Ok, this may sound strange, but I set the timing on my Riv to 10 before TDC. After a few high speed street runs the car started to run rough. After rechecking the timing it was at 2 before TDC! I then reset the timing to 10 before again and marked the position of the distributor. After a couple days, 70 miles, and one serious burnout it started to run rough and lack power again. Once again I checked the timing and it was off by 6 degrees... the distributor did not move, I checked my marks. Is it possible the pin on the distributor gear is sheared and may be spinning on the shaft at high RPM's, or would the gear simply just fall off? Any help would be good. (I suppose I could just stop being lazy and pull the distributor and check it out but I was interested to see if anyone else has had this problem) Thanks, Clay
timing you might want to check for timing chain slop.what you do is line up timing marks to zero ,take off dist cap mark rotor location turn crank with socket and ratchet to 15 degrees or so and mark rotor location then turn back to zero and if rotor doesnt line up with first mark you will see how much slop is in chain and gears. do you have extended gears on oil pump?this can put a load on dist gear and shear that pin but i think its in the timing chain . andy:TU:
Slop Hey Andy, This motor only has around 1000 miles on it I would hope the chain was still good, as far as extended gears, I don't think it does. I am swapping out the original dist. with ignitor, to an HEI on tuesday so I suppose I will know what's up with it then. It has been drivin me nuts for the last 2 weeks. Next step will be to see if I can ever get this junk QJet to work well. (ok, so it's my tuning skills not the carbs fault) If I still have the issue after the new dist. I will try what you said as far as the chain, maybe it was defective?... Clay
Clay, Definitely pull out the distributor and examine it very carefully. It is possible for the shaft to spin where it is welded to the top advance plate. I saw this with my own eyes at the GS Nats. John Massoud's car is an iron headed Stage1 that runs mid 9's. He has a crank trigger and locked out timing, so the only adjustment at the distributor is for rotor phasing. His car started to run rough and backfire, so he checked the phasing. It was off even though the distributor was tight. He readjusted it, and went to the line. The car backfired and it sounded like it blew up! Back to the pits, the distributor comes out, and sure enough, you could hold the gear and actually move the top plate on the distributor. The shaft was spinning through the weld. A little weld job, and he was back to running those mid 9's the next day. Check that distributor!:TU:
timing Happy Fathers day to those that are..., As for as my car goes... Actually that sounds exactly like the problems I have with the car, (except for the problem with the 9 second quarter mile!) I am gonna pull the dist. today and see what I got. Thanks, Clay
Clay, you need to grease the rubbing block on the points, then re-adjust your timing. The timing changing is the rubbing block on the points wearing out from lack of lubrication. Tom
timing Sorry Tom, I must not have been clear in my earlier posts, I have a pertronix Ignitor... I ditched the points years ago. Thanks, Clay
Its also likely that your advance weights are sticking, when you pull the distributor be sure to clean that assy well and spray on some dry film lube. Also check your rotor locking key to be sure it isn't damaged and spinning, I've seen where the rotor wasn't pushed down all the way and the plastic locking key sheared.
Ok, think it was the advance weights... I cleaned it all up and swapped in different distributor springs and seems to be good.:beer Thanks for the help! Sometimes it is easy to overlook the obvious. Clay
Well... OK, the problem did not end up being the advance weights either like I had thought, just part of the problem... I pulled the distributor and the gear was all but chewed up! The teeth were sharp like knife blades, seemed to skip teeth and screw up my timing. What causes this, the cam gear looked pretty good from what i could see. I put in an HEI that I got from D. Berry and things are running great now. I am just worried that this gear may get trashed too. Should I change the cam too? Is it possible that the gear is not quite right on it or what ? The distributor gear was fine prior to the rebuild.(about 1400 miles ago) Any suggestions?
Clay, The #1 cause is the use of a high volume/high pressure oil pump. The pump puts too much back pressure on the cam gear/distributor gear, and front cam bearing. When using these pumps it is wise to use as light a viscosity oil as possible, as little relief spring pressure as possible, and don't rev the motor until the oil comes up to temperature. Was the gear you found chewed up, a bronze gear? They are made to sacrifice themselves instead of taking out the cam gear. If your oil pressure is too high, take steps to get it down into the normal range. Your present gear will be worn unless you take steps to reduce the load on it. Hope that helps.
timing Hi, The gear looks to be steel, my oil pressure is 20 at idle and 60 under load, there is alot of play (up and down) on the old distributor shaft, will that cause the teeth to wear like that? Ya think I should change the cam? not like I don't already want to upgrade anyway... Thanks, Clay
Distributor Gear DOES YOUR CAR HAVE A HIGH VOLUME OIL PUMP? Sorry for shouting, but that really is most likely your problem. If your engine is freshly rebuilt with proper clearances you should have no need for the HV pump. If it is causing enough strain to ruin your distributor gear, it is also side loading the camshaft and trying to gall out your front cam bearing. You may have 60 psi hot, and that may be because you are running against the pressure relief valve. Does the pressure go up to 60, then stay there as the engine revs up more? If so, your high volume pump is working against the rest of the oiling system, the majority of the oil is being bypassed, and you are ruining the oil pump/distributor drive system for no real purpose.
oil pressure.... ok , as always new problem though possibly related , my oil pressure is now always at 50-70 psi...this is a new problem up till yesterday it was 20/60 what would cause this? clay
