1st Generation Specific (1979-1985) 1979-1985 Discussion including performance modifications and technical support sections

13b downdraft manifold?

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Old Jan 6, 2007 | 11:31 PM
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13b downdraft manifold?

I'm going down after class (happy to be back in school...) monday to see what can be done, but I'm sensing a rebuild. I bought the car expected that but I was optimistic.. anyway hopefully it's somewhat rebuildable (I have 2/3 compressions on the rear, someone told me that my rear iron is probably toast fpr the side seal ) Anyway since this will not be an everyday car I'm considering a street port and a carb swap for simplicity sake. My question is that I saw a carb upper manifold (meaning I assume that you use the stock efi lower intake and can bolt a carb on top after plugging the ingecters) I dont remember where and I think it was sidedraft. does anyone know where I can find a manifold like that but for a more common (i.e. holly) downdraft?
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Old Jan 6, 2007 | 11:38 PM
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I found some downdraft manifolds (the whole one). I might have made that up about the upper, dont even know if the manifolds are split. anyway, would a normal 650cfm holly work for this?
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Old Jan 6, 2007 | 11:55 PM
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The recommendation for a street port 13b is a 600CFM.
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Old Jan 7, 2007 | 02:31 AM
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The recommendation is a 600cfm, but a 650 will work just fine. Either go with the RB holley, or use an Edelbrock 600CFM like I am. I've got a stockport NA S4 engine running quite nicely on the 600 edelbrock performer series. Seems to really like a lot of fuel though.
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Old Jan 7, 2007 | 08:12 AM
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run a side draft with the rb beat upper manifold very easy setup to tune
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Old Jan 7, 2007 | 08:39 AM
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the rb upper is for a Dell'orto carburetor, I couldn't find those anywhere. Everything that I read said that they dont make them anymore
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Old Jan 7, 2007 | 09:39 AM
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Originally Posted by josh...just josh
the rb upper is for a Dell'orto carburetor, I couldn't find those anywhere. Everything that I read said that they dont make them anymore
That manifold also fits Weber/Mikuni and OER carbs which there are plenty out there. IMHO the side draft carbs are a better choice.
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Old Jan 7, 2007 | 09:58 AM
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I have a Holley, and before the engine went bye bye on me, the flat spots around corners would kill you. The carb was a good line - so long as you kept going straight. Go with a Weber, Mikuni, or OER Carb. Simplicity makes them much easier to tune and they don't get flat spots half as bad as the Holley does.
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Old Jan 7, 2007 | 12:43 PM
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i wonder if the racing beat prepped holley does this or if it is magically cured with the wave of mederer's magic wand? i am buiilding a bridge at some point when i have the time (and chassis-i have all the engine parts) and am debating on using the 650 douple pumper i have or buying the racing beat version. ive heard many good things from owners who have the RB prepped ones about just bolting up and goin' with no tedious tuning or troubleshooting
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Old Jan 7, 2007 | 03:21 PM
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An old trick I have seen done on old nikki or maybe hitachi carbs was the installment of 4 springs in the barrels of the carb below the venturi.
While your driving around normally, the fuel will flow past the dangling springs with little or no noticable effect, leaving a bit of fuel condensed on the springs surface.

But...when the car is turned hard and subsequently starved of fuel for a fraction of a
second where you would have felt a lean bog, the fuel on the springs will atomize in the oxygen rich air and add the little bit of fuel needed that the carb just couldnt give you.

This may sound crude but it has shaved seconds off lap times on a short track for people I know. An old racers trick, but I dont see why it wouldnt be an option for those who experience starvation when cornering (ie: you holley guys). Just make sure that those dangling springs are gonna stay in the carb! haha
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Old Jan 7, 2007 | 08:28 PM
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Talking what is this crap

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Old Jan 7, 2007 | 08:44 PM
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Wacky I have seen that pic so many time but dont know if i ever seen the rest of the car.
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Old Jan 7, 2007 | 08:49 PM
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man I like the way that looks...normally I'm against all things carb'd, but it just cleans up the engine bay so much. I know that a lot of things can be taken out of the SE's engine bay, but nothing simplifies it like a carb.
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Old Jan 7, 2007 | 08:57 PM
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How is the car to live with with an aftermarket carb? Does car have problems with engine flooding like with the efi? does the car stumble or hunt when you drive it. the fact that all of these sidedrafts don't have a choke makes me wonder...Iowa can be cold in may
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Old Jan 7, 2007 | 09:42 PM
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got a dellorto setup i will swll you and it does have a choke
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Old Jan 7, 2007 | 09:54 PM
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Talking

Originally Posted by nick812
Wacky I have seen that pic so many time but dont know if i ever seen the rest of the car.

here ya go.



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Old Jan 7, 2007 | 10:32 PM
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Originally Posted by wackyracer
48 IDa weber/2nd gen alt/2nd gen fuse block/Msd blaster coil/2nd gen leading coil/MSD 6AL/relocated battery/inline FPR with top mount guage/adapter block for mechanical guages/2nd water pump housing/fiero/taurus fan/modified camber plate/fram oil filter(WTF)/lots of nyties and a pair of red cutters. Did I leave anything out?
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Old Jan 7, 2007 | 10:57 PM
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From: Iowa City, Ia
I thought the 48 IDA was sidedraft not down? gorgeous engine bay...love the simple. it seems to me that an EFI rotary takes a lot more to make work than an EFI piston engine. I have no idea what half the sensors under my SE's hood are!
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Old Jan 7, 2007 | 11:06 PM
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LOL Thanks wacky i have seen pics of the outside before just didnt relize it. I am getting ready to swap to all mechanical gauges. I am doing the 2nd gen coil and 2nd gen fuse box. LOL seems like I am going the right way with this.
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