Timing trouble....

[Red Lehr]

I put a new set of BBM heads on my 428 and the dist. needs to be recurved. I put the lightest springs in the MSD and checked the timing. Initial timing is 11 and all in at 31 at 2900 rpms. We advanced the timing to 12 and the engine wouldn't start... ..turned it back to 10 degrees and it starts fine.
My compression was 10.5:1 before the new heads...
Is it possible my damper has slipped ??
Just scratching my head why I can't get the initial timing higher....

Thanks,
Red

[plovett]

I can't see why two degrees difference of timing would make the engine start or not start. I don't have any idea what it is, but I think it is something else. 

Have you tried the timing at 10 and 12 more than once to verify that is the problem?

paulie

[jayb]

Does it crank the same at both timing settings, or is it more sluggish to crank at 12 degrees?  If it cranks the same, put a timing light on it and see if the light flashes when you crank it at 12 degrees.

[scott foxwell]

Did you degree your cam?

[Red Lehr]

Does it crank the same at both timing settings, or is it more sluggish to crank at 12 degrees?  If it cranks the same, put a timing light on it and see if the light flashes when you crank it at 12 degrees.

When I tried to start up at 12 degrees , the engine hardly turned at all, about a quarter revolution and just stopped... I'm going to double check the timing at 12 degrees again to see if does the same thing...Stay tuned..

[Red Lehr]

Scott, I did not put the short block together.......I was wondering the same thing myself. ....

[scott foxwell]

Scott, I did not put the short block together.......I was wondering the same thing myself. ....

Valve events not being right can make an engine really sensitive to ignition timing.

[C6AE]

Camshaft or "Distributor" timing, which is generally what is specified in "the book",  is half of crankshaft timing.
This little detail can lead to some confusion.

[Red Lehr]

Dumb question,,,is it possible to degree the cam with the engine in the car ? I have the tools to do the job, but I didn't know if anyone has done this before...I actually took all the plugs out last night and put a stop plug in the 1st cylinder and I must not have had the stop in far enough because I never did get the piston to hit the stop....Newbie.....

[plovett]

You can definitely degree the cam with the engine in the car.  That's how I did my last cam.  You just have to get the front dress and intake off the engine. and find a stable way to mount your dial indicator gauge on a lifter.    A fair amount of work, but very doable.

JMO,

paulie

edit:  I'll post a picture tonight if I can find it.

[Faron]

put the heavyest springs you have back on and reset  , if you have the lightest on, its all in under 1500 so your numbers are off 

[BattlestarGalactic]

Rotor phasing out of whack?  Trigger is firing at 10*, but the rotor is not putting the fire in the right place.

[scott foxwell]

Dumb question,,,is it possible to degree the cam with the engine in the car ? I have the tools to do the job, but I didn't know if anyone has done this before...I actually took all the plugs out last night and put a stop plug in the 1st cylinder and I must not have had the stop in far enough because I never did get the piston to hit the stop....Newbie.....

Yes. Biggest thing is finding true TDC but sounds like you're all over that. Then all you have to do is pull the rockers on #1 and you can use the end of the pushrod to measure lifter rise...if you can find a way to stabilize it. I've made some pretty long extensions for my dial indicator in the past. You sound like someone who gets the details...you just have to be patient. Mounting the degree wheel and pointer...well, you just have to mount them. Thousand different ways to do that. If you;re within a degree either way (advanced is preferred) then IMO you're golden. Even a couple degrees advanced is OK. More than that and I'd start thinking about correcting it. I won't tolerate retarded cam timing but that's just me.

[Red Lehr]

I also took a picture of the plugs. some of them look like there a little on the lean side and I'm not sure what will make a plug turn orange but you can see  in the picture also on plug number 3. The first picture on top is 5 through 8 the picture below that are plugs 1 through 4

[fryedaddy]

put the heavyest springs you have back on and reset  , if you have the lightest on, its all in under 1500 so your numbers are off

i had the litest springs in my 428 and my initial would bounce up and down making it hard to set.i have mine set on 15 initial and 33 total and it starts instantly