LIFTER FIXED--BUT

[scamper]

Fired the 454 up today. Did the distributor timing thing, but it was backfiring lake crazy. Moved the distributor around, helped some. Finally got it to run at about 1000RPM. Has a miss in all ranges one maybe two cylinders. After the head came back from the shop I put R45T’s same plug I used to run in other 454’s but the man told me to set them at .45. Seems to me I used to set them at .35. Don’t know if this could cause the miss. On the bright side no lifter noise. Engine sounded good, no water in oil no water in the cylinders either I hope. Was getting a little tired near the end. You know your tired when you lay a wrench down, don’t move from the spot and go to pick it up but it ain’t there no more. So called it a day. I am wondering about the backfire and the miss. Any thoughts?

 

[scamper]

Re: LIFTER FIXED--BUT

Would you flip that over for me JB?<br />Thanks.

 

[JB]

Re: LIFTER FIXED--BUT

Done, Scamper. Gone to I/O

 

[LubeDude]

Re: LIFTER FIXED--BUT

Sounds like you may have some sparkplug wires mixed up or the distributor is installed incorectly! Or maybe a valve too tight!!<br /><br />LubeDude

 

[SS MAYFLOAT]

Re: LIFTER FIXED--BUT

You might have a couple of intake valves too tight. Check you valve adustment....SS

 

[scamper]

Re: LIFTER FIXED--BUT

Checked the wires, they are ok. The valves were all done the same way. Slack out plus ¾ turn. The rocker would still wiggle a little, but no slack on the rod. It only backfires when I start it. Once at 1000rpm all you feel is the miss. The backfire is coming through the carb. I guess it could be out the exhaust too but with all that water I can’t hear it.

 

[Buttanic]

Re: LIFTER FIXED--BUT

You need to put a timing light on it and see what you have.<br /><br />Buttanic

 

[scamper]

Re: LIFTER FIXED--BUT

Yea, thats for sure. But I still don't know about the miss. Could that be caused by a .45 gap on the plug. 454's have pretty good compression, is it possible with that large a gap and the compression the spark can't jump the electrode?

 

[airman]

Re: LIFTER FIXED--BUT

I pulled the wrong specs (heavy-duty vs. reg duty) once and over-gapped my plugs once. That engine missed a lot until I regapped.

 

[scamper]

Re: LIFTER FIXED--BUT

I guess I better hope that's what it is.

 

[Yepblaze]

Re: LIFTER FIXED--BUT

Generally the .045 gap is used with Late model High Energy Type Systems. That being said you could try regapping smaller just to take that issue out of the equasion.<br /><br />It still could have a tight valve at 3/4 turn if one of the lifters is stuck or just a bit sticky in bleeding down. Try doing a running adjustment with those squirt stoppers clipped on the rockers.<br /><br />Are both idle mixture adjustments reacting well during tuning procedure? Perhaps it could just be a dirty idle circuit on one side?

 

[rodbolt]

Re: LIFTER FIXED--BUT

hello<br /> scamper<br /> double check all your wires. check the plugs remember when I posted the the 3/4 turn down from zero lash set a preload on the lifter plunger? this is what I wished to avoid. if you have a lifter plunger that is stuck in the full up it will hold a valve off the seat. check all the wires if all are ok do a compression/leakdown and see if the valves are sealing. I use the 3/4 turn method but I also check to make sure I get at least a .05" preload on the plunger. that is why I said do it with the intake off. I have been bit by this years ago.<br /> good luck and keep posting

 

[BRIAN03]

Re: LIFTER FIXED--BUT

18436572

 

[scamper]

Re: LIFTER FIXED--BUT

Yepblaze I’m going to reset at .35. Pulled a plug out the other engine and that’s what it was.<br />Rodbolt, did exactly as instructed. At least to the best of my ability. The thing only backfires when I start. Will check wires again. You might get a chuckle out of this. Your instructions on dropping the distributor in, if it didn’t go down all the way dtc and rotate the engine twice. Did that and the distributor went right in. Decided I would check the valve operation as well. Since it was easier to watch the rotation of the engine by looking at the distributor that’s what I did. Started dtc, if I rotate the engine a little passed 180 at this point we should be at the exhaust stroke. Well rotated the engine until the distributor was a little passed half rotation. Went to check the vales knowing that the exhaust valve should now be open and intake closed. Horror of horrors the exhaust was closed and the intake was open. Just for sport rotated another half turn on the distributor and now both valves were closed. I couldn’t believe that I could screw the cam up without my even touching it. But there it was on the exhaust stroke the intake was open. Believe it or not, did this for about an hour. Each time same as before. The last time a was bumping the engine around got half was around on the distributor and decided to look were the time mark was. Half way around the mark should be at the bottom Oh no what have I done the mark was at the top. Went as far as to check if for some reason I had two marks the one at the top and one where it was supposed to be on the bottom. Nope just one. Oh wait a minute scamper, one rotation of the distributor = two rotations of the engine. Doooh! Bumped it around a quarter and there it was, exhaust valve open. And you want me to check to make sure I get at least a .05" preload on the plunger? <br />BRIAN03, that’s what I got.