i have a fresh rebuild 350 olds .30 over,edelbrock performer rpm package with a comp cam instead of the edelbrock cam,750 brock carb 3.73 rear gear 10inch convertor 2800-3000 on a 350 turbo tranny. the car boggs down on take off unless i mash it realy hard. the tech guys at edelbrock said to go with a 2500 stall, tech guys at b/m said keep the stall i have. can anyone give some advice on this, im not sure what to do.

 

Have you adjusted the secondary air valve on your carburetor? It sounds like it might be out of adjustment. I would try that before changing the stall converter.

 

when you say bog down do you mean it turns off or just has no power untill you get on it?? olds blocks produse torque not high rev horse power, a olds motor dosnt need a big stall!! i like small 1800-2200 stalls with a cam and 308-342 gears, with a 2800-3000 stall your olds motor has 2 rev high just 2 get moving so its going 2 be a dog untill you jump on it!! chevy motors are high rev motors they use big stalls olds are torque motors they dont rev high for big stalls, also i made the same mistake when i was young i had a simi built olds 350 in a 72 cutlass s 2800 stall, and 750 carb i kept having flood problems, back fires, and smal carb fires the 750 was 2 much for the 350 i switched 2 a 650 and the problems went away but my motor never ran as hard as it could of with a smaller stall, i missed the olds power band with the high stall! everything must match= your cam, compression, intake, stall, tranny gears, and rear gears if everthing is right youll run HARD!!

 

sx455 everything matches,the only difference is i went with a comp cam slightly higher than the one edelbrock had with the package. the car doesn't die,just no power unless i mash it,it runs fine when its up and going i'm just not happy with the way it takes off,i don't like having to mash it so hard for to get up go. edelbrock says the package works best with a 2500 stall,my mechanic says the same and it seems like thats what your saying also, but guys at the speed shop where i get my parts from say the opposite. so im confused

 

the guys at the speed shop are trying to get into your wallet.

 

What is the powerband on your cam? In other words, where does that cam begin producing its power? Is that powerband compatible with the RPM intake's range?

Most Olds street cams are designed to start making their power between 1800-2200 rpm, so I think you have about 500 rpm too high stall. You're almost out of the initial powerband by the time the converter flashes and grabs. 2500 stall will be better, but a 2000/2200 would be great unless your cam is, say, 2500-6500 powerband- in which case I'll tell you up front you have way too much cam for a street driven car.

You gotta remember that converter stall speed is not an exact science and varies in the car. Stalls are designed mostly for racing applications anyway where you're revving the engine into it's initial powerband. The converter will flash at that speed and launch the car when the engine has started making power- "on the cam" as we used to say. Their side benefit is that they will allow use of a big lumpy cam where you have to have idle speed set high to keep the engine running. They allow enough slippage that you won't burn out a stock converter from high idle speeds.

Yer speed shop buddies have fallen victim to the bigger is better fallacy. My guess is they fool mostly with SBC and Mustangs.


EDIT: just looked at the pic of your car in yer profile. Do you still have those big donk rims on it? Those are not helping with the engine/trans mods you have... How tall are those tires?

 

What Rocketraider is telling you is correct. For the track you would want to match the converter to the engines torque peak which is why B and M said it was fine. The problem is you have a street car. In that case you want to match the converter to where the engine just gets on the cam. That would be listed on the cam card or Comp Cams info on the cam. If the cam is for 1500-5000 then a converter in the 1800-2000 range is great. In other words you are trying to stay close to that lower number where the cam basically kicks in. I think your converter is too big and agree with Rocketraider. I didn't look at your profile but if you do have huge rims on your car you've effectively taken the gear out of it which would cause it to bog depending on the size of your cam. A converter will not cause your car to bog, it's not the converter that's at fault here.


OK, I looked. Yeah those are huge. You probably lost anywhere from half a point to a full point out of your gear ration with those monsters. That would make it a dog on the low end and possibly cause the bog also. I would still start with other things like the carb, timing, vacuum leaks, etc. before blaming the converter. It's still too big but it won't cause the bog.

 

If you have the standard Edelbrock 750 then you won't be able to adjust the secondary air valve. You need the Thunder AVS Edelbrock 750 to make that adjustment.

 

you have a monster cam in a small block

you have to mash it to make power,it probably doesnt start to hit it's powerband until 3500 rpm.

get rid of that POS off the shelf convertor,those are a crap shoot at what the stall really is.

step up to a minimum of 410 gears,too

 

[quote=84 supreme;186622]sx455 everything matches,the only difference is i went with a comp cam slightly higher than the one edelbrock had with the package. the car doesn't die,just no power unless i mash it,it runs fine when its up and going i'm just not happy with the way it takes off,

im 100 percent positive that the reason it has no power untill you punch it is because of your big stall!!!! thats what stalls do!!!! you will not have power if your just giving it a little gas because your not at 2800-3000 rpm's!! when your tring 2 drive slow and you give it just a little gas it moves real slow right?? but if you punch it it jumps and takes off right?? thats the stall thats what they do!! if your going 2 drive this car daily change the stall 2 a 1800-2200 stall and youll be alot happier you will not have 2 jump on it 2 get it moving because the stall is lower!!!! i have a 455 olds 1800-2000 stall, a nice cam, rebuilt heads and 323 rear gears, i run 12.4's all day and can still cruise on the freeway at 2400 rpm, the torque is nasty i can punch it at 30mph and burn long rubber, i love olds motors!!! they burn long rubber run hard and still cruise at 75 on the freeway without od

bigger is not allways better like some1 just said b4 me!!!!

 

i just thought of something if your cam is 2 big than youll need a bigger stall, you might not be able 2 go with a 1800-2200 you might have 2 go with a 2500, what comp cam number?? i just looked at my papers i have a magnum 270h compcam in my 455 i cant find my converter papers fo rthe exact stall

 

the rims r only 22's i don't think that would cause it to b so sluggish, i have a friend who has bigger wheel than me on an 86 with a stock 350 rocket gold block 3.73 rear gear,2500 stall and he has no trouble turning the wheels. @rocketraider your correct about the guys at speed shop thats all they run is chevy and ford.@sx455 your comment describes my problem to a t. i was able to locate my spec card and i called comp cam they recommennd a 2500, the cam is rated for 1500-6500 rpm.

 

the 22's souldnt make much of a difference there almost the same hight because of the low profiles

if you tell me your exact comp cam part number ill look it up and tell you what converter wil work, most likely youll be able 2 use a 2200 unless its a full race cam but it shouldnt be full racee cuz its 1500-6500!! youll love the difference with the smaller stall!! it will still be a little slugish when you give it just a litttle gas but not close 2 as bad as a 2800-3000 stall, a 1800-2200 stall works great with a daily driver/week end track olds motor, youll be suprised at how much exceleration/jump it has when you get on it!! i let my mom drive my sx and she thought it was slow because of the stall lag when driven easy i took her around the block after she got back and scared her when i got on it, i love it when it kicks down, lifts up and takes off!!!!

 

what are the specs on the cam.
is it a 280?

 

232/236 520/523 lift 110degree lobe

 

i just searched comp cams this has 2 b your cam its a little off but its the closest cam 2 your specs

http://www.compcams.com/Cam_Specs/CamDetails.aspx?csid=1172&sb=2

it says use a mild stall, if i were you i would change it!! i have a 270h and i run hard for a daily/freeway driver, i cant remember my exact stall speed but its between 1800-2200, your cam is a 274 it almost the same as mine the 2800-3000 is way 2 much!!