MustangWorks.com : Ford Forums - View Single Post - Aluminum RRs good for only 20-30K miles??

PKRWUD · 10-31-2001, 11:23 AM

I haven't read the article you're talking about, but I would tend to agree with it. I honestly can't remember if I read it in a catalog insert, was told by my number one parts man or if I was taught it in my college engines class, but at somepoint in my career, I was educated to the fact that the biggest downside to aluminum full roller rockers was their lifespan. I wish I could remember when and where I learned this, but it must have been a while ago because to me, this was common knowledge. Wrenching on engines with them installed over the years confirmed this. I might question the 20k - 30k mileage statement, but I'm sure they're just averaging. In a full race 1/4 mile engine, aluminum RR's need to be replaced at seasons end due to wear, and they probably have seen less than 15 miles. In a mild street/strip application, 25k miles is pushing the limit. In a daily driver that doesn't see a track more than 2 or 3 times a year, 50k miles would be the maximum expected lifespan. This doesn't mean they can't last longer, just don't expect them to. We replace the aluminum RR's in our Sprint car mid-season, after maybe 75 miles. They are noticably worn and loose when we replace them, but are by no means shot. We just have alot riding on the engine remaining "tight", and have stricter standards. Basically, it boils down to the fact that there are alot more contact points to wear, and once wear starts, it accelerates rapidly. In NASCAR, they are thrown away after every race. Jim, if you've got 55k miles on yours, I would back them off and inspect them, along side a brand new one if possible. I think you'll be surprised.

Take care,
-Chris

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10-31-2001, 11:23 AM	#6
PKRWUD Junior Member Join Date: Mar 1999 Location: Ventura, California Posts: 8,981	I haven't read the article you're talking about, but I would tend to agree with it. I honestly can't remember if I read it in a catalog insert, was told by my number one parts man or if I was taught it in my college engines class, but at somepoint in my career, I was educated to the fact that the biggest downside to aluminum full roller rockers was their lifespan. I wish I could remember when and where I learned this, but it must have been a while ago because to me, this was common knowledge. Wrenching on engines with them installed over the years confirmed this. I might question the 20k - 30k mileage statement, but I'm sure they're just averaging. In a full race 1/4 mile engine, aluminum RR's need to be replaced at seasons end due to wear, and they probably have seen less than 15 miles. In a mild street/strip application, 25k miles is pushing the limit. In a daily driver that doesn't see a track more than 2 or 3 times a year, 50k miles would be the maximum expected lifespan. This doesn't mean they can't last longer, just don't expect them to. We replace the aluminum RR's in our Sprint car mid-season, after maybe 75 miles. They are noticably worn and loose when we replace them, but are by no means shot. We just have alot riding on the engine remaining "tight", and have stricter standards. Basically, it boils down to the fact that there are alot more contact points to wear, and once wear starts, it accelerates rapidly. In NASCAR, they are thrown away after every race. Jim, if you've got 55k miles on yours, I would back them off and inspect them, along side a brand new one if possible. I think you'll be surprised. Take care, -Chris ------------------ Retired Moderator MustangNet My site: Peckerwoods Pit Stop My teams site: Jim Porter Racing RACECAR spelled backwards is RACECAR HEY !!! Are you ASE Certified ??? If you are, ask me about iATN.