What do you consider a normal service life of offshore H beams in a sportsman application?
Moderator: Team
-
- Guru
- Posts: 2151
- Joined: Fri Apr 07, 2006 8:23 pm
- Location:
What do you consider a normal service life of offshore H beams in a sportsman application?
Scat/Eagle/K1/Manley/etc.
Higher RPM (low 8000 max) sportsman style oval track, drag race, etc N/A applications.
What's a reasonable time to replace them?
Unlimited? Replace bolts during refresh + magnaflux? "X" laps? X seasons? What hack would use this level of rods?
Just curious what the general consensus is. Yes we would all love to use the best of the best rods in our customer's engines, but there has to be several sets of these in service for every "premium" set.
Higher RPM (low 8000 max) sportsman style oval track, drag race, etc N/A applications.
What's a reasonable time to replace them?
Unlimited? Replace bolts during refresh + magnaflux? "X" laps? X seasons? What hack would use this level of rods?
Just curious what the general consensus is. Yes we would all love to use the best of the best rods in our customer's engines, but there has to be several sets of these in service for every "premium" set.
Re: What do you consider a normal service life of offshore H beams in a sportsman application?
That is a really good question, one that may not have a clear answer. I am just a back yard hack so take this with a grain of salt. I have built a few circle boat and drag race engines that run in the 7000-7500 rpm range every time they hit the track. They are BBC with 4.25 stroke. Three of them have been running the same rods for about six years, all of which are either eagle or scat H beams. Every time they come apart they are checked and the bolts are checked for stretch. Only set I have seen that needed real attention was a set of mystery rods as the bolts were all over the place and the big ends were out of round. I heard they put in new bolts and had them resized and put them back in the engine. I don’t know the specifics of that engine, but my machinest was surprised they lasted and they have not come back so he figures they are still running ok.
I once had a conversation with a pro stock engine builder and he was asking what we do for our bottom ends. We told him that we like to run steel rods, and then we asked him when we should change them based off of our piston speed and piston weight. He said “check your bolts at each tear down and swap out your rods when you start collecting social security”. That was spinning our 4.25 stroke at 8300 rpm.
Heaven knows a bad tuneup can destroy even the best parts, but I have had good luck with eagle, scat and callies offshore rods.
Paul
I once had a conversation with a pro stock engine builder and he was asking what we do for our bottom ends. We told him that we like to run steel rods, and then we asked him when we should change them based off of our piston speed and piston weight. He said “check your bolts at each tear down and swap out your rods when you start collecting social security”. That was spinning our 4.25 stroke at 8300 rpm.
Heaven knows a bad tuneup can destroy even the best parts, but I have had good luck with eagle, scat and callies offshore rods.
Paul
"It's a fine line between clever and stupid." David St. Hubbins
- Caprimaniac
- Guru
- Posts: 1060
- Joined: Fri Nov 18, 2011 1:17 pm
- Location: NORWAY
Re: What do you consider a normal service life of offshore H beams in a sportsman application?
That IS a good question.
Set of Eagle rods have lived for 10 years, up ro 8000 rpm in drag racing, road racing and auto-x. Rebuilt once, withou noticing anything fishy on the rods or bolts.
Am in for a new set now and wonder if there are any «better» ones- eagle, scat, k1, molnar?
Noticed a new «procomp» PRO-I rod. Looks interesting.... But is it better than the other 600$ a set rods?
Set of Eagle rods have lived for 10 years, up ro 8000 rpm in drag racing, road racing and auto-x. Rebuilt once, withou noticing anything fishy on the rods or bolts.
Am in for a new set now and wonder if there are any «better» ones- eagle, scat, k1, molnar?
Noticed a new «procomp» PRO-I rod. Looks interesting.... But is it better than the other 600$ a set rods?
How to turn GURU in an instant.....
-
- Guru
- Posts: 2270
- Joined: Wed Jul 27, 2011 5:22 am
- Location: brisbane AUSTRALIA
Re: What do you consider a normal service life of offshore H beams in a sportsman application?
Heaven knows a bad tuneup can destroy even the best parts, but I have had good luck with eagle, scat and callies offshore rods.
Paul
[/quote]
Agree 100% on this statement, a poor tune is probably more responsible for engine failure no matter who's rods you are using.
Paul
[/quote]
Agree 100% on this statement, a poor tune is probably more responsible for engine failure no matter who's rods you are using.
steve c
"Pretty don't make power"
"Pretty don't make power"
Re: What do you consider a normal service life of offshore H beams in a sportsman application?
Well the fatigue life of steel is pretty high, i doubt you’ll ever wear them out compared to bearings maybe
Just think how many oem motors have hundreds of thousands of miles on them same rod bolts and all. Granted not high abuse but lots of stress cycles and heat cycles over a decade or three depending lol.
My buddy used k1 crank and h beams in a turbo lsx. Ran 4 yrs on them, with 2 yrs being at max power before replacing. Car has been 7.17 at 196 in the 1/4 at 3280 lbs lol. Not bad for china rods. Put in callies ultra for peace of mind but nothing was wrong with the k1 stuff. Rod bolts probably had 6-8 torque cycles on them too
Just think how many oem motors have hundreds of thousands of miles on them same rod bolts and all. Granted not high abuse but lots of stress cycles and heat cycles over a decade or three depending lol.
My buddy used k1 crank and h beams in a turbo lsx. Ran 4 yrs on them, with 2 yrs being at max power before replacing. Car has been 7.17 at 196 in the 1/4 at 3280 lbs lol. Not bad for china rods. Put in callies ultra for peace of mind but nothing was wrong with the k1 stuff. Rod bolts probably had 6-8 torque cycles on them too
Re: What do you consider a normal service life of offshore H beams in a sportsman application?
Rods, cranks, bolts are all a form of steel and all have an associated strain-life and/or stress life curve to estimate cycles to failure.
The curves will start out with a stress value above the ultimate tensile strength and last one cycle before failure.
There will be another point on the curve where you can maybe get a couple thousand cycles at yield strength of the steel.
Most values for fatigue life are given in terms of a percentage of yield stress that returns 1,000,000 cycles.
This is typically around 50% yield stress.
I've done some math and a 500 mile roundy round race will put a million cycles on the rotating group. I don't know if they refresh the rotating group after this type of race but let's just assume they do.
The second assumption is that we taught the offshore peeps the recipe for 4340 and how to forge metal properly. (The Taiwanese are particularly good at forging when I visited there around 2009.)
Using a million cycles as the target, that is around 1100 quarter mile laps including burnouts, barring no mishaps along the way like driveline breakage, oil starvation, smeared pistons, balancer mishaps, TC issues, etc.
Knowing all that, my experience is telling me that a million cycles on a drag race engine (not "street/strip") is a bit optimistic.
I'd like to hear from others if they have kept records on laps versus replacing parts for maintenance.
For the original question, create a simple spreadsheet that tracks rpms, turns them into a rotating group cycle and adds the cycles up.
Smarter people than me may have an HP/cubic inch number that translates into a life expectancy which would be helpful.
All's I know right now is that if I did it over, I'd target 500,000 cycles on a 1.75HP/cubic inch BBM for rotating group replacement independent of what shore they were made on.
The curves will start out with a stress value above the ultimate tensile strength and last one cycle before failure.
There will be another point on the curve where you can maybe get a couple thousand cycles at yield strength of the steel.
Most values for fatigue life are given in terms of a percentage of yield stress that returns 1,000,000 cycles.
This is typically around 50% yield stress.
I've done some math and a 500 mile roundy round race will put a million cycles on the rotating group. I don't know if they refresh the rotating group after this type of race but let's just assume they do.
The second assumption is that we taught the offshore peeps the recipe for 4340 and how to forge metal properly. (The Taiwanese are particularly good at forging when I visited there around 2009.)
Using a million cycles as the target, that is around 1100 quarter mile laps including burnouts, barring no mishaps along the way like driveline breakage, oil starvation, smeared pistons, balancer mishaps, TC issues, etc.
Knowing all that, my experience is telling me that a million cycles on a drag race engine (not "street/strip") is a bit optimistic.
I'd like to hear from others if they have kept records on laps versus replacing parts for maintenance.
For the original question, create a simple spreadsheet that tracks rpms, turns them into a rotating group cycle and adds the cycles up.
Smarter people than me may have an HP/cubic inch number that translates into a life expectancy which would be helpful.
All's I know right now is that if I did it over, I'd target 500,000 cycles on a 1.75HP/cubic inch BBM for rotating group replacement independent of what shore they were made on.
Re: What do you consider a normal service life of offshore H beams in a sportsman application?
I think (but don’t know) that one can design a steel rod with effectively infinite life. I think most production rods in production car engines are like that. By my logic, for that kind of rod, the number of cycles that the rod has seen without failure is positively related to the rod’s remaining life expectancy. Survival of the fittest (or in the case of heavy steel rods that my 1980’s Porsche has, survival of the fattest).
This doesn’t apply to rods that are made very light and designed to last a finite number of cycles, of course.
This doesn’t apply to rods that are made very light and designed to last a finite number of cycles, of course.
Paradigms often shift without the clutch -- https://www.youtube.com/watch?v=cxn-LxwsrnU
https://www.instagram.com/ptuomov/
Put Search Keywords Here
https://www.instagram.com/ptuomov/
Put Search Keywords Here
Re: What do you consider a normal service life of offshore H beams in a sportsman application?
Does the same hold true for I-beams in the same price range and application?
-
- HotPass
- Posts: 9391
- Joined: Tue Nov 22, 2005 5:41 am
- Location:
Re: What do you consider a normal service life of offshore H beams in a sportsman application?
The sinter-forged rods made by GKN for the Porsche 928 underwent some grueling testing (from Project 928, page 47):ptuomov wrote: ↑Wed Jul 03, 2019 8:41 am I think (but don’t know) that one can design a steel rod with effectively infinite life. I think most production rods in production car engines are like that. By my logic, for that kind of rod, the number of cycles that the rod has seen without failure is positively related to the rod’s remaining life expectancy. Survival of the fittest (or in the case of heavy steel rods that my 1980’s Porsche has, survival of the fattest).
This doesn’t apply to rods that are made very light and designed to last a finite number of cycles, of course.
Assuming the full load tests were run at 5000 rpm that 3000 hour test put 900 million cycles on the rods.Then there was the total of seven condensed-time
endurance tests over 5000 miles of the ultra-difficult
Weissach loop which corresponded to normal road use of
nearly 100,000 miles each. The demands of those
merciless tests were so great that newcomers to the
driving team often became nauseous in a very short
time.
There were the especially spectacular endurance runs on
engine test brakes: a full-load bench run of more than
3 000 hours as well as five runs of 600 hours each
between December 1975 and March 1977.
Driving Force Online: BREAKING NEWS—Ohio Governor Signs SEMA-Supported Vehicle Freedom Bill Into Law!
Re: What do you consider a normal service life of offshore H beams in a sportsman application?
Guess RPM and acceleration cycles have a lot to do with it. I built my street 427 Windsor with the SCAT H beams and forged SCAT crank but only rev it to 6200 at most and on rare occasion. Going on 10 yrs now!
Re: What do you consider a normal service life of offshore H beams in a sportsman application?
All steels have endurance limit of 10 million cycles.If the part take that (at some definend max load) it will last forever.However even few overload cycles and the game change.. Properly designed steel part (for the task) will last longer than you.
"when uncomptent order unwilling to do unnecsessary the probablity of failure is high"
Re: What do you consider a normal service life of offshore H beams in a sportsman application?
Use this document for a guideline (graph on page 3).rustbucket79 wrote: ↑Tue Jul 02, 2019 9:40 pm Scat/Eagle/K1/Manley/etc.
Higher RPM (low 8000 max) sportsman style oval track, drag race, etc N/A applications.
What's a reasonable time to replace them?
Unlimited? Replace bolts during refresh + magnaflux? "X" laps? X seasons? What hack would use this level of rods?
Just curious what the general consensus is. Yes we would all love to use the best of the best rods in our customer's engines, but there has to be several sets of these in service for every "premium" set.
If you never load the rods hard, they will have infinite life.
If you load them nominally, they look to have a life of a million cycles.
If you run high BMEP, power adders, or shots of nitrous, you can easily cut that in half.
China rods are not fully developed GKN/Porsche rods so the comparison is not really valid for your question, though it is interesting they put that much investment in a slow V8 that sounds really cool with the convertors removed.
https://www.asminternational.org/docume ... Sample.pdf
Re: What do you consider a normal service life of offshore H beams in a sportsman application?
From the same source that Kevin Johnson quoted:
"In the interests of good mass balance and to hold weight tolerances of the connecting rods within the tightest possible limits, rod design was given considerable attention. They decided to develop a sinter-forged rod which promised fine weight accuracy with minimum machining and thus low production costs. Test results were indeed outstanding. At 0.0168oz./in.^3, they achieved a material density close to that of forged steel. Alternating tension and compression tests produced clearly better results for the sintered parts than those for steel rods forged in a similar shape."
This was back before Mark Wahlberg was Marky Mark, when Porsche was a combined marketing and engineering company. Instead of just a marketing company that they are today.
Paradigms often shift without the clutch -- https://www.youtube.com/watch?v=cxn-LxwsrnU
https://www.instagram.com/ptuomov/
Put Search Keywords Here
https://www.instagram.com/ptuomov/
Put Search Keywords Here
-
- HotPass
- Posts: 9391
- Joined: Tue Nov 22, 2005 5:41 am
- Location:
Re: What do you consider a normal service life of offshore H beams in a sportsman application?
They used the same basic design but scaled in their Formula 1 engine.ptuomov wrote: ↑Wed Jul 03, 2019 9:41 pmFrom the same source that Kevin Johnson quoted:
"In the interests of good mass balance and to hold weight tolerances of the connecting rods within the tightest possible limits, rod design was given considerable attention. They decided to develop a sinter-forged rod which promised fine weight accuracy with minimum machining and thus low production costs. Test results were indeed outstanding. At 0.0168oz./in.^3, they achieved a material density close to that of forged steel. Alternating tension and compressi1on tests produced clearly better results for the sintered parts than those for steel rods forged in a similar shape."
This was back before Mark Wahlberg was Marky Mark, when Porsche was a combined marketing and engineering company. Instead of just a marketing company that they are today.
Driving Force Online: BREAKING NEWS—Ohio Governor Signs SEMA-Supported Vehicle Freedom Bill Into Law!
Re: What do you consider a normal service life of offshore H beams in a sportsman application?
And then switched to much inferior cast rods in the late '80's to save some pennies per rod.Kevin Johnson wrote: ↑Wed Jul 03, 2019 9:49 pmThey used the same basic design but scaled in their Formula 1 engine.ptuomov wrote: ↑Wed Jul 03, 2019 9:41 pm From the same source that Kevin Johnson quoted:
"In the interests of good mass balance and to hold weight tolerances of the connecting rods within the tightest possible limits, rod design was given considerable attention. They decided to develop a sinter-forged rod which promised fine weight accuracy with minimum machining and thus low production costs. Test results were indeed outstanding. At 0.0168oz./in.^3, they achieved a material density close to that of forged steel. Alternating tension and compressi1on tests produced clearly better results for the sintered parts than those for steel rods forged in a similar shape."
This was back before Mark Wahlberg was Marky Mark, when Porsche was a combined marketing and engineering company. Instead of just a marketing company that they are today.
Paradigms often shift without the clutch -- https://www.youtube.com/watch?v=cxn-LxwsrnU
https://www.instagram.com/ptuomov/
Put Search Keywords Here
https://www.instagram.com/ptuomov/
Put Search Keywords Here