Standard S trim and cog drive?

[Mike SVOR]

Could the reason of these alleged bearing failures be due to the fact that people who buy cog drives usually run 18 to 20 psi on the blower?

[frdfandc]

You can go to a larger pulley. I believe Ian can custom make you a 3.5 inch pulley for the blower. You would probably see about 11-13 psi.

here are MY calculations for that comparison.

6.87 + 3.33 @ 6K = 42705

8 + 3.50 @ 6K = 47314

[Mike SVOR]

I have a V2 SQ. Sorry I didn't specify.

But they should have an internal multiplication of 3.61:1
That would mean,
6.87 + 3.33 @ 6K = 44685
and
8.0 + 3.50 @ 6K = 49509

so possibly around what you said, like 10 to 13 psi

[blueoval92]

Your original ? asked about the strain on the bearings if you were to use cogs on a standard sq s-trim, and was wondering if it were a scam. First key point that vortech told you that they use a wider bearing on their HD s-trims. Just because the bearing is wider does'nt mean it's taller. it would use a needle bearing at that point,which is more likely to stay true,than a ball that could go out of round.The cog pulley's are wider than serpentine which requires the use of a wider bearing, the narrower bearing in a standard s-trim cannot withstand the stress on the blower shaft by using cogs, but if you put a wider bearing in, the shaft will have less flex which = less stress. if the shaft were to flex to much, the impeller will crash into the scroll like mentioned previously,then you'll be SOL, and will end up buying a HD unit and or new motor! this is JMO, but cogs are for serious HP in a racing situation where every ounce of HP is crucial. but for 9-10lbs save your sq s-trim and your money. another thing you mention is you have a 351 and steel crank,good internals, 10-14lbs on that is a nice setup!! Go with the renegade setup like what was mentioned and your boost gauge won't be bouncing up and down! Put a 3.75 pulley on it if your worried about to much boost, with your setup i wouldn't worry at all!!! I've dealt with bearings for a long time, and procharger does the same thing,but instead of using a wider bearing they put dual bearings together,two in front two in back,for the use of cogs for RACING. Hope this shines a little light on the Subject. :D JMO One other thing the wider the bearings on a shaft spinning at 50,000rpm!! will produce less harmonics, and that shaft will live longer also!! So a scam i would think not, engineering/physics/technology is what i would think.

[Mike SVOR]

First key point that vortech told you that they use a wider bearing on their HD s-trims. Just because the bearing is wider does'nt mean it's taller. it would use a needle bearing at that point,which is more likely to stay true,than a ball that could go out of round.

Thanks for the feed back. I really do appreciate it.

as for the bearing being a needle bearing:
It can't be. Any shaft supported by bearings which requires lateral support (side to side) requires ball bearings. The shafts can't hit the case, so they must rely on the bearing to stop the movement.

The simplest way to sketch a picture of this is to think of a car's rear end axle config.
Any axle that uses press on bearings onto the axle, requires ball bearings.
Axle configurations that use "C" clips normaly use needle bearings because they float on the axle.

The lateral force on a SQ S trim is probably great due to it's angle cut gears.

So I'm back to the point of how does vortech fit a wider ball bearing in the case without going taller. :)



P.S. as for the cogs, you guys have convinced me not to try it. I'm going to have a 10 rib pulley setup made.

[blueoval92]

It has to be the case to house the wider/taller bearing, not sure if this is true or not but it would seem that vortech would make standard cases for street duty and HD cases for racing, maybe this is why the cost is so high to upgrade. I guess if we new someone that worked at vortech we would know that information. But i still don't think it's a scam, that's why you have street/ strip blowers. I'm glad you decided not to run cogs, I really don't think anyone here would steer you wrong. When your ready to boost it up then sell your unit and get the HD YSI! :D p.s. With cogs LOL