Just Turned 300 hrs On HP500 Carb Motors
08-15-2006, 09:14 AM
#1
Just Turned 300 hrs On HP500 Carb Motors
The valve springs were changed at 200 hrs. The oil gets changed every 20 hrs using Mobil 1 15w-50 EP. Is there anything other maintenance issues to be concerned with??
08-15-2006, 09:36 PM
#2
Registered
Re: Just Turned 300 hrs On HP500 Carb Motors
The roller lifters are next on the soon to fail list, 300 - 350 hrs. appears to be the life span on the original Crane pieces. I have two close friends who have experienced lifter failure in this hour range, both were failures at the roller and pin, the base of the lifter broke at the pin. In one case the lifter turned sideways and broke out the bottom of the lifter bore as well as the cam being destroyed, he was able to have it sleeved and save the block. Both failures occurred at about 4500 rpm resulting in major repairs for both. You are also at a point where you should look into changing the roller rockers, if you are still running the original Crane Gold rockers. They are prone to failure at the pin on the roller tip end.
There are a number of threads on here about the Merc HP 500's. Failure points of the stock parts seem to be ---- Valve Springs @ 200 - 250 hrs. ---- Roller Lifters @ 300 - 350 hrs. ---- Crane Gold Rockers not real sure on hours here, only that my engine builder has little good to say about them and has seen the fail constantly in race engines, and consistently in the roller tip pin area. His recommendation to me was Crower Stainless Steel Roller Rockers, expensive items but very high quality and long lasting.
My 500's were freshened last season due to the valve spring failure, about 24 out of 32 had broken inners and dampers, both engines were completely torn down, cleaned and rebuilt due to metal throughout and one dropped valve @ 168 hrs, my good fortune was that the outer spring failed and dropped the valve at 650 rpm and stalled the engine without any major damage. I used the Isky SP Endurance springs which are much higher quality than the original Crane springs used by Merc originally, and higher in quality than the Comp 929's they recommended to replace the Cranes.
I could ramble on about this forever, but will quit after one last comment. Having read a lot of threads, talked to a lot of people, and seen quite a few failures, I have decided that I will from here out change out the valve train items long before their expected life is up, I also have started that program, I had the Crower Rockers installed this spring, as well as having my builder thoroughly check the rest of the valve train. After this season we will change out the roller lifters, they were fine at 168 hrs, but will be changed a little past 200. My opinion is that it is cheaper in the long run to change out a few parts than to deal with the possible consequences of their failure, let alone the loss of time boating.
There are a number of threads on here about the Merc HP 500's. Failure points of the stock parts seem to be ---- Valve Springs @ 200 - 250 hrs. ---- Roller Lifters @ 300 - 350 hrs. ---- Crane Gold Rockers not real sure on hours here, only that my engine builder has little good to say about them and has seen the fail constantly in race engines, and consistently in the roller tip pin area. His recommendation to me was Crower Stainless Steel Roller Rockers, expensive items but very high quality and long lasting.
My 500's were freshened last season due to the valve spring failure, about 24 out of 32 had broken inners and dampers, both engines were completely torn down, cleaned and rebuilt due to metal throughout and one dropped valve @ 168 hrs, my good fortune was that the outer spring failed and dropped the valve at 650 rpm and stalled the engine without any major damage. I used the Isky SP Endurance springs which are much higher quality than the original Crane springs used by Merc originally, and higher in quality than the Comp 929's they recommended to replace the Cranes.
I could ramble on about this forever, but will quit after one last comment. Having read a lot of threads, talked to a lot of people, and seen quite a few failures, I have decided that I will from here out change out the valve train items long before their expected life is up, I also have started that program, I had the Crower Rockers installed this spring, as well as having my builder thoroughly check the rest of the valve train. After this season we will change out the roller lifters, they were fine at 168 hrs, but will be changed a little past 200. My opinion is that it is cheaper in the long run to change out a few parts than to deal with the possible consequences of their failure, let alone the loss of time boating.
08-16-2006, 06:53 AM
#3
Re: Just Turned 300 hrs On HP500 Carb Motors
i replaced mine at ~350hrs (valve springs) not 1 broken.
Head gaskets are another thing to go around those hours. i replaced mine with cometic.
while you have the heads off, get a valve job done.
Head gaskets are another thing to go around those hours. i replaced mine with cometic.
while you have the heads off, get a valve job done.
08-16-2006, 09:33 AM
#4
Re: Just Turned 300 hrs On HP500 Carb Motors
Originally Posted by RaggedEdge
The roller lifters are next on the soon to fail list, 300 - 350 hrs. appears to be the life span on the original Crane pieces. I have two close friends who have experienced lifter failure in this hour range, both were failures at the roller and pin, the base of the lifter broke at the pin. In one case the lifter turned sideways and broke out the bottom of the lifter bore as well as the cam being destroyed, he was able to have it sleeved and save the block. Both failures occurred at about 4500 rpm resulting in major repairs for both. You are also at a point where you should look into changing the roller rockers, if you are still running the original Crane Gold rockers. They are prone to failure at the pin on the roller tip end.
There are a number of threads on here about the Merc HP 500's. Failure points of the stock parts seem to be ---- Valve Springs @ 200 - 250 hrs. ---- Roller Lifters @ 300 - 350 hrs. ---- Crane Gold Rockers not real sure on hours here, only that my engine builder has little good to say about them and has seen the fail constantly in race engines, and consistently in the roller tip pin area. His recommendation to me was Crower Stainless Steel Roller Rockers, expensive items but very high quality and long lasting.
My 500's were freshened last season due to the valve spring failure, about 24 out of 32 had broken inners and dampers, both engines were completely torn down, cleaned and rebuilt due to metal throughout and one dropped valve @ 168 hrs, my good fortune was that the outer spring failed and dropped the valve at 650 rpm and stalled the engine without any major damage. I used the Isky SP Endurance springs which are much higher quality than the original Crane springs used by Merc originally, and higher in quality than the Comp 929's they recommended to replace the Cranes.
I could ramble on about this forever, but will quit after one last comment. Having read a lot of threads, talked to a lot of people, and seen quite a few failures, I have decided that I will from here out change out the valve train items long before their expected life is up, I also have started that program, I had the Crower Rockers installed this spring, as well as having my builder thoroughly check the rest of the valve train. After this season we will change out the roller lifters, they were fine at 168 hrs, but will be changed a little past 200. My opinion is that it is cheaper in the long run to change out a few parts than to deal with the possible consequences of their failure, let alone the loss of time boating.
There are a number of threads on here about the Merc HP 500's. Failure points of the stock parts seem to be ---- Valve Springs @ 200 - 250 hrs. ---- Roller Lifters @ 300 - 350 hrs. ---- Crane Gold Rockers not real sure on hours here, only that my engine builder has little good to say about them and has seen the fail constantly in race engines, and consistently in the roller tip pin area. His recommendation to me was Crower Stainless Steel Roller Rockers, expensive items but very high quality and long lasting.
My 500's were freshened last season due to the valve spring failure, about 24 out of 32 had broken inners and dampers, both engines were completely torn down, cleaned and rebuilt due to metal throughout and one dropped valve @ 168 hrs, my good fortune was that the outer spring failed and dropped the valve at 650 rpm and stalled the engine without any major damage. I used the Isky SP Endurance springs which are much higher quality than the original Crane springs used by Merc originally, and higher in quality than the Comp 929's they recommended to replace the Cranes.
I could ramble on about this forever, but will quit after one last comment. Having read a lot of threads, talked to a lot of people, and seen quite a few failures, I have decided that I will from here out change out the valve train items long before their expected life is up, I also have started that program, I had the Crower Rockers installed this spring, as well as having my builder thoroughly check the rest of the valve train. After this season we will change out the roller lifters, they were fine at 168 hrs, but will be changed a little past 200. My opinion is that it is cheaper in the long run to change out a few parts than to deal with the possible consequences of their failure, let alone the loss of time boating.
