Holley 4175 anyone?

[Bigerik]

Hi All
Anyone ever run a Holley 4175? In this years catalog, they are listing the 080555C as a direct TQ/QJet replacement, with all vacuum fittings, etc.
Anyone ever run one? How do they tune? How do they run? Is the fuel mileage decent?
Thanks!
Erik

[fox]

20 plus years ago I used a 4175. Spread bore, ran real lean at first and the idle screws are backwards.
Good street carb after it was tuned and the mileage was up.
It replaced a 2 bbl set up - manifold also.

[Bigfoot]

I ran one last winter. It was a new model that I purchased when I was in Montana on vacation and brought it back with me. Installing it on the stock 4 barrel manifold was a pain in the rear end. The bowl hung down so low that you can't put the 4 screws for mounting in the holes and bolt it up. You have to take off the bottom plate, insert the mounting bolts and then put the plate back on the carb. You then have the job of trying to thread the bolts into the manifold with the carb in the air because if you put the carb down the bolts will get cought on the bowls. So in a nut shell, figure at least 45 min. just to secrew the 4 bolts in. The plumbing wasn't to bad, there of course was no literature that explained which ports were which, I actually asked here for help and someone pointed me in the correct direction. This model had the electric choke and took for ever to open fully, I fiddled and diddled until I could at least drive away in under 5 minutes, annoying as all hell if you are in a hurry. Those problems aside the carb did run really good once warmed up. It never failed me all winter and gave me good gas mileage at about 15 mpg in the city for winter. I changed the cam on my car and added headers and dual exhaust and the carb would hardly idle becasue I needed to increase the jets a bit. After fiddling around with various sizes I think I ended up with 63's instead of the stock 55's. Remember, I had to take the carb off each time a tried a different set of jets, no big deal on other setups but a horror story on this one. Mileage was about the same which kind of sucked because I added a better cam and headers to the equation. I was given a 73 340 thermoquad and I rebuilt it and tried it for the heck of it. Once I found the correct rods for my setup the Holley has sat in the garage in a vacuum sealed container as a back up. I get 17 mpg in the city with the thermoquad and when I need the power it is there. The Holley was good but this thermoquad is better in my books.

[skankweirdall]

I agree with bigfoot on this one. The TQ is a better carb in this application. I *might* even take a Rottenchester Quadrobog over the Holley in this instance.

[b-1ken]

Bigfoot: Why didn't you install studs onto the manifold? You could then just drop the carb on and spin the nuts on.

[Bigfoot]

b1-ken: When I switched it over it was on a Saturday evening and the stores were all closed. Stud's would have made it a bit easier but really there isn't much room to manover in there between the bowls and the baseplate. Especially on the back two there is barely enough room to even fit a wrench in to tighten the bolt, not thought out really well, and for a big guy like me it was a pain. In all fairness to the Holley I realy didn't know much about it and I am sure somebody more knowledgeable could have got the choke working correctly so you didn't have to sit there for 5 minutes before you moved. But as I said I love the thermoquad and it is working excellent for me.

[pishta]

are we talking about the zinc spreadbore carbs that have the fuel fitting coming off the front of the front bowl? I ran one on my 340 years ago and the thing idled like a swiss watch. I never had a carb idle my motor better. the performance was decent but never had to do any tweaking on it. I bought my Demon because I went to a square bore intake and got a great deal on the Demon. I have much better mid and high end power with the Demon, but my idle is a bit lumpy. Im sure I could fiddle with the air bleeds and stuff, but Im not too bothered by the lumpety lump. Now the silver round looking Holleys are a strange breed indeed!