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Trunion upgrade

lmoengnr

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they use bronze bush so they are tuff and last a long time and have oiling groves to aid lubrication, brass wouldnt last long as a rocker bearing

Hopefully they are sintered bronze bushes, they retain oil and should last the life of the engine.
 

lmoengnr

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^ based on cost of doing a cam, what $3500 odd?, I’d think that would include a trunion upgrade. But if it’s not included, it seems unwise not to add it for the little extra cost.

Still in two minds whether I’d bother doing the upgrade on a stock motor while it’s still under warranty. If it breaks while under warranty, it’s either a new motor or a pp refund (as I see it) :p

I wouldn't worry about the trunnion upgrade until you upgrade your stock valve springs.
 

Skylarking

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Yeah, laziness in language resulted in typing brass bush but I really meant sintered bronze bush :oops:
 

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Most trucks use brass bushes in their king pins done a few in my time. a truck will get 300,000km out of a set of king pins.

I would assume 100,000km out of the rocker bushes but you won't get a major failure just play in the bush so the valves wont open as far.
 

426Cuda

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they use bronze bush so they are tuff and last a long time and have oiling groves to aid lubrication, brass wouldnt last long as a rocker bearing
They also create more friction than good bearings. Some of my Abu Garcia fishing reels have bronze ( and some brass) bushes. They don't wear out, but they drag a great deal. I always upgrade them to ABEC 7 bearings and the spools will spin for days. Makes long distance casting a breeze and casting with small weights possible. So the inference is, trunnion bearings may wear over time, but they are no doubt better for fuel efficiency and power.
Interestingly, the slipper bearings used in big ends and crank bearings are quite soft. Yet they last for many years with good oil and pressure. So, there is no reason bronze trunnion bushes wouldn't last just as long.
 

shane_3800

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They also create more friction than good bearings. Some of my Abu Garcia fishing reels have bronze ( and some brass) bushes. They don't wear out, but they drag a great deal. I always upgrade them to ABEC 7 bearings and the spools will spin for days. Makes long distance casting a breeze and casting with small weights possible. So the inference is, trunnion bearings may wear over time, but they are no doubt better for fuel efficiency and power.
Interestingly, the slipper bearings used in big ends and crank bearings are quite soft. Yet they last for many years with good oil and pressure. So, there is no reason bronze trunnion bushes wouldn't last just as long.
The issue with needle roller bearings in rockers is when they fail they can release the needles all through the engine. And most of us know how hard bearing steel is which is something you don't want through your engine. This is the whole idea behind brass/bronze bushings in engines, it's there to eliminate the need for rollers as insurance against catastrophic bearing failure.
 

426Cuda

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The issue with needle roller bearings in rockers is when they fail they can release the needles all through the engine. And most of us know how hard bearing steel is which is something you don't want through your engine. This is the whole idea behind brass/bronze bushings in engines, it's there to eliminate the need for rollers as insurance against catastrophic bearing failure.
Yeah, I get that. I was just responding 're some others comments.
 

07GTS

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They also create more friction than good bearings. Some of my Abu Garcia fishing reels have bronze ( and some brass) bushes. They don't wear out, but they drag a great deal. I always upgrade them to ABEC 7 bearings and the spools will spin for days. Makes long distance casting a breeze and casting with small weights possible. So the inference is, trunnion bearings may wear over time, but they are no doubt better for fuel efficiency and power.
Interestingly, the slipper bearings used in big ends and crank bearings are quite soft. Yet they last for many years with good oil and pressure. So, there is no reason bronze trunnion bushes wouldn't last just as long.
a bearing would be good but i think the bush can get a wider surface of contact area which helps spread load and help with oil cooling, if u could use the max lift BSR shaft mount LS upgrade with pressurised oil would be the best, ive been thinking bout upgrading to that for my new engine
 

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They also create more friction than good bearings. Some of my Abu Garcia fishing reels have bronze ( and some brass) bushes. They don't wear out, but they drag a great deal. I always upgrade them to ABEC 7 bearings and the spools will spin for days. Makes long distance casting a breeze and casting with small weights possible. So the inference is, trunnion bearings may wear over time, but they are no doubt better for fuel efficiency and power.
Interestingly, the slipper bearings used in big ends and crank bearings are quite soft. Yet they last for many years with good oil and pressure. So, there is no reason bronze trunnion bushes wouldn't last just as long.

i agree with cuda , the bronze bushings will not be as free moving as needle roller bearings and create more friction and rob the engine of a few horsepower but at least for a small cash outlay will stop any foreign bits of metal wrecking your engine,
i think the way to go is the full roller rocker by yeller terror, cost is around $800 and features a roller tip that the stand rocker does not have, the roller tip on the yeller terror rocker reduces valve guide wear because of less side load, so not only do you get less wear but also a slight increase in power from less friction over the standard GM and bronze bushed GM rockers
 

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i agree with cuda , the bronze bushings will not be as free moving as needle roller bearings and create more friction and rob the engine of a few horsepower but at least for a small cash outlay will stop any foreign bits of metal wrecking your engine,
i think the way to go is the full roller rocker by yeller terror, cost is around $800 and features a roller tip that the stand rocker does not have, the roller tip on the yeller terror rocker reduces valve guide wear because of less side load, so not only do you get less wear but also a slight increase in power from less friction over the standard GM and bronze bushed GM rockers
I dissagree over the yellaterra rockers, I believe whith no evidence that the comp cams single bar mount rocker upgrade is the best for cost effective upgrades. If you want true shaft mount rockers at the highest level than a jesel kit is what you need.
 
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