Big Block with duals or blown
- Thread starter herman
- Start date
Lee_in_KC
Active Member
Gonna mainly depend on your cam and timing. What RPM does you your motor want to idle at? Where is your power curve? You want your stall near the bottom of your power curve if you're looking for best pull off the line. My blower motor wants to idle at about 1000. My cam comes on about 2500. I have a 2800-3000 stall converter... seems just about right to me.
By the way, dual quads on a performance intake are going to respond a lot different than a blower. What works for the dual quads may or may not work for a blower.
By the way, dual quads on a performance intake are going to respond a lot different than a blower. What works for the dual quads may or may not work for a blower.
Lee is right. It all depends what your expectations are and what you want the engine to do. I have 2 fours on tunnel ram made for racing but I bored a 454 out a .100 for a 475<73 vintage> with the 049 heads. Crane cam is a saturday night special and have 3400 stall converter and 3.73 gear. My setup is NOT fuel mileage friendly. Call Crane cams tech guys with what your wanting to do and they'll recommend gears,converter,carbs and cam for your car. The lower the stall the better the cruising and won't build a lot of heat. The higher the stall over 3000 the trans will build up heat. I have 2 coolers and 1 has a fan. Use synthetic fluid.:tmi:
how about quad's, I ran 2-600's on Nas T 1 blown 396. I am running 4-600's on the two headed monster that is 2400 cfm of carbs, on nast t 1 i ran a 2500 stall and worked great. On Nas T Too i am running a 3800 stall with one big ass cam and I was not worried about losing 2/10's off my quarter mile time. The new car idles at 800/1200 800/1200 all day long, But when i had my cam built they told me that i would have a rough idle will the blowers takes all that away and has a mind of there own. If i were to build another with a blower and a BBC i would run a 3000 stall. 3800 is really wild and a blast to drive, but you start getting carried away and you will have temp. issues.
herman
New Member
:hooray: Sorry Guys: Been out of town and just got the messages..Way to much info..Lets start over.. I have a 460 big block came out of a boat with dual 650 holleys and a tunnel ram. Don't know what cam is on board but the engine started a ran fine with medium lope at idle. I talked to my local shop and they called a tourque converter company, Don't remember which one, but they said a low stall is best so they sold me a 900-1000 stall and I have chevy S-10 rear with 3.73 gears...Motor seems to idle at stall speed with no problems but converter is not installed yet... Tks Herman
Ted Brown
Member
You are totally right about that, Quads to Blowers... With carbs the exhaust completely controls power, as to where and when it happens... I found a stock 400 turbe passenger car type works GREAT for me, with a carburetor... But then again I drive my T everyday, that makes a big difference in SPEED choices...
PS I just read your latest on the stall problem or non problem.. I myself slip my trans out of gear, at every stop, I find it safer this way, as these cars move waaay to far in a split second.
Bump, Pardon Me! hehe
PS I just read your latest on the stall problem or non problem.. I myself slip my trans out of gear, at every stop, I find it safer this way, as these cars move waaay to far in a split second.
Bump, Pardon Me! hehe
Boost Daddy
New Member
A blower will calm a camshaft down. A blower motor will also lower the stall on your conveter. Converters are stall rated based on 350HP. (I think thats the right number) A blower engine makes more torque at low speed thus lowering the stall. It is kind of a moving target because every engine is different.Nas T said:
Usually as a guide line for stall speed on a converter is what RPM your cam starts to come in and come to life. If you know any of the cam specs it will tell you operating range. A truck 454 stock stall most of the time is about 1000 to 1200 rpm. The cam I have comes in about 3500 and the converter has a range of 3200-3600. It is not real good for putting around. But when you mash the gas the rpm's of the motor come up quik, by then the converter speed catches up and you are gone. 
herman
New Member
Just a note to say thanks to everyone for their help. Sorry not around much becuase I have sold my business and am trying to tie up the loose ends and have more time for the bucket. I have decided to go a holeshot 2400 b&m coverter... Looks to be the happy medium.. Again thanks and I get some pics as we finish. Spring is almost here..... Herman
