Technical 40 degrees of initial timing?? WTF?! (347 stroker)

Hi folks,

I'm posting here because I can't make heads or tail of what is going on with my engine:

• 347 stroker
  
• Pertronix III HEI dist (stock silver springs)
  
• Sniper EFI system (although the problem was the same with the carb I used for break-in)
  
• Trickflow 170 heads
• Lunati Barebones cam: advertised Duration (Int/Exh): 282/292 ; duration @ .050 (Int/Exh): 218/228; gross Valve Lift (Int/Exh): .496/.494 ; LSA/ICL: 112/108

Everything is new on the engine, I put it in my truck a couple weeks ago and I have a weird issue, that crazy amount of timing at idle. 40 degrees is nuts, right?

All the vacuum lines are plugged, that includes the vacuum advance on the distributor. There are no vacuum leaks that I can detect; all the sensors on the sniper read good (AFR, coolant temp, rpm) and for all intents and purposes the engine idles pretty good at 800 rpms.

What really concerns me is that when I put the engine at TDC on the compression stroke for cylinder 1 (I triple checked this, my mark on the balancer is bang on), move it to 10 degrees BTDC and move the distributor to get the rotor in line with #1 on the cap, and try to fire it, it bucks against the starter, like the timing is way too advanced.

So I back the dist off quite a bit, and boom it fires right up, runs like a dog though. So I start advancing timing slowly by turning the distributor until it idles nicely, I get 16in of steady vacuum. But the timing light reads 40 degrees of advance! I confirmed this with 2 other lights, they all read the same. Put the clamp on #6, same reading.

So with the engine off, what I'm witnessing (compression stroke on #1 approaching TDC) coincides with the mark on the balancer (verified true TDC with a piston stop, marking the balancer in 2 different directions and finding the middle), but when it's started, not only am I not even in the same ranges of mark on the balancer where I put the paint ( There are 3 spots with timing marks from 0 to 40), it reads an absurd amount of timing.

I tried to lower it and it starts running like crap, vacuum lowers etc, all symptoms of too little advance.

I'm scared to drive the truck now, or even worse hooking up the vacuum advance on the dist, because if the timing reading I'm getting is correct I'm going to detonate into oblivion as soon as there's a load on the engine... Any idea?

Thanks in advance.

 

Hook up the vacuum advance to the distributer and see what you get. Can you dial in advance with your light?

 

Sniper, ut o.

 

Wouldn't that add advance though? If I hook it up to the manifold vacuum, I'm going to add 14 degrees of advance according to Pertronix; if I hook it up to the ported fitting, I won't get zilch at idle with the throttle blade closed, wouldn't I?

Yep, the light is a dial back

 

?

 

I'd say your timing pointer is off or the damper, it would not crank over at 40° advance.

 

He says it was verified with a piston stop....

 

1-5-4-2-6-3-7-8 or 1-3-7-2-6-5-4-8 firing order?

 

Yeah, the pointer is definitely pointing where it should be, triple checked it to make sure I wasn't crazy.

 

1-3-7-2-6-5-4-8

 

Did the timing chain have three keyway slots for 4 degree advanced, straight up or 4 degree retarded ?

I miss matched the dots on a sbc, ran like a pouch also.

 

Could you elaborate? Sorry if I sound dumb but it's my first engine build; I did a lot of research but that doesn't compare with having a bunch of experience.

 

It did, I installed it dot to dot. Degreed the cam too. But even if I didn't install it dot to dot, it wouldn't show 40deg on the balancer, would it?

 

You are correct, cam installation would not change crank to T.D.C. balancer relationship.
If I read the original post right, T.D.C. pistion stop method, didn't line up with the marks on the balancer correct.

 

Centrifugal advance working properly, not stuck advanced, springs still on?

 

It did work right, 0 mark lining up with true TDC

 

Unfortunately yes :/ Popped the rotor off this morning to check.

 

I'm running out of WAG's. Might verify the dist. drive gear is where it should be and hasn't slipped.....?

 

I sure as hell hope not... I'll check though

 

How old is the balancer? There are several timing pointer locations on Fords. You might post a pic of what you have . It could be the wrong location for your balancer. Don't take everything apart until you've looked at all the simple things 1st. Be calm. None of us think well when we're upset.

 

Brand new balancer, I have an adjustable timing pointer on it (aftermarket). Yeah no kidding . Wouldn't the fact that I have the TDC mark correct on the balancer mean that the timing pointer is also correct?

 

My SBC distributor kinda did that. Centrifugal advance came in super early. Like at 1000 rpm. Way I found out was it was the same at 3000 rpm. Wouldn’t advance any more. Mine was pretty obvious when I took the distributor apart. Springs were just barely hanging on the pegs. Spring kit fixed it.


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As I've said before your sbf will not crank with 40° of initial timing and that mild of a cam. Are you sure you have the correct pointer for the position you are using it in? Are you finding tdc for 180 out?

 

I believe he means you're not getting your timing signal from the #1 plug wire.

TDC on #1 is the same whether the distributor is dead on or 180º out.

 

Where is #1 on his engine?

 

Passenger side, frontmost cylinder

 

That's a possibility I guess, but when I rev the engine and watch the balancer, it does advance smoothly with rpms

 

What it most likely means, is you have the wrong pointer location on the wrong "zero". In the example below, one pointer's zero is 32 degrees ahead of the other pointer's zero.

 

Thanks for the explanation! Yeah I'm getting it from number 1... It just baffles me.

 

This looks almost exactly like my balancer! Ok so how does that compute with me getting air pushing past my finger when I come up on the zero mark that I highlighted with the paint pen? That's what I don't seem to understand, if I'm not mistaken there's only one spot on the balancer where my finger will get pushed out by air and the piston coming up on top dead center