52 8rt engine pings going up hill

[Richard in Florida]

Originally Posted by john mullen

So Richard are you saying i need no more than 20 deg total timing ???

Generally, yes.

Specifically for your engine and car, I don't know. However, the basic starting place that Ol' Ron developed over the years for converted GM distributors (and one I've had the pleasure of helping him validate of late) is this:

• Maximum Advance Range - 20 degrees.
• Maximum Engine Advance - 20 degrees BTDC.
• Springs chosen so all 20 degrees of available advance are in by 2000 rpm.
• Adjustable vacuum canister set to produce 10 additional degrees of advance.

This will give you a WOT timing of 20 degrees BTDC, a cruise timing of 30 degrees BTDC, and an idle around 10 degrees BTDC. All good things.

While cruising along at 30 degrees, you floor it to catch the blonde in the Corvette. At that instant the timing drops to 20 degrees, and you're flying after her.

But remember --- this is a starting point. It may not be perfect for your engine/car combination, but it'll be safe and give you a place from which to experiment.

Ol' Ron told me something earlier today that sums it up beautifully: The flathead is NOT a plug-and-play engine!

[JWL]

It is possible for a Flathead engine to need 24 or more degrees of advance for maximum power. The circumstances would have to be unusual. For example: Using high octane race gas in a low compression Flathead with poor port and chamber turbulence and the ignition advance requirement will go way up. If you use race gas designed for 12 to 1 CR in a 9 to 1 engine the reaction will be slower.

However, after making hundreds of dyno tests and dozens of Bonneville runs I have NEVER found an example where more than 20 degrees of total advance gave the best power.

[john mullen]

OK so this is what I got for vacume 17 Inchs at idel speed of 700 rpm. around 12/14 at 55 mph. I dont know if this dist has provisions for vac advance Ill have to check with bubba... i'll let you all know ...thanks

[Ol' Ron]

I now understand why John is having trouble. Your distributor will have a canester on the side of the distributoe where the vacuum would be connected. This is the vacuum advance canester. It should be connected to the intake manifold. You might want to pick up some motor manuals at a flea and read about how engines work.

[jdl]

Originally Posted by john mullen

So Richard are you saying i need no more than 20 deg total timming ???

very interesting thread, I am enjoying it. just to add some more info the total advance for the original Ford 8BA engine ( from the 49-50-51 Ford shop manual) is " Total Advance W.O.T. Crankshaft Degrees. min 17 max 19 ... so 20* sounds right to me.

[Butch11443]

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Been paying attention to this thread. As you knowI'm also setting up a street engine. My next step is to afford one of Bubba's vac conversions for the flattie.
Butch

[BUBBAS IGNITION]

Originally Posted by john mullen

I have a 52 8rt .030 over with Eddlebrock heads, 3x2 setup, SU1-A cam and Bubba ignition.the timming is set dead on the mark. it starts and runs very well. it just pings like hell when its up to opr,temp (180)as you go up a hill or go throttle up. I have tryed timming it all over the place (no)help the carb setup is vintage speed end carb bases and center carb set up kit 48main jet in primary carb,the number on the power valve is ground off so i dont have a clue what it is It realy does run good til 180 deg and then PING PING PING .iTS DRIVING ME NUTS any help????

HELP, HELP !!! This thread has turned into a vacuum advance discussion ( nothing wrong with that i guess) however lets get back to Johns orginal problem and that is " spark knock" on accelleration !!!
Hopefully the springs will fix that problem and if it doesnt i will ship him a low advance distributor.
The posts are right on with the vacuum but the tuning on a flathead is a bit tough especially with multi carbs.....

[Richard in Florida]

Originally Posted by john mullen

I have a 52 8rt .030 over with Eddlebrock heads, 3x2 setup, SU1-A cam and Bubba ignition.the timming is set dead on the mark. it starts and runs very well. it just pings like hell when its up to opr,temp (180)as you go up a hill or go throttle up. I have tryed timming it all over the place (no)help

As the wise ones here have suggested, there are several possible causes for the pinging. Here's one more thought regarding ignition.

If your Bubba distributor is set up for 24 degrees maximum available advance, and you're "setting it dead on the mark," you may be trying to run too much advance. When you replace the stock distributor, the "mark" on the pulley is no longer your correct timing reference. If you're setting static advance on the mark (which could be 2 degrees BTDC), then your engine could be seeing 26 degrees BTDC with the mechanical advance all in. This is WAY too much.

From now on, you need to use the MAXIMUM advance as your starting place. This is the MOST important setting of all. It could save you from destroying your engine.

Try this. Without removing the distributor, take out both springs but leave the weights. This will allow the advance mechanism to go to full advance without your having to rev the engine way up while setting the timing.

With the engine idling around 1000 rpm, set your maximum advance at 20 degrees BTDC... just as a diagnostic experiment. With 24 degrees of available advance, your engine will now idle at around MINUS 4 degrees BTDC, so this isn't a good place to leave it. You may have to raise the idle speed for this test.

Now put back the springs (light ones if you have them) and go for a ride. See if it still pings when it did before. If it still pings, the cause is almost certainly not ignition timing.

Flatheads aren't plug and play.

[Old Henry]

Wow. Reading all of the convoluted machinations some of you must go through to adjust the advanced timing on the "new and improved" distributors makes me glad I've got Henry's original distributor with the fully adjustable vacuum advance that I can advance until it pings then back off until it doesn't and make that adjustment "on the fly" for major changes in elevation (which I do quite a bit) without replacing parts in the distributor. Didn't know how lucky I was.

[Butch11443]

I'm running 2-94's on mine.Using Offenhauser heads about 8 /1cr. I had to clean off the excess spark plug threads on the heads to get rid of the ping after the engine heated up. Just something else to look at if all else fails.
Butch

[john mullen]

Ok now, just to set things strait . I have and will consider all the info posted. However having bubbas ignition I want to try his remedy first giving respect for his customer service. That way if the ignition is not the problem then I can start by trying one thing at a time that everyone posted. I have the utmost in confidence that with all your advice I will get it straightened out ... You guys rock ...Viva la ford barn

[Old Henry]

After reading all of this about trying to get a precise advance on timing at higher RPM's I wonder where the discussion is about the need for advance timing being affected by elevation/alititude? I don't know how anyone can say what a "perfect" advance at high RPM's is without tying it to an elevation/altitude. As I said before, I can have mine all the way advanced, both idle and speed, as far as it will go at my elevation of 4,800 feet without any pinging ever (don't know what the numbers are, they're whatever would be maximum possible with stock distributor). But, as I drop in elevation, which in my state can be from 10,000 feet to 2,000 feet, I've got to retard the speed timing to get rid of ping. So, how can anyone say there is a precise optimal advance timing without saying that such is for a particular altitude. Or, are you all talking about sea level or at least below 1,000 feet where it would be the same for all of you. Am I the only one driving a flathead above that? Maybe it was addressed a little in the comment about timing being different for Bonneville (4,219 feet elevation) than for a "streetable" engine. Just wondering.

[Ol' Ron]

Well said Hank. Not only is ignition affected, but the A/F is even worse. You mention Bville, well the salt might be at 4000 feet but the air is around 8000 during the races. Now try tuning one of those engines. Tuning can be a bit**h, but when it's right, it's RIGHT.

[Vergil]

Ignition timing can be a b***h as Ol Ron said. When the air gets hotter the engine needs a little less timing than when the air is cold and the same goes for the engine temperature, it can stand more timing when cold than when it gets hot, moisture in the air can change the need a little. I think through the years they have done a good job keeping these old engines going without all the electronic help we now have to help us.

Vergil

[john mullen]

I guess I am spoiled as where I live i'm at around sea level to a max if I go up tp the hills of VA. I say hills because there only not much over 4000 ft. As an old racer I am used to tunning by looking at the sky and if its hazy I know it needs less fuel and timming If the sky is bright blue and no haze then it wants fuel and more timming .Ok having this knowledge tells me the timming in my 8rt is to much.I think the fuel is real close. this is my first flathead. even with the knowladge I have on tunning engines this is a whole new animal. the basics are similer but it is compleatly different who would belive that a flathead internal combustion engine would only need 20* total advance .I have had engines with 14 to 1 compression on a fuel so dence that I could run 55*total timming but then again is was a race only engine. Anyway I'm rambling on hear and need to get back on topic.secondly I'm trying to tune with a fuel that is junk but thats what I have to deal with. I dont want to use fuel that I cant buy just whever I go. Hi test is what I must try to get it tuned for.I apreciate the flathead experence you guys have .with all your help I gona get it sooner or later..John

[john mullen]

Thanks... Bubba for the spring kit. I tryed several combonitions and it helped some but it just moved it to a higher rpm and lost some performance down low. tomorow I'm gona fatten it up some and try to get the performance back. if that dont work I'll reset the timing... out of time today. I'll get back to you later

[Bums F-1]

I had the same ping problem with a Vintage Speed 3x2 set up with progressive
linkage. After polishing combustion chambers,changing timing etc. I found the secondary carb butterfly's leaking through just enough to lean it out.

[Old Henry]

Originally Posted by john mullen

I guess I am spoiled as where I live i'm at around sea level to a max if I go up tp the hills of VA. I say hills because there only not much over 4000 ft.

Don't you mean 400 feet?