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Hi this is my first post here. I have a 1969 442 that my father bought and we cleaned the car up pretty well when I was in Highschool. The experience is what took a small passion for cars and turned it into a lifetime hobby. A "professional" shop did the work but I got to be a large part of the process. Fast forward 15 years and he has put maybe 1,500 miles on it and I have put the other 3k-5k on it. He has had a few pretty crappy mechanics try to maintain it to not much success.
So I am going through the car and trying to get it running properly and back to him before he loses his license due to age and I am having some trouble. I am an armature garage mechanic in training but I am just clueless with carburetors. The car was put back together with an "RV" cam I think it was called. It has an Edelbrock intake and a Berry Grant Demon 650 carb.
I was told by a local tuner that those carbs were made with crap Chinese parts and its not worth rebuilding. I need to do something because it is spraying gas on top of the intake. The car has never run properly. My dad had it dyno tuned while I was active duty a decade ago but it still never ran right. One of the other issues had been the gas pedal sticking. He had a few "mechanics" look at it but no one realized the throttle cable was a 1/2 inch too long and binding up... also means the carb has never seen WOT..... Not sure how the car was ever tuned as the gas pedal could not put the carb into WOT. Am I missing something? I just got the car in my garage a couple months ago and started getting to work a few weeks ago. Goal is to be on the road by summer.
So any advice please! Ditch the carb and get a new one? Which brand and model? Holly owns Demon now and will take 12 weeks or more to rebuild and $250. I have hit all of my local contacts and do not have anyone I trust to rebuild my current carb.
Last edited by Alatar; February 6th, 2021 at 11:02 AM.
Your issue might be as simple as the float being too high or too much fuel pressure.
Any concern with todays gas gunking it up? If its that simple, do you think a rebuild is till in order? I am 1,000 miles away from my dad so it need to be as good to go as I can get it. He can't maintain it.
The Rochester carburetor for your carburetor engine (1969, 4-4-2) can be identified by following the advice on this thread (URL link below). Perform a search on this CO site and/or the Internet, they pop-up with some frequency; and, they are simple/easy to work on.
Will that carb match up with the modifications? Will the stock carb ... choke?.. bottle neck?... the larger intake and cam? Does not need to be a race car, just solid cruiser.
I cannot provide an answer - an RV cam is nothing more than a towing cam. I have absolutely zero knowledge about anything (pistons, cylinder bore, machined heads, block, etc.) on your car and apparently you do not, as well. Therefore, I cannot answer your question. Do not expect any work you perform or might have performed in the future (e.g. carb rebuild) including a correct Rochester carburetor to be a 'Plug-N-Play' scenario - that is not going to happen. It should not take any effort to 'tune' the carburetor to your engine, but it's not Plug-N-Play. You have an E'brock intake with a Demon carburetor that may not be any issue to swap over, but it may be an issue, as well. I have no knowledge about any carburetor throttle linkage modifications and/or fuel pump>carburetor intake line matings. Again, this is not Plug-N-Play - you will need to examine (carefully) what you currently have installed and continue to research to make an informed decision. You've only just begun. Do some research, continue to ask questions you'll receive good advice from many members on this forum. You already heard my suggestion, others may provide different suggestions - it's your call based upon the input you receive and the research you perform on your own. Eric has provided a good suggestion - again, this is not a Plug-N-Play deal, Eric's suggestion may work well for you - do you have the knowledge to work on the internals of the carburetor or the willingness to learn. You've started in the right direction, you said you have until summer as an end-point to get this working for your Dad. Good on you for getting it running for him so he can enjoy. Continue to ask questions.
Thank you for the support. Honestly I am in the middle of a complete top and bottom end rebuild of my track car and I am doing the bottom end myself. So as a matter of time, I will need someone else to do any rebuild work necessary and Ill have to take it to someone to tune. I would only be doing the install work. I would love to acquire these skills in the future but now is not the time sadly.
As to the motor it is stock internals, bore size, pistons, rods. They honed the cylinders and balanced the motor. Only internal change was the RV cam to give it a lope for my dad.
You need to know if that Edelbrock intake will accommodate a spread-bore carb like the QuadraJet. A Performer should. If not a 650-750 cfm vacuum secondary Holley will work well provided it's set up right. Big mechanical secondary Holleys on a mild street engine are good for nothing but dumping fuel and bogging an engine that isn't set up to handle one.
Bound to be tough trying to do this long distance. Tell us where your dad is and someone may be close enough to proxy for you till you can get there yourself.
**edit** just read the car is with you.
Last edited by rocketraider; February 6th, 2021 at 12:30 PM.
Only internal change was the RV cam to give it a lope for my dad.
That doesn't really make sense. An RV cam is a mild cam, similar to a factory cam, and should idle smoothly without a noticeable lope. The name derives from the camshaft profile used in an RV engine, which would need low RPM torque and smooth operation. Have you ever heard an RV loping at the stoplight, ready to rumble on the green? Probably not. So does this engine have a lope at idle? If so, that's more than an "RV" cam.
X2 3310 if the intake doesn't work with QuadraJet. Get an electric choke version for better driveability.
Used to get real tired of Chevy-heads yapping about "850 dobble-pompers" on a relatively stock 350. Too much carb for not enough engine. When you'd tell them that, and that was why the car ran like ***** sucked gas and belched black smoke and bogged when they got into it "Naw! Naw! 'At's what (insert Chevy magazine) said I needed!" All the while a QJet equipped car was running circles around their "850 dobble-pomper".
Ok so no one seems to be suggesting I rebuild my carb and that tracks with some advice I have gotten locally.
So now its a matter of what to change it to. Are Holly carbs as good as they used? I had heard to stay away, it is crap now made in china now.
I am looking at some Rochester quadrajet carbs on Summit and I only see 750cfm and up. Is that going to be too much?
I think Koda probably hit the nail on the head with the inappropriate name of the cam. I know that's the term that was used at the time but sloppy would fit the shop in question.
I will dig into the quadrajet thread tonight. Thank you all for the replies! This seems like a really nice forum, that can be hard to find.
Any 650-750 AVS carb with the correct bore pattern will work, (Square or Spread).
Ebrock makes a nice very tunable carb, the 1900 series...(buy the rod & jet kit), Watch the vids and learn how to interrupt the tuning graph.
It's the easiest shade tree carb to tune.
A Qjet is not a shade tree carb, however, it is superior when properly set up. Call Cliff Ruggles at Cliffs Performance.
Fusick or Year One will have restoration parts, cable, bracket etc.
Any carb can be rebuilt. Buy a high-quality non-chineasium carb kit.
ALL carbs need to be properly tuned. No such thing as ready to go out of the box.
The ignition system and advance curves will need to be tuned along with the carb to extract 100% of the performance potential.
Timing should be:
~12* base at curb idle with the highest possible vacuum signal.
8-10 on vacuum advance canister.
~38* all in under 3000RPMs
Need more info ask.
__________________________________________________ _____________________________________
Spread bore = 2 big & 2 small intake holes, bores.
Square = all 4 holes are the same.
AVS = Air Valve Secondary, not mechanical secondaries.
Since the engine is relatively stock this should not be a long drawn out job. If you have all the stuff this should not take more than a day. Start by watching some videos on how to tune a carb with a vacuum gauge. I would suggest doing a tune up as well, plugs, wires, cap, and rotor. Make sure any vacuum lines are not cracked and you do not have any vacuum leaks. Then set the timing at the factory specs and adjust the carb for highest vacuum. If you have all the parts and a timing light, vacuum gauge, and necessary hand tools this is a one day project and you know its done right. Watch plenty of videos and take your time. If you feel comfortable assembling the bottom end of an engine this should be no problem. Also dont forget about changing any fuel filters and having good gas in it also.
I called it a towing cam because that type cam delivers a higher LOW END torque, it does nothing to increase HP, it will lengthen the duration that’s all. That’s why it’s called an RV cam - more LOW END torque as you’d want if you were towing something. I gave you the part numbers of the Quadrajets for your car in the link. You also have one available from a member - read the Posts above. You can search eBay and the internet by carb number. As I stated earlier and has been suggested, the Quadrajet is the original carb for your car, the simplest and easiest to work on.
O my bad I did not realize the Quadrajet was the factory one. I was digging into it but had not gotten far. That makes the most sense then. I was only worried 750 would be too much, taking a 650 off.
Thank you all for your help. I am going to grab a quadrajet and go that route. I will post some pictures and update with some nice sound clip ****!
What do you mean "spraying gas on top of the intake"?
I prefer q-jets but I've done quite a few. If you're not comfortable rebuilding a demon, a q jet will be a learning curve and a half. A q-jet for your application depends on your cam specs, specifically duration at 0.050" and lobe separation. You can get away with a little "lump" with a q-jet, but usually internal modifications (holes drilled and idle bleed tubes etc) need to be done. Far from buying a rebuilt q-jet from summit. If you have a healthy cam and want a q-jet, cliff ruggles is a super dude, his book is a must.
Getting a reman unit from summit would be last on my list. Too many variables, wouldn't know what you have until it's way too late.
If you want a numbers 69 q-jet, you will likely need put a factory intake back on if you ever want a choke. If there is an aftermarket heat stove for that intake, it would be a pain in the rear to make it work right. Being in Michigan, a choke would be handy in the spring and fall.
I agree with the others, a simple Holley or edelbrock in your application would work well too. Very easy to tune, installing a wideband sensor in the exhaust for tuning is an option for you too, takes out a lot of guesswork. But an off the shelf is usually pretty close.
I would take a hard look at what you have already have. It's winter, not your source of transportation. Make a clean, organized area on a workbench. Watch a bunch of videos, get a "demon" book, take your time, get some gloves if you don't like the smell. A "kit" for a demon can't be too much $$. Take it apart a million times, be careful and don't break anything.
If this was your daily driver, under the gun time wise, all stressed out.. than yes you should grab a new simple and reliable new carb. But you're not, learn, enjoy and fix.
Not like we're talking about setting the clutch pack stack height on the 4-5-6 clutch pack in your 6l80e trans/ 2018 Silverado, your case is pretty simple.
Don't be intimidated, you ain't no dummy.
Chucking it into the "round file bin" because it might be from China, may not make sense. Good chance your new carb has some rice in it.
Sorry for the punctuation.
Chuck
Last edited by chuck_royle; February 7th, 2021 at 06:56 AM.
Reason: spelling
Any 650-750 AVS carb with the correct bore pattern will work, (Square or Spread).
Ebrock makes a nice very tunable carb, the 1900 series...(buy the rod & jet kit), Watch the vids and learn how to interrupt the tuning graph.
It's the easiest shade tree carb to tune.
A Qjet is not a shade tree carb, however, it is superior when properly set up. Call Cliff Ruggles at Cliffs Performance.
Fusick or Year One will have restoration parts, cable, bracket etc.
Any carb can be rebuilt. Buy a high-quality non-chineasium carb kit.
ALL carbs need to be properly tuned. No such thing as ready to go out of the box.
The ignition system and advance curves will need to be tuned along with the carb to extract 100% of the performance potential.
Timing should be:
~12* base at curb idle with the highest possible vacuum signal.
8-10 on vacuum advance canister.
~38* all in under 3000RPMs
Need more info ask.
__________________________________________________ _____________________________________
Spread bore = 2 big & 2 small intake holes, bores.
Square = all 4 holes are the same.
AVS = Air Valve Secondary, not mechanical secondaries.
Since the engine is relatively stock this should not be a long drawn out job. If you have all the stuff this should not take more than a day. Start by watching some videos on how to tune a carb with a vacuum gauge. I would suggest doing a tune up as well, plugs, wires, cap, and rotor. Make sure any vacuum lines are not cracked and you do not have any vacuum leaks. Then set the timing at the factory specs and adjust the carb for highest vacuum. If you have all the parts and a timing light, vacuum gauge, and necessary hand tools this is a one day project and you know its done right. Watch plenty of videos and take your time. If you feel comfortable assembling the bottom end of an engine this should be no problem. Also dont forget about changing any fuel filters and having good gas in it also.
Thank you both very much! I have some spark plugs on the way already, I converted the car from the old points system to an HEI with a high voltage coil way back when. I have the ACdelco R46SZ coming in and I plan to set them at .45. Do you really think plug wires need changed already? 12 years old. Ill get them ordered if needed. This is exactly the stuff that I want to change out for my dad now if its needed. Just trying to balance what's needed and what is overkill.
What is the cap and rotor? Distributor?
Also ty for the timing info.
I ordered a compression tester, figured I need one anyway with how deep I am going on motor work and if I am changing plugs anyway pry good to check. I have added checking all the vacuum lines onto my **** list.
Yes, cap and rotor are the top two replaceable parts on your distributor. I don't have any experience with HEI, so it gets fuzzy for me at this point. As others have alluded, this is not a quick thing and there are some steps involved. But you're a smart guy (bottom end replacement, etc.) so this will be a breeze for you if you watch the videos as suggested and take in all the advice offered. Rebuilding a Rochester QJ (if you need to) is really nothing more than following a recipe! Just be careful not to bend, break or lose any parts. The QJ offered up by 66-3X2 442 would work on your car whether Auto or 4-speed trans. Main thing to check if considering swapping the carb: check your intake, Is it square bore (holley style) or spread bore (Q-Jet style).
I am looking at some Rochester quadrajet carbs on Summit and I only see 750cfm and up. Is that going to be too much?
One of the magical things about a QuadraJet or any other AVS type carb is that they deliver only the airflow the engine requires for its current demand. Most QJet are rated 750 cfm, with some big-block Buick and Cadillac applications rated at 800.
Unlike a mechanical secondary carb that forces the secondaries wide open and floods the engine with fuel and air all at once, an AVS type carb relies on the engine's airflow demand to operate the secondary air and fuel side.
Some of the guys here have adapted EFI to Olds V8 with great results. cutlassefi knows his stuff on that. Have you considered that option?
If I may make a point of order, any Air Valve Secondary like a Quadrajet is still a mechanical secondary; it simply has the positive feedback metering AVS system on top of the air horn as well. I think the Carter AFB, aluminum four barrel, had a weighted air valve doing much the same thing. Actual vacuum secondary carbs, where engine vacuum opens the secondary throttles, are some Holleys and a I think Edelbrock has some. Here's a vacuum secondary input hole and a Holley vacuum secondary current carb with vacuum motor.
Last edited by Koda; February 7th, 2021 at 11:24 AM.
Ok I am in talks to purchase the factory correct Qjet offered above. I spoke with Cliff for a while and I am going to have him rebuild the old unit and send it back to me. The plan is to then stop by Cliff in May(ish) on my way to South Carolina to get it tuned after I install the new one. That guy knows his stuff, damn. He also said RV cam meant nothing and that the term is miss-used frequently. He is crazy busy and a solo shop so I will have to wait a couple months but I care more about getting it done right for my dad then a couple extra weeks or a few extra dollars.
In the mean time I am going to start by repair/replace the fuel filter, spark plugs, vac lines, engine timing, engine compression, and fuel line to the carb, (Cliff has a suspicion that they cut the gas tube and put a rubber one to run the speed demon). I am hoping between that and a proper tune we will be good to go. I will plan on bringing some tools with me incase we need to go a litter further.
Thanks again everyone! Ill post some pics and vids when I get her running again.
Last edited by Alatar; February 8th, 2021 at 09:47 AM.
No doubt Cliff is full of personality as well as QJ knowledge.
Stand in line my carbs are next! Hopefully, both ready in the next month or so, then you're next?.
TIP: Bring a bottle of top-shelf bourbon when you come-a-knocking.
I’d recommend Sean Murphy Induction in Huntington Beach. Just had my 68 Rochester gone through by him. Car sat for 14 months during covid refresh of sesupension, motor, and brakes. Last month 442 started immediately and idle was already dialed. He already has rebuilt Rodchester carbs (for Olds) there and can tweak it based on the cam, trans, and gearing.
February 6th, 2021, 10:06 AM
Just be careful not to bend, break or lose any parts. The QJ offered up by 66-3X2 442 would work on your car whether Auto or 4-speed trans. Main thing to check if considering swapping the carb: check your intake, Is it square bore (holley style) or spread bore (Q-Jet style).
