performance timing

Currently with basically a stock engine with a bit of head work and a much hotter ignition I am running stock NGK's and timing set at 5 degrees BTDC( fac rec is 6 degrees)..I am about to install a polished and ported intake,a 34 Weber and a mild street cam with a fresh set of springs ,retainers and lifters and we are going to clean up the oil galleys a bit while the head is off.The truck holds an even 160 pounds of compression across all cylinders,uses no oil and when I changed pans and trays a few months back I retorqued the lower end to spec.Question is if I go to 91 octane how far can I advance timing before I start getting predet and/or performance gets worse not better?Second question is I have adjusted the vac, on my A/T to full throttle shift at 4000 rpm(it was shifting at 3500).ANy idea how much further I can go before things start falling apart?Thanks much.BJ

that will depend on the cam, but i'd say another degree or two at most & run 93 not 91 octane, as far as the tranny i don't think that i'd push it past 4500, i don't know how reliable the a/t's are, i know i've wound my manual up to 4750 w/o any issues though......

Okey dokey,we will set time at 4 degrees BTDC,run 93 octane and see if I can squeeze 4250 rpm shift points outta the A/T.Will keep u posted.If u hear a loud noise and a mushroom cloud Nor East of u u will know that something came uncorked.Lol.BJ

just be careful, i work to darn much to come check out what's left of the mushroom cloud! do one degree, run it & if you don't have any issues with it, you could go one more, but past that i think you'd run into some issues.....as for the tranny.....i'd stick to the 4250.....otherwise it could grenade!

Nah.It is already at 5 BTDC and no problems so I am going to 4 and see if about 1/2 more turn on the vac screw will get me a tad over 4200 on the shift point, then I am going to quit tinkering and take it to the 1/8 mile strip here and run it.I already have a bsaeline at stock(slower than stink off sh--)lol, so we will see.If I have spent all this time and $ for little or no improvement I will take the poor thing out back of my house and shoot it in the radiator.BJ

Hey boys, what idle RPM are you supposed to set the timing on a stock 2.0?

When I set mine, the idle was between 850-950 and I set the timing at 7-8deg advanced. Anything lower and the motor ran rougher and is noticably weaker. It has the pinto holley 5200. No pre-detonation is happening either. Maybe my motor is weird?

awe now, don't shoot her, just put her out to pasture......you know on blocks so the grass can grow up around her, haha!

let me know how the 1/8th turns out..... that way when i carry mine to huntsville dragstrip we can compare....that is if i ever get mine running!

best i can remember mark, you should have the idle inbetween 750-900 rpm, then make sure the timing is set at factory spec & the carb is properly tuned & everything runs correctly there first, then start to advance the timing by 1 deg. at a time till you get the optimal amount of timing for the octane fuel you are running....

Factory spec is 750-850 rpm,timing is 6 degrees BTDC.It shouldnt run rough at 6 unless you r running something below 87 octane.BJ

hm.

well since it's at about 7-8 at 950rpm, it should be lower at around the recommended idle of 750-850, right?

so i guess i'm fine?

I have the idle set a little higher so that when I'm at idle, the truck will still idle above 700rpm when the air compressor is running and the a/c is engaged. I don't have my "idle-up" when the a/c compressor engages because of my 5200. So a quick fix was to raise the rpm.

i'll drop the idle rpm to 750-850 and check to see if it's at 6 BTDC

thanks for the info