What's the single most important component for good bhp?

stafford

Various claims are made for bhp, be they rear wheel or crank, but is there a single component that makes the big bucks?
Cubic capacity should always bring an increase in similar spec engines. Cams will do more more with the correctly associated pistons, add a touch of porting some bigger valves a decent map and bingo.
I've heard some pretty high claims for Corse motors from around 1992 recently and to think that a 996 lump with later hot (not g) cams, HC pistons, balanced and flowed with a blue print build comes up short is quite surprising.
What was the key component? Discuss 😉

BABA

The most important thing is... the "ducati performance" stickers.

You win at least an extra 10 bhp just by adding them.

(a little bit like the two "Viper" white stripes on a car, which means your vmax is around 15 km/h better)

😉

Don't close the door... I'm coming ->[] 😁

Mr.R

You've got to get the gas in and out again to make good power.
Most of the power comes from the heads/port shape and size, valve size and cams/timing.
Then they need to be matched to the headers/exhaust system, you need at least a 50mm system.
54mm throttle bodies also help with a tuned motor.

My 851/916 made 116 rwbhp @ 9,500 rpm with 33/29 valves, the power jumped to 128 rwbhp @ 9,200 rpm with 35/30 valves and ports to match them.
Both fitted with flat top pistons/no head skim and 9*6SPS cams, but with the inlet cams advanced by 12.5 degrees for 107/107 cl's on the bigger valve heads.
I've a pair of NOS '91 "G" Corse heads fitted with 37/32 valves with porting to match them for my 955cc motor, I hope for a similar jump in power at similar revs from the increased gas flow and extra capacity.
I'll be happy with 136 and over the moon with close to 140 rwbhp...

A former forum member Neil Mason's 851/955 fitted with 36/30 valves and 531/G cams built by Ducati John made 136 rwbhp @ 12,500 rpm.
Steve Hislop's Devimead 955 Factory motors made a claimed 150/155 bhp, but that was probably at the crank.
John Hackett claimed that the 996 that Troy Bayliss won the BSB Championship on made 169 bhp.

Steve R

wgsvintage

no replacement for displacement

griff851

The single most important thing for getting more bhp, is the thought that this can be better. Everything else is just time and money.

Or is that too deep for this discussion. 😁

Ps Currently redesigning welding and maching a squish band. Reangling an intake port to go from swirl to tumble.

Mr.R

wgsvintage wroteno replacement for displacement

That's true Bill but over here we say...
"There's no substitute for cubes." or "A good big one will (almost) always beat a good small one."
However Stafford's 1st 888 race bike was opened out to 944cc using a 68mm stroke 900 crank for it's run at the IOM TT, he's now starting with a 996cc motor.
So the extra cubes has been addressed.
It was with that in mind that I posted my answer in a rather long winded way, perhaps I should have just posted...
"The power is in the heads !"
Now if he were to drop the longstroke 900 crank into the 996 he'd get a long(er) stroke 1027cc motor.

Steve R

stafford

Mr.R wroteNow if he were to drop the longstroke 900 crank into the 996 he'd get a long(er) stroke 1027cc motor. Steve R

Which wouldn't be eligible for the Classic as over 1000cc, still 748R cams should help.

RWG

Weight, less of it and red

Mr.R

stafford wroteWhich wouldn't be eligible for the Classic as over 1000cc, still 748R cams should help.

I'm not up on the regs/rules Stafford,
But if your 996cc motor is eligible and your 944cc using a 900 crank was, then why can't you use a 1027cc motor? All the parts fall "In period" after all surely?
Unlike the winning Micky Dunlop XR69 that's running a oilcooled 1200 Bandit motor FFS!
Period XR69's had 2 valves per cylinder aircooled motors based on the Suzuki GS1000's.
A very good/old mate of mine owns 2 genuine ex Factory XR69's (and a spare motor) and the motors although peppered with RG500 parts inc' WORKS magnesium carbs, special mag' outer cases, Titanium exhaust systems and dry clutches are nothing like a Bandit 1200 or earlier GSXR1100 motor???

Steve R

stafford

1.2 FORMULA 1 AND FORMULA 2 CLASSIC TT ELIGIBILITY
The Formula 1 Classic TT Race
- Up to 1300cc, air-cooled 4-stroke Machines 01/01/1973 - 31/12/1986
- Up to 1300cc, liquid/air-cooled* 4-stroke Machines 01/01/1973 - 31/12/1986
- 700cc - 750cc 4-stroke, 4 cylinder Machines 01/01/1987 - 31/12/1992
- Up to 1000cc 4-stroke, 2 and 3 cylinder Machines and Norton rotary-engined machines 01/01/1987 - 31/12/1992
- 351cc - 750cc 2 stroke Machines 01/01/1968 - 31/12/1992
*Note:for the avoidance of doubt,the Suzuki GSXR is regarded as being liquid/air-cooled and will be entered in this category and not the 1300cc air-cooled category.

sagot

Thats easy.
Two things:

Go to store.
Buy fast bike.

stafford

sagot wroteThats easy. Two things: Go to store. Buy fast bike.

I only asked for the single most important thing, fail. 😝

brad black

there isn't one. it's a combination.

wgsvintage

Aren't model year '93 & '94 888's eligible as like models?

stafford

wgsvintage wrote

You could probably claim it as a '92 silhouette bike, engine wise I've tried to keep it 'real' without going for a Testastretta 1198 etc.

sagot

stafford wroteI only asked for the single most important thing, fail. 😝

HA!
Correction:

Hayabusa.😉

griff851

Just to combine Brad and Sagot. Hayabusa+ Nitrous= Hp= Death