big boys T5 options for the V6.

[vlad01]

I would use a more common ball bearing, but the crank housing is only 21mm and doesn't have much room to enlarge more than about 24mm even if I could, not that I would ever want to machine out the crank just for this purpose anyway, the gains in doing so are a waste of effort in my opinion. The V8 bush/bearings are much larger than the V6.

This needle roller is literally a drop in, as it is the same size ID and OD as the factory bush.

The higher RPM rating is not needed for the RPM itself, it may only ever see 7k actual bearing speed, but the higher ratting is an indication of the bearing quality and robustness more than the need for that spec in this case.

They aren't expensive either, so might as well go for the good brand.

[VK_3800]

That was my point above, there is additional diameter available in the torque converter spigot area without needing any machining - don't the V6s have this? By placing the trans very slightly further back you can use this area instead without losing any clutch spline engagement. The original spigot bearings for Holden V8 and small block Chevy are exactly the same small diameter sintered bronze bushing.

The speed difference the bearing will see should never be more than 1-2K RPM, momentarily. If you can't put a proper bearing in there I'd stick with the sintered bronze over a small number of hardened rollers running directly on the input shaft. I think you'll find those roller conversions are becoming hard to get because they don't have a good reputation.

[vlad01]

This is all I have to work with on the V6.

As a size ref, the flywheel bot heads are 9/16 (5/16 thread).


This particular engine only did 9K on this setup and the genuine Holden bush came out and got munched up, ID and OD, but OD far worse. I have had this happen twice before.
They are only 17mm deep and a lots of the shaft is supported by the thick external flange.

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Here is one I installed on my current project, I used an aftermarket one which I have just learned may contain iron as an additive to make it more durable (load and wear wise) at the cost of some friction. I don't have a spare to test with a magnet, but either way I am all for a harder durable bush given the factory ones have just mushed their way out.


I loctite'd this one and then did a vacuum de-gas and oil impregnation after the fact in situ via a home made tool to do so. So that's why there is masking tap and what not, prepping for vacuum oil bath.

These pics show how little room in the end of the crank there is prior to install and how much of the bush is actually external once installed.

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There are straight bronze bushes that are longer and will install straight in as a direct replacement but deeper, which will require that 6mm farther insertion of the input to make use of that.

And also the needle roller bearing is also one of the same ID/OD.


I did a bit of reading on bronze bush vs needle bearings. Yes it seems that bronze is more forgiving to mistakes, environment, more gentle on the spigot too and gracefully wears out and fails in a usually non catastrophic way, this make it appealing for those that just want it to work for a long time without worry.

However, in terms of wear in an ideal install and environment, the needle bearings do last significantly longer than bushes, have superior shift as a result of very low friction and tight tolerances that don't change with time unlike bronze. The load capacity of them is much higher than bushes too and as pointed out the rpm range is significantly higher as well, making them suitable for performance cars. They are know to sometimes need more maintenance relative to bronze, but this is not taking in account that bronze wears out of spec long before needle bearings pilots need re-greasing or replacing as preventative maintenance.

The big one I took away is many saying and some verbatim of the TKO documents a few people actually read before installing their TKO was that Tremec say do not use bronze as it's tolerance is not good enough and will cause shifting and internal wear issues, they say a bearing must be used. This will apply to the TKX as well and any of their newer gen OEM boxes.

I also noted in an earlier post that a lot of OEM use needles, actually I never though about a normal ball bearing used as most engines I had seen were Euro ones where needle was the default, I think this is because, like my engine, most 4cly engines use a non flanged 8 bolt crank where they are limited to a small needle bearing, where as the US old gen V8 including our Holdens and what not, all used 6 bolt large flanged cranks that allows large bushes and bearings to be used.

Another thing I found a lot of people saying is needle is sensitive to dirt getting in as user error as well as misalignment due to the improper bell housing spec, or even just cocking the trans a little during install is enough to compromise a needle bearing. I think this is the likely root of most bad rep seen on them.


As for the rpm seen, I calculated with the way I normally drive, the bush sees full rpm (red line launches) and almost full rpm on aggressive decel using both brakes and engine to the max, so for example I would shift into 1st at 80 km/h (shift only, clutch still held in), and by the time I actually let got of the clutch the brakes have slowed the car down to about 70km where the engine jumps from about 2.5k to 6k. I calculated at 80km, the input is spinning around 7k, and engine might be in the 2.5-3.5k during the drop, it all happens so quick I can't say for sure what rpm the engine would be at during the over-speed of the input.

But with my other project, the engine rpm is 7k, so input speeds would be likely a little over 8k on hard decel. Probably won't see the full rpm of what the engine can do, but more that the bronze bush is rated for anyway. Even just a redline launch would def exceed the bush. That was also covered in some article I read about bush vs bearing, the bearing is the way to go if launching off the line in a track or otherwise scenario for the reason that most performance engines by default exceed the bush specs just at a standing launch.


For a stock daily driver, even a mild one, I'd go bush with the T5 which is also more forgiving on slightly misalignment. On a TKO or TKX, I'd go bearing for sure. In my case, a ball bearing is not possible (unless I have the input turned right down and have the crank slightly enlarged, then maybe one of the small ball bearings might fit?) so the option is the needle bearing.

Availability wouldn't be an issue for my engine either as it's not a pilot/spigot bearing specifically, just a generic bearing that you can buy and looks to be fairly common too, that happens to be the right size out of the box, no mods required.

[vlad01]

Via a YT video on various gearbox stuff, I came across a video of a guy showing how his nissan sounded with what I thought were PPG straight cut gears, and I thought, damn that's actually pretty quiet. Turned out I assumed wrong, said he got his set from Par in Australia.

Took a bit of digging to finally find who he was referring to.
It's this place.

https://www.par-engineering.com/


Never heard of them nor ever came across them on google when spending years on and off trawling the net for places that do custom gears and sets.

So I reached out as it reads to me as they do pretty much any sort of gear set you like or other drive train/engine parts.

Glad I did! Turns out they are very familiar with the T5 and made many of them for various applications in the past, mainly ford barra turbo applications. The guy (owner I assume) said a set would be no issue and any input shaft design I want. Price is comparable to PPG, maybe a little less, but that include having it custom made where PPG, what they list, is it, basically. Custom is possible, but I read their spiel as you'd want a given quantity to make it worth while and while they can do custom work, it's not their core business, so the price could easily double I reckon. Quaife also do a gearset, but it's for the Cosworth, so the input is not ideal for anything we have here, the 5th is also a 23 spline main shaft, not compatible with the common ones we are all used to. Also, Quaife don't do custom work until units of 30 are ordered I read somewhere. Forget geforce, they never been interested in custom work. Astro is long gone in custom parts but also wouldn't do one offs back then, but very much going well in the replacement quality part side of things (my go to for all the rebuild and OEM parts). The mob I found that is setting up to do TKX dog sets seem to come across as custom parts, but when I asked even about their TKX stuff, they never replied. Quaife's partner that did the T5 design with them, no reply. AMP are another that are doing replacements and OEM+ style upgrades, they already sell the Holden v8 input replacement, they always made excuses when I asked if they would consider looking at the market for even just replacements parts as they did for the Holden V8 version, just side stepping, so I guess def not interested. So it was nice to talk to a business that actually responded right away, says not a problem and already had made more or less the product I want in the past.



Talking to them and checking out a few more videos, Par have a much better profile for street application as that's their aim, so reduced noise, low wear, reliable and streetable (push for sync over dog, even though they have both options) , so they stick to the synchro for most application like mine, despite dog being much cheaper and easier to make from a manufacturing prospective. The Price for a 1-4 set is about 6-7k.


Comparing videos of Par SC gears VS others like PPG, Par are much quieter whist still giving the nice sound. Very much the same as geforce reduced angle helical gears.

So I can literally get the gear set I want and I know that option will be then for when the time comes. They also do custom flywheels and cranks, so the whole build I have in mind can be sorted all at once. That means I can have the small dia tilton organic twin disk clutch that allows low moment of inertia for much better sync and shift performance, pretty light clutch pedal since the clamp can be low enough yet still have the torque capacity needed, all possible with the custom input and custom flywheel.


In my mind, I would change the splines out to 26 GM, make them the same length across the shaft as the modern 26 GM shaft spec (longer to suits twin disk) and I would increase the spigot length by 8-10mm, so that the spigot is fully compatible with stock bushings, SKF straight (non flanged bushing, much better drop in option for not coming loose out of the crank) and the needle roller option, similar to the SKF bronze in fit which is much deeper in the crank due to no flanged end, needle would be best in high rpm shift scenario but may need more maintenance. I would leave the length of the input from base to the end of the splines the same as stock so that if one wanted to use the OEM (in case I change my mind or something or if someone else also wanted to buy the same set), that way it will work with the stock arrangement minus the 26 spline difference.

I would probably opt for the 2.95 ratios and also get a 5th made to get 0.83 ratio as 0.72 has kinda always sucked, even in a stock engine it isn't all that useful in any speed under 100km. 0.72 5th is a big jump from all the other gear spacings.

0.83 is pretty spot on for the 2.95 set ratio when coupled with probably 3.73 rear on the engine I have planned, which has it's power band between 2500 ish to 6800k peak and 7k redline

That should see very similar max road speeds for most gears as stock sees at max rpm. So no issues of being too tall to be practical and underwhelming acceleration or too short that the engine winds out in that gear faster than the car can accelerate, which also slows the car down heaps (experienced that before with many A to B jap cars and a buggy I built where 2nd gear was 2x the acceleration as 1st for the same reason, just way too short for the engine).



I thought I'd post that, cos I feel like this was a big part of this multi year puzzle for me to find a way to get the OEM box for the V6 to work with more power than they were rated at, but also allow other aspects like the clutch so also evolve equally as much to break away from the constrains of OEM like clutches that are all that are available for these engines.
Something like this was never going to be as easy as swapping to another trans, the v6 and it's position in the car and the car itself virtually makes it impossible in the practical sense and also prohibitively more expensive than other common swaps seen in other models of cars and engine combos. Considering the custom T5 gear set was always going to be the more viable option once there was some company willing to make them at a relatively reasonable cost, simply becasue the V6 commodore makes everything so damn convoluted and difficult to solve and that adds up fast in not only price, but effort, time and sanity.