So, my 70 stage rattles(pings?) when I accelerate at about 3/4 throttle. If I go up slow, ya know like people normaly drive, I have no issues. All eight are getting a nice burn. The carb is extremely smooth no matter how much pedal I use. Total timing is about 32. I really don't know at what rpm I am all in, motor is torn down right now. My mech wants to use thicker head gaskets to lower compression. I don't think it is much over 11 anyway. From what I have been reading, my guess would be distributer curve could be better? Really can't see lowering compression. Am I close to being on the right track with timing curve?? Thanks
On even a higher compression engine, you can usually eliminate ping by retarding ignition andvance, although it can be at the expense of power and performance. Alternatively, you can mix pump gasoline with racing fuel to increase octane, slightly enrichen the carb's air/fuel mix, or lower compression. Devon
Hi Devon, Have used 110 octane and it normally don't help much. So, maybe more of a timing issue than anything??
That and possibly enrichening the secondary and/or primary sides of the carb. Does it rattle at WOT? Is vac advance seeing ported or manifold vacuum? 32 degrees total sounds pretty much where you want to be. How's fuel pressure at WOT? Devon
Well, now, thats some things we will have to check. I appreciate the knowledge sharing. Thanks again. I will let you knowhow is turns out. Your info is a bit beyond my talent. Will have to pass on as much as I can to my mech. I know he knows what you are talking about. Thanks
That motor should not ping/detonate with 110 octane......somethings out of tune. I go through the timing with a fine tooth comb. Check your inital, vac adv. how soon the advancement is coming in and total.
