58 replies to this topic

[purrlx]

Get a step drill Bunnings have them. Also called Christmas tree drill.

[UCSLE]

could you use a step drill bit , drill from one side then the other ?

 

(didnt see dannys post )

Edited by UCSLE, 18 October 2023 - 04:13 PM.

[claysummers]

Thanks Troy, you’re spot on. Sutton have a 36mm bit that will do the job on dads old mechanical Bosch 850W. The wrist breaker. Can be done just from the firewall side but I don’t see that as a problem.


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[claysummers]

The billet flywheel is 7kg, so a good third lighter than stock. Is this a good thing in a cruiser?


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[RallyRed]

No expert, but I always thought light flywheels were for race type applications where you wanted quick rev ups and down, through the gear etc. 

A big old heavy flywheel for cruising?  Think of those big old steam powered traction motors that dragged stuff around, huge big flywheels (prob. single cylinder too?), just lugged along.  

Happy to be corrected, as usual.

[yel327]

I always go back to what Rod Hadfield used to tell me about engine conversions in Landcruisers. He thought it was silly that people put 253 or 308 in these as they only had a 9" (253) or 10" (308) clutch and associated flywheel. As a 4x4 you needed flywheel diameter and mass and the larger clutch helped too of course. His opinion was the only sensible engine swaps for these were SBC using 11" clutch and its larger flywheel or I think it was a Ford 250ci 6 which also had a large flywheel diameter available. Otherwise you may as well kept the original 4.2L Toyota 6. I guess this does translate a bit across to a cruising FB but you are talking about mass not diameter, and that isn't exactly the same thing.

[Bruiser]

Pretty serious bit of gear there, Clay. The ceramic clutch, too
My understanding about the flywheel thing is to go lighter will
allow the motor to spin up quicker when accelerating, due to less mass
for it to get spinning. Great for throttle response and pickup,
revs also drop quicker for those racing downshifts,
more throttle input needed to keep constant speed under load.
More weight will allow for smoother take off from a standstill,
and it’s momentum would help keep engine speed up when going uphill
or other times when loaded up. Less power needed from the engine
to keep the thing spinning along.
One of those compromises again.
I had a Google of the part numbers and they all said 8.7 kg (if it makes a difference)
Maybe a slightly lighter flywheel wouldn’t make things change too much, going too
far would probably make the car rotten to drive daily
Those ceramic clutches are often described as “either on or off”
I can’t comment on that, never driven one myself
Might be worth asking around about that, too
In case that makes it even rottener

[claysummers]

Thanks fellas. I've just got the extra clamping force pressure plate Bruce, not the ceramic driven plate. That was a different spline for the dyno synod. You've confirmed my understanding. While it is lighter, partly due to being chromoly steel rather than cast, most of the mass is at the outer radius, maximising speed and therefore momentum. Does it sound like I'm talking myself in to it?

I was hoping for advice on the balancing aspect but I will talk to Lonsdale engines about that.

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[claysummers]

The hoses on the slave are speedpro -3 which is 1/8" id with what looks to be a 45 degree male flare, requiring a 3/16" SAE flared bundy and NPT female flare nut. I was able to source compatible "tube" nut and flare adapter locally, but they are black annodised alloy. I don't know if th alloy will be strong noug for th torque required to seal the flare. Adding to my concern is that their website says they are a 37 degree flare. So I ordered online a couple of steel ones. I expected their stuff to be dearer but the shipping was the dearest part.

A mate fished around in his collection and found me a male tube nut to fit the frod master. What do you know, it is NPT thread, for 3/16" bundy. The Holden item was 1/4" bundy and finer thread, which is probably BSP. Interesting the pommy specs that evolved their way into Holden manufacturing versus the parachuted in 1960s Yankee sales pitch.

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[claysummers]

I love the simplicity of this thing

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[dattoman]

The nut into the master is not NPT

Its 3/8 unf

 

If I was doing it I would put an adaptor into the master cyl and seal it on a copper washer... then flare the pipe to suit the adaptor

Doing that means you don't have to overtighten the pipe into the alloy master and possibly strip the thread if you flare doesn't seat properly

 

Also... that trailer master is avail in .625 , .7 and .75" if you discover it doesn't throw enough.

[claysummers]

Thanks Datto. I was wondering. I'll hunt up a 3/8"unf upon and brass washer for sure, and I'll test the throw before I install it all.

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[salamiman]

So Clay looks like you've set up the thrust bearing and it's bleed line, exactly the same way as I did.
You would think this would be ideal, but it didn't want to bleed so I used a syringe to actually suck through or from the bleed line from below and got it to bled that way.
As far as the master throw out bearing ratio goes. I was told to use a three quarter master with the bearing.
With all my calculations and thought I had it right, but three quarter master seems to give far too much pedal.
I reckon you're on the right track with 5/8.

[claysummers]

Thanks salami, good to know. 5/8" was suggested by Mal. I've got a vacuum bleeder, but a clever trick a mate told me is to use a tube to connect a caliper bleed to the clutch bleed, crack both, then push the brake pedal. Obviously keep your eye on the reservoirs, but effectively you can reverse bleed any air out through the clutch master, starting with an empty reservoir.

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[salamiman]

Great idea, love it.

 

Weird about the 5/8 master as I reckon it would be about perfect.

 

Was told to use a 3/4 & checked the website to see if i wasnt listening....

 

• NOTE USE A MASTER CYLINDER WITH 19MM BORE AND 35MM OF STROKE FOR BEST RESULTS.

I found the clutch was biting about 2/3 of the way out & still quite firm.

Ill re do some calcs & see if i can get a 5/8 to work.

Luckily i designed the pedal with an adjustable fulcrum, i can adjust between 20-40mm of stroke.

 

Best of luck

[claysummers]

I did see 19mm 3/4" recommended in documentation, so good to know your experience.

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[salamiman]

Without sounding weird mate what stroke on a 5/8 bore are you going for?

[claysummers]

No idea frankly. It’s a bolt in replacement for the existing master, clevis and rod assembly, geometrically. I was told it will be a light pedal, though I am running an extreme pressure plate, with the thicker one tonner driven plate. Previously clutch was heavy on pedal with much more throw than required, due to the rat trap to hydraulic conversion geometry.


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[Bruiser]

Ran across this the other day, these Russian mechanics do all sorts of extreme experiments with engines
This is a flywheel one taken to the extreme of heavyness
It’s a bit long with a fair bit of crap to wade through, but seeing what they are doing early on and the results at the end
is worth a looksee

https://m.youtube.co...h?v=0M92bfoJZMo

All the typed words in the world can’t demonstrate how a car with a super heavy flywheel
would be to live with like this does for me
Just a shame there isn’t one for the extreme super light end of the scale
They do some pretty outlandish stuff on their YouTube channel, it’s worth a look, even if only for a laugh

[claysummers]

Thanks Bruce. Anything Russian seems to remind me of comedy co. Good demo.

Their deduction that a lighter flywheel requires more throttle variation makes sense. That would equate to less fuel efficiency with a conventional induction. Lucky I've got the SUs.

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[claysummers]

Bolted up Xtreme cromolly flywheel, 1 tonner driven plate, and Xtreme clutch. Fingers sit 78.3mm proud of the sandwich plate.
I installed all five supplied shim cones to get 81.6 mm, bearing to bellhousing face. S clearence is a bit tight at 3.3mm. I may try remeasuring with one less shim but it was around 6mm ast measure, which is too much.

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[claysummers]

Dummied up the box with a piece of dab-off on the throw out face and confirmed 3.3mm.
So I took out one shim and reameasured, getting 83.1mm, which gives me 4.8mm clearence. I think that will be better.


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[LJ RB30]

Hey Clay are you using an organic clutch plate or ceramic/metallic type plate on the cromoly flywheel?

[claysummers]

It is a standard one tonner driven plate. Nothing special.


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[yel327]

Speaking of cab-chassis clutch plates. When the HQ cab-chassis was released in late 1971 there was bugger all options available. It was standard with 173, 3speed and 3.55 rear axle. You could option a 202, a wide ratio M20 4spd and an auto. I can't remember exactly but there may have been a 3.36 rear axle option as an economy option with Trimatic. But that was it. GMH was changing so many clutches in the manual cars that by the end of HQ there was a competition run across dealerships to see which mechanic could change a clutch the fastest. The answer in the end was introduction of the 4.44:1 rear axle for HJ cab chassis with manual 6cyl engine.

 

From memory the cab-chassis 6cyl clutch is the heavy-duty option for other 6cyl Holden and Statesman. The standard Holden/Statesman 6cyl clutch is the heavy-duty clutch for Torana. The clutch is the reason why manual LH Torana post LX pilot (8/75 onwards) kept the HD/HL engine numbers but the autos were the identical engine to a Holden so used QL engines.