67 imperial holley carburetor issue

[78Brougham]

Hi everyone, My 67 Imperial is acting up. The secondaries keep weeping gas into the engine after I shut it off and of course the oil is getting thinned out because of it. I've checked the float levels in both front and rear and they are perfect. Do you guys have any other thoughts? I believe its a 600cfm but there are no tags left on the carb to find out the exact model.

Where would I get a rebuild kit for it. Anyone have the kit number? I figured I would go that route first. If that doesn't work what replacement carb would be a close fit?

Thanks,

Kenny

 

[detmatt]

I have a spare one of these. R3667, part # 2843151 and the book says it's a 570 cfm. It's a model 4160 which are still available.

 

[70bigblockdodge]

Buy a eddy thunder series carb, better performance, better mileage, better reliablity hidden under the air cleaner. Put the original carb on the shelf and send it to the next caretaker of the car. Way ahead with$$$ and time.

 

[66/440]

+1 Totally agree.

 

[detmatt]

Yep that's what I did except I went with a performer series, just have to reroute the plumbing and maybe adapt the linkage a bit? My '67 already had an old avs on it so the Eddy was literally a quick swap.

 

[78Brougham]

Hi Guys, What is the model # from Eddy? I looked on the net and my head was spinning with all the different carbs on there.

 

[commando1]

650 Thunder.....#1806
800 Thunder.....#1813
______________________

600 Performer..#1406
750 Performer. #1411

 

[detmatt]

Actually I think the 600 CFM Performer is #1406. That being said, I have read mixed reviews on the #1411 after I bought one of course and I ended up going with the #1406 and found it much more responsive on my 440.

 

[70bigblockdodge]

I personally would to with 650 thunder series, the air valve secondaries are easy to tune with spring tension. I would normally say the 800 but I am starting to realize that not everyone wants to turn a engine to 6000 rpm. The performers are good as well just has a less ideal counterweighted secondaries.

 

[78Brougham]

Thanks for the input guys! To me it seems like the performer 1406 May be the way to go.I just want it to run good and an imperial doesn't need to crank out 6000 rpms to often. Maybe if it was a Road Runner lol
How difficult will it be to hook up the linkage, choke etc. Are the secondaries going to be vacuum or?
Sorry for all the questions.

 

[commando1]

Guys, what does 78Brougham have on there now. Sq. or spreadbore?

 

[detmatt]

Thanks for the input guys! To me it seems like the performer 1406 May be the way to go.I just want it to run good and an imperial doesn't need to crank out 6000 rpms to often. Maybe if it was a Road Runner lol
How difficult will it be to hook up the linkage, choke etc. Are the secondaries going to be vacuum or?
Sorry for all the questions.

You will need to reroute the fuel line as the carter's inlet is at the top rear on the passenger side. I got one from inline tube but for now you can just plumb it using rubber hose. You'll also need one of these linkage kits.
http://www.edelbrock.com/automotive/mc/carburetors/access-throttle.shtml
Stan, the Holley he's replacing is a sq. bore.

 

[1978 NYB]

I have used the Eddy 1406 carb on a dozen different cars over the years. Never had a problem. Bolt on, no adjustments and go. I haven't used a Thunder carb yet, I might try it since the Performer carb I have for the Newport is still in the box.

 

[78Brougham]

What did you guys do for the electric choke... does there need to be some kind of timer or just tap into a hot wire in the harness somewhere as long as it shuts on and off with the ignition... or would you be better off getting the manual one and try to hook up the existing heat-stove choke?

 

[detmatt]

Ran a hot wire from the ballast resistor. Easy Peasy.

 

[saforwardlook]

Agree with all the inputs above - the old original Holleys are just scrap metal for me. You will need a revised fuel line (I think I got mine from Dante's). I referenced a B body with 440 engine and carter carburetor and that line should work for you. For the throttle, Edelbrock sells an adaptor kit for Chrysler products that works fine, p/n 1481 (gold anodized) or 1843 (black). The 650 carb will give you good low end torque/response compared to the 800. Just bolt them on and go is usually my experience, and they seem to give more go off the line than the original Carters, probably due to a little richer flow curve off idle than the factory originals. Might have to adjust the idle is all sometimes. The only negative I find with these carburetors is that they do not have bowl vents, which sometimes makes for long cranking after hot soaks in hot weather, so at least use a thick base gasket with this carburetor to help insulate them from heat a little, available at NAPA for example.

 

[commando1]

. The only negative I find with these carburetors is that they do not have bowl vents, which sometimes makes for long cranking after hot soaks in hot weather, so...

After all theses years I find out.
No bowl vents = hard hot start.
I never made the connection.
Thank you.

 

[78Brougham]

I just ordered the 1406 and the 1481 adaptor. Thanks for all your help and advice. I'll be in touch when it comes in Thursday. I'm sure it will be a cake walk to put in.
Kenny

 

[78Brougham]

Well, I got the carb, put it on, and it runs AWESOME! Thanks to everyone for your advice and support. I dumped the old oil and filter and it never ran better! Will the same carb work on my 73 Imperial as well? I have a starting issue with that one too. Starts fine when cold but I have to hold the pedal to the floor to start it once it warms up...so annoying and embarrassing. Thanks guys!

 

[saforwardlook]

Well, I got the carb, put it on, and it runs AWESOME! Thanks to everyone for your advice and support. I dumped the old oil and filter and it never ran better! Will the same carb work on my 73 Imperial as well? I have a starting issue with that one too. Starts fine when cold but I have to hold the pedal to the floor to start it once it warms up...so annoying and embarrassing. Thanks guys!

It should run very well on your 1973 Imperial too. Just the same caveat with the hot starts, but they should not be as bad as what you are describing currently, but will require some cranking after hot soaks. With your Imperial, you probably have the original Thermoquad Carter 4 bbl carburetor. That model carburetor has some O rings at the bottom of the plastic bowl to seal the fuel pick up tubes. Unfortunately, after time and thermal cycles, when the carburetor is shut off after hot soaks, worn O rings will allow solid fuel to leak past those O rings right into the engine, and will nearly drain the bowls of fuel, making for a compound problem of cleaning out the flooded engine and refilling the bowls to get the engne started again. Thermoquads have other issues with the plastic bowls over time and can cause driveability problems that may not be fixable - at least I have had a couple that I could not get to run right, kind of like every old Holley from that era (but most TQs can be rebuilt successfully). If you get a good Thermoquad that you can rebuild, they seem to run very well. The plastic bowls (phenolic) can to warp in ways that are near impossible to detect and can be frustrating. So the Edelbrocks are good changeovers there too, in those cases where a rebuild doesn't do it, without the need for a new fuel line but you will still need that throttle adaptor.

Steve