Because I had another motor on the big dyno I had to put a formula 5000 on the Mini Dyno.







This was the motor on the big dyno. A supercharged MGB. Over the seven days these engines were on the dyno. Using the SAE correction factor, the Correction was between .995 and 1.013. Unlike the unrealistic figures that were thrown around on another forum...







Graham Russell

_________________
"It's better to be not informed than ill-informed"

The MGB has a 5 port head. I wondering why it doesn't run a LCB exhaust manifold?

Looks like it's an even bigger custom 3 into 1 exhaust manifold. 3 into 1 is better than LCB for big HP motors

_________________
Lillee - 1969 Morris Mini K

GR are you commenting on the efficiency and repeatability of your dyno's? Cheers, Mick

_________________
"Show me the Mini!"

Hi Graham

Darryl here Cairns. ( same one you are doing the head work for, Good to see the motors you were talking about.


I tried to get some perspective on the other forum, that seemed to me that the correction factors were all within 3- 5% ( so not really a big deal going on about uncorrected dynos being used.)

Also using SAE is generally 3-4 % lower readings in terms of neddies-
so any reading off these would be true and probably on the lower end of the scale in terms of what other dynos may read out. - but you already knew that. Cheers Darryl

edit spelling

Hi Rocket
These are my own design extractors which i make for the 1000/ 1275 and MGB's
motors they make more torque and hp on the motors i build, down fall they are expencive.
GRaham Russell

_________________
"It's better to be not informed than ill-informed"

With your extractors v's LCB.....is the increase torque right across the rev range or does it tend to be in the upper end?

HI MG Rocket
Mostly right across the board but from peaK TORQUE TO PEAK HP
Graham Russell

_________________
"It's better to be not informed than ill-informed"

Hi Darryl
I know John Collins very well he is one of the best tuners around and a very good engineer, he not worried about correction factors as long as the motor comes off the dyno better than when it went on the is happy.
But if you multiply a 100 hp motor by his correction factor you wind up with 158 hp, now in all the dyno rooms that i have worked in the highest correction factor i have seen is 1.04 along way from 1.58 i dont know how they arrive at that if they use the SAE correction factor that GT MOWOG put up on the other forum which is the one that i use 29.9 BP 0 humidity and 60 deg F, if you look at SLO998 dyno factor it is 2.1? i would love thoes kind of factors.
The only drive on dyno that i know of that works correctly was in stalled by ERVE KATAMOTO (i think thats how you say his name/ spell it) a llittle man from japan when i was doing bike heads we were using his dyno here in australia it had a large duct facing the front of the bike and a massive fan blew air onto the front of the bike so as the bike speed increased in mph the air speed would match up to 140 mph, you had to have very good ear plugs not because of the bike noise but because of the fan noise, i think the dyno is still here but he may have taken it back to japan as he was involved with GP bikes an did a lot of testing hare in australia.
Graham Russell

_________________
"It's better to be not informed than ill-informed"

Excuse my ignorance but I dont quite understand how dynos can differ so much. How can a group N mini have an engine that apparently puts out 140hp at the crank yet only read 88atw on a dyno dynamics chassis dyno. Does that mean that there is a huge drivetrain loss or can a bench dyno be made to read high or a chassis dyno read really low?
Can anyone explain this to me as it just doesnt make any sense?

_________________
1970 Cooper S ex-Bathurst & ATCC
1964 Austin Cooper S ex-Group C race car
1967 Morris Cooper S ex-Group B
1962 Mini Speed sports sedan
1968-71 ex-Peter Manton Shell car

There are huge drivetrain losses (including the tyre/roller one) on a chassis dyno.
In comparison to an engine dyno, where there are hardly any losses or variables. A Froude engine dyno (water) directly measures torque (reaction) at the pump housing and engine rpm, mathematics then gives the HP. Torque loadcell is calibrated with a 50kg weight. Only variables are atmospheric and temp. No fudge factors.

Back in the 60s at NSW railways we used to use a `home made' water one for testing GM 6/71 & 6/110 motors out of diesel railcars. Even it was accurate.

_________________
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.

It looks to me like there are 3 or so commonly used correction factors - barometric, temp etc but i have been told that the true standards includes lots of others factors also - but whether they account for lots or little seems to be the question. I think i will stick with the premise that a dyno is a good tuning tool to compare one car with itself in a before and after tune scenario

So Doc, are you saying that a bench dyno is always accurate?

_________________
1970 Cooper S ex-Bathurst & ATCC
1964 Austin Cooper S ex-Group C race car
1967 Morris Cooper S ex-Group B
1962 Mini Speed sports sedan
1968-71 ex-Peter Manton Shell car

Hi GR, The guy that did the tuning on my 5 port motors is the some guy that dose the tuning on your "race" motors in adl. So I guess maybe he has done similar correction factors and wonder how much they are really making?

Thanks Nathan.

Hey GR, that Chev is lookin good, is that all flat-slide, mech fuel inj & Magneto ? all old skool stuff, gooat love that era, real hard-core stuff that should punch some good numbers out

& the Blown 1800 should be torque munster not my cup of tea tho,,, too heavy for not enough fun-factor

Both real nice tho

& (to everyone else) --> all dynos (used the correct way) will be good for comparisons of the work you do while it`s on the dyno... i don`t nit-pick on what the numbers are between different dynos,,, that`s just bein silly/stupid & if you argue the fact then you really are bein silly-stoopid

I know of some trains with big-heaps of grunt & big heaps of Hp but i bet my buggy still beats em

_________________
No offence intended here but--> anyone writing a book about minis 30 years ago may not have experienced such worn or stuffed-with components as we are finding these days.

You should put your heart & soul into everything you do.