Help engine ???

[mally69]

As some of you know I just installed a new set of stealths on my engine. Well something is wrong I beleive its in the ignition ( not the heads ). It almost sounds like its running on 7 cylinders BUT I just put in brand new plugs in these heads ( ngk) and ran my old wires but changed them with new MSD 8.5 mm wires thinking it would solve this but it didnt. What it is doing is when I hold the rpm steady it sounds like it just goes da da da da. If anyone has ever heard what an engine sounds like running on 7 cylinders it sounds just like this .. I have a mopar ignition system with a chrome box this wasn't an issue before I tore everything apart. I also set my cam timing back to the 0 mark it was advanced but I doubt that has anything to do with this.  Give me some ideas as to what I could try tomarrow o correct this...   

[firefighter3931]

Check the timing....it should have at least 18* at idle and around 36* total. You could also have a lean condition or vacuum leak. Those heads are moving a lot more air so the carb will most likely need to be richened up. Pull a plug and see what kind of color you have on them....pay attention to the ground straps.



Ron

[mally69]

Plugs are a light tan, kinda like a brownish yellow.

[billhillytim]

I read on 440source that a longer plug is needed to get the plug end in the chamber since the aluminum head body where the plug goes in is wider/thicker.  I'm just a noob to this stuff, so I am only offering it up as a possibility.  Good luck with it.

[firefighter3931]

Plugs are a light tan, kinda like a brownish yellow.

Good ! Get a vaccum guage on it and see what you've got for readings. You can also pull sparkplug wires one at a time to see if the idle quality changes. If you pull a wire and the engine continues to run the same you've found the suspect cylinder.

Where is the timing set at ? idle timing ? total timing ?



Ron

[mally69]

10 or 12 degrees advance at idle

[firefighter3931]

10 or 12 degrees advance at idle

Bump it up....needs at least 18* at idle with that cam. 

After you readjust the base timing see how much total you have and where it stops advancing. 



Ron

[mally69]

10 or 12 degrees advance at idle

Bump it up....needs at least 18* at idle with that cam. 

After you readjust the base timing see how much total you have and where it stops advancing. 



Ron

  Ill post up tomarrow how things go.

[mally69]

Checked my ground wires and made sure all the plug were firing and checked everything. I set my timing at 18 degrees at idle. after messing with all of this I started it up and it runs fine pulls hard  It also revs up really fast  must have been a loose connection somewhere. Man those stealth heads made a huge difference.  But I do have another question my cam is degreed correctly I know that. But I am curious as to what symptoms an engine would have if the timing gears were off by 1 tooth. This isn't a factor with any of my builds or anyone else's  I am just wondering what would happen.

[Steve P.]

Off a tooth from crank to cam would advance or retard the cam. How many degrees I don't know.

Helped a buddy with a cam seal issue on his wife's Bubaru a few months back. He had bought this car used with many miles on it. Well we took it down to the cam seals to replace them, but in getting to that point we noticed that the drivers side cam was one tooth off when the Pass. side cam is dead nuts.

OK, so we change out the seals and put on new timing belts and move the driver cam to zero. He has mentioned that the car had always had a slight skip to it and I thought maybe we would cure that, but it actually made no noticeable difference..  Being a flat 4 I especially thought you would feel a big difference. It did seam to idle better, but nothing to note on the road.

Keep in mind this is a Subaru with 200+K on it and is more than likely NOT a very high compression motor. Just a grocery getter.

[firefighter3931]

I set my timing at 18 degrees at idle. after messing with all of this I started it up and it runs fine pulls hard  It also revs up really fast 

Told ya ! 

But I do have another question my cam is degreed correctly I know that. But I am curious as to what symptoms an engine would have if the timing gears were off by 1 tooth. This isn't a factor with any of my builds or anyone else's  I am just wondering what would happen.

a one tooth error will adjust the cam timing 10 + degrees....it would be very noticable. A 10* advance would probably have piston to valve clearance problems and not run very good on the top end. A 10* retard would kill any bottom end power and make the engine run like a slug off idle.

From your "seat of the pants" description it's safe to say you got it right. 



Ron

[mally69]

I set my timing at 18 degrees at idle. after messing with all of this I started it up and it runs fine pulls hard  It also revs up really fast 

Told ya ! 

But I do have another question my cam is degreed correctly I know that. But I am curious as to what symptoms an engine would have if the timing gears were off by 1 tooth. This isn't a factor with any of my builds or anyone else's  I am just wondering what would happen.

a one tooth error will adjust the cam timing 10 + degrees....it would be very noticable. A 10* advance would probably have piston to valve clearance problems and not run very good on the top end. A 10* retard would kill any bottom end power and make the engine run like a slug off idle.

From your "seat of the pants" description it's safe to say you got it right. 



Ron

Thanks    I degreed mine and it came out right. But that was somthing I always kinda wondered about.