i'm building an engine dyno for the mini engines i've got the stand almost complete (i;m doing the mountings) now but i was wondering what kind of speeds can the average disk brake take - i don't want to spin it up to 5000 rpm and have it explode on me (the missus would get a little angry with bits of disk flying all over the place in the front yard)

has anyone else here built one or should i just go hydraulic and modify a torque converter
[/b]

_________________
why does everyone want a Cooper S when you ca have a better Clubby

I dunno... water sounded cool so i'll vote for that

I voted hydraulic.

Depends on the cost of establishment (hydraulic/water) vs the ongoing cost (discs/pads).

Sounds like a cool idea anyway, got any pics?

JC

_________________
But he's thriving and striving and hugging the turns.

i'm erring on the side of disk brake because all they give out is heat they are easy to mount all they chew through is pads and eventaully a disk where as water and hydraulic, heat is easier to control not only that they can provide higher loads where a disk brake can do this only to a point as before it heats up and glazes
although i may not have this problem on a mini engine
as far as pics goes i have to get some batteries for my camera then i'll stick a few up of the stand by then i should have an engine on it

_________________
why does everyone want a Cooper S when you ca have a better Clubby

Hook it up to a generator and make some money on the side.

I'll leave the practicalities about how to actually use it up to you, but it's based on my idea for gyms. Why are gyms on the national grid, when they've got all those people on running machines, rowing machines and exercycles? There's a business idea in there for someone.

actaully thats not a bad or totally unpractical idea considering the average human riding a bike can typically put out up to 200w give or take 100w if you had say 10 people in the gym at the same time going at it on the tread mills each generating 100w eachall up 1000 w, going off current electricity prices thats roughly (don't crucify me for this) $1 per hour these 10 people are making with outmuch effort and getting fitter... no negatives other than cost to setup but hey whats cost in the name of fittness

here another thought how much fuel would an a series engine chew if it were running at say 2500 rpm continously for 1 hour producing 50kw ($50 per hour)
it would be interesting i don't think it would chew $50 worth in fuel even if it was a little lean..........ponder might just turn that old 850 into a genset

_________________
why does everyone want a Cooper S when you ca have a better Clubby

Water brake is the go- simple in principle, designed eons ago, and they work. Unlike some other they will stand being loaded for extended periods- like for running in a motor.
I worked at the NSW Railways years ago and they had made their own, for testing Detroit Diesel 6/71 motors.
They just copied the design of the Froude water brake sitting in the next bay...

_________________
DrMini- 1970 wasaMatic 1360, Mk1S crank, 86.6HP (ATW) =~125 @ crank, 45 Dellorto (38 chokes), RE282 sprint cam, 1.5 rockers, 11.0:1 C/R.

Arrrrrfffh, Arrrrrfffh, Arrrrrfffh, Arrrrrfffh...in best Tim the Toolman voice.

I have seen a very very heavy marine transmission disk brake dyno...not a pretty sight for your backyard mate

_________________
"Show me the Mini!"

My brother used to use those dynos, they got about 400 horses out of a Leyland bus engine (from about 140) before it went bang!

sounds like water is the best so far i'm going to have a look at a few torque converters and see what i need to do to modify 1 so i can vary the amount of water in it also i can use a 44 gallon drum to hold the water and re-circulate it i was even thinking of mounting it on a box trailer with a simple swivel crane thing (to lift the engines) so if the neighbors get a little testy after a few hours of revving i can take it to an industrial estate/local shopping centre/middle of nowhere and make as much noise as we need to or if somone wants to borrow it...

_________________
why does everyone want a Cooper S when you ca have a better Clubby

was thinking how about using a dick brake but constantly flooded with water inside a container shouldn't heat up much
i've also found a torque converter i'm picking it up on the weekend see what i can do with it should be interesting

_________________
why does everyone want a Cooper S when you ca have a better Clubby

Whatever you do just make sure you remember the 90° rule. That is never stand in a 90° axis to any rotating part.

yes some people who havn't adheard to that rule have really learnt from their mistakes
i've heard too many horror stories about flywheels breaking up

but i won't be alowing anyone near the motor it's all going to be remote and computer controlled so even if some fails the risk is somewhat reduced

if i did end up doing disk i would have a concrete enclosure around the disk brake just incase it does break up given the extreme heat and stress

but at the moment i'm picking up a torque converter tomorrow from a gearbox place in greenacre the measuring device is going to be a hydraulic ram and a pressure gauge

(cheapest and most accurate way of doing it) unless i can come by a cheap load cell hint hint anyone out there got one they could swap for a little cash

the only thing that is going to hinder this is the coupling device from the engine to the absorber

_________________
why does everyone want a Cooper S when you ca have a better Clubby

hmm

_________________
Baracade
Relationships! The only time you get to sleep with the enemy!
1972 US Export Moke in Bundaberg QLD