jakeachy

Ive heard these can add up to 25 horse compared to the stamped 1.6 rockers? Is this possible to do with the heads still on the engine?
.0495 is stock ratio 1.6
.510 is 1.7 ratio.
will i need new springs or can i get away with it?

MadMan@TheWheel

You can still use the springs you have. And I don't think you will have issues with your pistons. You can change to the 1.7' with the heads still on the car, yes.

jakeachy

thanks.
have you done this? did you have enough room to do so without taking the upper intake off? granted taking off the valve covers.

MadMan@TheWheel

I have never done it with the intake on so I cannot help you there, you may have to take the upper off, pop the old hood and lok at what you have for room. If it looks like it's too tight it normally is

FullAuto

Are these 2 different cams?

A cam that has .495 lift with a 1.6 rocker has a .309375 lobe lift. With a 1.7 rocker, that cam will have a .5259375 lift (so .526).

A cam that has a .510 lift with a 1.7 rocker has a .300 lobe lift. With a 1.6 rocker, that cam will have a .480 lift. So a B cam with 1.7s has .510 lift.

FullAuto

Stock E7 springs are junk with anything other than a stock cam. But people will still run them with B and E cam. They will bind past .500 lift.

jakeachy

Im going to use the factory cam. Im guessing your formula is wrong because in the 2 mechanic books ive spent hours reading about this it gave me on a stock cam:
.495 with 1.6
.510 with 1.7
all i plan to do is change rockers, as they develop wear that doesnt allow them to fully open and close the valve

my77stang

if you think your stock cam is a .495 lift..... well..............:e ek:


and yes people can get away with using stock springs with a B cam, but even that is pushing the limits cause as stated coild bind is @ approx .500 and i don't feel comfortable going over the .475 mark

Joel5.0

Throw those "mechanic books " to the trashcan then, THEY are the ones with the wrong information......FYI.... the stock cam has a lobe lift of .278", which is .445" w/1.6 rockers and .473" w/1.7 rockers. Like FullAuto tried to tell you......if a book is wrong in simple math, don't trust its content.....unless it's an interpretation problem......

5.0stanger

also, going from a 1.6 to a 1.7 will add around .030 lift. I am running them on my car with upgraded springs. Also to remove the driverside valve cover, you will have to remove the upper intake.