Raising the compression?

[jpward]

I thought torque depends on if the engine design. long stroke engines produce more torque but rev less, and short stroke less torque but rev more

to do with the distance of the big end from the centre of rotation of the crank, obviously bigger distance will create more turning force and a longer stroke (as in american cars)

The only reason why long strokers are lower rev's are due to higher piston speeds and the chance of rod failure is greater you can stroke an engine and keep the redline the same if you use top end rods/pistons etc as the other area possible to let go is the pin.

So it only plays a part in so far as mechanical strength limitations just like some big V8's dont rev that much but the reason american cars would apear to have more torque is down to them being larger displacement and multi cyclinder a v8 will have 2 cyclinders firing together so in theory its like having twice the cyclinder pressure on a smaller engine

or in laymans its like pushing down on a lever of say 1m with 20kg if you lengthen the lever to 2m or the force to 40kg thats twice the force acting about the pivot point if your lever was not strong enough then you could only put a max force of say 35kg on the lever then that becomes you limiting factor.

;-)

 

[jpward]

how long before they are actually made

Mines being started today

 

[riske]

Inner CV Boots???

Hi guys i've searched everywhere for some new inner CV boot joins, you know the ones that are on the drive shaft nearest the gearbox.
Been to the parts suppliers such as partsco and lenco but nothing...

Only place near me were Nissan and they want £55 for a pair!:doh:

Anyone that can point me in the right direction or supply me some new ones by Tuesday?

Much love

 

[tenfoloten]

have you got pics?

 

[noriek2003]

a v8 will have 2 cyclinders firing together so in theory its like having twice the cyclinder pressure on a smaller engine

a 4 banger has 2 cylinders firing together :doh: thats how they work :lol:

 

[steve963]

I thought on 4cylinder while one cyl was firing the other was on induction stroke?

 

[noriek2003]

thats sort of right, but they work in pairs, 1-4, 2-3

 

[steve963]

I`ve been wondering how 3 or 5 cylinder engines work!

 

[riske]

Any help?

 

[nickr]

what about this one

https://www.gspec.com/p-7378-fuel-rail-gti-r.aspx

 

[popeye]

Hi, I have just had to change one of mine Nissan knocked me the vat off and it was still £27 so think thats the going rate from them, I know theyre not available from most motor factors as theyre an unusual shape, try a few specialists but you will probably end up getting your wallet out!

 

[Fusion Ed]

If you have wasted spark system you fire 1-4, 2-3 in pairs, same for semi sequential injection...

 

[stevepudney]

Larger volume (essential for running larger injectors reducing the pulsing effect)

John, I assume the ID of the rail your having made is significantly larger than the JGY rail then ?

 

[snoon]

Not bad Young'n

At what RPM's?

350.5 BHP @ 5718
344.2 lbft @5008

The curves on the graph show them being fairly close up to 5250 ish then the torque drops to 250 by 6750 whereas the BHP only slowly drops to 340 at 7200

This was done on what turned out to be a tubby with pieces of the blades missing :shock:

 

[jpward]

what about this one

https://www.gspec.com/p-7378-fuel-rail-gti-r.aspx

Its more expensive ;-) but looks pretty much like these will!

 

[jpward]

John, I assume the ID of the rail your having made is significantly larger than the JGY rail then ?

14mm ;-)

 

[jpward]

have you got pics?

Finalised the drawings today looks well (as well as CAD for cnc's does anyway!)

The rail i have specified to be as like the AEM rails as can be made I also have got the option of a bung where i can screw on a fuel pressure guage during dyno sesions and then just blanking plug when not in use!

Also just found out i live 15mins from an anodiser so i may be enquiring about what he can do price wise but i have seen a set of yokes done and they are very smart looking.

The whole rail is being milled out of a solid lump of alloy 50X50X500

 

[tenfoloten]

can you send me CAD draw to my mail mar2004@fastwebnet.it
thanks a lot

I have autoCAD 2007

 

[steve963]

its only one side which is unusual shape, you can get away with universal stretchy boot on the other side (make sure you do it up tight as mine popped off after 1 week, but has been fine since)

IIRC its passanger side which needs the internally triangular shaped boot

 

[steve963]

by the way, wait till you need rear damper boots, £33 each from nissan !!!!!


(ive been told you can make universal steering rack boots fit)