Well the inevitable happened. My HV oilpump chewed 2 teeth off my stock distributor gear resulting in a snap backfire and pop. The great news is that both teeth fell straight into the front sump of the oil pan and did not mess up the teeth on the cam. I was lucky I guess. My question is will a bronze distributor gear fix this problem? I put another stock gear in the motor to get it home but I want a stronger replacement.
Thanks

 

first of all what r you running for a cam roller or hyd?

 

sorry for my lack of specs.

74 460 Comp cams hyd X4256H. stock distributor 70 timing gear melling HV pump

 

A bronze gear is soft for use on steel roller cams, it's a sacrifice item, wear the $50 gear out instead of wearing out the $300 cam. now I have heard the HV pumps wear out the dist gears story for years, I run roller cams, so I run a bronze gear, same gear on my motor for the past 3 years, and always run HV pumps against, I am going to change the gear this year just as a precaution not because it particularly worn. Fact is I have never seen a HV pump be the cause of a broken or worn gear it's always something else, I have broken gears, and sheared pins with both HV pumps and standard duty pumps which tells me it wasn't the pump, I have also snapped oil pump drive shafts in half and not broken the gear at the same time.
Personally I would look for something else causing the problems, like a misalignment if the dist gear and the cam gear, possible small debris in the oil pan getting into the pump, etc.

 

Rob,
How would I check my cam distributor gear alignment? What else could it be?

Once again thank you for your help

 

STG, I would agree with Monster, the pump is not likely the problem. At the shop that I have worked with and at for many years, we install an HV pump in EVERYTHING that we can get one for, unless the customer specifically asks us not to. In over twenty years, I have NEVER seen a dizzy gear fail because of an HV pump. That really is just an old wives tale. But if the oil plugs aren't done right, and the gear isn't getting oil, there will be problems. The most common problem that I have noticed is that Comp's gears are not always cut correctly on the cam core. It is easier for them to blame you for running a big pump than it is to pay for a warranty on a bad cam. I have seen enough bad cams from them to never use any of their stuff in my engines. DinosaurFan, on the work 'puter

 

One thing in the tech sheet sent by Comp is to use break in lube on the cam gear and distributor gear. The gears supposedly have to wear together just like the lifters. Not to mention that the lack of proper lube will also eat the gear teeth like DinosaurFan said.

 

I used plenty of lube when assembling this motor. I bought an 8oz bottle infact. Im going to pull the distributor tomorrow and see if the new gear is being worn also. With the few miles I have on the first gear, the second gear should be showing some signs of damage.

 

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Excessive distributor gear wear can be a problem with Ford engines. Most of the time, the problem is a result from the use of a high volume oil pump. High volume oil pumps put a lot of stress on the distributor and cam gears. A high volume oil pump is not necessary on a street driven engine that turns no more than 7000 rpms. Only extreme racing engines require the high volume pump. Should you use this type of oil pump, the following precautions will save your distributor gear from early destruction.

(1) Drill a .030" hole in the lifter/oil galley plug behind the distributor. This will allow additional lubrication on the distributor and cam gears. This will not lower oil pressure enough to hurt the engine.

(2) Ford oil pump mounting brackets have elongated holes. Due to this, the distributor shaft and oil pump shaft should be aligned so that the distributor turns freely before tightening the mounting bracket bolts. Failure to do this will cause a binding situation, thus damaging the gear.

(3) Stock Ford hex oil pump drive shafts are know to vary in length which could cause a bottoming or binding situation.

(4) Brass distributor gears can be used to avoid damaging the cam gear. Brass gears are softer and can wear out quicker than the cast gear, but will not cause damage to the cam gear. If using a brass gear, check it occasionally for wear.

 

Don't run brass gears except on roller cams, they were even faster against a iron cam for some reason and they aren't needed except on the steel cam cores used on rollers.

 

The only reason we mention running a brass gear is for those who INSIST on running a high volume oil pump.

Otherwise, we thoroughly agree with you-only use a brass gear with a roller cam.

 

Actually we both got it wrong, it's bronze not brass.

 

Right-maybe because they both begin "br.."-Good point!

 

STG, I wouldn't listen to the tired old wives tale PerfDist is feeding you. The 'extra' stess you dizzy gear and pump shaft feels when running a high volume pump is real, but it is insignificant. If you look at it carefully, the HV pumps usually push 25-30% more volume than stock. In an engine with lots of oil clearance from wear or because it was built that way intentionally, there might not be any more stress than normal. Now, to play devil's advocate, just imagine that you have normal clearances and the big HV pump, and an engine full of cold 50W oil. You turn the key to crank it on a zero degree morning. Is there more stress on the gear and pump drive ? Sure there is ! But the important thing for us to remember is that the pump's drive and dizzy gear don't care. If you want to find out how strong your pumpdrive is, clamp one in a vise and then take a torque wrench and try to break one. Let me know what you find. Then, put a stop bolt on a cam, and put the torque wrench on the dizzy, and see how much pressure the cam and dizzy gears will take with out breaking, if you can break them at all. I'll bet you can't do it, unless you're built like Arnold. The two reasons that dizzy gears can be chewed up I already mentioned in my earlier reply, there could be not enough oil supply, or the gear could be ground incorrectly. The stress levels just aren't enough to matter. The story about HV pumps harming dizzy gears is nothing but a myth put forth by manufacturers of camshafts and dizzy gears that screwed up and cut the gears wrong, and they want YOU to take the blame for something THEY did wrong. Out of several hundred engines that I have personally seen go together with HV pumps, I have seen 6 of them chew up dizzy gears. One, an AMC 401, wasn't getting enough oil to the gears. The others were Fords and Chevys, all of which were using the same brand of camshaft, which were cured by changing the cam, the HV pumps remained, and caused no trouble. On one of them, a stock pump chewd through 3 gears, but the replacemant cam supported a HV pump without trouble. The fact that PerfDist thinks the big pumps are only needed for racing shows us they really have no idea what they are talking about. Lots of pickup truck guys run the bigger pump with looser clearances because it flows more oil across the bearings and keeps them cool and happy, like when you're pulling a heavy trailer or something. The HV pump is a durability item, not a 'high performance' or racing item, like PerfDist suggests. Don't old myths ever die ?! If you want a better explanation of how much stess there is on a pumpdrive and gear, why not ask Mellings ? They're the folks who make the pumps and they make cams too. DinosaurFan, on the work 'puter

 

Dino,
that was very helpful. I guess I have always heard that HV pumps are hard on dist. gears. Its one of those things I guess. When I fixed the truck a little over a week ago I just swapped a new dist in from a truck I have with a 351M and it seems to be fine so far. I pulled it last night to check the teeth and I cant see where it has been wearing like the previous one. I would assume with the evident wear after 700 miles the last gear had that I would see some signs on the new one after about 300 miles. Maybe something was wrong with my first gear. For me its much easier to keep my eye on the current gear and hopefully it will be ok. I really dont want to buy another $200 cam but will if I have to.

Thanks everyone.