Rebuilt 360 won't fire up...

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tedlovesjeeps71
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Re: Rebuilt 360 won't fire up...

Post by tedlovesjeeps71 »

ColoWagon wrote:Order of events when I can get time in the garage.
Remove valve covers.
Remove spark plugs to make the engine easier to turn by hand.
Push down on each rocker to see if any are loose or "wiggly".
Look for any bent pushrods.
Manually turn engine watching the rockers.
Pattern should be in firing order with the Intake moving first and then followed by the exhaust...I think.

What am I missing?

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Nothing? Intake opens then closes. That will be your compression stroke. Bear in mind that it's the second rocker on the driver's side from the front. 1st is exhaust. When it's at TDC, both in and ex should be closed and you may feel a little play in the rockers as they are "relaxed".


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babywag
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Re: Rebuilt 360 won't fire up...

Post by babywag »

babywag wrote:if it has been grinding away a lot w/o running, that's a camshaft killer/death sentence.
#1 culprit in cam failure, need to STOP trying to start it and find out why it wouldn't run.
Tatsadasayago wrote:Your camshaft may have a lobe that didn't wear in properly and went flat due to all the cranking.
You really need to stop running the engine, cranking the engine, etc. and find the problem.
Unless you were/are able to run the engine for ~20 minutes already, to properly break in the cam, it is already toast, or will be shortly.

You can measure valve lift manually cranking engine in a few ways.
With a good ruler, marking the pushrods.
Better would be grab a dial indicator & base from HF.
Measure lift, and if you have a cam/lifter problem it will present itself.
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ColoWagon
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Re: Rebuilt 360 won't fire up...

Post by ColoWagon »

Tacos anyone?

Still diggingImageImage

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Tatsadasayago
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Re: Rebuilt 360 won't fire up...

Post by Tatsadasayago »

That would surely cause the engine to sound like a cam lobe went flat. The rocker shouldn't have done that if the stud is slotted. Many aftermarket rocker kits require you employ purshrod guides. Your setup may need them to keept things straight, but also to get your arm geometry correct.
What brand/part number are they?
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ColoWagon
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Re: Rebuilt 360 won't fire up...

Post by ColoWagon »

Tatsadasayago wrote:That would surely cause the engine to sound like a cam lobe went flat. The rocker shouldn't have done that if the stud is slotted. Many aftermarket rocker kits require you employ purshrod guides. Your setup may need them to keept things straight, but also to get your arm geometry correct.
What brand/part number are they?
Edelbrock lifters...comp cams studs and rockers...let me get the numbers. I have the "slotted" heads from a stamped 72 on here and not the 88 larger hole. I got the guides but couldn't get them to fit and was told they were not needed on this year...either way...getting to the bottom of it all is nice.

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Re: Rebuilt 360 won't fire up...

Post by ColoWagon »

Passenger side...2 more bent. 1 at the top to easily pull. The other bent sharp at the bottom...cant pull it out. Anyone have any sage advice before I pull the manifold to fish it out? May be worth pulling just get a good inspection after 3 bent rods...thoughts?

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Re: Rebuilt 360 won't fire up...

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Gotta have a pic!Image

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Re: Rebuilt 360 won't fire up...

Post by ColoWagon »

Comp Cams Pushrod Guideplates AMC V8 - 4851-8

Comp Cams high energy studs. 4500-16

Magnum Roller Rockers AMC V8 - 1442-16



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tedlovesjeeps71
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Re: Rebuilt 360 won't fire up...

Post by tedlovesjeeps71 »

Probably isn't a bad idea to pull the manifold and inspect each lifter as well. That sucks it's so jacked up. Be interesting to hear what the cause was.


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Tatsadasayago
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Re: Rebuilt 360 won't fire up...

Post by Tatsadasayago »

Definitely needs guideplates. Other year heads have a much narrower slotted holes in the head that acts like guide plates. The plates raise the stud the thickness of the plate and should provide correct rocker geometry. If the stud is designed to be used with guide plates and they aren't used, you could get into a situation where the lifter piston is completely bottomed out...leading to bent pushrods.
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Tatsadasayago
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Re: Rebuilt 360 won't fire up...

Post by Tatsadasayago »

At this point I would suggest you roll the engine to max lift and check the clearance between the valve spring coils and also the valve retainer to valve guide boss. If you are running a higher-than-stock lift, 1.6:1 rockers, stock springs and add more lift by not using the guide plates...that's a recipe for bad things to happen :(
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ColoWagon
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Re: Rebuilt 360 won't fire up...

Post by ColoWagon »

4 bent so far. Intake off and look what I found!
Question: is that all of it? This was the lifter that sharply bent the pushrod low.Image

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Re: Rebuilt 360 won't fire up...

Post by ColoWagon »

Will be pulling all rods and replacing. Fyi before suggested.

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Tatsadasayago
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Re: Rebuilt 360 won't fire up...

Post by Tatsadasayago »

Woah, wait up...
Did you take the lifter apart? Where did the disc and check at the left come from?
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Re: Rebuilt 360 won't fire up...

Post by ColoWagon »

When I pulled the Intake the two pieces were laying on the top of the engine right by the lifter. Wondering if there are more parts. Have not hit up the google yet. If no then i can assume no metal down below. If yes well....crud.
This is all sorts of fun let me tell you. Feel like I built a box and the instructions missed the part about it being Pandora's!

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memo43
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Re: Rebuilt 360 won't fire up...

Post by memo43 »

Drain the oil and cut/ inspect the oil filter for signs of metal particles.
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ColoWagon
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Re: Rebuilt 360 won't fire up...

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Google makes it look like just the two pieces but with everything else that is a good idea memo!

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Tatsadasayago
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Re: Rebuilt 360 won't fire up...

Post by Tatsadasayago »

Those two pieces are the check disk and cover for the bottom of the lifter piston. They should never get out unless the lifter clip is removed and piston taken out. Major sign of catastrophic lifer failure. Sorry Bro, but it looks bad from here.

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ColoWagon
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Re: Rebuilt 360 won't fire up...

Post by ColoWagon »

Tatsadasayago wrote:Those two pieces are the check disk and cover for the bottom of the lifter piston. They should never get out unless the lifter clip is removed and piston taken out. Major sign of catastrophic lifer failure. Sorry Bro, but it looks bad from here.

Image
Oh yeah all sorts of Fun! Clip is still there...slightly bent to allow the passage of the parts. So are there more parts down in the engine? Should I pull the engine and tear down and inspect everything? Or is it as "simple" as replace lifter (maybe all of them), pushrods, install guideplates and try again? Still like the idea of checking the oil so throw that in there. If there are metal parts can I fish with a magnet in the pan? Really hate dropping the pan but if pulled no biggie. Thoughts? ( other than "Damn, he is screwed!)

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Tatsadasayago
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Re: Rebuilt 360 won't fire up...

Post by Tatsadasayago »

If I was in your position, I would pull the engine and completely disassemble and check everything. I think you got some bad info and anything less is a roll of the dice. This would be a good time to invest in a digital dial caliper, feeler gauges and a dial-indicator. I kind of suspect many things went wrong with this rebuild. No offense toward you intended.
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