Is there more then one type of timing pointer for an RB

Is there more then one type of timing pointer for an RB - 05/30/14 12:28 AM

I put together a 78 smog 440 out of a winnebago. Assembly went well and I double checked cam timing marks. I set the initial timing with a vacuum gauge. The idle timing at best vacuum minus 1 is off the pointer, if I had to guess 40 or more degrees. Runs great and drives great, what am I missing?

Posted By: RapidRobert

Re: Is there more then one type of timing pointer for an RB - 05/30/14 01:36 AM

I'm rusty on BB's but ain't the timing tab on pass cars at ~10:30 (pass side). Is that where it is at on this eng? I would assume that even if there was different t covers/dampeners that you have the correct ones in your pile for this eng. You might check exact TDC with the ten dollar tool but slipped dampeners are rare but we gotta start somewhere & k.i.s.s. is always a good plan. What's the idle speed? What springs? what was the highest vac and what was the initial before you backed it off 1 in hg of vac?. Whats the total? Keep us posted! I love the toughies

Posted By: ahy

Re: Is there more then one type of timing pointer for an RB - 05/30/14 03:53 AM

I know with a repop front cover on a later car BB my pointer was off ~ 10 degrees. Starting with a truck engine who knows. Best bet is to find true TDC with the positive stop method and go from there.

On my stuff, I added a light punch mark and paint dot on the damper at true TDC on the timing marks. Timing tape would be even better.

Posted By: Cab_Burge

Re: Is there more then one type of timing pointer for an RB - 05/30/14 04:35 AM

Quote:

I put together a 78 smog 440 out of a winnebago. Assembly went well and I double checked cam timing marks. I set the initial timing with a vacuum gauge. The idle timing at best vacuum minus 1 is off the pointer, if I had to guess 40 or more degrees. Runs great and drives great, what am I missing?

If you didn't verify TDC on your balancer compared to the timing tab your really lost as far as accuracy, aren't you

The outer ring on the balancers can, and will, slip and spin

You can pull a spark plug(#1 or #6 ) and put in a screw driver or a positive piston stop, and slowly, and gently, turn the motor over until you feel the piston touch the screw driver end, keep rotating the crank, by hand, until the piston reaches TDC and then compare your balancer to the timing tab

If you use a piston stop follow the directions for it to locate TDC

BTW, there are multiple different timing covers and balancers for the BB Mopars, depending on which year and body style, car, pick up, motor home, industrial or marine

Mopar put a small hole in the class A motorhome tranny bell housings and a mark on the torque converter to check the initial ignition timing with the engine cover off on them

Posted By: cougar_cat_25

Re: Is there more then one type of timing pointer for an RB - 05/30/14 05:31 PM

The new balancer lined up with the repop cover at TDC, I`ll triple check with the positive stop method. I`m running MSD ignition (standard weights and springs) and Atomic EFI. I plan on locking out the distributor and let the EFI control the timing curve. Could a vacuum leak, say a leaky break booster, mess with initial timing?
On top of everything, the passenger side lower hose water pump make it just about impossible to see the timing tab.

Posted By: sthemi

Re: Is there more then one type of timing pointer for an RB - 05/30/14 09:56 PM

Initial timing is set with the vacuum disconnected and plugged. Check the shop manual for correct idle speed to check it at.

Motorhome engines use a hole in the bellhousing to check timing.

Cast crank engines typically have timing marks on the passenger side of the engine and forged on the drivers side.