Guest Anonymous Posted April 18, 2003 Share Posted April 18, 2003 Has any one used a 4bbl manifold on a Z motor? if so, what size carb did you use, and any tips when doing it? thanks Quote Link to comment Share on other sites More sharing options...
Lockjaw Posted April 18, 2003 Share Posted April 18, 2003 There is a thread about this already, I have seen it in the past couple days. But to answer your question, most people run a holley 390 CFM 4 barrell, and this is not the best way to go. SU's are a better choice. If you want a manifold, I have a friend who has two in his shop he would like to get rid of. Quote Link to comment Share on other sites More sharing options...
Poundz9oh9 Posted April 18, 2003 Share Posted April 18, 2003 I'm kinda looking for one of those manifolds. How much are they looking to get for one? Quote Link to comment Share on other sites More sharing options...
Lockjaw Posted April 18, 2003 Share Posted April 18, 2003 Well he has two of them, and one is better then the other, I am not sure exactly why. If you would like, PM me and I will give you his phone number and you can call him. Quote Link to comment Share on other sites More sharing options...
Guest Zcarsmakemyheadhurt Posted April 18, 2003 Share Posted April 18, 2003 I've seen a few L6's with this set up that work. Correct cam selection and proper head/manifold porting make it work. Quote Link to comment Share on other sites More sharing options...
geotek Posted April 19, 2003 Share Posted April 19, 2003 I bought a '73 rust bucket recently and it has that set up. I don't know anything about it, but someone who does told me it's crap. I have no experience with it, but I don't know why it wouldn't work well. If you'd like more information, I can post some info from the intake. George Rust Technician Quote Link to comment Share on other sites More sharing options...
Guest thepenguin99 Posted April 19, 2003 Share Posted April 19, 2003 I think the reason it doesn't work to well is the 90 degree bend right below the carb. The same holds true for weber DGVs. Keep in mind I have no experience with either of these carbs. Quote Link to comment Share on other sites More sharing options...
Guest Zcarsmakemyheadhurt Posted April 19, 2003 Share Posted April 19, 2003 I like the 4brl on a Clifford 6=8 intake. Better on the street and makes better torque than the 6 pack. It will work on the boost also. Quote Link to comment Share on other sites More sharing options...
Guest JAMIE T Posted April 19, 2003 Share Posted April 19, 2003 You could weld some injector bungs to it and use a carb style throttle body for a decent EFI set-up. Or if nitrous was you bag, it would be nice, since you can stack plates for multiple stages under a carb. Quote Link to comment Share on other sites More sharing options...
Joe-Z Posted April 19, 2003 Share Posted April 19, 2003 i have the 4bbl manafold on my 71 but i got the one that hooks up right to the su intakes and it also has a 75 shot of nitrous on it,plate under the carb. this set up runs great and i have never had problems with it,and its very easy to tune. Quote Link to comment Share on other sites More sharing options...
Guest DaneL24 Posted April 20, 2003 Share Posted April 20, 2003 I don't think using the 4bbl on the L28 is a very good idea. Flow and fuel distribution will be a problem. Compare the SUs to the 4bbl. The SUs are side draft carbs, meaning that the air takes a relatively straight path to the engine (good for flow). The 4bbl is a downdraft carb, meaning the air will have to make a sharp 90 degree turn before entering the engine (bad for flow). Now look at the differences in the intake manifolds. The SU intakes use runners of very similar lengths/shapes for good air/fuel distribution. The 4bbl manifold will have intake runners of greatly different lengths/shapes, which won't be good for fuel distribution. It may run lean on cylinders 1 and 6 but rich on cylinders 3 and 4. The fact that the SUs are dual carbs as opposed to a single carb helps to avoid this problem. SUs were designed for L6 motors and 4bbls were designed for V8 motors (which both have completely different manifold designs)...there is no disputing that. You can't take parts designed for completely different applications, put them together, and expect them to work BETTER than before, it just isn't logical...even if it does supposedly still "work". If your L28 has high fuel demands, just get the right needles/jets for your SUs and tune them, but a 4bbl just isn't the way to go. Quote Link to comment Share on other sites More sharing options...
Lockjaw Posted April 20, 2003 Share Posted April 20, 2003 So are all V8 manifolds equal length with regard to runners? Just thought I would throw that question out there. Quote Link to comment Share on other sites More sharing options...
Joe-Z Posted April 21, 2003 Share Posted April 21, 2003 4bbl might not be the way to go,but i do have equal length runners due to having the 4 bbl bolt up to the SU intakes. and in order for me to change back to Su's witch i don't plan on doing i would have to change my whole fuel system and take off my nitrous. Quote Link to comment Share on other sites More sharing options...
fl327 Posted April 21, 2003 Share Posted April 21, 2003 dont take off the nitrous please. su's are good carbs period, if you maintain them and run a good air filter on em, but they dont like being rushed or forced in general, wheras a 4bbl, can be made to run plenty juicy juice really easily, depends on application i guess. a 4bbl nitro setup just seems easier to tune, i guess really much on the rich side, since it does have to make a 90 degree turn, vs. the su straight shots, anyways it depends on application, holley edelbrock parts are cheaper. Quote Link to comment Share on other sites More sharing options...
Mudge Posted April 21, 2003 Share Posted April 21, 2003 So are all V8 manifolds equal length with regard to runners? Do you mean on a V8 car or on a Z car? I dont believe I've seen an equal length intake for a 4 barrel for a Z car yet, it would look very functified if it were accomplished. With the carb in the center of the intake, and the intake reaching across the length of the L28 head, it would have very long runners in the center to achieve equal length with only one carb, and I've never seen it yet. Quote Link to comment Share on other sites More sharing options...
Guest Damn Cracker Posted April 21, 2003 Share Posted April 21, 2003 I'm pretty sure v-8 intakes don't have runners that are exactly the same length, but they arent different enough to make it a problem. Quote Link to comment Share on other sites More sharing options...
Guest Zcarsmakemyheadhurt Posted April 21, 2003 Share Posted April 21, 2003 The Clifford intake does have stright and even and you have lots of material to port and shape. I'm not going to go off on why I don't always think multi carbs is the way. How driveable is a daul carb set up, on a car that makes good power with a cam? How much vacume does a daul set up produce? Is it enough to use the brake booster correctly? How much torque can you make with them, do they operate well under 3000rpm? I know that you can switch from 380cfm to 750cfm with the Cliford intake and they do flow very very well. Even with a so called bend. If you build a hi RPM screamer of a engine go with duals. If your looking for a engine to keep on the street or drag strip let me know I can put a combination together for you. Good Luck Quote Link to comment Share on other sites More sharing options...
Guest Zcarsmakemyheadhurt Posted April 21, 2003 Share Posted April 21, 2003 The Clifford intake does have stright and even runners and you have lots of material to port and shape. I don't always think multi carbs is the way. How driveable is a daul carb set up, on a car that makes good power with a cam? How much vacume does a daul set up produce? Is it enough to use the brake booster correctly? How much torque can you make with them, do they operate well under 3000rpm? I know that you can switch from 380cfm to 750cfm with the Clifford intake and they do flow very very well. Even with a so called bend. If you build a hi RPM screamer of a engine go with duals. If your looking for a engine to keep on the street or drag strip let me know I can put a combination together for you. Good Luck Quote Link to comment Share on other sites More sharing options...
Lockjaw Posted April 22, 2003 Share Posted April 22, 2003 So are all V8 manifolds equal length with regard to runners? Do you mean on a V8 car or on a Z car? I could have some fun with you, but I won't this time. Quote Link to comment Share on other sites More sharing options...
Guest Venture-Z Posted April 22, 2003 Share Posted April 22, 2003 I have the same set up, a holley 390 with the manifold that bolts up to SU intake. I haven't got it on the car yet. I'm in the process of building my motor, it's a F-54 with an N-42 head and a mild street cam. Any tips or is it pretty straight foreward? Also, someone said something about porting? Quote Link to comment Share on other sites More sharing options...
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