New Small Block Stroker Engine Noise

[340sFastback]

I don't want to run it any longer with this noise. If there was an exhaust leak that made this much noise I would think there would be carbon marks some where and there aren't any. When I had the headers off to get the flange beads thickened up I looked them over and no signs of bad welds were found. I'll pull them off again and take a closer look. At this point its time to start taking things apart and looking for the problem. Could it be a bad weld in the header down where the tubes meet? Maybe. I'll be pulling the headers soon and most likely keep taking it apart and pulling the engine.

Ryan at Shady Dell has listened to all the videos and he told me if it were his engine he would get it on the stand, take it apart, and look everything over.

 

[340sFastback]

Its pulled. Left engine up right and pulled oil pan down. No metal, none, was found in the pan or in the oil. No silver traces, no small specs, nothing but oil in there. I was pretty shocked. And nothing is hitting anything in there. The crank is at least 1/8" away from the crank scraper and there are no signs anything is hitting there. All bolts were tight. Nothing is discolored. Nothing is scraped. Every thing looks perfect in there. When I turn it around with no TV or radio on it is silent.

I removed one of the rocker shafts. The rockers don't hit the retainers, the push rods don't hit the heads, the push rods are not bent, all parts look like new. The roller tips do not come close to rolling off the valves tips either. I'll be removing the rocker shaft and push rods on the other side tomorrow but I am sure there won't be any problems found. All that stuff was heavily scrutinized during the build.

I plan to pull the heads tomorrow and look for signs of valves hitting pistons. That was checked during the build but I need to look everything over.

I'll probably pull the timing cover and see if anything is going on in there. I am sure its fine but I'll look any way.

I pulled the torque converter out of the trans. It spins nice and free, the pump tangs don't look damaged, no abnormal scoring on the torque converter snout. Nothing looks fishy there.

The welds on the passenger's side header look fine when you look in where the collector is. No carbon marks any where on the outside. If I don't find a problem I probably will pressure test it just to rule it out but I don't think anything is wrong with that header.

I think the noise sounds like valve train. The cadence sounds just like its in time with the valves. Most other people feel the same way. I am wondering if the springs are not strong enough to control the lifters and they are bouncing off the cam and smacking when they land??? Sure sounds like it, echoing in the oil pan and loud under the car. Noise does not seem to be out where the rockers reside.

One other thing, the engine quiets up a lot when it gets warm, and I mean a lot. And is much noisier when its cold, much nosier. It definitely changes depending on engine temp so it has to do with something expanding. Valves smacking pistons maybe? Aluminum heads expanding and provide more clearance?

 

[pettybludart]

I,ve been following your thread and you,ve done everything possible.It could be your valves?After watching your last video,you can really hear the noise come from heads and travel down your exhaust.Is there any wrenches stuck in your shop walls??From throwing in frustration.LOL!!Hope you figure it out before Christmas.Good Luck!!:clock:

 

[crackedback]

Are the pushrod holes clearanced?

On mine the holes had to be oval to clear. The Roller lifters make the compound angles worse than hyd or solid lifters because of the height.

If they aren't clearanced, pull the pushrods and look for interference marks in the area just above the deck surface.

 

[340sFastback]

Are the pushrod holes clearanced?

On mine the holes had to be oval to clear. The Roller lifters make the compound angles worse than hyd or solid lifters because of the height.

If they aren't clearanced, pull the pushrods and look for interference marks in the area just above the deck surface.

You are completely correct. The roller lifters stick up higher and change the angle. During engine assembly I had to open up the push rod holes in the head on the lifter valley side. I spent close to a day grinding, checking, grinding because I wanted to be sure no contact would be made between head and push rod. All the push rods on one side have been pulled and no marks are visible. I'll be pulling the heads tomorrow so I'll be checking the other side but I am sure the push rods won't be hitting on that side either.

The noise sounds like its in cadence with the valve train but so far that all checks out.

If I pull the heads and there are no signs of valves hitting pistons I don't know what to say then. During assembly I checked piston to valve clearance on #1 cylinder after I degreed in cam and there was lots of room.

The good news is so far my engine looks perfect inside so that is a very good thing. And it ran good too, great oil pressure, no blue smoke, sounded great out the tail pipes, idled smoothly, and rev'ed hard and strong. But the noise was very loud so there is a problem some where. I just haven't found it yet. But the list of things not making the noise is starting to get pretty long.

 

[camd64]

I have been following this post and its starting to drive me nuts. it doesn't seem like its anything like a bolt hitting because you would think all that run time would have worn it down and at least made the noise less noticeable. im leaning towards the valvetrain but am thinking it could be a roller or trunion issue? that might explain why the sound is very audible down low too since it has a straight path to the oil pan.

 

[green1]

those pushrods seem to be an an extreme angle.

 

[fishy68]

those pushrods seem to be an an extreme angle.

All Mopar small blocks with roller cams are at that angle.

 

[ramcharger]

Come on in and pull up a chair and help us figure this M..F'N thing out!

Hell I'm trying to crank a motor without a torque converter for crying out loud!! (my last post above) geeezz!

If that is normal I would hate to hear abnormal!

Thanks Ax. This is driving me nuts too! When my RC started to lose a lobe I knew as soon as I brought all cyl to TDC on the compression stroke and one rocker was loose. One lobe lost .030 and I could hear it easy and still was not as bad as I heard on this video.

Fishy is right about the SB pushrod angles and he has done a real life study (with the same cam I trashed) and the real deal is that the valves see a very, very minor lift reduction due to pushrod angles. IIRC, it's just a few thousandths. If you want to see crazy angles, check out a real stock ford 351C. Great heads and rockers are 1.73 stock. Back in the day, mine used to spit pushrods out @ 5000 rpm every time till I upgraded the valvetrain.

Crank scraper is still my culprit of choice in this issue....

 

[mullinax95]

Well I know if I was you 340 I more than likely be exhausted. Glad you got it out so you can get a better look and everything.

Crank scraper is still my culprit of choice in this issue....

I do not like crank scrapers... it's like sitting a keg of gun powder close to a camp fire... to close for comfort.

 

[bobscuda67]

Seams like your getting it narrowed down to the valvetrain. Are the springs the the right ones for the cam? How about the retainer to guide clearance? Or the retainer to rocker arm clearance? I'm sure these things were checked when it was built, but it doesn't hurt to double check them.

 

[340sFastback]

Thanks all for the all the suggestions.

Its not the crank scraper. There are no signs anything ever hit it. With engine upside down I removed the oil pan's end half circle rubber gasket pieces, and slid the oil pan over 1/4" so scraper would be closer to the crank. Turned engine with breaker bar and it does not hit even if its 1/4" closer. Can't be scraper.

I think I need to start looking at the valve train a little more closely. It was all heavily scrutinized during assembly but now I need to really start looking for any strange signs.

The springs are adequate but I was told it could float the valves at around 6200 RPMs. The springs don't coil bind and the retainers don't bottom out on the valve guides. The springs are not too stiff for the lifters to deal with either.

I find it very strange no metal was in the oil pan. And I mean none. I left the engine upright after being pulled and pulled the pan straight down. The oil was changed after it was run for 20 minutes. This oil had a few hours of run time on it while looking for the problem. Didn't even have any silver tint in it. I am pretty happy about that!

And I didn't scratch the newly repainted engine compartment, thats good too!

 

[bobscuda67]

Did you buy the springs with the cam? Maybe the valves are to heavy for the springs. Maybe there's a slight bounce causing the noise.

 

[pettybludart]

Just a suggestion.While you have it out,get it Dynoed?They,ll find the problem imediately.And you,ll also know what HP/TQ.

 

[TheCrackHead]

The crank scraper want to be about a 1/4 from the crank to really do it's job.
I'm getting as frustrated as you about this and wish I was there to help.

When you had the stethiscope did you listen at the rockers where they meet the push rods?
And motor and trans bolted together can you crank with the starter and still hear the noise?
It's in rhythm with the valve timing isn't it?

 

[340sFastback]

When you had the stethiscope did you listen at the rockers where they meet the push rods?

I couldn't hold it where the push rod was because it would get bumped off. I was able to hold it where they pivot and they all sounded the same.

And motor and trans bolted together can you crank with the starter and still hear the noise? It's in rhythm with the valve timing isn't it?

No noise when you just run the starter. No noise when its spun with a break bar. Noise appears to be in sync with the valve timing.

 

[340sFastback]

Just a suggestion.While you have it out,get it Dynoed?They,ll find the problem immediately.And you,ll also know what HP/TQ.

I have an engine dyno 15 minutes from my house. Same shop that machined the bottom end. They are a very good shop. Its $300 to bolt it to the dyno and fire it up. $100 an hour after that. I would like to find the problem first, if possible, before taking it there because I could run a bill up into the thousands very quickly if they have to start taking stuff apart.

I do think its best to take it over there before it goes back in the car.

 

[340sFastback]

Did you buy the springs with the cam? Maybe the valves are to heavy for the springs. Maybe there's a slight bounce causing the noise.

I bought the heads from Shady Dell Speed and they set the heads up. Ryan at Shady Dell has listened to the video and he says the springs and retainers are not causing this noise. He is helping me and giving advice.

 

[340sFastback]

The noise always seemed to be on the right side so I pressurized that header. I can guarantee you there is not so much as a pin hole in that header or collector.

 

[340sFastback]

I took the rockers off the right side today. All rockers and shafts look like new. The push rods on that side do contact the head some. Some of the paint was rubbed off but none were scraped beyond that. All 16 push rods are completely straight.

 

[340sFastback]

I flipped the engine over and put one cylinder at a time at TDC. I could see all sides of the bores and they all looked great. Wrist pins are still centered and no spiral locks are hanging out.

ALL rods bolts are far from the block, rods are far from oil pick up tube, piston skits do not come close to crank shaft throws.

 

[moper]

I'm curious... do you have a snap gage or inside mic to meaure the lifter bores? I would be most curious about any taper on the pass side bank near the bottom of the bore. Also, check to see if any of the bottoms of the lifter get exposed when they are on the base circle of the cam. a small mirror should be able to go down thru the ovel holes in the valley to see this. I dont think the rubs on the pushrods would make that kind of noise... Any scars on them, or jjust the coating removed where they rubbed?

 

[340sFastback]

Moper, just the paint is rubbed off the push rods. It does not appear the metal of the push rod is scraped up.

I don't have tools to measure a lifter bore. All I have is a regular dial bore gauge and calipers. I know the shop lightly honed the lifter bores. From what I remember the lifters do fit snug in all the bores, especially when on the base circle. During engine mock up I ran the oil pump with all the lifters in, rotated the cam, and I don't think any bled oil off excessively out of the bottom when on the base circle. I do remember checking for that. I remember the lifter bores on the passenger's side shrouding the oil grooves better then the ones on the driver's side. I could make a video of the oil pump running while turning the engine with the intake off? I could also check to see if any of the lifters are loose in their bores by wiggling them around with the push rods out? I should probably pull all lifters out and see if I see any thing abnormal.

I think the noise sounds like valve train. Maybe a valve smacking shut and echoing down the header tube. I don't think the problem is with the rockers/retainers/valve springs though. The noise had the sensation of coming right from within that passenger's side header tube. Right around the oil filter.

The noise did get significantly quieter when the engine was hot. It was much much louder when the engine was cold. I was running Penzoil 10-30 regular motor oil. The engine "almost" sounded normal when it got up to about 190 degrees.

 

[bobscuda67]

As I said in an earlier post, maybe some noise with that cam is normal. If you used stainless steel valves,they are heavy and will slam shut causing a noise. I wouldn't stop looking since you have it apart. Good luck, as I know madding that can be.

 

[340sFastback]

The passenger's side is where the noise seemed to come from. It sounded like it was coming from with the passenger's side header tube, like a valve smacking shut and echoing down the tube. Or a bad exhaust leak which I know for sure is not the case. The push rods on that side have signs of hitting the head. Could it be when the engine got hot the head expanded allowing more push rod clearance therefore less binding of the push rod and less noise??