cheby 350, th350, short wide pickem up truck. might end up dumping it off and getting something cleaner. need to have something that idles in gear with a stock trannie.
COCHEV
224@.050 is just about max with a 350, i've seen 400's use 230's with a 112 centerline and stock convertor.
I've used the 290 Cam Dynamics with a stock converter in a 351W with no problems, the stock Ford converter was rated for 1800-2100 stall. Converter stall speed only determines the RPM it locks up at, not if it will idle in gear or not. If it won't idle in gear you have other problems, usually carb tuning.
I ran a stock converter between rebuilds on my street fighter in my '57 for a bit. It has a .246 @.050 and 106 lsa. Pretty nasty for a stock converter, but it wasnt too bad. The main thing was that the truck was an absolute dog since I was used to having that 3800RPM instant converter flash.
chris
chris
The cam that I'm thinking about for my 440 is a 224/234 unit from Summit that has something like a 112-114 LSA. Nothing really radical but better than stock. I'm going to try the stock convertor and see how it goes.
You could play around with different LSA's, but generally, the bigger the cam, the less vacuum you are going to have, period. When you start talking really big, even the biggest LSA might not do anything for your vacuum!
You could play around with different LSA's, but generally, the bigger the cam, the less vacuum you are going to have, period. When you start talking really big, even the biggest LSA might not do anything for your vacuum!
Cochev, if you can only realize 10 inches of vacuum at idle I would look at your initial timing and your idle mixture settings.
What kind of carb are you running?
What kind of carb are you running?
If the idle mixture screws are unresponsive you have found one factor that might be causing your problem. Now I know I'm going to get some flak on this but your Quadrajet is not the ideal carb to use with a wild cam. Sure you can tune it but the reality is the passages and design of the carb is not ideal for the type of engine combo your running. Besides, getting parts and tuning it to suit can be an ordeal because of the mosifications involved. There are many Quadrajet supporters out there that have made their Quad run sweet on their engine and defend it's high perf capabilities. That's fine but for me a Holley or Carter/Edelbrock carb is a far better investment and much easier to tune, if I had to pick which one is easiest to tune I would pick the Carter/Edelbrock.
Your timing is very important to getting the combo tuned right, as is the distributor curve. If the Quad is running lean then adjusting the timing to optimum will be impossible, you must have the carb running perfectly with good plug color and excellent throttle response throughout the RPM range before deciding on an initial timing setting.
It sounds like you have a combination of engine parts and pieces that were just thrown together in the hopes for speed, getting all the pieces to work together and run well in all types of weather can be a very trying experience, you've just begun.
BTW My old 69 Mustang with the 290 Cam Dynamics cam pulled 8 inches of vacuum at first with the stock four barrel and intake. After tuning and timing and curve adjustments and a carb/intake change and jetting I managed to get 16 inches at a 900 rpm idle. A substancial improvement over what it was originally, I also managed to get between 15-17 MPG in the city if I drove nicely. The car started always on the first turn and ran properly on the choke no matter how cold it was. I have done the same to countless other cars since then, you can too.
The Gods live in the details, never forget that.
I actually saw a young buck today driving his late model Camaro and it was spewing a huge amount of black smoke (RICH!!!), when I finally caught him at the next light I told him "she's running just a tad rich there bud!".
He responded by yelling out the window "I just put a chip in her on Monday and a high pressure regulator to match, more fuel...more power!!!!".
I smiled and nodded and off he went in a little cloud of black smoke, I doubt I could ever convince him that his car was probably slower as a result of his "mods". He probably thought the bog of the fat fuel mixture was a boost in power?
Whatever!
I guess the moral of the story is to use your common sense and listen to your ears and nose for clues and never think that the car must need more fuel because it is hot rodded, many times I have had to jet down because that was what the engine needed. Check your exhaust pipes for soot, the color should be a nice battleship grey for max power and a full throttle stomp from a standstill should yield a very minor hesitation (or none at all) and then a nice puff of grey smoke out the pipes. If it's black it's too rich, if there is no smoke you need more accelerator shot on launch.
Honestly I could go on and on about tuning your car, but everyone is different and some have limitations you must live with, like your Quadrajet carb. If I were you I would start scouring the web for info and parts and tuning tricks for Quads, that is the only way to get that carb running ideally with your large cam...
Or you could buy a Holley/Carter and tune it in one weekend, it's up to you where you go next.
Your timing is very important to getting the combo tuned right, as is the distributor curve. If the Quad is running lean then adjusting the timing to optimum will be impossible, you must have the carb running perfectly with good plug color and excellent throttle response throughout the RPM range before deciding on an initial timing setting.
It sounds like you have a combination of engine parts and pieces that were just thrown together in the hopes for speed, getting all the pieces to work together and run well in all types of weather can be a very trying experience, you've just begun.
BTW My old 69 Mustang with the 290 Cam Dynamics cam pulled 8 inches of vacuum at first with the stock four barrel and intake. After tuning and timing and curve adjustments and a carb/intake change and jetting I managed to get 16 inches at a 900 rpm idle. A substancial improvement over what it was originally, I also managed to get between 15-17 MPG in the city if I drove nicely. The car started always on the first turn and ran properly on the choke no matter how cold it was. I have done the same to countless other cars since then, you can too.
The Gods live in the details, never forget that.
I actually saw a young buck today driving his late model Camaro and it was spewing a huge amount of black smoke (RICH!!!), when I finally caught him at the next light I told him "she's running just a tad rich there bud!".
He responded by yelling out the window "I just put a chip in her on Monday and a high pressure regulator to match, more fuel...more power!!!!".
I smiled and nodded and off he went in a little cloud of black smoke, I doubt I could ever convince him that his car was probably slower as a result of his "mods". He probably thought the bog of the fat fuel mixture was a boost in power?
Whatever!I guess the moral of the story is to use your common sense and listen to your ears and nose for clues and never think that the car must need more fuel because it is hot rodded, many times I have had to jet down because that was what the engine needed. Check your exhaust pipes for soot, the color should be a nice battleship grey for max power and a full throttle stomp from a standstill should yield a very minor hesitation (or none at all) and then a nice puff of grey smoke out the pipes. If it's black it's too rich, if there is no smoke you need more accelerator shot on launch.
Honestly I could go on and on about tuning your car, but everyone is different and some have limitations you must live with, like your Quadrajet carb. If I were you I would start scouring the web for info and parts and tuning tricks for Quads, that is the only way to get that carb running ideally with your large cam...
Or you could buy a Holley/Carter and tune it in one weekend, it's up to you where you go next.
Quote from 4 jaw:
"It sounds like you have a combination of engine parts and pieces that were just thrown together in the hopes for speed, getting all the pieces to work together and run well in all types of weather can be a very trying experience, you've just begun."
You hit the nail on the head right there. picked her up cheep and was put together by a young buck lookin to go fast. so now i have to weed through all the mess.
i love q jets for off roadin and daily driving. can't beat em there in my opinion. but i will be going holley or edelbrock when i can afford it on this truck.
thanks for the response and knowledge,
jason
"It sounds like you have a combination of engine parts and pieces that were just thrown together in the hopes for speed, getting all the pieces to work together and run well in all types of weather can be a very trying experience, you've just begun."
You hit the nail on the head right there. picked her up cheep and was put together by a young buck lookin to go fast. so now i have to weed through all the mess.
i love q jets for off roadin and daily driving. can't beat em there in my opinion. but i will be going holley or edelbrock when i can afford it on this truck.
thanks for the response and knowledge,
jason
I love the Quadrajet for stock or only slightly modified engines, can't beat them for fuel mileage. I even used one on my 351W and a couple 302's. No doubt one of the best street carbs ever made. I'm not too sure on if they are better for offroading or not because I always ran Holleys with extended vent tubes in this application. I do know a Holley can be made to run fine in offroad applications quite easily with jet extenders and side hung bowls and a few other minor tweaks.
Someone here once poste a link to a site that had Quadrajet parts for sale in kit form I believe, I reformatted my drive just recently and lost all those links in the process <img src="graemlins/sweat.gif" border="0" alt="[sweat]" /> .
Does someone else have it? You could also try searching the forums for the term "Quadrajet" and see if it comes up.
Good luck with your project and come back often, you would be surprised how many here will have some hints or tricks to share with you.
Someone here once poste a link to a site that had Quadrajet parts for sale in kit form I believe, I reformatted my drive just recently and lost all those links in the process
<img src="graemlins/sweat.gif" border="0" alt="[sweat]" /> .Does someone else have it? You could also try searching the forums for the term "Quadrajet" and see if it comes up.
Good luck with your project and come back often, you would be surprised how many here will have some hints or tricks to share with you.
I've had the same experiance with Q-jets and healthy cams. I had a 284 duration @ .048 lift in a 350 Chev. I had to idle the thing up so high the primary butterfly's were half open just to get it to idle. this made it very cold blooded. All my problems were solved with an Edlebrock 600, manual choke that I rarely had to use.
If your exposing the transfer slots, you can drill the primary plates (opposite side from transfer slots center of plate). Start with about a 1/16" hole in each side first. Gradually enlarge the holes until the slots aren't exposed anymore with the desired idle speed. You will notice that the idle mixture screws will work again.
Originally posted by BstMech:
<strong>If your exposing the transfer slots, you can drill the primary plates (opposite side from transfer slots center of plate). Start with about a 1/16" hole in each side first. Gradually enlarge the holes until the slots aren't exposed anymore with the desired idle speed. You will notice that the idle mixture screws will work again.
i think i'll try this next
I read about that in a Holley book I had, so I tried and it worked perfect. But they said not to go larger than an eighth of an inch, I couldn't imagine having to go any larger than that. It means having to remove/replace the carb a few times but it works.
[ November 29, 2002: Message edited by: BstMech ]</p>
[ November 29, 2002: Message edited by: BstMech ]</p>
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