(In Butthead's voice) Fiat is cool. He like, knows how to make horsepower....
Originally posted by LakesOnly
Now, somebody assist me on the lifespan of aluminum rods; it seems there are as many answers to this question as there are people (or so it seems). The general answer I hear is that aluminum has no indication of level of fatigue (or whatever)...just use them 50-60 passes and throw them away before it's too late.
Sangster may have some advice for you on this one.................
Ok, my current SS83 runs alum rods. It has been running for three years. Each heat is 2 1/4 miles of racing with 1 mile of warmup. Two heats per day equals 6 miles times two days of racing is 12 miles per race weekend. Lets see, we average 4 races per year so 12X4=48 miles per year X 3 equals [144 miles on my motor]!! That's a little more than 60 1/4 runs but then I dont have a puffer and 13 to l compression. Approximately 12 to l on gas and it spins 7300 during the race. Am I on borrowed time? The rods were made in the early 80s and I dont have a clue as to their make. I am told the material could be a little better than current alum rods. I am a little concerned and will probably pull it apart to check length and size. Do you think I have just been lucky? I do know alum rods dont like backing down when the throttle is closed but the whirlaway somewhat cushions this action by releasing the prop while coasting. Is this true?
Originally posted by Sangerboy
Sangster may have some advice for you on this one.................
I agree
Originally posted by CircleJerk
Ok, my current SS83 runs alum rods. It has been running for three years. Each heat is 2 1/4 miles of racing with 1 mile of warmup. Two heats per day equals 6 miles times two days of racing is 12 miles per race weekend. Lets see, we average 4 races per year so 12X4=48 miles per year X 3 equals [144 miles on my motor]!! That's a little more than 60 1/4 runs but then I dont have a puffer and 13 to l compression. Approximately 12 to l on gas and it spins 7300 during the race. Am I on borrowed time? The rods were made in the early 80s and I dont have a clue as to their make. I am told the material could be a little better than current alum rods. I am a little concerned and will probably pull it apart to check length and size. Do you think I have just been lucky? I do know alum rods dont like backing down when the throttle is closed but the whirlaway somewhat cushions this action by releasing the prop while coasting. Is this true?
I have always heard that the decleration is a big deal in rod life. But then again, may be another "racer religion". My opinion has always been hammering the rods by detonation is the real killer. When you beat bearings out of the thing because you missed the tune up is when you hurt the rods.
But in a light rotating assembly and unblown and rpm's in the 7000 area, I know a lot of racers push the rods 150 runs. I've talked many times to Bill Miller and he has confirmed that. There has been some changes in aluminum rod materials the last 10 years. C&A claims they have a deep cycle rod that even the fuel guys run longer. Bill Miller claims the C&A rod is too brittle and has shown me shattered C&A rods. Then there is the Billet rod claim that they are superior. Never run them but someone may have some input on that.
I think in your application I would get them out there. And I would go with a quality steel rod like a Lunati Pro Mod rod, Crower, Carillo or the like. Since you run laps, there is always the heat issue with aluminum rods and we know they don't like heat. I'd measure the rods when I got em out but like I said, I never find anything to tell me cycle life is over.
Originally posted by 78Eliminator
Not sure what you are saying Smalls? You mean call them for advice, or what? I am building and doing most of the machine work myself. The last thing I want to do is pay someone to build it.
M&D Is good source for Info and work.
I have about 80 to 100 pases on the Millers in my motor. Its a 14.5 to 1, motor With a 300hp shot of NOS. its only been on the bottle for the last 30 or so passes.
Ive heard 100 pases on NOS and 150 With out.......
Yea I'm putting Rods, Rings and bearings in it as we speak............. Dont want to tear it down in the middle of the season...
Originally posted by Fiat48
...in a light rotating assembly and unblown and rpm's in the 7000 area, I know a lot of racers push the rods 150 runs....
This is encouraging as it fits my upcoming application...
LO
Originally posted by Fiat48
There has been some changes in aluminum rod materials the last 10 years...
Hey,
Anybody into hi-tech motor stuff has got to get a look at these ceramic composite aluminum rods with splayed rod bolts. WOW.
http://www.competitionplus.com/05_14...tgen_rods.html
Take the time to read the whole thing as it is truly groundbreaking and downright bad-ass.
LO
Originally posted by Fiat48
I have always heard that the decleration is a big deal in rod life. But then again, may be another "racer religion". My opinion has always been hammering the rods by detonation is the real killer. When you beat bearings out of the thing because you missed the tune up is when you hurt the rods.
But in a light rotating assembly and unblown and rpm's in the 7000 area, I know a lot of racers push the rods 150 runs. I've talked many times to Bill Miller and he has confirmed that. There has been some changes in aluminum rod materials the last 10 years. C&A claims they have a deep cycle rod that even the fuel guys run longer. Bill Miller claims the C&A rod is too brittle and has shown me shattered C&A rods. Then there is the Billet rod claim that they are superior. Never run them but someone may have some input on that.
I think in your application I would get them out there. And I would go with a quality steel rod like a Lunati Pro Mod rod, Crower, Carillo or the like. Since you run laps, there is always the heat issue with aluminum rods and we know they don't like heat. I'd measure the rods when I got em out but like I said, I never find anything to tell me cycle life is over.
thanks Fiat, I'm sure we could share some gloomy blown alcohol horror stories, like the time we missed the tune up and launched the magnesium enderle hat 500 feet in two directions! It simply coughed when 509 cubes ran out of prime just like a cold carburetor does with a bad choke! Sad for the wallet! We never lost an alum rod in the rail, in fact the last turn key car went to Texas where it totalled over 200 passes. For all I know it is still running. It also was a 427 internally balanced and only 20#s of boost and ran 6.90s at 200mph in 1984!
I only have 500 bucks in this short block and a spare engine is almost done so I guess I will gamble at the risk of a 1968 chevelle block! You should be paid for the advise you offer here since YOU paid for the wisdom in broken parts and hard work! JeRk :wink:
I've been pretty fortunate on the blow ups. Broke a wrist pin once but that was because I was too cheap to buy taper walls. Thought I could get by without them. Did for 3 runs! Piched a few ring lands by getting "greedy" with the tune up. But the ongoing problem never solved is occasionally spinning a main bearing. I still fight that today.
The forgiving stroke of the 427 probably had a lot to do with the long life. I had one make over 200 runs also. Just finally wore it out. We actually had funeral services in the back yard.
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