[72z240]

Please refer to my other post about 'severe bogging'. I need to check my timing. This 240 has an L28 (N42block, N47 head, E88 intake). I have no idea what year, prolly 75-78ish. Carburated turbo kit installed (Rotomaster TO4B). I beginning to wonder if the timing is severly retarded (or just me), and causing the bogging problems. Should I be running stock timing with the turbo, or slightly retarded? And, what IS the stock timing setup?

Boost question: My guage shows 0 at the top. Clockwise reads boost, counter-clockwise reads vacuum. With the debut drive this morning after rebuilding the turbo, it seems to be reading on the vacuum side (10-20psi) all the time....if I punch it it does approach 0, but doesn't seem to read any boost (of course, it's bogging so bad, it's hard to get a good acceleration) Is this normal to read on the vacuum side while driving normally around town?

-Kurt

 

[dbryan70z]

Custom Timing

OK, guy,

I am no expert on pressureized systems, but have plenty with normally asperated vehicles.

IF it were mine, I would probably try to remove as many variables as possible, even consider disconnecting the boost until it got to running better. Might need to be careful there, the tubo may over rev if not loaded (I really don't know). Do you have a clogged fuel filter! Many a mechanic chases his tail for a while and it turns out to be fuel starved from an old filter!

Anywhoos, check to see that you have good fuel delivery first, are the floats right, are the mixture needles set at a reasonable point and balanced. (rough in gently close them and open 1.5 to 2 turns) if idling smooth, then turn one in at a time until starts to bog and back off (hot engine) with a load (AC and or lights/ and fan on whatever). Is your vacuum and mechanical advance smooth, can you put vacuum on the vac line and see rotation?

On custom cars, once they are running about right, I fill them with the fuel octane I plan to run most of the time and take it out for a run. With the distributor just tight enough not to turn on it's own you can advance it (or back of as the case requires) until it just starts to ping under heavy throttle. Your Timing is now Custom set for your fuel, compression and altitude!

 

[yo2001]

Re: Custom Timing

timing should be retard on turbo engine. and if you are not getting boost, the car will bog. Check your turbo I guess. not my experty.