thesoundandthefury

iTrader: (3)

I was looking at these bearings from Comp Cams:



http://www.compperformancegroupstore...gory_Code=BRNG

The pros to these bearings that I've found so far:

1. They're happy with splash oiling. Because they don't have oiling holes, they provide the same benefits of running oil restrictors with standard cam bearings without the "risk."

2. They lower valvetrain friction.

3. Don't have to worry about ever spinning one.

Maybe there are more pros, but as of yet that's all I've been able to find. Now I'm curious about the "cons." So far, additional machining costs to the block to make them fit are all I've seen. What are some other reasons to NOT run these bearings?

Mighty Whitey

to the best of my knowledge, aren't the cam bearings the same size (OD) as a standard bearing, and the ID is smaller, necessitating a smaller cam bearing journal on the camshaft?

NotACop97Z

iTrader: (7)

"Cams must be ordered with correct bearing journal diameters." Strait from the website.

thesoundandthefury

iTrader: (3)

From what I've gathered, the cam tunnel in the block needs to be line bored for these to fit. As far as getting a cam with the correct size journals: not sure how major of an issue that is. Maybe one of the cam gurus here can comment on that.

Ed Wright

iTrader: (1)

You don't need/want those.

thesoundandthefury

iTrader: (3)

Normally, I'm willing to put up with a little bit of condescension if it means I'll learn something from the one who's condescending, but in this case I'll have to respectfully decline.

Anyone else?

96capricemgr

iTrader: (1)

Now I could have seen it if you asked Ed WHY, heck I would like too know why he said that. But too me it sounds like you do not value his input and if that is the case there is no helping you, Ed and I have disagreed in the past but I always value his comments because I know he has a lot of experiance not just time believing whatever marketing BS is flung at him like most here do.

thesoundandthefury

iTrader: (3)

I thought that the title to the thread "what are the downsides" in addition to asking in my first post "what are some other reasons to NOT run these bearings" pretty much covered the "why" question, but I guess not.

Okay Ed, so why should I not run these bearings?

engineermike

I'll jump on that. There are only about a MILLION other things you could do that would give a larger improvement than roller cam bearings. The guys that use those only use them because they are running ridiculous spring pressures (300+ lb seat) and can't make babbit bearings last.

Ed Wright

iTrader: (1)

I appologize if I offended you. I didn't mean to sound condesending. Down sides: Lots of money for VERY little gain, you probably couldn't measure the power increase roller cam bearings woulld give you. Those are intended for large diameter cam cores which prevent cam twisting with extrememly high (Like 1") valve lifts, extreme spring pressures, and extreme RPM. None of which you would likely see with an LT1. Many engine builders are going back to babbit cam bearings, even with large diameter cam cores. I have never heard of anybody spinning a babbit cam bearing, but I guess if you did enough things wong enough, anything is possible.

I hope you will accept my applogy, Ed

engineermike

The local dirt track shop has had problems with wear on the bottom of the cam bearings due to extreme valvespring pressures. Honestly, most of the damage probably occurs during startup when there is little oil and no oil pressure. They switched to coated cam bearings and have had very good luck since.

SStrokerAce

iTrader: (2)

Listen to Ed on this one.... it's a waste of money on anything that's not a 100% Pro Competition motor.

Bret

thesoundandthefury

iTrader: (3)

Thanks to all who responded. And Ed: no offense taken. The only way we can keep these LT1 dinosaurs on the radar screen is by trying out new ideas right?