Ok oldsmobile family finally at the end of the engine install . Ok when i say budget build im sure mine is on the low side nothing fancy . New gaskets cam and lifters all else was just cleaned and restored. Now its a 455 olds out of a 73 delta 88 like i said small overhaul . Then topped off with an elderbrock 1405 , sounds damn good and idles great timing light shows balancer mark and tab at 0 ( im no expert just a forum readed and youtube look up on the timing so far ) but hits a mean chop and sounds great . But when i sit and rev it up and tap the pedle at high rpm ( vroom - vroom the two taps back to back vroomvroom ) theres like a back fire as i seen a fire ball flash . Let it get back to idle sound goods then vroom - vroom , vroomvroom again same outcome . But i can ease inro a high rev and all is good . So far . . Havent check it under load yet im currently freshing up the brakes . But is this a timing issue when i put the timing light on it should i adv. Or retard it a little ? If need any more info just ask i will get it . Stage 2 448/472 lift mc1777 cam is what i put in it .

 

0⁰ is computer timing crap. You need 16-20⁰ initial/static timing, set with the vacuum advance line unhooked from the canister and plugged.

 

Most of those had initial timing at around 7 at 850RPM with vacuum advance plugged. Have the spark plug wires been replaced? Cap and rotor replaced? Those could arc internally/externally to create a misfire that would cause flames.

 

Ok did some more searching and this is what i found , due to i only have an old school none adjusting timing light . Harmonic balancer diameter times 3.14 , the answer divided by 360 , that answer times the number of degrees , equals measurment need . I did mine in milli meters . [ so 6.5" was 165.1mm x 3.14 = 518.41. 518.41÷360=1.44. 1.44x36=51.84 which is 2.04 inches ] so from balancer mark at 0 on tab i used a paint marker made myself a mark 2 inches below original mark (clockwise direction) . Loosen distributor bolt a little and plugged vacuum advance warmed engine and then went in . I had to rotate my plug wires due to the vacuum advance and firewall . But i went in twisted distributor till my new mark was at 0 on the tab . I must say it sounds so much better . I reconnected the vacuum hose tighten distributor and took it down the road . So my questions is is there any other timing left to do , is 36* proper and would it be a little harder to start ? It was starting quicker before the adjustment . Ohh and no more back fire also .

 

At what RPM did you set the timing to 36*?