Rpmspeed New HD rocker sets (not comp)
07-19-2017, 10:17 PM
#23
TECH Senior Member
Yeah, we all have our part to do. You don't buy a Ferrari and change the oil every 20,000 miles. We as the customer MUST do OUR part and install CORRECTLY or don't bother. Parameters must be adhered to, both in manufacture AND installation and use. High performance engines require higher performance attention to detail, again in manufacture AND use.
07-20-2017, 12:38 AM
#24
I would really like to test these out on one of my engine builds coming up. If they work out, I may by 10 or so sets for future engine builds once our shop goes through our Smith bros kits.
The problem with Comps trunnion kits, that I have noticed, is the needle bearings are much harder than the trunnion itself which causes significant wear on the trunnion. Now, there are many variables to this equation such as spring open/closed loads, cam ramp rates and lift, valve weight, oil used and how often it is changed and so on. GM actually did a good job on their stock trunnnions regarding wear, the part that fails is the outer race falls out and since the needles are loose, they fall out and go everywhere. I dissassembled a stock trunnion on a bone stock LQ4 with 280k miles just recently, and it had very little wear. This was on a personal work truck that uses Full Synthetic oil that is changed every 5k miles. I have had the vehicle since its birth in 2006. I swapped them out for Smith Brothers bushings.
I have also dissassembled a Comp Trunnion on a stock LM7 engine that I rebuilt 4 years ago for a customer. He had about 60k miles on it since the rebuild, and the trunnion looked great. It is when you start adding different variables, like heavier springs, larger cam, and so on when they start showing signs of heavy wear at an accelerated rate. I have seen significant wear on a Comp trunnion after 10k miles when used with a cam with moderate lobes, .610 lift and 155/400 dual springs. Every Comp trunnion I have seen has only had wear on the trunnion itself, tho I have never looked at the needle bearings under a microscope which could have pitting.
Have you done any longevity testing on these?
The problem with Comps trunnion kits, that I have noticed, is the needle bearings are much harder than the trunnion itself which causes significant wear on the trunnion. Now, there are many variables to this equation such as spring open/closed loads, cam ramp rates and lift, valve weight, oil used and how often it is changed and so on. GM actually did a good job on their stock trunnnions regarding wear, the part that fails is the outer race falls out and since the needles are loose, they fall out and go everywhere. I dissassembled a stock trunnion on a bone stock LQ4 with 280k miles just recently, and it had very little wear. This was on a personal work truck that uses Full Synthetic oil that is changed every 5k miles. I have had the vehicle since its birth in 2006. I swapped them out for Smith Brothers bushings.
I have also dissassembled a Comp Trunnion on a stock LM7 engine that I rebuilt 4 years ago for a customer. He had about 60k miles on it since the rebuild, and the trunnion looked great. It is when you start adding different variables, like heavier springs, larger cam, and so on when they start showing signs of heavy wear at an accelerated rate. I have seen significant wear on a Comp trunnion after 10k miles when used with a cam with moderate lobes, .610 lift and 155/400 dual springs. Every Comp trunnion I have seen has only had wear on the trunnion itself, tho I have never looked at the needle bearings under a microscope which could have pitting.
Have you done any longevity testing on these?
Last edited by 07NBSChevy; 07-20-2017 at 12:57 AM.
07-20-2017, 05:52 AM
#27
Yeah, we all have our part to do. You don't buy a Ferrari and change the oil every 20,000 miles. We as the customer MUST do OUR part and install CORRECTLY or don't bother. Parameters must be adhered to, both in manufacture AND installation and use. High performance engines require higher performance attention to detail, again in manufacture AND use.
Just because you install them correctly does not make them a quality product.
07-20-2017, 05:53 AM
#28
Dug your own hole on that one fella.
07-20-2017, 08:07 AM
#30
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07-20-2017, 08:21 AM
#31
The trunion is not made nor machined in china.
I knew exactly what i was saying that is why i worded it like i did.
You dont have to use them if you do not want to. I am sure they will prove themselves as we have 2 ls3 buids going into fbodies with these in em. One cathedral and one rect port
The failures and threads on here dont keep comp from selling their trunions or summit from selling theirs either. Its just how people are. I personally do not sell what i either have not used, installed, or researched or would not use in my own vehicle. These rockers are proof of that. Ill take em off soon and inspect them. if they are no good, we will pull em off the shelf and offer alternatives to the customers, not just keep on selling them like others like comp do.
I knew exactly what i was saying that is why i worded it like i did.
You dont have to use them if you do not want to. I am sure they will prove themselves as we have 2 ls3 buids going into fbodies with these in em. One cathedral and one rect port
The failures and threads on here dont keep comp from selling their trunions or summit from selling theirs either. Its just how people are. I personally do not sell what i either have not used, installed, or researched or would not use in my own vehicle. These rockers are proof of that. Ill take em off soon and inspect them. if they are no good, we will pull em off the shelf and offer alternatives to the customers, not just keep on selling them like others like comp do.
07-20-2017, 08:24 AM
#32
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So which part does Melling do? I am just trying to understand the description. As long as they are a quality product, however, the country or company of origin really is a non-issue.
07-20-2017, 09:30 AM
#35
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Of course in my defense he was sorta rambling. My personal opinion is these have to be better then comp junk, which has a proven track record of failure. I would have no problem running these. IDGAF if the bearings are made in china.
07-20-2017, 10:37 AM
#37
TECH Senior Member
07-20-2017, 11:08 AM
#39
On The Tree
Again...are you willing to bet your $14k engine on a $2 Chinese made bearing? Would you put Chinese made tires on your Ferrari because some guy selling them on the Internet said they were good?
Just because you install them correctly does not make them a quality product.
Just because you install them correctly does not make them a quality product.
07-20-2017, 11:19 AM
#40
On The Tree
So these are:
Melling made trunions
Chinese bearing
Stock GM rockers
Put together by Melling