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-   -   First motor start, terrible knocking (https://67-72chevytrucks.com/vboard/showthread.php?t=719271)

Marshy 10-03-2016 11:50 AM

Re: First motor start, terrible knocking
 
Quote:

Originally Posted by Lefkada (Post 7731706)
I'm having trouble figuring out the head gasket thickness. I used the heads gaskets from this Fel-Pro KS2600 kit: https://www.summitracing.com/parts/fel-ks2600/overview/

Those have the fel-pro 7733PT-2 gasket and is .039-.040" compressed.

Let us know the cylinder head casting #'s when you get a chance.

Last week there was a guy asking if he could bolt on a pair of Vortec heads and replace a set of 882 heads. I told he he could but needed to consider the change in compression because the vortec heads were 64cc's vs the larger 74cc's of the 882 heads. I gave an example with flat top pistons with -4cc valve reliefs and a .040" quench clearance the compression was 9.5:1 with the larger heads but jumped to something like 10.5:1 (IIRC) by bolting on the smaller heads. The example I chose sounds like it could resemble your build but obviously just a guess because you don't know your deck height. It wouldn't be uncommon to zero deck a block and run flat top pistons and that head gasket like you have. Just something to be aware of.

Lefkada 10-03-2016 12:22 PM

Re: First motor start, terrible knocking
 
Quote:

Originally Posted by Marshy (Post 7731734)
Those have the fel-pro 7733PT-2 gasket and is .039-.040" compressed.

Let us know the cylinder head casting #'s when you get a chance.

Last week there was a guy asking if he could bolt on a pair of Vortec heads and replace a set of 882 heads. I told he he could but needed to consider the change in compression because the vortec heads were 64cc's vs the larger 74cc's of the 882 heads. I gave an example with flat top pistons with -4cc valve reliefs and a .040" quench clearance the compression was 9.5:1 with the larger heads but jumped to something like 10.5:1 (IIRC) by bolting on the smaller heads. The example I chose sounds like it could resemble your build but obviously just a guess because you don't know your deck height. It wouldn't be uncommon to zero deck a block and run flat top pistons and that head gasket like you have. Just something to be aware of.

I just pulled off the valve cover.

Original head casting number: 3998991

New heads given to me by machine shop: 3986388

Lefkada 10-03-2016 12:24 PM

Re: First motor start, terrible knocking
 
I will start going down that checklist, suprachrgd82. Thank you.

haycatcher 10-03-2016 12:39 PM

Re: First motor start, terrible knocking
 
I had a valve get stuck in the guide once after an engine rebuild and waiting a few months to fire engine. The valve bent and hung open creating dead cylinder condition. Had to pull head and replace valve and the guide to remedy. check compression to see if a cylinder is way off from others.

Was the water pump replaced? Someone advised check ancillary components or remove them from equation when restarting engine.

Marshy 10-03-2016 12:47 PM

Re: First motor start, terrible knocking
 
Quote:

Originally Posted by Lefkada (Post 7731771)
I just pulled off the valve cover.

Original head casting number: 3998991

New heads given to me by machine shop: 3986388

Ok, they are the same CC so should not be an issue but worth the time to check.

If you are looking for a boroscope and don't want to spend a lot of money you can buy ones on ebay that connect to your phone. Check this out...
http://www.ebay.com/itm/3-5-5M-7mm-A...nq6Jx8qOrBmASw

Gmc.guy 10-03-2016 01:29 PM

Re: First motor start, terrible knocking
 
Check your dipstick and fuel pump pushrod

Lefkada 10-03-2016 04:09 PM

Re: First motor start, terrible knocking
 
Quote:

Originally Posted by Gmc.guy (Post 7731835)
Check your dipstick and fuel pump pushrod

I have an electric fuel pump so I removed the fuel pump pushrod and installed a plate over the engine opening.

Lefkada 10-03-2016 04:10 PM

Re: First motor start, terrible knocking
 
Quote:

Originally Posted by haycatcher (Post 7731786)
I had a valve get stuck in the guide once after an engine rebuild and waiting a few months to fire engine. The valve bent and hung open creating dead cylinder condition. Had to pull head and replace valve and the guide to remedy. check compression to see if a cylinder is way off from others.

Was the water pump replaced? Someone advised check ancillary components or remove them from equation when restarting engine.

Boy, I really hope that isn't my issue. I will check compression next if I don't find anything wrong with the valve adjustments.

I did not replace the water pump. Just cleaned it, painted it and put it back on.

BILT4ME 10-03-2016 04:18 PM

Re: First motor start, terrible knocking
 
Are all the bolts tight on the torque converter? It sounds to me like a rotational issue, not a linear "hammering" issue.

Also, do you have a stethoscope to check location of the noise? I know you don;t want to run it any more than you have to, but in order to find the problem.

I think a TC bolt is loose just a bit (or all of them) and they are hitting the lower lip of the back of the block. I think this because it has kind of a "ratchet" sound to it.

Good luck.

geezer#99 10-03-2016 04:53 PM

Re: First motor start, terrible knocking
 
When you adjust the lifters again, remember to do the 'wiggle' the pushrods and not the 'twist' the pushrod method.

Lefkada 10-03-2016 06:22 PM

Re: First motor start, terrible knocking
 
Alright, I checked the flex plate and torque converter - both feel solid.

I loosened all rockers up by 1/2 turn and ran the motor. The sound was still there, so I crawled underneath and put my ear right up to the oil pan (I have no stethoscope) and could definitely hear something knocking inside. Looks like I'll be pulling the pan now.

I really appreciate everyone's guidance on this so far. :)

BILT4ME 10-03-2016 06:41 PM

Re: First motor start, terrible knocking
 
You can use a long screwdriver and press it to your ear and touch it to different areas on the block, valve cover, oil pan, etc.

Did you do anything with the oil pump while you had it out? Did it suck up some debris in the oil pan and the pump screen fell off?

It does NOT sound like the crankshaft is hitting anything and does not sound fast enough to be related to the cam (it turns half the speed of the cranks).

Distributor not seated
Starter dragging or rubbing the flywheel
Timing chain rubbing the cover
Oil pump shelling out
Accessory (AC Pump, Alternator, PS pump) dragging/rubbing/hitting/dry
Transmission pump dry (Is there fluid in the transmission?)
Parking Pawl dragging inside the transmission
Transmission in gear due to improper adjustment....
Too long of a bolt in the TC cover dragging on the teeth of the TC


Just spitballing to throw out ideas.......

Lefkada 10-03-2016 07:11 PM

Re: First motor start, terrible knocking
 
Quote:

Originally Posted by BILT4ME (Post 7732137)
You can use a long screwdriver and press it to your ear and touch it to different areas on the block, valve cover, oil pan, etc.

Did you do anything with the oil pump while you had it out? Did it suck up some debris in the oil pan and the pump screen fell off?

It does NOT sound like the crankshaft is hitting anything and does not sound fast enough to be related to the cam (it turns half the speed of the cranks).

Distributor not seated
Starter dragging or rubbing the flywheel
Timing chain rubbing the cover
Oil pump shelling out
Accessory (AC Pump, Alternator, PS pump) dragging/rubbing/hitting/dry
Transmission pump dry (Is there fluid in the transmission?)
Parking Pawl dragging inside the transmission
Transmission in gear due to improper adjustment....
Too long of a bolt in the TC cover dragging on the teeth of the TC


Just spitballing to throw out ideas.......


I didn't remove the oil pump but did remove, clean and reinstall the oil pump screen. I guess we will find out if something fell apart after I pull the pan tonight.

I have a little over 4 quarts of ATF in right now as I read you should not put all 10 quarts of ATF in, but start with around 4qt, shift through the gears, and then put the rest of the 6qt in. I hope this is correct.

Boog 10-03-2016 07:46 PM

Re: First motor start, terrible knocking
 
I don't know about the differences between those two head castings but could it be the rockers are binding with the valve rotators? That's an angry sounding noise. It stands to reason the only changes made were the head exchange so this noise should be related to the heads.
How is the oil pressure?

Lefkada 10-03-2016 08:06 PM

Re: First motor start, terrible knocking
 
Quote:

Originally Posted by Boog (Post 7732230)
I don't know about the differences between those two head castings but could it be the rockers are binding with the valve rotators? That's an angry sounding noise. It stands to reason the only changes made were the head exchange so this noise should be related to the heads.
How is the oil pressure?

I looked up the head castings (http://outintheshop.com/faq/casting/heads.html) and there seems to be no difference in specs. One was used on 307's/350's and the other used on just 350's.

Oil pressure reads high on the stock gauge.


I just added 2 more quarts of ATF (I'm at 6-7qt now) and the sound remained, so I don't think it's the tranny pump.

Boog 10-03-2016 08:35 PM

Re: First motor start, terrible knocking
 
Oil pressure is higher than before the head swap?
Have you run the engine with the valve covers removed to see that all the valves are moving up and down an equal amount and that oil is getting to the top of the rockers?
I don't believe that noise is tranny related.

Lefkada 10-04-2016 11:57 AM

Re: First motor start, terrible knocking
 
Quote:

Originally Posted by Boog (Post 7732288)
Oil pressure is higher than before the head swap?
Have you run the engine with the valve covers removed to see that all the valves are moving up and down an equal amount and that oil is getting to the top of the rockers?
I don't believe that noise is tranny related.

Sorry for the confusion. I meant that the stock gauge reads oil pressure as "High". I'm not sure what oil pressure was like before the rebuild.

All rockers seem to be getting good oil flow.

Marshy 10-04-2016 12:22 PM

Re: First motor start, terrible knocking
 
Quote:

Originally Posted by Lefkada (Post 7732908)
Sorry for the confusion. I meant that the stock gauge reads oil pressure as "High". I'm not sure what oil pressure was like before the rebuild.

All rockers seem to be getting good oil flow.

Did you turn the motor over without plugs in it yet? I'm wondering if maybe you should take the plugs out and turn it over by hand to see if you can feel where it might be "catching" and listen to the possible source of noise. That will eliminate all other background noise. Good luck.

If you dropped a valve it would be hammering away. The plug might give you some insight if its off color of has metal flake on it.

Lefkada 10-05-2016 04:49 PM

Re: First motor start, terrible knocking
 
Well now things have gotten bizarre. I'm working on removing the oil pan right now. I had 5 bolts out, and while removing the 6th bolt, untainted coolant begins leaking out of the bolt hole.

I have no idea if this is a secondary issue, related to a bad gasket or something, but this is strange. The oil doesn't look to have coolant mixed in, and the coolant doesn't seem to have any oil mixed in.

Lefkada 10-05-2016 04:56 PM

Re: First motor start, terrible knocking
 
Quote:

Originally Posted by Marshy (Post 7732929)
Did you turn the motor over without plugs in it yet? I'm wondering if maybe you should take the plugs out and turn it over by hand to see if you can feel where it might be "catching" and listen to the possible source of noise. That will eliminate all other background noise. Good luck.

If you dropped a valve it would be hammering away. The plug might give you some insight if its off color of has metal flake on it.

I haven't cranked it without the plugs in yet, but I will give this a try.

Jason Banks 10-06-2016 08:10 AM

Re: First motor start, terrible knocking
 
How bent was the one pushrod? If the cam was messed up underneath that lifter and you put in a new pushrod. Whoever suggested running with the valve covers off could be on to something.

Shinysideup 10-06-2016 08:43 AM

Re: First motor start, terrible knocking
 
Quote:

Originally Posted by Lefkada (Post 7734092)
Well now things have gotten bizarre. I'm working on removing the oil pan right now. I had 5 bolts out, and while removing the 6th bolt, untainted coolant begins leaking out of the bolt hole.

I have no idea if this is a secondary issue, related to a bad gasket or something, but this is strange. The oil doesn't look to have coolant mixed in, and the coolant doesn't seem to have any oil mixed in.

Sounds like a spun bearing from the beginning. Now you confirmed noise from bottom end and coolant in oil. Good thing top end already rebuilt, now freshen up the lower end and have a tight motor again.

Marshy 10-19-2016 09:53 AM

Re: First motor start, terrible knocking
 
Any update?

mcbassin 10-19-2016 11:19 AM

Re: First motor start, terrible knocking
 
That video was hard to watch. Unfortunately, it sounds like some catastrophic damage to a piston or rod bearing or something. I'm hoping to hear good news but dang...


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