The all carb diet.

[speedtek40]

I use the Misab gaskets and the rubber washers with the cups, I found they work far better than the crappy plastic spacers and thackery washers (which are absolute garbage). I just tighten the nuts until I have a fingernail width between the two cup washers....seems to be the easiest to tell for gap (you can feel it). It worked for me, no more massive leakage problem, although if you're using the nylock nuts, you'll probably have to use blue loctite (the removable stuff) to keep the nuts from backing off. I found that my studs weren't long enough to engage the nylon locking compound before the cups and washers were fully compressed.

Oh yeah....and pics.

[B4S]

That's what I ended up doing last night. The gap (according to the Des Hammill book) is supposed to be 2mm or so IIRC, but that sucks. It tidied up most of my leaks, but since I've got emissions carbs, they've got idle bypass screws on each barrell, and two of them are leaky. I'll be fixing that today, and checking again.

[candm]

turn those bypass screws in until they seat, then tighten the locknut. you dont really need fiddle with them. get the carbs setup and balanced first, using the inner bores of each carb to balance with a flow meter. once those are dialed in, if you feel like it, then adjust your bypass screws to get all bores the same for a little bit smoother idle

[B4S]

Idle air bypass screws completely seated, and the towers they're recessed into are now filled with silicone. Never using them again, and they could be a leak source IMO. I managed to get rid of the leak by going a bit extra tight on the two middle barrels, so I think the manifold isn't flat in that area. I've also got one idle screw that requires a full turn further out than the other three, confirmed by the colortune. I'm expecting another one in the mail soon, so I'll be able to run two at once to compare color of burn. Right now I've got the max rpm out of each cylinder, and turning any screw in more than a half turn results in an RPM drop, so I'm not worried. Once the butterflies open, then it's a non-issue. I have zero intake leaks now, so I'm not worried about a lean cylinder.

[VenaGTi]

success?

[B4S]

Pretty much, I'm a bit concerned with the one idle screw that is radically different, but at least the leak is gone. I'll pop the idle jet out and see if it's the same as the others. If it is, I'll just stop fussing and get to finishing the car .

[candm]

sometimes you will have the mixture screw of 1 bore in or out more than the others. if you are more than 31/2 turns or less than 11/2 turns then you should get a richer or leaner idle jet for that cylinder

[B4S]

On three of the screws I believe I'm at 2.75 turns, and the fourth one I am around 3.5-3.75. As much as I try to convince myself there is no leak, and even though the empirical data (ie: liberal spray of brake cleaner) points to the same thing...I'm not convinced. I'm going to give it one last check tonight, I'll empty a can of brake cleaner if I have to.

[B4S]

@#*&)(@#*$)(@*!_!_+$(%)*(*@)*_!!!!!!!!!!!!!
I'm dumping those silly Misab gaskets and going to the cast aluminum spacers with O-rings I have. I still have massive leaks. This time I sprayed the brake cleaner right down between the manifold and carbs, along the misab edge, and the rpms dropped hardcore .

If the spacers don't work...then I'm going solid. I'm on stock engine mounts with a stock cam...I doubt aeration will be an issue.

[VenaGTi]

maybe take the manifold to a machine shop and have them cut new surfaces on both sides. it can't hurt and it gives you a nice flat to work with. the carbs can be surfaced too, if your willing to take them apart totaly. you can do this in an afternoon as i'm sure you know by now........it only cost me $40 to have the manifold done. when you get the carbs off, check it with a straight edge. good luck and let us know how you do.

[the12for12]

Quote, originally posted by VenaGTi »

maybe take the manifold to a machine shop and have them cut new surfaces on both sides. it can't hurt and it gives you a nice flat to work with. the carbs can be surfaced too, if your willing to take them apart totaly. you can do this in an afternoon as i'm sure you know by now........it only cost me $40 to have the manifold done. when you get the carbs off, check it with a straight edge. good luck and let us know how you do.

[B4S]

Quote, originally posted by VenaGTi »

maybe take the manifold to a machine shop and have them cut new surfaces on both sides. it can't hurt and it gives you a nice flat to work with. the carbs can be surfaced too, if your willing to take them apart totaly. you can do this in an afternoon as i'm sure you know by now........it only cost me $40 to have the manifold done. when you get the carbs off, check it with a straight edge. good luck and let us know how you do.

This will be what happens if the spacers fail on me too .

I was so wound up last night, that I ended up in the garage in my boxers last night, removing the carbs before I went to bed . 10 minutes and they were off the manifold...I love the simplicity of these things.

I will not give up!

[vdub4life_89]

here is mine

[B4S]

Nice! Solexs'? My Mikunis look similar.

[B4S]

Dumped the misab gaskets today, and went with the cast-aluminim O-ring holders. Going on a tip from an Alfa Romeo forum (alfabb.com), I put a bit of high temp grease on the O-rings before installing them in the holders. Also dumped the rubber isolators and cups, straight nut and washer. The leaks, I've discovered now that the manifold is off, is due to the over-porting of the manifold (from previous-previous owner). The misab gaskets overlap into the port, offering very little sealing surface. The O-ring holders eliminate that issue .

Now...I need a new intake gasket, the new one I had on there was gas-soaked and crumbled away .

[VenaGTi]

you don't need a gasket between the intake mani and the head. if your mani is cut flat, just a little bit of high temp copper snot and you will never have a problem. i learned that from Dana of Dana's autosport in N.H. He raced a bunch of 8v rabbits in the 90's and had a shop in Heniker, iirc. i used his advice on my 32/36 carbed motor and never had a problem. again, i had that mani cut too.

[B4S]

There was some gasket residue on the manifold when I got it, maybe I should check it with a straight edge and see what it's like.

[B4S]

Heh...got a goodie coming in the mail, hopefully before the end of the summer. Can't wait .

Might mean I have a dual sidedraft setup for sale, now that it's finally perfect, .

It's still carb-related though...no worries .

[VenaGTi]

Quote, originally posted by B4S »

now that it's finally perfect,

glad to hear it
hope to get mine running soon too. still resolving some a/c issues. yes, that's right....a/c on a dual carb set up. ought to be a freakin' nightmare

[hans j]

carbs... soon to be just throttle bodies.

[CozySpeed]

counterflows on carbs my dream engine, some day

[B4S]

Heh...got my tracking number today .

My dual carb setup might be for sale sooner than expected...

[VenaGTi]

and what exactly are we tracking now?
didn't ya just get your shizzz to purr?

[B4S]

Yep, but I've always had a nagging doubt in the back of my head that my dual carb setup goes against the plan I have for the car. I'm more concerned with low end driveability, grunt, and getting the best fuel efficiency I can get out of a carbed car. I'm wasting dual carbs on grandpa-driving IMO.

I'm not dead-set on swapping them out just yet though...it's just nice to have options .

[speedtek40]

You can't grandpa drive dual carbs. Your right foot will take over and won't let you................

[candm]

learn dual carbs and the force will be with you

[VenaGTi]

wait...these are NOT the carbs i was tuning....

[B4S]

I can't keep it in any longer, this is what I'm waiting for:

My plan was to use one of the Mikunis on it, but I can't find any Mikuni PHH pump jets . They currently have 40s, but I would need some that are a tad larger, like 48s or 50s. My Dells are emissions units with 5 LARGE progression holes, and until I see how the tuning goes on the dual setup, I'm not going to commit one of them to the new manifold setup. My other option would be to buy more carbs...twist my arm .

[VenaGTi]

twist twist *cough *dcoe 45 *cough*coughand one more twist

[B4S]

Trust me...I'm already eBaying .

[MkIIRoc]

Single 48 or 50 is way overkill. When you have a 1 barrel per cylinder setup, each draws through a 40, 45, 48, etc barrel. With 2 cylinders per barrel, each one is still only drawing through one barrel, one cylinder at a time. Put a single 40, maybe a 45 on that manifold and be extremely happy with it.

[B4S]

Oh yeah, if I do end up running it, which is entirely possible seeing as how I just got finished with the struggle to re-balance by duals and am fed up to *makes chopping motion at forehead* here, I'll be using a 40 with 34mm chokes.

I just got finished reassembling everything, and FINALLY have no leaks.

[the12for12]

Quote, originally posted by B4S »

My plan was to use one of the Mikunis on it, but I can't find any Mikuni PHH pump jets . They currently have 40s, but I would need some that are a tad larger, like 48s or 50s.

$6 each

http://www.wolfcreekracing.com/

[the12for12]

Quote, originally posted by MkIIRoc »

Put a single 40, maybe a 45 on that manifold and be extremely happy with it.

Baja recipe of success for years !!

[B4S]

Quote, originally posted by the12for12 »

$6 each http://www.wolfcreekracing.com/

Hot DAMN! I completely forgot about those guys! Thanks for the memory jog, I'll be ordering some larger pump jets, 1.8 needle valve, and maybe some 34mm chokes (if they still have any) .

I love this forum, and GREATLY appreciate the sharing of info that isn't common knowledge anymore. for all!