Technical GSR cam vs. P75 cam

[GoBe]

that's a very mild cam, it's produces a lot of torque low down but not much up high.

 

[balidey]

so what is the 4x4 punto 1.2 cam the equvilant of ?

I don't understand your question, what do you mean equivalent of? thats just what it is. Or do you want to know its lift and duration? If thats what you want, i haven't got it.

 

[cinq117]

Sorry i could of explain that better but Go be answered my question.

Thanks
Ricky

 

[OxO]

cheers for the replys

ive decided im gonna get a p75 cam this weekend and fit that then in november im going to go down essex and get me some gsr goodness im wanting the induction kit/cam and a sexy new remap which hopefully should take me to 70/75 bhp-ish
than all ive got to do is think of some more ways to get my car over that 100bhp mark without the big £££ (i know about turbo root but i cant fork out £1000 all at once)

 

[Oldschool]

that's a very mild cam, it's produces a lot of torque low down but not much up high.

Actually, it is the other way round.

 

[GoBe]

the 4x4 cam comes on the MPI Seicento, and at least 1 person has noted that moving from a 4x4 to a 866 cam given the engine much more go at the top end of the rev range. The power figures for the MPI Sei' also show this by giving lower rpm for peek torque and power compared to the SPI 1.1 & P75.

 

[Smiler121]

1242 MPI CAM spec..
Cam lift= 9.5
Opens before TDC 7deg
Closes after BDC 41deg
Opens before BDC 43deg
Closes after TDC 5deg

A P75 cam is a nice mild step-up from a MPI or SPI cam and is nice n' cheap, however a C&B 268 or GSR Fast Road cam will deliver a bigger increase & are sill very road drivable cams.

From changing a P60/SPI to a P75 cam and experiencing a P75 to C&B 268 cam I'd say the latter is a bigger step than the P60/SPI to P75 step up, it's also more costly.

Know it isn't as simple as only comparing one figure, but would I be right in thinking that the P75 cam is a 228 duration & the 268 is 268 wonder if they are measured at same lift height?

Anyone know any figures for the 4x4?

 

[fingers99]

what i meant instead of bothering which checking the tolerances and replacing shims for that particular valve, can't i just buy all 8 shims new and put them in?

Like GoBe says, the shims take up the clearances. You cannot know what shims you need until you've measured the clearances.

This is what I'd suggest. Take your head apart. Label the parts 1 to 8 (according to cylinder, starting from the cambelt side) and keep them in seperate bags. Put the valves, in the right order, preferably with the numbers in tip ex on the heads to the engine shop. Get it skimmed, get the valves re-cut/re-ground, ask the nice man to put the new valve guide seals on (it's a pig of a job getting the old ones off).

Assemble the cam with the old shims and the new cam. Use plenty of clean oil, measure the clearances, 1 to 8 with the base circle of the cam downwards (the lobe -- pointy bit -- pointing upwards) and write it down. If your feeler guages show the clearance to be too tight, you need an appropriately smaller shim, if too great, a larger one. Within the limits allowed, a wider clearance is safer than a tight one.

It's not rocket science, but requires a clean environment and methodical working practices.