Aluminum rod lifespan.

[Totally T]

What is the cycle life of a 6" MGP aluminum rod.

SBC injected (alky only)
12:1
7400 rpm max

[GlennLever]

What is the cycle life of a 6" MGP aluminum rod.

SBC injected (alky only)
12:1
7400 rpm max

I'm interested in this also. I have been told that I should replace after a season.

[JrFuel Hayden]

I replace my MGP rods after 70-75 full runs in my 9500 to 10,000 rpm 16:1 compression, all iron SBC alky JF motor. But if I have 60 runs on them by the end of season, when I have the off season to freshen it up, then of course I replace them. I have sold some of my 60 run rods to racers that only run 7500 rpm, and they have used them up to 120 runs, counting my 60.
Count your runs and call the rod manufacture with your engine combo, bore, stroke, RPM range, fuel type, blower, no blower, etc.
I guess you could use the "replace at end of season" plan if you are lucky to race 70+ hard runs in a season.

Jon Hansen, Jrfuel, Hayden Wheels, and JrFuelDragsterAssociation

[GlennLever]

I replace my MGP rods after 70-75 full runs in my 9500 to 10,000 rpm 16:1 compression, all iron SBC alky JF motor. But if I have 60 runs on them by the end of season, when I have the off season to freshen it up, then of course I replace them. I have sold some of my 60 run rods to racers that only run 7500 rpm, and they have used them up to 120 runs, counting my 60.
Count your runs and call the rod manufacture with your engine combo, bore, stroke, RPM range, fuel type, blower, no blower, etc.
I guess you could use the "replace at end of season" plan if you are lucky to race 70+ hard runs in a season.

Jon Hansen, Jrfuel, Hayden Wheels, and JrFuelDragsterAssociation

I have cut way back on the number of races I go to, This year will be 6 races, Went on the first round at Bowling Green HRR, but have gone rounds, and expect to continue to do so for the rest of the season (42 runs?) Top end RPM is 6700, 813 HP

[wideopen231]

Yea the rpm you run has HUGE effect on number of runs.Most of the time its rod bolts that are issue more than rods. Some of the bracket guys mostly BBC have told me thet get 500 runs out of a set,turning 7500 range for the most part. Thats pushing it in my opion. I would have no issues running them 200 runs if rpm stayed below 8000 for most of the runs. Now uif spinning it I would say 100 and change.When you consider what they destroy on the way out its not worth pushing them to the limit.How do you know limit ,that one run before they came out.

[dreracecar]

2 killers of alu rods is heat and frequent teardown. Proper side clearence to keep the oil flowing will draw the heat out of the rod and the bore will stay round. Every time you reset the torque on the aluminum beam you pull the threads more and soon you will pull past yeild and incur rod failure.
Things that help in rod life is to have the big ends re-sized after a few passes when the rod settles in and a purchase of a GO-NO GO thread tool to inspect the rod threads. If the tool does not fit - junk the rod.

[masracingtd1167]

I use the MGP rods in mine and change them at around 100 runs . My motor see's about 9400 during a run . Another thing to think about is how much power the motor makes . If it is making over 1000hp and only turning 7500 I would still want to change them around 100 runs .

[dusterdave173]

Totally T
With the low RPM you mentioned I think you could use a set for a long time. I have built dozens of Big Block Mopars with BME aluminum rods for bracket racers--before we had aftermarket blocks they helped keep stock blocks from breaking once we had Indy heads etc and started really making some decent HP for stock blocks--We used to get 400-500 runs easy with those turning no more than 7000 RPM.
I have always been of the opinion that aluminum rods need a good warm up before racing. BME says un-torque aluminum rods over the winter or when stored--we Never did this ever and could get 500 plus runs. My experience tells me in your application you could run them a very long time betting you don't get near as many runs as average bracket racer --many will see 300 runs in a year.
Follow the mfg's specs on bearing clearance, warm them up good before racing, torque them with a quality inspected tq wrench using the EXACT lube as outlined by the rod maker and let er rip tater chip--no worry.
Now..If you are turning big RPM and making big HP then you know... that they should be replaced much more often.
BME offers racers inspection, correction, and some piece of mind if you send them in--always better to let THEM do any of that than regular machine shop on alum rods IMO.

[MaggiFinn]

Sbc nitrous, ca 900-950hp. Shifts at 7300 traps in 8000. Bought them plenty used from a nitrous formula offroad car. 6years in our engine, street and track use. Manley 6".

[wideopen231]

Totally T
With the low RPM you mentioned I think you could use a set for a long time. I have built dozens of Big Block Mopars with BME aluminum rods for bracket racers--before we had aftermarket blocks they helped keep stock blocks from breaking once we had Indy heads etc and started really making some decent HP for stock blocks--We used to get 400-500 runs easy with those turning no more than 7000 RPM.
I have always been of the opinion that aluminum rods need a good warm up before racing. BME says un-torque aluminum rods over the winter or when stored--we Never did this ever and could get 500 plus runs. My experience tells me in your application you could run them a very long time betting you don't get near as many runs as average bracket racer --many will see 300 runs in a year.
Follow the mfg's specs on bearing clearance, warm them up good before racing, torque them with a quality inspected tq wrench using the EXACT lube as outlined by the rod maker and let er rip tater chip--no worry.
Now..If you are turning big RPM and making big HP then you know... that they should be replaced much more often.
BME offers racers inspection, correction, and some piece of mind if you send them in--always better to let THEM do any of that than regular machine shop on alum rods IMO.

Bill Miller swear leaving rods torqued over winter with oil will cause a catlyist  and rods will crack,or so he told me was reason for one blown engine and other had 4 out of 8 with cracks at bolt holes.This was in the last set of BME rods we ever bought. Guess brooksb 88 had different aluminum as it was never issue with their rods.