hand or a folded towel over the carb opening, release throttle, keep carb covered untill the engine almost dies. Do this 3 or 4 times, if these things don't straighten out the idle come on up to my house this summer and we'll get em right. :D


PS, I have dealt with Larry at Hot Rod Carbs also, he is one nasty sob to deal with :takethat .

[Seon]

PS, I have dealt with Larry at Hot Rod Carbs also, he is one nasty sob to deal with .

And here I was trying to be tactfull with my comments :clap .

[w ogden]

WOW, Guys I have never had one issue with Larry in Montana. Talked to him several times andhave purchased quite a few parts from him. He has always been straight up with me and never once showed any bad attitude. Hey, you never can tell can you? :dunno :dunno

[alshotride]

Alshotride, A mistake that is sometimes made on the 3 duce set up is the fuel pump. The factory 2 barrel carbs needle and seat will not take a lot of pressure. If you have a pump other than stock, you may be over riding the needle and seat causing all three carbs to drip gas, causing the rough idle. these carbs will not take much over 3 1/2 to 4 PSI. I had this problem on my 59 El Camino 3-2s and a stock pump cured the rough idle and running rich fuel mixture.

W Head

59 El Camino 348 3-2s
59 Impala 409 2-4s
Thanks.
I have the stock pump going. You are talking about the float seat , right? :dunno

[alshotride]

If you have progressive linkage dissconnect the front and rear linkage, make sure the end carbs are shut off all the way. Start the engine and see if this smooths the idle. Some times the progressive or stock linkage will bind between the front and rear carbs and keep one just cracked a bit, this would be equal to a vacuum leak as there is no idle circut in these carbs. Are you carbs original? The front and rear carbs should have no idle bleed screws! Another thing that will cause rough idle is dirt in the circut. With the engine running whack the throttle wide open, let the rpms build to around 4000 rpm, quickly place your hand or a folded towel over the carb opening, release throttle, keep carb covered untill the engine almost dies. Do this 3 or 4 times, if these things don't straighten out the idle come on up to my house this summer and we'll get em right. :D


PS, I have dealt with Larry at Hot Rod Carbs also, he is one nasty sob to deal with :takethat .
I have disconected the front and rear and it did help but still wont run consistent smooth. They do have the throttle base without the needles. I will try the other things you said. Actually I sort of quit working on it mostly through the winter and just waiting for better weather to go again on it. I have done everything I can to check for vacuum leaks and find none. I even put on a MSD electronic ing. on it. I had the motor rebuilt by a reputable speed shop in Dallas about 11 years ago. Hope there is nothing wrong inside.
Al

[W Head]

You stated the front and rear carbs have the mixture screws, these screws must be screwed in all the way to cut off mixture on the end carbs. The idle mixture and rpm is set with the middle carb only. If you have a vacume guage, hook it to a vacume source and adjust the mixture screws in the middle carb to acheve the highest vacume reading. When you adjust the mixture screw in too much, the vacume (and RPM) will fall off and when you adjust it out too far, the vacume (and RPM) will fall off also. If you don't have a vacume guage, you can use a tach and set screws to highest RPM. After you have set the mixture screws then set the idle screw to desired RPM. Good luck.

W Head

59 El Camino 348 3-2s
59 Impala 409 2-4s

[w ogden]

Al, I had a similar problem with my 348 and found that the front carb was leaking by at idle. Turned out tobe a misadjustment on the throttle blades. They have to seal perfectly or they will leak by and cause a vacuum leak basically. Usually you can feel this by placing your hand over the carb at idle. If it is leaking it will suck on your hand and normally stall the engine. If you want to isolate it further you could cut out two square gaskets and block the secondary carbs off all together.(disconnect your linkage also) Then you will be running on the center and you can chase the problem from there knowing that you have eliminated the other two carbs. Just a few thoughts, if you haven't done it already. Let us know how you make out.

[fatride]

W head, Al did not state that his front and rear carbs had idle bleed screws! He said just the opposite! You must have read it wrong?? If you have the 2G carbs that have the idle bleeds they are primary carbs and not suitable for the secondary carbs on a three two setup even if you turn the screws all the way in. The throttle blades on the primary carb are not cut to shut all the way. If they are shut they will bind and in some instances will not open at all. Three two end carb throttle blades are thicker and will not get stuck in the throttle bore when shut completely!

[alshotride]

No. The front and rear carbs have no adj. needles. I will do the vac and RPM test though.
Thanks

[alshotride]

WOW, :love I feel very enthused . All the good suggestions. The heck with the 4bbl idea :rofl . With all the help from all of you guys I think I will get it going right :takethat .That is what I always wanted anyhow. When I was a kid with my first 59 I always wanted 3x2s :love . I am encouraged :D , thanks to all of you.
Al
If you want to see the car we are talking about ,I have it in the album. :clap

[saboo]

try this, as fatride stated, unhook the end carbs, a must, cut two circles of cardbard out a little oversized of the 2 5/8 carb intake, tape cardboard over carb opening. now start car,if it idles bad most liklely center carb, but you can squirt a little oil around carb shafts, see if that is the cause of a vacuum leak, if it idles ok at first, open the top of one carb at a time so you can tell which one might be the problem. also almost forgot, check carb gasket on center carb to make sure it is not backwards, seen this twice it just happens. do not give these carbs up, they can be made to run ok. also in Pa there is a guy who sells DAG 213 this is what the factory put on the end carbs in and out on the throttle plates of the end carbs only to help seal them. i have seen this on many a carbs even after a few years, the stuff does last awhile. go luck these guys will help you get it figured out. saboo

[jboatno4]

Would there be a similar situation with a 2 x 4 set up?

Jack

[W Head]

Thanks.
I have the stock pump going. You are talking about the float seat , right? :dunno


Correct, float seat.

W Head

59 El Camino 348 3-2s
59 Impala 409 3-4s

[348NUT]

Just for info, I got the right adapter from Show Cars for about $30 to go from AFB style base to old 4jet style intake. part # is 6169. On the other hand I agree you should keep the tripower! :brow Check out this site: www.vintagespeed.com They have everything you could need to fix your tripower. I was looking at complete rebuild kits for all three carbs with new end bases and plates for about $300. This kit can be used to convert three regular 2gs into tripower. I've never bought anything from them or even talked to them so I can't speak of thier service. I'm planning on rebuilding a tripower setup for my 350/348 to put in my 55. Good luck with yours! NUT :)

[alshotride]

Just for info, I got the right adapter from Show Cars for about $30 to go from AFB style base to old 4jet style intake. part # is 6169. On the other hand I agree you should keep the tripower! :brow Check out this site: www.vintagespeed.com They have everything you could need to fix your tripower. I was looking at complete rebuild kits for all three carbs with new end bases and plates for about $300. This kit can be used to convert three regular 2gs into tripower. I've never bought anything from them or even talked to them so I can't speak of thier service. I'm planning on rebuilding a tripower setup for my 350/348 to put in my 55. Good luck with yours! NUT :)

I will look into it.
Thank
Al :)

[W Head]

W head, Al did not state that his front and rear carbs had idle bleed screws! He said just the opposite! You must have read it wrong?? If you have the 2G carbs that have the idle bleeds they are primary carbs and not suitable for the secondary carbs on a three two setup even if you turn the screws all the way in. The throttle blades on the primary carb are not cut to shut all the way. If they are shut they will bind and in some instances will not open at all. Three two end carb throttle blades are thicker and will not get stuck in the throttle bore when shut completely!


Don't remember ever having this problem running 3, 2s on my old 265 Chevy back in the 1950s, or on my old C/Gaser in 58-59. ( I think the C/Gaser carbs were 2GCs, If I remember correctly) Back then if you wanted 3, 2s you ran 3 primary carbs. Maybe I was lucky.

W Head

59 El Camino 348 3-2s
59 Impala 409 2-4s

[fatride]

Don't remember ever having this problem running 3, 2s on my old 265 Chevy back in the 1950s, or on my old C/Gaser in 58-59. ( I think the C/Gaser carbs were 2GCs, If I remember correctly) Back then if you wanted 3, 2s you ran 3 primary carbs. Maybe I was lucky.

W Head

59 El Camino 348 3-2s
59 Impala 409 2-4s


That's probably true but I don't think you would last on ther street with the prmary carbs as secondarys. One of the reasons that three two's got an awful rep was because a lot of shade tree mech's were placing primary carbs in place of secondarys. Three primary carbs would be almost imposable to tune for correct idle. Secondary carbs for the three two setup were available in 55or 56! They were running correct multiple carbs on flatties before this. Primary carb throttle plates will bind and stick in the closed position. Probably wouldn't be an issue on a drag engine that does not see prolonged idle.