BHP

C

campingstoveman

New Member
Gentlemen,

What is the actual BHP for a 10.5 : 1 3500 V8 from a series one.

My owners manual quotes 184 BHP, the Haynes quotes 176 BHP
A friend and I are having a pub quiz moment :D

Martin P
 
It depends on what you mean by "actual " Flywheel or BHP at rear wheels ? With water pump alternator etc or without ?
In those days of misleading adverts all sorts of things were done to get the figures as high as possible to impress .
I'd imagine the actual figure with modern measuring methods would be pretty dismal
 
Hello Martin,

Maximum BHP is the engine power delivered at the flywheel on an engine dyno without any ancillaries attached. No alternator, fan, waterpump, etc. So 184 HP is the usual figure quoted.

Net or SAE Horsepower is the flywheel power delivered with all ancillaries attached...so 152 HP is the usual quoted figure. The net power is that which is applied to the transmission / gearbox.

If making a comparison with car engine specifications of today, you need to see if they quote Gross engine (maximum) or Net power.

Ron.
 
I've also had many misleading figures, 184 BHP being a favoured one esp. with P5Bs. I reckon HP ratings up my way should be something similar to SAE, and all P6Bs autos I've heard of are supposed to have 145 of them, while the 'S' has either five or ten more with its bigger-bore manifolds. Never heard of a HP difference btw high and low compression motors. SD1s are supposed to have 155 HP.
 
There would be a reduction in both BHP and maximum torque with a corresponding reduction in compression. However, that does not mean that a lower compression engine would deliver less torque at all points in the rev range compared with an engine with higher compression. Having larger diameter exhaust manifolds can be beneficial when it comes to maximum horespower, but at the same time it can be detrimental to torque delivery at low revs. On the 3500S with its manual gearbox the larger manifolds provide a benefit, but on the 3500 with its automatic transmission the loss of low rpm torque would be both detrimental to fuel economy and throttle response.

At the end of the day though, BHP is largely unimportant. Torque and especially a nice broad flat torque curve which is typical of a V8 engine is of far greater significance. Our V8 engines in OEM form deliver lots of usable torque from not far off idle peaking not far off 3000rpm, and then gradually declining from there. An engine is at its most efficient at the point of peak torque, and having that peak at a point in the rpm range which is frequently used is of great benefit.

Ron.
 
SydneyRoverP6B said:
On the 3500S with its manual gearbox the larger manifolds provide a benefit, but on the 3500 with its automatic transmission the loss of low rpm torque would be both detrimental to fuel economy and throttle response.
Click to expand...

Only the early autos have the smaller bore exhaust and manifolds, later ones, (I think from the intro of the 65 box) have the same manifolds as the "S" and the same large bore pipe, albeit with different configuration frontpipes.
 
HarveyP6 wrote,..
Only the early autos have the smaller bore exhaust and manifolds, later ones, (I think from the intro of the 65 box) have the same manifolds as the "S" and the same large bore pipe, albeit with different configuration frontpipes.
Click to expand...

Hello Harvey,

We might be opening the proverbial can of worms here.. :? I had always taken on face value the information that I had heard regarding the exhaust manifolds but,.....now having had a look in the parts book I find....there are a raft of them... :shock:

For the 3500 without qualification 602693 R/H, 612975 L/H, plus... 602623 both sides the same as applicable to cars in the range of 451-455 up to suffix 'D' and 451-455 from suffix 'E'.

For the 3500S Manual gearbox models, only one manifold is quoted, being the same for both sides and for all engine numbers,...613457,...and this is different again from all of the 3500 issued manifolds. :?

Ron.
 
Manifolds fitted to early cars fitted with AED's had a different N/S manifold for the heat riser, after the AED's finished they had the same small bore manifold each side, then the 3500S got the larger bore ones which the autos then got roughly around the time of the BW65. Part numbers did change to allow for price increases. Export cars may have had different manifolds as well.
 
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