BHP & Torque.

Post by **wanderinstar** » Sat Jun 23, 2007 1:40 pm

Can anyone tell me the BHP & torque readings (I know thats the wrong word, but can't for the life of me think of the right one.) for a standard 1098cc engine.

Post by **Peetee** » Sat Jun 23, 2007 2:24 pm

48bhp at 5100rpm
60lb/ft at 2500rpm

Post by **wanderinstar** » Sat Jun 23, 2007 2:36 pm

Are you sure about that Peetee.
Have just had mine on a rolling road this morning. It has Cooper head, HIF44 carb, alloy inlet manifold and a SW5 cam. Goes fairly quick compares to what it used to do in standard form.
It showed 52 BHP at engine, 33.5 at wheels and 61ft/lbs torque. Do not understand that.

Post by **paulhumphries** » Sat Jun 23, 2007 2:51 pm

Specs can be seen here -
http://www.austin-rover.co.uk/engineaseriesf.htm

Paul Humphries

Post by **wanderinstar** » Sat Jun 23, 2007 3:04 pm

Hmmm. Thanks Paul. Something wrong somewhere then. Anyone got any ideas. RR was at Minisport in Padiham.

Post by **Packedup** » Sat Jun 23, 2007 3:31 pm

The road could've been a bit pessimistic, you've only driven worn out standard 1098s, or something is not quite right with your engine...

Bear in mind the Midget 1098 had a factory figure of 59hp, so if you've got the right head (Cooper 295 I assume?) and cam you should surely be approaching if not beating that figure.

Maybe you've simply got too big an inlet and (waits for bmc to disagree) carb? Could mean you're simply not getting enough explodey stuff in the cylinders.

Post by **alex_holden** » Sat Jun 23, 2007 3:33 pm

How much of a difference did switching between petrol and LPG make? What RPM did the power and torque peak at? Did Minisport tune the carb needle?

Also: how much do Minisport charge to tune the carb on their rolling road?

Post by **jonathon** » Sat Jun 23, 2007 3:34 pm

Was the engine set up on the rollers, or was it just a power run. Rolling roads are I'm afraid sometimes wildly optomistic, and can be manipulated by the user to show figures that the customer wants to see.My engine builder gives a guesstimate of an easy 60bhp but I only gave him the details mentioned above, ie don't know comp ratio or valve sizes or any head work.
Maybe too that the perfect 1098 would give the figures quoted but the average one might be well down on this. Manufacture's claim all sorts of figures which are sometimes impossible to achieve, and keep the engine in one piece.

Post by **wanderinstar** » Sat Jun 23, 2007 4:38 pm

Alex,
Torque peaked at 3.800 ( more or less flat line from 2,000-3,800)
Power peaked at 4,500.
Yes they did fine tune needle.
Cost £60.
( Didn't bother with gas side.)

Jonathon,
yes mate they did tune it on rollers then did a power run.

Post by **alex_holden** » Sat Jun 23, 2007 5:30 pm

Admittedly I don't know a lot about engine tuning, but 4500 RPM sounds too low for the power peak - the unmodified engine supposedly peaks at 5100 and an engine with improved breathing should be able to go higher.

Post by **bigginger** » Sat Jun 23, 2007 5:58 pm

but 'people' say you shouldn't take it over 4000 for any length of time.

Post by **jonathon** » Sat Jun 23, 2007 6:02 pm

If the motor was a new build then the tuner would be wise not to fully extend the rev range until the motor has 'run in' enough. So maybe the run was on the considerate side.

Post by **Alec** » Sat Jun 23, 2007 6:42 pm

Hello Ian,

your power measurement is net but I believe that manufacturers of that era quoted power for their engines as gross, i.e. without ancillaries that rob some of the power? Mind you I think that the peak power quoted is at a low rpm (assuming your SW5 cam is a 'lively' one?)

Alec

Post by **wanderinstar** » Sat Jun 23, 2007 7:53 pm

Dont suppose anyone has had a standard 1098 on a rolling road? Probably not.

Post by **bmcecosse** » Sat Jun 23, 2007 9:24 pm

Ian - was this your 'new' engine ? Did they make any effort to fine tune the ignition timing side of things? And - did you have the lpg 'venturi' removed from the carb - because if it was on there (even though not in use) it would rob some air flow and therefore power. But of course the SW5 cam is designed for torque (they say) and not top power and you have a straight line torque curve - so that may be what it's good for. After all - how often do you drive flat out - and even then, for how long ?

Post by **wanderinstar** » Sun Jun 24, 2007 8:15 am

Very true Roy. It is on existing engine and yes venturi for lpg still in situ. The ignition was checked and found to be spot on, much to my suprise.
I was just very surprised that the figures were only marginally above standard. Considering the spec of engine. Just a pity that no one with a standard motor has been on a rolling road.
Will ring them up tomorrow and see what they say.

Post by **Alec** » Sun Jun 24, 2007 8:17 am

Hello Ian,

did your car originally have a standard engine, and if so how do you feel it drives on the road now? That is the teal test, not figures?

Alec

Post by **wanderinstar** » Sun Jun 24, 2007 10:28 am

Yes Alec it did, the one that is in now. Until I started adding bits to it. Oh it certainly drives a lot better now.

Post by **paulhumphries** » Sun Jun 24, 2007 10:28 am

wanderinstar wrote: venturi for lpg still in situ.

I think that might be part of the problem.
I've converted several vehicles to LPG and in every case the LPG mixer had a smaller dia than the carb inlet.
When running on petrol the performance was definaltey affected at top end ie top speed reduced.
I reckon therefore that although the carb might have the correct needle it's size is theoretically reduced ie LPG mixer makes a 1.5 carb like 1.25.

Paul Humphries

Post by **wanderinstar** » Sun Jun 24, 2007 12:53 pm

Don't know about that Paul. The bloke who did the tuning reckoned that the HIF44 I have is a touch on the large side and an HIF38 would benefit at lower end. So if what you are saying is true I would already have the equivalent of the 38. As I have said before the power is there, I am just curious what power and torque you can ACTUALLY get out of a standard 1098, as opposed to the official "massaged" figures.