Just moved to Colorado from Ohio where I had dyno'd and tuned my 360 (in a 76 f100) and now need to get that performance back, without the cost of another dyno.

Where do I need to put my timing now? (it was at 12 deg btdc, cause I have the crane 901 cam thanks to your beautiful recomendations, edelbrock 600cfm carb and intake, msd ignition, and dual exhaust headers, and exhaust, with stock pistons).

The other part of this is, do I need to re-jet my carb because of the thinner air, or will a timing change do this for me? ( i'm at about 6000 ft above sea level) If I do have to re-jet, how much leaner or richer?

Thanks

Oh, if anyone can tell me what kind of power I should be getting that would be great. The dyno guys couldn't tell because I had oversize tires and no tach, though I did increase overall Hp and torque.

 

your timing is cool its all about the air fuel mixture. If the air is thinner than it is in ohio then your probobly running rich because now there is more gas and less air. I dont know all the logistics of it but Its just getting the carb tuned i know that.

 

yes you need to advance your timing I would say about 2 deg would be good, and lean the carb out some that is one you will have to experement with it best bet buy the jet kit for the edelbrock it has a bunch of needles, and jets, and a book that will tell you what combination will give you what amount of change start with 10%, and go from there but that would be a good starting point, and will probably be pretty close. As far as your power you will never make as much at altitude as you will at sea level but you can definatly improve it alot.
this comes from experience I moved from laramie (7258 above sea level ) to Iowa, and had to back my timing off 3 deg, and richen my carb up 15%, but it ended up with alot more power at sea level.

 

At 6000' you will have to lean it out a bunch. In my Mighty Demon they recommended 1 jet size per 1000' as a starting point. You have almost 20% less air at 6000' than you have at sea level. Timing does indeed typically like to be advanced a little more up on the hill than sea level.

The only way to get your power back is forced induction. I'm at 7000' as I write this and my next rebuild is going to include a supercharger.

-Scouder

 

My wife is from Galion Ohio. I hope that you're enjoying the state.

Like the others have stated, you won't have the same power without some major changes. Your best bet is to lean the A/F ratio and adjust the timing to prevent detonation.

If you live on the front range (East of the Rockies), you'll have to deal with the Emmissions Program and oxygenated fuel. It's not a very pretty picture, but niether is the brown cloud that obscures the view of the Rockies from the plains. I'm sorry to paint the gloom and doom picture, but there are trade offs to living here.

Send me an email. I'd be willing to harrass my resources for some jet recomendations, when they're awake anyway.

 

Thanks guys,

I was trying to avoid re-jetting, but I suspected I'd have too. If anyone has a source inside of edelbrock some specs on how much to tune would be awesome.

Hey, this could be the excuse I was looking for to put on a turbo or supercharger. Any recommendations this way?

 

You dont need a source inside edelbrock. Their tech department is at 1-800-416-8628. I'm sure they'll help you tune that carb.

OBTW, what kind of dyno results did you get with that 360?

 

I agree on leaning the air fuel mixture and to recover
max power you need turbocharge or supercharge.
I am not so sure about timing. You want to lean rich
of peak combustion temperatures to avoid detonation.
[A/F burn instead of A/F explosion]. It seems that your
timing would stay about the same?

 

At 6000 feet altitude I'm running my stock 360 2V with 10 to 12 degrees initial advance, a little more and I begin hearing the "death rattle" as this cheesy fuel begins to detonate.

Funny thing is that the motor still outworks the 1/2 ton chassis. When I'm first in line at the stop light: the light turns green, I push on the gas, dump the clutch, check the mirrors as I clear the intersection and the other vehicles have barely moved. If there is someone near me, they spent more than I gross in two or three years to buy the thing. The power is there, and it would really like to come out and play-WHAAHAAHAAHAA!

f100guy, you have mail.

 

I dyno'd it on a mustang dyno that a local speed shop had just got in. I don't know if the guys working it were still learning or what, but because I had oversized tires (31X10.50) and no tach, the Hp curves weren't accurate. However, after doing a baseline run, and then a lot of tuning I came out with around 10% better hp and torque ( The torque curve on a 360 shoots up within about 500 rpm after idle and is almost a straight line, it's pretty amazing! Hp increases until just before redline and then falls off slightly)

My A/F ratio was lean at takeoff till around 1000-1500 rpm, it then went to around 13 (pretty much ideal) till around 4000 rpm and then went rich slightly. If you have an edel carb, (600 cfm)and a 360 (which mine has around 20 inches of vacuum and then runs to around 8 or 9 inches under full throttle) a stronger spring set will improve immediate takeoff A/F ratio, and power. I went smaller primary jets and smaller rods, and went one size bigger on the secondary jets. You'd have to experiment, but the springs made the biggest difference in initial take off. Watch those secondary jets cause if you go too big they override everything (and your A/F ratio goes to pot). Once you get it dialed in though, that is a sweet power house. Gas mileage is actually decent too (for an FE)

Hope that wasn't too boring.