While replacing the mechanical advance springs on my HEI distributor, I noticed a large amount of clearance in the distributor drive and cam gear. I haven't pulled the distributor yet, but I know what I'll see..... excessive drive gear wear. This engine has around 4k miles since the new HEI distributor was installed on the new roller cam. It has a new front cover assembly with a standard oil pump from TA performance. This is a 350 small block. Have you guys experienced this yet? What is the best solution to prevent having to replace every 4k miles?
If your cam button end play is excessive, you may be developing excess wear on the dist gear, cam gear or both from the cam walking back & forth.
Roller cams require hardened distributor gears. Being the 350 drive gear is replaceable, that may not be the case for the 350, but it is for the 455.
If memory serves.... The initial install had around .006" of clearance, but haven't checked since Thanks, I will check into it. Thank you, I will call TA and find out.
What Larry said. I would think that even with a roller camshaft the distributer drive gear for a 350 is the usual removable one that comes on all 350's so a regular distributer driven gear would be compatable. The good news is you won't need a new cam just the drive on the cam and dist. Maybe try a gear oiler. I have those on BBB's that have worn gears and that keeps it from wearing any worse. Is there a chance that the roller cam doesn't have the usual oil hole that factory cams have to get oil out to the gear? However, could be just too much oil pressure when cold and revving it up. I don't know if you have one but I like the idea of an anutomatic choke on my engines but I hate the idea that the engien tries to go 1800 rpm when cold. I try to kick it down immediately so it is not trying to run that rpm right after startup even if it requires a few stalls until warm.
Interesting, When I pull my engine to install my aluminum heads Im going to have a look at mine just in case as Im running the hi volume pump, BUT I take it very easy with the rpm till its warmed up, be interesting to see what I find as I have a whole season on it including whaling on it at the track.
I mentioned this in one of the many conversations with my machinist. I saw a picture of what Mike Jr. did to his 350. This is my machinist’s version. I believe the hole is .035. He thoroughly researched oil mods with Buick’s and he’s done a lot. His take on oil pressure is what your measuring is the restriction of flow. He wants less pressure (restrictions) with more flow.
stay away from 6k + rpm's and you shouldn't have problems. excessive oil pressure/volume will be a drag on both gears as i wear them out every year. my current gears are polished and harden, but need to be inspected this winter. i had to build another cover as the dizzie hole was expanded, dizzie wobble, from high rpm racing. if somebody wanted to spend the time bisecting and measuring all, they might find a better answer.
and having any gauges on the dragster doesn't do any good with my son's driving. 'oh, btw, i went a little high on the rpm i think'.....thanks sonny. lol
That little tube oiler that TA shows in their tech bulletin looks to me like a good idea as it points a continuous spray of oil right into the mesh area of the gears. It wouldn't take much volume to really help out there and we know it's a weak point. Of course doing it in such a way that it couldn't loosen up and move would be a real good idea too. Jim
I've always used steel gears with roller cams. TA has them. Bronze is sacrificial and alright for race cars that tear down frequently. Stock is cast iron.
