D Appeldorn

mmmmm

i asembled a edelbrock 4bll on my 350 olds engine that was former a 2bll
it runs nicely but if its cold it will bickfire if the engine is nice and warm it doesn't. than it runs quite wel.

is there a difference in valve settings between 2bll an 4 bll?
the carb is a 600 edelbrock with handchoke that set on performence.

I hooked up my vacium advanced Hei on the timed port of the carb.
It is posseble that i must reset the engine timing (with of without vacium advancing) and remark the new balancer i assembled.

It's a bout my 69 olds delta 88 conv.

Yes stil work in progres

D Appeldorn

Netherlands

Rallye469

Backfire...
is it a pop through the carb? Or a pop through the exhaust?

D Appeldorn

It pops up trough the carb.
it does it only when its cold while i have the choke wide open.

When it's hot it doesn't
I replaced the 2bll intake for a 4bl and mounted a edelbrock 600 handchoke carb on the 350.
And i replaced the timingbalancer.

PetChemMan

The last time I encountered a backfire through the carb was on my '79 Olds 88 Royale. There were small particles in the fuel tank which were going right through the stock fuel filter and accumulating in the carburetor. When enough particles had settled in the carb, it caused a lean condition and backfiring through the carburetor. I eventually solved the problem by installing an aftermarket spin-on diesel fuel filter with a 5 micron rating to trap the tiny particles. The immediate cause of the backfiring, however, was a lean air/fuel condition, and perhaps you simply need to keep your choke on longer until the engine warms up. You may also have a vacuum leak under the carburetor or in the intake manifold that causes the lean condition. Sometimes there are incompatibility issues among carburetors, base gaskets, and intake manifolds that make a carburetor run way too lean, or rich, at idle. Make sure all of your pieces fit together. Be sure there's no EGR valve kept open by vacuum at the wrong time.
Incorrect ignition timing can also be responsible , so you might want to bring number one piston to top dead center, and see if the timing mark on your new harmonic balancer lines up correctly. Or, carefully compare your old balancer and the new one for timing mark location.