new carb build

[cdwelch]

 :)i have a nice 79 buick large body i'm going to build for my winter project. carb number 17059247. it's going on my 388 small chevy with pro action cast iron heads (58cc) 1.94 1.50 valves. dish pistons internal bal. performer intake, comp cams xs262s solid lifter, 477 lift, 262 advertised, 224 at .050, 110ls, 106 center. this will be a 5500 max rpm motor. 80 percent of the time it will be under 2500 rpm. it's a street car for weekends. carb specs are idle tubes .038, idle down channel .055, upper idle bleed .063, lower idle bleed .070, main body air bleed .066 (stock), 74 jet, ax sec. rod, 45 pri. rods.wide open for suggestions or advice.  many thanks

[Cliff Ruggles]

Which 45 metering rod, L, K, etc? 

I'd use 72 or 73 main jets and our .044" metering rods on the primary side, and orange PP spring.  Install a set screw in the airhorn for easy access to the APT screw.

I'm not overly fond of those camshafts, and 262 degrees duration with a flat solid is too small for a 388cid engine unless the static compression ratio ends up pretty low.....IMHO

As for the carb, I would rebuild it with one of our kits, it will contain the high flow upgraded Viton needle/seat assembly, small float, and complete HP accl pump assembly with new springs.  None of these blue seals found in the over the counter kits will hold up in this new fuel.  I'd LOVE to have a dollar for every "blue" seal we get in here from folks having troubles with their carburetors that have failed in this new fuel......I could take the rest of the year off!....Cliff

[Shark Racer]

I could take the rest of the year off!

Now now - we can't have that! Who will I send my friends to for parts?

[cdwelch]

 :)it's a 45k rod. i want this to be a torque motor starting at low rpm. the comp. guys wanted to go with a 268s which is max rpm at 6000. the 262s is max at 5600. this is a street light to street light motor. i would like good vacuum (power brakes) and use the stock converter,and be all in by 5500 rpm with a little rumble to it. i favor the solid lift cams. i have never had a performance hydraulic cam but i am wide open to any suggestions for this type of motor. it's going into my 81 malibu 3:73 rear 350 trans. thank you very much for the response.

[Cliff Ruggles]

It's no big secret but I am NOT a big fan of that line of camshafts.  Not enough seat timing, opening closing velocity too quick, LSA too tight.  Those cams can and will induce running issues as they slam the valves around pretty hard in actual use.  Also keep in mind that a flat solid cam is going to act at least 10 degrees smaller than a comparable flat hydraulic cam.

I'd have to know the true static compression ratio to make a cam choice, but it would be on a wider LSA with at least 10 degrees more seat timing than what you are looking at. 

It would be a flat hydraulic, something around 275-285 seat timing, 112LSA, with the ICL at 108-109 degrees should be about right.

As for the carb, I would install one of our kits, new jets, and our full tapered .044" primary rods, to get it up to par for modern fuel, and it will contain the high flow Viton needle/seat assembly, small float, and upgraded gaskets......Cliff

[dwelch]

 :)thank you very much for the reply. i will search for a camshaft with those specs. this spring when i thaw out. compression is 9.7 w/64 cc head. i have a 58cc head and the pistons are .060 dish with 1.433 compression height,5.7 rod. i will stop by this spring to get the carb kit. i live close by so it will be a nice drive. the kits i have in my carbs now are napa kits from the late 80's and early ninety's. i'll probably have a few questions about a couple of the carbs.(i'm keeping four of them).   denny

[Cliff Ruggles]

Sounds great....Cliff