advice on carby

[Joeyvk308]

Ive got a 5L block 30 thou over flat tops, biggish cam, l34 heads with 5thou over valves, and a 600 vacuum secondry holley. i have just done a complete rebuild and it is sluggish down low in the revs has back fired through the carby and has also stalled it also feels like should have a lot more power. Would a 650 double pumper help out??

[Sabbath']

Get the car tuned properly.

[VS_Pete_1]

Have a talk to this guy.

Carb and Gas

[showbags]

I've had good results with the Holley 670 avenger on Holden v8's. Much better carb than the 650dp and easier to tune.

[ari666]

go quaddy. get rid of anything that says holley on it.

[ajvx01]

Question, is your charcoal canister connected to the Holley? I only ask as if your venting fuel vapors and backfiring I'd stop driving!

[Joeyvk308]

I spoke to a mechanic he said put the double pumper on and than get it tuned. Its given me nearly twice the power just by changing the carby. Just needs a tune and a kit put through it and i think it will be fine. Thanks for helping

[ari666]

lol, 650 double pumper hey? fair enough. somewhat too much for that engine, but if it gave you "twice as much power" then i guess it must be good.

you got before and after dynos done, right?

[Blown V6 Hatch]

I would have stayed with the 600 vac personally. If you got "twice as much power", the 600 must have been royally rooted.

[Joeyvk308]

I havent done a dyno run yet as the engine is still being run in from a rebuild. The 600 is only two months old and ran fine on the engine before the rebuild when the engine was completely rooted.

[Sabbath']

Not sure how you can say it was running fine if it was on a completely rooted engine.

Im finding it hard to believe that you're getting "double the power" from going up to a bigger carby. It's a false sense of comparison.

[Joeyvk308]

After the rebuild with the 600 it was very sluggish and had no real feel of power up to about 3000rpm in every gear. With the 650 its instant power in every gear and holds it