Author Topic: carb choice  (Read 2724 times)

Offline dlong70elcamino

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carb choice
« on: December 02, 2015, 06:36:56 PM »
Hello everyone I,m new here and I have a question to ask.I,m building a Qjet for a Chevy 350 in a 70 El Camino car currently runs 13.9 in quarter mile with a 600 Holley.Carbs I have are 7028248,7027262,17058213,7043240 800cfm,7044213,17057213 some are complete and some have parts missing.Trying to decide which to build.Any suggestions? Thanks Dan

Offline Cliff Ruggles

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Re: carb choice
« Reply #1 on: December 03, 2015, 04:19:30 AM »
I would avoid the 7027247 and 7027262.  The 7027262 is valuable to restorer's, might want to consider selling that core if you aren't using it.

The 17057213 and 17058213 and nice carbs for what you are doing, side inlet, 750cfm, both will be divorced choke models.....Cliff

Offline dlong70elcamino

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Re: carb choice
« Reply #2 on: December 03, 2015, 02:01:51 PM »
Cliff so you like the carbs with the single main air bleeds.In your book it says those are hard to tune so I did not look at those.I was leaning towards the 7043240 says its off a 455 Buick and it is a 800cfm and has large bypass holes .109 is what i measured does have large main upper bleeds .118.The other two i was considering were the 7044213 off a 350 trk eng as its almost just like the 800cfm Buick but its a 750 and it has bypass air already in the base.And the other is the 7028248 off the 68 Buick 430 its complete un tampered with but i know it has the old float design.The 7027262 is missing choke parts on the side and internals are gone but the airhorn,base and body are there. If you want that carb maybe we and do some trading for parts for the carb Im going to build.I live close do you I was just at your shop a few weeks ago and bought your Qjet book lots of good info been studying the heck out of it.My engine and car specs are this 70 Elcamino 350 torker2 intake 202-1.6 double hump knock off summit heads 165cc intake runners 10.5 cr cam is 520 lift 234 dur at114 LSA currently idles at 1000 rpm car has T350 trans with a 2800 stall converter 410 gears. Pistons do have .125 domes Dont know if this changes your recommendation let me know. Thanks Dan Long

Offline Cliff Ruggles

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Re: carb choice
« Reply #3 on: December 04, 2015, 03:10:53 AM »
The side inlet SMAB later Chevy divorced choke carbs are nice units, and actually easier to tune than the large MAB models.

The big Buick carb would work, but no real advantage anyplace for what you are doing.

If you are close call the shop, we can take a look at what you have and help getting one of them set up for what ou are doing.......Cliff

Offline dlong70elcamino

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Re: carb choice
« Reply #4 on: December 04, 2015, 10:45:44 AM »
Thanks Cliff those two carbs are the roughest of the bunch but I think they are rebuildible. I looked yesterday and those have bypass air in the base also. Both have baseplate issues one binds and the other has a broken spring on the secondary plate. I live just north of Bellville so I'll be down to get some parts when I get some$$ gathered up. I'm excided to build this carb it's had a Holley 600 on it since I built the engine and I hate that carb never been a Holley guy. I feel the engine has more potential with the right carb......Dan

Offline Ethan1

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Re: carb choice
« Reply #5 on: December 04, 2015, 07:27:55 PM »
I would avoid the 7027247 and 7027262.  The 7027262 is valuable to restorer's, might want to consider selling that core if you aren't using it.

The 17057213 and 17058213 and nice carbs for what you are doing, side inlet, 750cfm, both will be divorced choke models.....Cliff

 I would definitely go with Cliffs recommendations as well. The 7213 and 8213 would be best for what you are doing.

 Also, Welcome to CHP! ;D
Ethan

1972 Chevelle

(oo______oo)

Offline dlong70elcamino

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Re: carb choice
« Reply #6 on: December 05, 2015, 11:05:26 AM »
Thanks for the welcome Ethan.cliff does seem to know his stuff so I'll try to use on of those two carbs. I've been around qjets along time as I worked at a Buick garage for 28 yrs as a mechanic but only stock rebuild and cleaning not much modifying. When I used to drag race years ago I'd do stuff like drill jets and loosen secondary air valve spring and maybe bend up rod hangers and always took that vacuum break off and always had that dreaded secondary bog Lol now I know why lack of understanding I guess so I'm really enjoying Cliffs book.....Dan