Hi guys,

Just need a hand filling out my change of engine number form..

Previous engine number is 99h7919100933 so..

what is the R.A.C horse power and is it a 4 cylinder?

My current engine is 12ha871106652 so again what is the R.A.C horse power and number of cylinders?

I want to make it official so I can get fully comp insurance and piece of mind so I don't get into any trouble. I have it booked in on monday for a minor inspection on the engine so I can get it registered at the Liscencing centre.

Many thanks

Rich

I thought they got rid of that antiquated RAC `HP' rating in Australia years ago, NSW sure did.

Anyhow, here is the (ridiculous) RAC formula:
HP = bore dia (inches)² x no of cyls (4) /2.5

So, for a standard (70.6mm) bore, my calculator says it is 12.36HP.
Put 12.4 on the form.

Note- the stroke isn't considered! (this is why UK engines all used to be long stroke and small bore).

_________________
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.

I don't have my rego papers or I would just tell you the figures, but you can calculate it:

RAC h.p. = (D^2 x n)/2.5

where D = the diameter of the cylinder in inches, and n = the number of cylinders

Yes, it's 4 cylinders.

_________________
Too many cars, and too little time.

Oh, Kev beat me to it.
And we still have it over here, WA really does stand for Wait Awhile

_________________
Too many cars, and too little time.

12.4 hp for a 998cc? I had a quick look on google and found..

998cc = 38-58hp (depending on what engine its from)
1275cc = 63hp

tho i'm guessing these would be the figures if they were brand spanking new?

Rich

I would imagine that is the figure for per cylinder?

12.4*4= 49.6hp...?

_________________
Here am I sitting in my tin can far above the Moon
Planet Earth is blue and there's nothing I can do...



“A turbo: exhaust gasses go into the turbocharger and spin it, witchcraft happens and you go faster.” - Jeremy Clarkson

RAC hp rating is really just a tax code for rego purposes, don't expect a realistic number.

_________________
Too many cars, and too little time.

If you remember the first Minis were sold as the Austin Se7en. The original Austin Seven was named after its RAC HP figure.

The RAC figures for the different engines is...
848cc = 9.8
998cc = 10.3
997cc = 9.64
1098cc = 10.3
1275cc = 12.4

An engine's BHP has nothing to do with the RAC HP rating, as others said it's a tax code.
I calculated it for a 1275, from memory for a 998 or 1098, RAC rating is 10.4.

_________________
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.

The above info looks right, below is a cropped section of the original rego on my 1969 Cooper S I bought new, it has the horsepower listed as 12.



Edit: Just noticed they stuffed up the prefix on the engine number on the rego papers.
9F FA Y instead on 9F SA Y.

that's fantastic - I knew that cars were taxed based on the bore size, but never knew what the calculation was

Its the whole reason British engines were so terrible. To try to keep the tax down while still getting enough capacity to be any good, they ended up with tiny bores and long strokes. It really stifled engine development, tiny bores meant tiny valves and terrible gas flow. Taxation by RAC rating was abandoned in the 1940's but it wasn't until the new generations of engines that came out after the war that cars started to get modern engines.

Tim

_________________
1951 Morris Commercial J Type Van
1955 BSA C11G
1961 Morris Mini Traveller
1969 Triumph TR6R
1977 Leyland Moke Californian

Ford bucked the longstroke (undersquare bore/stroke) trend with their 997cc 105E motor and later derivatives. The 997 was so far oversquare the torque was poor. And the 3 main bearing bottom end wasn't real strong either, so if you revved the tits orf it, it broke!
Later bigger engines got 5 main bearings...

One advantage of undersquare engines = better emissions. Check the bore/stroke ratio of (eg) modern Hondas and Mazdas...

[edit] for some good reading on RAC rated HP see here- http://en.wikipedia.org/wiki/Tax_horsepower

_________________
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.

This is fantastic guys thank you so much for all this info!

I'll be putting down..

R.A.C Horse Power for 998cc = 10.3
R.A.C Horse Power for 1275cc = 12.4

Again thanks for all your info guys, i'll let you know how I get on after tomorow when I take my car in for the minor inspection on the engine, if anybody has any tips to help me get it passed it will be much appreciated.
The electronic ignition is more or less brand new and has been professionally set-up, also been serviced within the past few months so hopefully there is no reason the inspection should not go smoothly.
This is where i'm taking it - http://www.pebco.com.au/

Rich.

O.k so I took it to the garage and once it was inspected , all I had to do was fill out a LA1 equivilent engine installation form which was sent off to Vehicle liscensing and they responded within 30mins via email with the thumbs up! So now I don't have to go to the vehicle liscencing centre to change over details as they will send me a letter to confirm the engine change.
And all it cost was $62!!

p.s - I definatley reconmend this garage for inspections as they guy is an honest and generous bloke who had also helped me fill the form as it was filled with mechanical jargon.

Rich.