andre_k

iTrader: (2)

For all you in the know...

how can a motorbike engine rev so high, and produce 170+bhp from a fookin 1000cc engine???

dre

Anonymous

It revs so high due to the lightweight high quality parts used, and it makes the power because of the revs.

andre_k

iTrader: (2)

how do they avoid the valves hittin the pistons, also how come then i would have to pay absolutely thousands to make my cvh rev to 8k reliably, let alone 15k+

cant be as simple as better and lighter parts, or people would be driving cars that rev to 15k...


also, they have hardley any torque aswell, whys this?


dre

Anonymous

They have hardly any torque cause they are small engines and because they are cammed to be high revving.

The sheer weight of the crank needed in a car helps stop them revving very well.

They are just designed totally differently.

Pete.W

i think they are so well lubricated, oil will need changin so much more regular, im a novice tho talk 2 someone abit more qualifyed

Anonymous

honda car engines rev to 9K+ in standard trim (S2000 for example)

So its certainly possible, but its expensive cause they engine actually needs to be built correctly, ford production budgets arent high enough for that!

andre_k

iTrader: (2)

why havent skylines etc ever been modded to rev even close to that?

whats the highest revving engine of car origins?

Anonymous

Car engines need torque, torque needs strong components.

Formula 1 engines rev to nearly 20K mate, so car engines can, its just not a good idea for reliability when carrying that much weight around!

Skylines run over 10K sometimes, but can go to 15K due to the weight of the crank and rods etc that are required to handle the torque involved.

As soon as you turbo an engine, you need more heavy duty components due to the extra torque.

Neil S

iTrader: (1)

Some bikes physically pull the valves closed - that way they cant bounce or over-extend

The reason they rev like fook is due to low rotational mass (they're over-square, so short rods and short-throw cranks help a lot)

As chip says, power comes with revs.

Neil.

It's Czech Mate

Seeing as most current ford bottom ends are all keyless and laser aligned such as the Zetec SE i hardly think you can question the accuracy of their mass production techniques and budgets, the tolerances are incredibly small.
It's down to the design and what they decided the end user needed. If they wanted to make a 9k rpm car i'm sure they could. I just dont think a relatively guttless n/a engine is likely to be developed by them for a family saloon/hatchback tho....when they dont really push performance models like honda do.

Everythings designed to a set of paramaters for a given price.....it's deciding on the paramaters that matters

F1 engines rev to 20k rpm so it's plenty possible.

As chip says weight and durability of the crank, rods, bolts, gudgeon pins etc is a major issue in getting cars to rev.

andre_k

iTrader: (2)

ok chip

forgot about the F1 engines etc

a bloke who works for me dad, got a zxr900r, said someting about a cam to open the valve and a cam to close it... is this bollocks?

u going to ford fair then?

Anonymous

Im not at ford fair im afraid, too busy this weekend, as was at TOTB last one and due to working away from home during the week, i only get weekends to play toy cars sadly.


Matt, the production standards arent a patch on honda, they arent designed to be, things like bore clearances etc, although selectively assembled no doubt, they just arent as fussy, because they dont need to be, its easier to build an engine to rev to 7K than to rev to 9K, and honda are obsessed with reliability and engine life.

Rich_w

Just to add to what Chips saying. Consider the size and stroke of a R1's pistons. (4 pistons 1 litre Compared to a CVH engine.(4 pistons over 1600) Same as a F1 engine. The pistons and stroke are very small which means higher revs are possible. (3 litres over 10 pistons)

The valves being pulled shut mentioned above is Ducatis desmosedici system. Basically all gears from crank to cams. No chain or belt and IIRC rockers instead of valve springs.

andre_k

iTrader: (2)

nice pics

anyone know any sites where i can have a read on F1 engines, wanna know about abit more than just the cvh

Markb_s1

tep.. rockers, no springs. my mate had to have a load replaced this year at the service.. was $$$$$

Hooligan

Square or over-square engines (i.e bore larger than stroke), less inertia due to small size and lightweight parts amongst others...

Neil S

iTrader: (1)

No hydraulic lifters either Rich

Neil.

gurnE

Bike engine are such great value for money!

Yamaha's 1000cc sportsbike went 20valve in the early 80's

Rode a CBR250 once, 250, 4 cyl, 16v engine

19,000rpm limit

markk

iTrader: (2)

import 250RR makes the line a 22000rpm