rejetting holley 650

[smooth_358]

Carb is a spreadbore vacuum secondaries carb. Car runs really rich on the secondaries. someone at the track told me it was blowing smoke the whole way down the track and could probably go down at least one to two jet sizes. btw, motor is a pretty much stock 307 olds, junk th200 trans with a 2.41 gear, has a performer intake as well. basically a stock replacement intake. seems to run pretty good aside from the rich condition. Well and the fact that the motor is an 80's era smog motor.

[MR.hp]

Check to see if there is a metering block in the rear of the carb but most of those VS holleys do not. is there a list number on the air horn that will give me a place to start.
Also have you changed the secondary spring [it's under the little cover behind the choke assy.] those carbs usually have the black spring in them and will never open fully no matter what you do to it.

[smooth_358]

haven't touched the carb at all, besides dinking with the primary screws and unsticking the float once. can get the numbers when i get home. its got a built in fuel rail going to the rear bowl.

this should be the carb, if not it is extremely similiar
http://store.summitracing.com/partde...5&autoview=sku

[MR.hp]

If that is the card there is nothing you can do to the secondary jetting so I would ditch that one and try to find a 6210 speadbore holley atleast that one you can jet up or down. Get rid of the 2.41's would help too. Does the car have a 7.5 rear axle or 8.5 rear axle?

[smooth_358]

its just a 7.5. i can keep running it like this if there is nothing i can do. bumped the timing down and got 16mpg the whole way to byron, 800 mile round trip. so i should be able to just go with it. when i get the swap done it will be a 350 with a t56 and 3.73's so i can deal with it then i suppose.

[jollywrencher]

If its really running rich on just on the secondaries then I'd look at the metering plate gaskets. If they are bad and not sealing I would guess that would make it run pretty rich. It maybe just needs a quick rebuild, that carb should work good on your stock set up. Look up the list number off the choke horn and then go to Holley's website. There it will tell you what that carb should have stock out of the box for jets, shooter, PV, etc... Its good to know if the carb has been messed with and how far off from factory it is.

[smooth_358]

i bought it brand new last year so perhaps its just needs a quick set of gaskets. hasn't ever really been touched so... idk.

[MR.hp]

I found a 6210 650 dp spread bore holley here but it is not mine if you are interested I will ask how much he wants for it but I am sure it will be cheap as it needs a rebuild.
You would be able to tune both sides of the carb and not have to fiddle around so much.
If not I will still help you with your current setup.

[smooth_358]

ya, let me know what he's thinking to get out of it. plus then it will be easy to retune for a 350. but im assuming its mechanical secondaries? if so my wee little 307 may not be too happy with it? idk might pick it up anyway

[Titan5]

Carb is a spreadbore vacuum secondaries carb. Car runs really rich on the secondaries. someone at the track told me it was blowing smoke the whole way down the track and could probably go down at least one to two jet sizes. btw, motor is a pretty much stock 307 olds, junk th200 trans with a 2.41 gear, has a performer intake as well. basically a stock replacement intake. seems to run pretty good aside from the rich condition. Well and the fact that the motor is an 80's era smog motor.

Just my 2 cents, 1 or 2 jet sizes would not effect things much as far as making it smoke down the track, you may have something else causing the rich condition (if the smoke is black) 602 has the best suggestion with a change to the secondary spring, (if it is too weak) it can cause the secondaries to open too far too fast (or if too stiff) not enough soon enough, and don't forget that the float level can effect rich or lean conditions also.

Don't change too much too fast trying to fix the condition, the carb you have should work well in stock form with some small changes to the tune for your motor.

I would not be afraid of a mechanical secondary on your setup and I would suggest one as you start to plan your changes for the next motor, trans, gears, converter, etc.

Sorry, it got to be more than 2 cents worth,

Good Luck, T5