LS trunnion upgrades & longevity

[turbo camino]

LS1/LS2/LS6/truck style non-offset rockers. What's the lift limit before there's interference at the d-shaped bearing cap thing at the trunnion?

None of the aftermarket 'upgrade' options really fill me with confidence (bushing wear with splash-lubed bronze, mystery-metal trunnions with direct-running needle bearings), and the stockers, as long as the outer races don't fall out, will last forever. If only there were an option to add positive retainers to the stock bearing setup...

How hard are the stock trunnions? Can they be drilled and tapped in the end faces? Is it possible to disassemble/reassemble the stock needle bearings without totally destroying them?

[CGT]

LS1/LS2/LS6/truck style non-offset rockers. What's the lift limit before there's interference at the d-shaped bearing cap thing at the trunnion?

None of the aftermarket 'upgrade' options really fill me with confidence (bushing wear with splash-lubed bronze, mystery-metal trunnions with direct-running needle bearings), and the stockers, as long as the outer races don't fall out, will last forever. If only there were an option to add positive retainers to the stock bearing setup...

How hard are the stock trunnions? Can they be drilled and tapped in the end faces? Is it possible to disassemble/reassemble the stock needle bearings without totally destroying them?

My street car has .640 lift on completely stock rockers. The contact between the valve tip and rocker tip gets pretty ugly before the stock trunnion runs out of travel from my experience.

[turbo camino]

Thanks, real info! Getting harder to find every day in this world.

Not to pick on anybody in particular here's an example. Just about every kit I've looked at has some similar ambiguity. Nobody talks about trunnion material, heat treat specs, anything. Just 'Buy this and go fast, trust us!'

https://www.stevemorrisengines.com/engi ... rvice.html

Note 2nd picture shows a smooth, non-grooved trunnion. I like that. Lateral or spiral grooves would be better, but I'd take smooth over a full radial groove any day. A plain bearing (bushing) where the surface never sweeps across the oil groove is Bad News. Now scroll down that page, the picture of the kit in the plastic tray shows the generic full-radial-groove like everybody else sells. Fantastic. So if you buy that kit, which parts will you find when you open the box? Good ones that have had some actual thought put into them or generic offshore rebranded crap?

[tt 383]

This thread has some good discussion and I believe they address the grooves https://ls1tech.com/forums/generation-i ... ts-11.html
Also somewhere clos to the the end of the 40 pages they mention CHE, looks like they have radial grooves.

[turbo camino]

I suspect a bronze bushing kit would last longer at .700" lift than it would at .480" because of the longer swept area, more chance to pull an oil film down to the bottom from the upper, non-loaded sections in both directions of travel (one side during opening and other side closing).

Machinery's Handbook, Modern Tool Making, & Foundations of Mechanical Accuracy seem to disagree with the ls1tech consensus of "But these are POLISHED, they should last forever."

[midnightbluS10]

CHE uses a proprietary bearing material and they are made in the USA. What's wrong with those?

https://www.cheprecision.com/part/trunnion-kits/


It appears that Steve Morris may be selling the Straub Technologies Kit. They look pretty similar. If that's the case, why don't you contact Chris Straub and ask him about the kit instead of making assumptions? Pretty sure he used to post here and posts at yellowbullet. You can also reach him through his website.

https://straubtechnologies.com/ls-bushi ... nion-kits/

[CGT]

Thanks, real info! Getting harder to find every day in this world.

Boy that ain't no shit.

My street car has about 10k miles on it like that...nice bullet hydraulic lobes, Manley Nextec beehives 221438-16

viewtopic.php?f=1&t=51466&sid=8c303007e ... &start=255

This is a link to an engine I just built and dyno'd. It has .680 lift with stock rockers, I used the Smith Bro's kit in these rockers. Longevity yet to be determined, 30 dyno pulls so far.. but I can tell you that .680 lift works with the stock rocker on this mainly because the valve is sunk a bit, making the contact at the rocker-tip interface more acceptable at and around max lift....of course less acceptable at low lift off the seat...damn tradeoffs

[turbo camino]

CHE uses a proprietary bearing material and they are made in the USA. What's wrong with those?

https://www.cheprecision.com/part/trunnion-kits/


It appears that Steve Morris may be selling the Straub Technologies Kit. They look pretty similar. If that's the case, why don't you contact Chris Straub and ask him about the kit instead of making assumptions? Pretty sure he used to post here and posts at yellowbullet. You can also reach him through his website.

https://straubtechnologies.com/ls-bushi ... nion-kits/

Thank you for the CHE link! I was under the impression they only sold them as a service so I didn't investigate further, didn't know they had DIY kits. Now THAT design shows there's somebody out there who truly understands splash lubrication of plain bearings. Note the inner & outer grooves are in opposite directions, they cross each other. There is no swept area that doesn't see an oil groove. Just knowing those exist make me happy. (So I'm weird. LOL)

All the pictures I have seen of Chris's kits show no radial groove, which as I said is better than the generic bellybutton kits. The Steve Morris page shows both the grooved & smooth designs for the same P/N. Doesn't inspire confidence.

[turbo camino]

All the pictures I have seen of Chris's kits show no radial groove, which as I said is better than the generic bellybutton kits. The Steve Morris page shows both the grooved & smooth designs for the same P/N. Doesn't inspire confidence.

Oh. The Straub kits have been 'improved' by adding the full groove in the latest version. Ick.

[midnightbluS10]

It's been said that the Straub kits are made by Smith Bros. If that's the case, they're made in the USA, also, AFAIK.

[turbo camino]

I know they're quality materials, that's not in question. Wear may be acceptable, depending on whose definition you use for that, but the single center oil groove is the wrong way to go. It's not an improvement.

I think the idea was to add the groove to allow oil to the bottom where the load is, but somebody tell me, how does oil get out of that groove and onto the loaded surface? The loaded surface has to sweep across an oil groove to pull oil out of it. Running over a groove that's inline with the direction of travel does nothing. It doesn't improve lubrication, it only reduces the load bearing area. It's magical thinking.

In the first design with no grooves the oil gets to the bottom by being pulled down from the top as the bushing rotates. With the grooved journal it still only gets there by the same process, there's just less contact area to do the oil distribution. In fact I can see where the groove could be an escape path for the entrained oil, not a distribution source.

[modok]

this is the best oil groove design IMO.

[turbo camino]

this is the best oil groove design IMO.

That is very good. I think it could be improved though.

The 4 notches I assume are for indexing during install? So if they are gonna be there anyway, move them up to the tips of the 'Y' and use them as little funnels to collect more oil. The 'Y' might work better as a 'V', without the straight leg. More swept area, still feeds the lateral groove at the bottom where the real work is being done, etc.

[modok]

Hmmm, maybe.
i think a single groove is preferable on the sides to reduce leakage.

[Kevin Johnson]

The insert is not regularly shaped (kinda like conic sections but obliquely through the cylindrical shape). It will only fit the small end in one way correctly and the notches are to control the insertion exactly.

(I say this because it appears that the small end is tapered.)