I am new to this forum, but I have already found a lot of nice post while surfing here - lots of info on the 472s and 500s
Anyhow, I have a 1974 472 in my Coupe Deville and am planning on a massive upgrade after my US vacation in March . Currently, the stock Q-Jet is leaking badly (fuel and air) and I was thinking about one of the following options:
- Get a new Q-Jet
- Get a new carb (non-Q-Jet, no clue what...)
- Get a 670cfm Holley TBI (2-Barrel)
or get a 700 cfm Commander 950 Holley TBI.
For that, here is my question: Has anyone installed either one of the TBIs on a 472/500? My goal is not (necessarily) to get much more performance, but a better running engine (better idle, smoother "pull" to, say, 4000rpm, and maybe even a little better economy) - The performance will come thru the new Edelbrock intake and the reworked heads. For that, I would like to know how hard the installation & setup was? Also, what additional parts were needed (distributor, etc etc??). Thanks!!!
Well it all depends on if you're a Q-Jet guy or not. Most will argue that Q-Jets are awesome and one of the best carbs out there, and some will not. I myself put a 750cfm Edelbrock squarebore on my 472 and like it a lot. My old Q-Jet was very beat up so I needed the new carb and went with non q-jet. I don't think I'd go with a 2 barrell for a big engine like a 472 though. I believe the stock carb on the 472 is a 750cfm (that's all that I found from researching on the internet), but some people say it's 800cfm. I still think that's a little too big for stock so I'm sticking with around 750cfm. Hope this helps you out.
Well, I admire the concept and function of the Q-Jet and was, so far, quite happy with it - it certainly operated good during the non-stop cruise from Phoenix to Miami last year. But as it is broken now and I really have no clue of how it actually works (with few shops in Germany to work on it), I was not looking at buying a new one. I am more of an electronics person and tuning a car with a laptop is easier for me than tuning a carb (me thinks).
Anyhow, I went to the other forum and posted my questions there. I just want to avoid buying a 1300 USD system and finding out the hard way that it wont work on the Cad.
Those EFI setups are pretty expensive. Go with a new carb. Q-Jets are Ok, and some people build them, but I personally prefer an Edelbrock. It doesn't have the design issues that allow it to leak like the Q-jet does, and it doesn't have some of the maintence issues Holleys have. Take the money, and put it into other mods. Also, did your car come with A/C? If so, you might have some trouble installing that intake. I believe MTS (http://www.500cid.com/) sells a bracket that you can use with a different compressor to keep your A/C system.
P.S. Someone should know the rules better than that.
__________________ David Smedley
1968 Cadillac Sedan Deville, 81k Original Miles!
1987 BMW 325iC, 240k
1994 Chevy G20, 152k
Wie geht's German472? I run an Edelbrock 650 on my 350 Chevy and it has given me over 100,000 miles of trouble free operation. For my fairly modified 425 Caddy engine I'm using the Q-Jet that I modified to suit this engines needs. As for leaks, re-bushing the throttle shafts should get rid of any vacuum leaks and sealing up the plugs under the carb with some kind of liquid weld, like J-B Weld, should cure that. ( They're supposedly notorious for leaking fuel from those plugs.)...P.S. I could see that engine swapped into a great handling BMW or similar auto and speeding around Koeln at madcap speeds
Wie geht's German472? I run an Edelbrock 650 on my 350 Chevy and it has given me over 100,000 miles of trouble free operation. For my fairly modified 425 Caddy engine I'm using the Q-Jet that I modified to suit this engines needs. As for leaks, re-bushing the throttle shafts should get rid of any vacuum leaks and sealing up the plugs under the carb with some kind of liquid weld, like J-B Weld, should cure that. ( They're supposedly notorious for leaking fuel from those plugs.)...P.S. I could see that engine swapped into a great handling BMW or similar auto and speeding around Koeln at madcap speeds
Hi Angela. Mir gehts gut, danke Well, I think I will go with a Q-Jet for now and keep my eyes and funds open for a future upgrade to some kind of Fuel Injection - I heard that CadCompany was working on a TPI-kinda setup. And for then, I will get a new Q-Jet. I wonder if a JET Stage II will already be sealed up?
The BMW idea sounds great, but I got an old Mercedes and the fourbanger in it is good for somewhere around 230 km/h - I think thats enough for Koeln
Another good Rochester book is the "Haynes" techbook series book on Rochester carburetors. Plenty of good Hi-Po modifications in there also...By the way, German472, I've gotten a speeding ticket on one of your Autobahns outside of Dortmund at 7:00 am on my way from Koeln to Berlin.I would be on one of the few Bahns to have a speed limit on it!
Another good Rochester book is the "Haynes" techbook series book on Rochester carburetors. Plenty of good Hi-Po modifications in there also...By the way, German472, I've gotten a speeding ticket on one of your Autobahns outside of Dortmund at 7:00 am on my way from Koeln to Berlin.I would be on one of the few Bahns to have a speed limit on it!
Jeez, Angela. How did you manage to do that? Anyhow, are you living in Germany or just visiting from time to time?
Early mornings and early evenings are bad times for speeding. But sorry to hear that you got a ticket. I hope it was not too much. I got a speeding ticket the first week I had my drivers license (doing 50 in a school zone might not be smart, but I was late for class ). But that was the last one never got caught again.
Oh, talking about books. Does anyone have Doc Frohmanders Big Inch Caddy book? I was trying to get it thru amazon, but they dont have it. I wanted to buy a few good Q-Jet books and that book, but it really is a pain to have to go thru multiple sources (shipping just multiplies...)
Greetings and hope you all have a good new year!
Andreas
Actually I'm of german desent ( my maiden name was Reiss) and haven't gotten to visit since '92, but i do speak almost fluent german.The ticket was 20 marks but I noticed the ticket had 10 marks outlined in red, so I think the cops ripped me off for 10 marks. They took the money right on the spot. I have the "Big Inch Caddy" book and found it somewhat useful in my 425 re-build, but it's nothing special. It can be bought through "maximum torque specialties", the place where many of us purchase parts for our engines.
TBI on a 472? 
. Currently, the stock Q-Jet is leaking badly (fuel and air) and I was thinking about one of the following options:
Re: TBI on a 472? 
