Cam timing with a degree wheel (7AGE specifically)

[--Redwork--]

Ok.. Just so as not to confuse me.. cause i'm crazy tired... which one was the right one.?? And I'd still like a pic of your dial gauge onto the bucket setup so i can duplicate..

[marvis]

What just happened?


Haha. Kidding.
You will need to do a wright up

[84AE86]

i need to know what to do, i am confused. as i am doing a 7AGZE engine and need to know if i need to use the 7AFE cam Gears, or just replace the 7A crank gear with a 4A crank gear. can someone help me?

[Frak]

ok, I find the best way to dial in a cam is to use some form of piston stop to find TDC, I'll explain how I do it,

First off install the degree wheel(doesn't matter what position it's in, you will move it)

Now place some form of pointer on the front of the engine such that it overlaps the degree wheel, I use thick welding wire.

Now insert the piston stop, with the piston down the bore on number one.

turn the engine over until the piston lightly touches the piston stop, turn your degree wheel to 0 degrees

Now turn the engine backwards until it touches the piston stop again, what ever the reading is, we'll say it's 40degrees, now loosen off the degree wheel and turn it half this amount, you now have TDC.

Now you guys are mentioning amounts like 150degrees for your centre point.....I think what you guys are forgetting to do is add or subtract the number of degrees the valve is open BTDC/ATDC

let me explain, lets just say the intake valve open 40 degrees BTDC and you are getting 150 for your lobe centre, well just minus the 40degrees to get the right lobe centre amount.

Now if you are doing your measurements at 0.050" you may find that the intake valve opens ATDC, well what ever centreline measurement you get you must ADD the valve open ATDC, I hope this make sense.

so in short, if the valve opens BTDC minus from your centre line measurement
if it's ATDC add to your centreline measurement this is for intake, for exhaust it will be slightly different.

Now when you are doing the exhaust cam, it's the number of degrees the exhaust valve CLOSES BTDC/ATDC(this will depend if you are using 0.050" or advertised)


also if you say have an inlet cam which has these specs,
advertised duration 264deg
intake valve opens 22deg BTDC
intake valve closes 62deg ABDC

you can work out centreline from these figures,

what you do is get 264 and divide it by 2, which will give you 132degrees
now we MINUS the intake valve opening from this figure(as it's BTDC, if it were opening ATDC we'd add, this may occur if you are using measurements taken at 0.050") so we end up with 132 - 22 = 110degrees.

Hope this helps.

[70XIN]

84AE86: Yeah mate, just use the 4AGE crank gear.

And yeah, we eventually worked it out using ATDC/BTDC/ABDC/BBDC, so just 0-90 measurements.

[84AE86]

thanks mate. so have you heard her run yet?

[70XIN]

Absolutely, been running perfectly for a few weeks now

[84AE86]

nice. i cant wait to hear mine run