Where do you set the initial at?

[Bigfoot]

How do you know where to set your initial timing at when you have converted over from a Lean Burn system? I know about the total mechanical timing at 34 deg btdc for small blocks as per the Mopar Performance instructions and back it off 2 degs at a time if you hear pinging until you don’t. If you look at most Lean Burn car stickers in the bone yard for a 318 they will say 7 deg to 14 deg as initial. So when you convert over where do you set the timing because it will be different somewhat. I know with my car once I converted and switched to 4 barrel, if I put the timing at 7 deg btdc as the sticker suggested I could get out and walk quicker. I basically played with the timing, watching the gas mileage and the seat of the pants power meter until I found an acceptable initial that didn’t go over the 34 btdc mechanical high end and didn’t ping. I think it was somewhere around 13 btdc. I have heard a good rule of thumb is to hook up a vacuum gauge to the manifold and slowly adjust the distributor to see what the maximum vacuum reading is and then subtract 1 hg and move the distributor timing back down till you get that number. Another wards if the max vacuum is 20 then adjust the distributor back down till the gauge reads 19 and then see where you are at. From there I can figure out the rest as far as recurving the distributor and vacuum advance etc. Has anyone heard of this method or any other method to figure out the initial other than the old 2 month’s of playing around constantly to find the ideal sett

[6 packin]

Dont worrie so much about your inital time seting! Set total atleast 30 deg and see were you stand at intial which is at idle! You did not mention what cam you had but if stock about 7-10 deg is planty! If it has any cam in it you may want 12-15 initial! Dont let people on here make it to technical for you. Just set total and see were your at! I found that most distrbutors will require recurving if your using more duration! Factory distributors seem to have alot of mechanical advance built in to them! This is good for stock engines with there 4-6 deg inital! But you add more cam that needs 12-14 initail plus 26-32 mechnacal advance (which alot of them had) thats way to much!! You may find you self not using vacum advance at all. Just use intial and mechanical = total! So you need 10 deg inital and you have 26 mechanical..........ohy just right about 34-36 in by 2700 rpm's! Easy way to do this is toss the heavy springs in the distributor advance cams and leave the small ones! I find this to work with most distributors methods. The other way is to shorten the advance cam slots in the weights! for a #15 cam needs to be about .050 shorter! Just remeber to shorten both the same to decrease mechanical advance. File them longer to increase!

Bob

[5thAve]

Ignore the leanburn setting.

It also depends on what distributor you're using. When I used a stock vacuum distributor I had the timing set up around 12-14, somewhere under the water pump anyway, and that's where it liked it. But with the MP distributor anything more then about 5 or 6 and it pings, probably because the advance is coming in a bit sooner then the engine wants it. I usually start off without the vacuum connected, when it started pinging or it didn't feel like it had as much power I'd move it back a bit. Then connected the vacuum. Never checked where it was with the stock distributor but with the MP one I was close, I didn't touch anything else but probably will again next year.

[Bigfoot]

Thanks for the responses. My car has a stock 318 1985 engine and from what I remember the cam specs are Lift 373/400 Duration 240/248 what ever that means. With my stock vacuum distibutor I get about 16 deg mechanical advance and replacing the heaviest spring with another smaller spring from another distibutor I get it all in at about 2800 rpm. There was supposed to be an excellent article in Mopar Muscle April 98 issue that was dealing with recurving dist. and some guide lines. If anybody has that article could you verify that so I can start a search to obtain one. With the 2 barrel carb I had on the car it loved 15 BTDC with good power and great mileage. With the 4 barrel conversion I did recently it seems to like 13 BTDC with about 30hp more when you open up the secondaries. I just filled the tank and will see by the end of the week what kind of mileage I am getting. On a different note, I was just looking at CNN about the sniper stuff in Washington and happened to notice that gas was $1.49 gallon. Here in Canada where I live it is 74 cents a litre so that is 3.8 X .74 or $2.81 a US gallon for the cheap stuff, just about double. So if you are whinning about the price of gas quit it.

[cuda66273]

Yabutt...you have free medical...LOL

[ajmopar]

Free medical for MOST things, after getting our asses taxed off on EVERYTHING. Free Medical if you don't mind waiting a day or two in the emergency room. Free medical if you don't mind waiting a few months to get a procedure done. Whew. End of rant.

[71SATELITE]

Hey bigfoot I have been recently been playing with the timing on my 318. Mine is a 71, stock distributer w/2 barrel. It did'nt start making good power until about 8 deg BTDC at 10 it is seriously noticeable in the the seat dyno, like the car woke up. This realy is'nt the topic on this post but I have read that allot of power is lost on the stock distibuters due to slop. I mean making the rotor hit every time where it is supposed to on the cap( I beleive it is called phasing). Does any body on here know how to do this? I feel this would seriously help idle quality and high rpm. I know above 5000 when I jump on mine hard it sounds like a machine gun, bap bap bap and gives you motion sickness from the bucking.

[6 packin]

On more thing I dont like about Mopars OEM distrbutor is the caps size! The bigger the cap more likely the phasing is correct and less chances of misfire! I have seen a few Ford caps modified for mopar distributors. It can be done! Who says Ford is all bad.......... They can do some good! LOL

[George G. Leverette]

The best method I have found is the one in the engine performance books. Set initial and get the car warmed to normal operating temperature. Set the idle at 2500 RPM with dist set at 32 degrees, if a vacuum advance is used connect a source to the dist and pull vacuum to get 52 total degrees if adjustment is needed use the built in adjuster in the avance cannister to get the desired 52 degrees. Using a vacuum guage during the procedure to get maximum vacuum reading by adjusting the carb idle screws is also helphul.

[Bigfoot]

George and others: I also set up my engine as per the mopar performance book, and even used a vacuum pump as the instructions said. My main question is still this. If the total mechanical advance of a distributor is lets say 16 deg. and you set the 2500 rpm timing setting at 32 btdc as per the performance book then your initial will be 16 btdc (32-16 mech. deg=16 initial) which is kind of high I would suspect or am I totally off in left field. I guess another question that relates to this is , What effect on an engine would a high initial setting have other than much harder to start?

[cuda66273]

Bigfoot...yes...

See signature line

...distributors....

[VetteKilla]

Make sure your timing is steady no slop.
I owned a 2 barrel at 318 that I converted from lean burn.
I first installed 2 lighter springs so I could get more initial timing.
I then took out the spring activating the metering rods in my 300 cfm Carter and set it to operate under load (throttle) I then filed down them big old fat metering rods to real skinnies and BAM what a difference. No more pinging just cruising. Its real easy to do. Another tip was to adjust the rate at which the vacuum advance came in using an allan key. Just insert a small enough allen key to fit inside the vacuum cannister and turn clockwise for faster and counter clockwise for slower advance. And if you happen to have the Holley clone JUNK IT and get a real Carter 2bbl and make sure that the throttle plates don't have 2 wee holes in em or plug em up. One more tip if you can't find a vacuum source for the vacuum advance just use the manifold and adjust accordingly. After I spent a week fine tuning I was getting excellent gas milage and good throttle reponse.

TRY and get parts for old Carters up here in Canada
We improvise

[5thAve]

Only thing with those instructions Bigfoot is that they're written for the MP distributor, and they add in 20+ or more degrees. There's more differences between the stock and MP units then just the springs, especially the new style that are fully adjustable and can be set to add in anything from 0-28 degrees of advance.

[Bigfoot]

I did as Cuda suggested and did a search on the signature line distributors and near the bottom is an article from "PRO" about how to set up the timing and phasing etc. It was what I was looking for and answered some questions that were lingering in my mind. When I did the 1-1.5 drop in vacuum setting my timing was from right at "0" all the way to about 14 deg so as I suspect it is an extremely mild cam so I will start to play around at about 8 deg btdc and increase it from there. I actually looked inside a Mopar Performance Distributor that a friend had and sure enough it has adjustable weight stops and probably some of the phasing is taken care of also so that you can set the timing low and adjust it for the 2500 rpm setting without having to fiddle around with the weight slots etc. Slowly I am learning more and more. Thanks for the replys.

[cuda66273]

Here's one for you street guys...on Atoetly's 440 Dart we just locked it at 34 advance right across the board...never ran better

Don't be afraid of initial be very afraid of max.