Noisy 304 and Crank Marks

7

77SSII

Member
Hi all,
this is maybe my 3rd thread on this "newly" rebuilt 304. It was done 11 yrs ago and sat while I finished the truck.
The motor has about 1500 miles on it and started making noise after a long highway trip after the motor had accrued about 500 miles.

I removed the timing cover and oil pan. The following pix are what I found. The counter weight adjacent to the #3 piston has some shiny parts to it where none of the others do. Again the motor is 11 years old and there is some oxidation but not on the shiny areas. Any thoughts if this could be making the noise?

Here are the pix:
https://picasaweb.google.com/107722218277971181704/crankmarks#

I have some video of the noise:
youtube - massachusetts2010's channel

youtube - massachusetts2010's channel

I haven't pulled the motor to check on the rear cam bearing.
I do have great pressure (50 psi) using a drill at the head feeding the rockers, I do have both oil galley plugs behind the timing cover.
Thanks.
 
Hi Mark. I added some notes to two of your photos. If possible check the items I recommend and the photo view from the bottom.

That rubbing looks more like it came from the crank grinder. The rod adjacent to the rub Mark really can't get close enough to rub with the narrow beam and wide big end bearing boss.

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12980d1300718402-noisy-304-crank-marks-005mu.jpg
 

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If there was any skirt/piston interference, it would go away in short order like 5 seconds. You can see the skirts from the bottom :icon_eek: :devil: no pun intended. Do a quick once over. You would see it clear as day.

Listened to your videos again ans still hear only valve noise. Remember only the rear cam bearing was anything to do with lifter gallery oil feed. The front bearing oils the timing set.
 
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How about the rocker arm shafts? Were they new or opened up and cleaned? Sounds about like what you would expect to hear if they were plugged with muck or otherwise not oiling the rockers.
 
77ssii said:
well, finally pulled the motor and broke it down a little.
Here are some pix. Robert had mentioned rear cam bearing a while back. The guy who assembled the motor 11 years ago is coming over tomorrow I think to break it down a little more to see what we see...
https://picasaweb.google.com/107722218277971181704/enginenoisedissasembly511#

Both heads have v304 in the castings...pretty cool.
Click to expand...

From the photo, the rear cam bearing looks like it is at the right depth. Question remains whether it is clocked correctly.

I do see odd marks on the pistons and on the heads. If you could before you tear it down any further rotate the engine slowly and see how high up the piston tops get to the deck surface. In the hole or out of the hole (above the deck). If possible a measurement if out of the hole.

Also listened to your video again and definitely flat lifters. Very possible it wiped the cam bearings or spun one.
 
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The guy who assembled the motor came by today and we tore it down to a bare block. I was dragging 4 pistons.....2, 1, 3 & 5.
All the bearings are good and in position. He said there is a lot of carbon build-up on the tops of the pistons for 1k to 1.5k miles. My Holley 500cfm 2300 series carb has I believe 71 main jets. The egr circuits in the intake are full of fuel. He also said that when the shop was open, the machinist like to run tight tolerances 0.003" in the cylinders. The assembler would have preferred 0.005" as he said the block has really thick walls expansion wise.
We're going to get the block re-honed and buy new pistons (0.060" over and hyper-eutecktic (?)). He also said the lifters look like they have too much wear for 1500 miles. He said they look almost like the motor was cranked dry. They aren't concave but have an outline of a circle in the middle.
So honing, pistons/rings, lifters and a gasket set.
A 304, 0.060" over, mild cam with a compression bump, stan's tri-y headers and exhaust porting. Would a stock 2bbl carb be sufficient?
He also mentioned a former Holley engineer that started a company in florida building cusotm metering blocks or custom tuned carbs?????

https://picasaweb.google.com/107722218277971181704/enginenoisedissasembly511#
 
Your old pistons look like they are already hypereutectics. They are perfect at .003 clearance. Factory is .003 on cast slugs. Eutectics can run 30% less clearance.

Second the non symetricall wear patern on those pistons is not what I would expect from a clearance issue. It would need to have the same galled area
180* around from that location. Suspect rod assembled the wrong way. What does the other side of the piston look like?

What do the cam bearings look like? Nothing you are showing is the root cause for your noise.

Also noticed in your other photos that the head gaskets are leaking. Might point to an over heat event.
 
You need to read michael mayben's posts on the Holley 2300...

The 500cfm 2300 is "way too much" carb for your engine (probably the source of the "extra" carbon on the pistons).

The 350 cfm 2300 (0-7448) is considered the better carb -- especially for a 304...
 
I'm gonna say some/all of the rods are installed
"backwards". Review the service manual for correct rod-to-piston assembly instructions.

You have an internal water leak based upon the head gasket and block rot. That one piston assembly is showing much engine coolant has been floating in that hole!

The rear cam bearing did not have it's two sides radiused to blend into the oil passage cutaway, though the installed depth appears to be ok. But we can't see the rest of the bearings, it is #2 and #4 that are the critical items for oiling the rocker shaft assemblies.

Three of the pistons I can see in your pic show major signs of seizure. If all the pistons have that type of seizure showing, then again, this engine was not properly clearanced when it was machined and/or the pistons (some or all) May have been installed "backwards".

Overall, I see this as a very poor engine assembly process from years ago. Every engine from any manufacturer has definite assembly points that must be adhered to. These sv engines are not chryfordrolets and can't be simply tossed together like one. They have unique assembly points that must be addressed.

No way a Holley list 4412 carb can be used on this engine! No way to make the metering block "right" as that goes along with all the other orifices in the carb body. It is a completely wrong carburetor for any ihc-produced sv engine. These engines need no "special" carburetor in any form, simply a properly reconditioned or new unit that is jetted properly will run forever. And #71 main jets???? That is huge. With the proper 2300 carb I'd jet it #64 if you are running e10 fuel.
 
I spoke with 77ssii at length yesterday and the rods are ok. The scoring is still from an unknown event. The engine has a head gasket leak and possible over fueling.

The rear cam bearing has been wiped smiler to Jesse bartons and the oil flow restricted significantly. So based on that we know the lifter banging cause.

He will be going with an oem IH 2 bbl per my recommendation at this time and probably having it rebuilt by ihon.

He is going to post some more pictures time permitting.
 
Thanks Robert,
I was typing this when your reply was submitted.

So I have more pix of the cam bearings and a bad #5. The cam I'm not sure. The #5 bearing surface has 3 imperfections on it that catch my fingernail. 2 on 1 side near an oil passage and the other on the opposite side near the other oil passage. The cam is a schneider w/a 256-2h grind and a rocker ratio of 1.6. The cam card is on one of my online albums.

https://picasaweb.google.com/107722218277971181704/teardownasofmay132011#

The #5 bearing has about 180 degrees of significant wear. I can feel it easily w/my untrained fingers. The grooves are largest at the oil hole and tapers the farther away from that hole they get.
How should the #5 bearing be radiused? Out the back of the block that goes to the lifter galleries?

How would I tell if the pistons are on the conrods incorrectly? The chamfered sides of the conrods go against the counter weights on the crank. The pistons all have a "top" arrows and are correct.

I am going to send that stock carb in after I speak w/Jeff today. If $ where no object what would you guys recommend for a carb? 304 bored 0.060" over, mild cam, exhaust ports ported slightly (air injection plugs installed and ground down bungs), dui and stan's tri-y headers.
Thanks!
If not for Robert and IH Parts America yesterday I probably would have put the same cam/bearings in and the same carb and would have been back hear again w/enging noises!!!!!!!!!!!
I've also read michael saying he hears it all the time about shops w/really good reputations rebuilding an sv so it must be done correctly. I kept reading and saying "yeh but not my shop, those guys know a lot about motors...."
you guys are incredible! Thanks again!
 
I'll throw in my two cents worth. I have not talked to 77ssii nor do I want to take away from anything Robert or michael has posted as any of these are possibilities. From looking at the pictures and knowing that the carb was too big for the application I would say one of two things possibly happened. Upon initial start-up and break-in of the engine it either got too hot or all the raw fuel that oversized carb was dumping washed the cylinders/pistons of oil.

I've also seen where pistons that looked like this sounded like an engine with bad lifters but all it was were the pistons slapping the cylinder walls. A few of you might remember the Scout traveler I once owned called "the clacker". That thing sounded like it had bad lifters. After tearing it down to the cam and replacing the lifters it still made the same racket. After another tear down all the way we found all eight pistons were damaged. Still ran good but again it was a noisy engine.
 
Mark,
I snooped your photos before you posted and the rods are correct.

Link to Jesse b. Cam bearing photo. http://www.forums.IHPartsAmerica.com/39137-post41.html

Your bearing doesn't look nearly as bad. Hard to tell from the photo but seems like I can see the steel layer on your bearing.

Jeff did you listen to the video posted earlier. Might help to have another ear on the noise. I hear valve noise but you've heard what you are describing.
 
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Thanks Jeff,
that actually makes me feel better!
The head gaskets had a quick look-over and nothing was said about them looking suspect. The amount of carbon build-up on the pistons w/maybe 1.5k miles and some actual sniffing around is what made the assembler come to his conclusion. I didn't see anything coming out the tail pipes and I really didn't smell anything "strong". I have a small coolant, x-fercase and a good sized power steering fluid leak. I left "artwork" on the ground if I was parked long enough.
The motor ran strong and stated on the first 1/2 crank.
Obviously my only concern is that this doesn't happen again and I don't mind doing this in a non-scientific, multiple variable way. It will obviously have new head gastkets and cam bearings (maybe a cam too) but also I'd like to use my stock carb. Where should I send it to you guys for inspection/rebuilding?
 
Robert kenney said:
Mark,
I snooped your photos before you posted and the rods are correct.

Link to Jesse b. Cam bearing photo. http://www.forums.IHPartsAmerica.com/39137-post41.html

Your bearing doesn't look nearly as bad. Hard to tell from the photo but seems like I can see the steel layer on your bearing.

Jeff did you listen to the video posted earlier. Might help to have another ear on the noise. I hear valve noise but you've heard what you are describing.
Click to expand...

No I didn't listen to the video but will.
 
The 22xx oe carb is a total smog carb. They're problematic and not at all tunable. Since you are sinking money and performance parts into this engine, you May as well not waste your time with that stocker. As mentioned, the Holley 2300 list 0-7448 is the preferred choice as opposed to the 4412 that you have now. If you must rebuild the 2210, mayben is the one who performs that service.
 
So the motor has been re-honed and cam bearings put in. When he was installing the cam bearings he was also fitting the cam. When he got to #3 he said it started to feel a little tight (he started w/#5, then 4, etc.) when he got #2 in he stopped. He measured the bearing holes in the block and #2 was under tolerance. He said he has a book w/bearings by application to get the diameters. He is now going to line bore the cam holes. The #2 bearing looked a little worn upon tearing the motor down and has been bothering him since. He said some blocks get "core shift" after machining then running for a short while as they go thru the normal heat cycle.
He also mentioned pontiacs and chryslers having cam bearing holes out of spec from the factory way back and they would machine the cam bearings after assembly if they were out of wack.
Has anyone heard of this in IH motors?
 
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