Author Topic: Rod Knock Sound Only At Hot Idle  (Read 8798 times)

0 Members and 1 Guest are viewing this topic.

Offline rbabos

  • Full Member
  • Posts: 7936
  • Country: ca
Rod Knock Sound Only At Hot Idle
« on: Sunday, April 25, 2010. 04:09:29 PM. »
My build is a HQ 113, 10.5 compression, 575 cams, .032 quench.
Since the very first heat cycle there was a dull rod knock sound coming from it, but not until it hits operating temps of about 200+. Same SE comp that came off the 96 and was installed correctly. Has been removed and checked recently and reinstalled. It's in good shape and torqued to spec. Rotor showed no signs of movement during inspection. Rockers are shimmed to .003, pushrods are 3.5 tight on intakes and 4 on the exhaust, due to exhaust having longer durations.
Stock crank has been redone by Hoban, with H beam rods, balanced, trued, pro plugged and tig welded. Don't think it's piston slap, since it's quiet when cold, but don't know if they could be making contact at BDC when hot. If so, they should have beat in some clearance by now but the noise is exacly the same as the first startup, 1500 miles later. That leaves the rod clearances. While the stock 07 rod fit was quite snug the Hoban cranks rods had a rocking movement of 1/16" total at the wristpin. The rear has 1/32". I could not detect more than .0005 radial play on the big end, so I don't think it's that. Running 94 octane at 19* idle timing, and the sound goes away above idle. Throw some ideas at me. I'm sure I'm not the only one on the planet that has experienced this before.
Ron
« Last Edit: Sunday, April 25, 2010. 04:13:37 PM. by rbabos »
I came over to the Dark Side. They have chocolate kisses.

Offline roadglide65

  • Full Member
  • Posts: 241
Re: Rod Knock Sound Only At Hot Idle
« Reply #1 on: Sunday, April 25, 2010. 04:22:12 PM. »
Roller bearing or Timkin on the crank?

Offline rbabos

  • Full Member
  • Posts: 7936
  • Country: ca
Re: Rod Knock Sound Only At Hot Idle
« Reply #2 on: Sunday, April 25, 2010. 04:29:24 PM. »
Roller bearing or Timkin on the crank?
Timkens on the left and lefty bearing on the right. End play set at Hoban, and I added .0005 to that. Comes in at .001 end play.
Ron
I came over to the Dark Side. They have chocolate kisses.

Offline choseneasy

  • Full Member
  • Posts: 703
Re: Rod Knock Sound Only At Hot Idle
« Reply #3 on: Sunday, April 25, 2010. 04:39:46 PM. »
Does the knock get worse when you load the engine down with the front brake and let the clutch out slowly?

Offline rbabos

  • Full Member
  • Posts: 7936
  • Country: ca
Re: Rod Knock Sound Only At Hot Idle
« Reply #4 on: Sunday, April 25, 2010. 05:04:54 PM. »
Does the knock get worse when you load the engine down with the front brake and let the clutch out slowly?
Actually it stays the same or even quiets some. Weird, huh.
Ron
I came over to the Dark Side. They have chocolate kisses.

Offline barny7655

  • Full Member
  • Posts: 960
Re: Rod Knock Sound Only At Hot Idle
« Reply #5 on: Sunday, April 25, 2010. 05:44:10 PM. »
Enough clearance under cylinders for piston stroke, seems noise is due to growth of parts,pistons, rods,piston pins,the right head gaskets used , piston tops been hit, valves,lifter faulty,now the idea is to work out whether its on cam speed or piston speed, id get it running and kill front cylinder, then check to see if noise is still there, then try rear cyl you may have to adjust idle ,hopefully this will show you where the noise is, if its common to both cylinders and is at engine speed we can look at crank. compensator,crank pin,i know you have had alot of work done to this motor,some times clearances on parts do grow with heat ,others will chime in hope you can isolate it to front or rear cyl,stethoscope some times helps, cheers Barny
riding since 62, BSA bantum the first bike

Offline rbabos

  • Full Member
  • Posts: 7936
  • Country: ca
Re: Rod Knock Sound Only At Hot Idle
« Reply #6 on: Monday, April 26, 2010. 06:15:22 AM. »
Barny: Lifters are quiet, and as far as the piston clearances at the bottom or between the tow at BDC, I don't know. Have heard that some CP pistons got shipped out without sufficient cutouts. Don't know if this is the case or not. If I ever do another I will definately check this area next time. Some have chased this sound and never found the cause. Had one guy with 27k on it go to bigger C.I.with new crank , pistons and cyls only to have the same knocking at idle. That's why I don't want to tear into it without looking for a specific area as the cause. Seems weird the sound goes away above idle. You would think if it's a contact problem it would get louder with rpm. Don't think it's the crank, since it hasn't had time to heat up, with cold oil still feeding it. Definately and cyl/head and piston heating expanding thing somehow with the time frame it happens. Gets a bit louder as the engine gets hotter.
Ron
I came over to the Dark Side. They have chocolate kisses.

Offline Max Headflow

  • Site Supporter
  • Full Member
  • *****
  • Posts: 18478
  • Country: tr
  • Not Admin
Re: Rod Knock Sound Only At Hot Idle
« Reply #7 on: Monday, April 26, 2010. 06:45:35 AM. »
Could it be intake reversion? If running a football AC it reflects the sound back at the motor..  If not that, grab a stethoscope... Max
Aka Mousinator, Another Wasted Minute With Max,
No Collar to the Bone

Offline rbabos

  • Full Member
  • Posts: 7936
  • Country: ca
Re: Rod Knock Sound Only At Hot Idle
« Reply #8 on: Monday, April 26, 2010. 08:13:55 AM. »
Could it be intake reversion? If running a football AC it reflects the sound back at the motor..  If not that, grab a stethoscope... Max
Running the SE heavy breather and it has a popping sound at idle but not the source of the knock. Steth won't pinpoint the exact source. It can be heard some in each cyl but it's the loudest right on the center case bolt between the cyls. Lifters are quiet. The only other sound in the engine is from the front exhaust valve and it's loudest at the exhuast port and on the front right rocker cover bolt. I wonder if there's a connection here and will check this valve area cold to see if it follows the heat and somehow the two are connected. I tripple checked cam timing before installing the plate, so I'm positive it's not that. Have to bore scope it and look for contact first, then do a check on the exhaust lifts relative to piston stroke between the two to varify if the front cam is out of time. Not sure if it would even hit at one tooth out however, but new to these engines so who knows? Even so, rpm would amplify the situation, and it can't be heard all the way to 5800 rpm rev limit. Only idle area.
Ron
I came over to the Dark Side. They have chocolate kisses.

Offline Max Headflow

  • Site Supporter
  • Full Member
  • *****
  • Posts: 18478
  • Country: tr
  • Not Admin
Re: Rod Knock Sound Only At Hot Idle
« Reply #9 on: Monday, April 26, 2010. 08:33:37 AM. »
Quote
Even so, rpm would amplify the situation, and it can't be heard all the way to 5800 rpm rev limit.

Well if you were worried about the valve hitting the piston at slow speed.. I think you can rule that one out.. What about pistons hitting the heads?? You might not see that with a bore scope till you get some miles on it.. Max
Aka Mousinator, Another Wasted Minute With Max,
No Collar to the Bone

Offline rbabos

  • Full Member
  • Posts: 7936
  • Country: ca
Re: Rod Knock Sound Only At Hot Idle
« Reply #10 on: Monday, April 26, 2010. 09:15:31 AM. »
Quote
Even so, rpm would amplify the situation, and it can't be heard all the way to 5800 rpm rev limit.

Well if you were worried about the valve hitting the piston at slow speed.. I think you can rule that one out.. What about pistons hitting the heads?? You might not see that with a bore scope till you get some miles on it.. Max
Can't see it since it's set up for .032 quench, (measured) and again with rpm rod stretch it would sound brutal at higher rpms. Did a check with solder once but it showed .045, which only proves how inacurate a method that is to measure quench. Still keep coming back to the bottom of the skirts as the most reasonable explanation, over everything else.
Ron
I came over to the Dark Side. They have chocolate kisses.

Offline splitting_lanes

  • Site Supporter
  • Full Member
  • *****
  • Posts: 659
  • Country: us
  • Nor Cal
Re: Rod Knock Sound Only At Hot Idle
« Reply #11 on: Monday, April 26, 2010. 09:35:39 AM. »
Ron -

I've got the same crank/rods setup as you in my 117 that I just rode last night for the first time -- and I noticed a loud, dull rod knock at hot idle.  I came to the forums and found this thread...  so I'm working on an issue that sounds the same as yours.

I'm going to do some vtunes -- I had a starter map that seemed good on my ride, but my engine did get rather warm.  We'll see if the noise changes with tunes.

I am running the stock compensator, as the SE unit that was shipped to me got broken in transit and no replacement was available.  It seems that a certain amount of rattle should be expected from the compensator and VPC  (not sure if you have a VPC, but I do).

the knock on my engine comes out both sides of the engine quite clearly at hot idle.  I have not restarted it cold to see if it's gone, but it wasn't there during the heat cycles.

have you played with your tune at all?

Offline rbabos

  • Full Member
  • Posts: 7936
  • Country: ca
Re: Rod Knock Sound Only At Hot Idle
« Reply #12 on: Monday, April 26, 2010. 12:15:25 PM. »
Ron -

I've got the same crank/rods setup as you in my 117 that I just rode last night for the first time -- and I noticed a loud, dull rod knock at hot idle.  I came to the forums and found this thread...  so I'm working on an issue that sounds the same as yours.

I'm going to do some vtunes -- I had a starter map that seemed good on my ride, but my engine did get rather warm.  We'll see if the noise changes with tunes.

I am running the stock compensator, as the SE unit that was shipped to me got broken in transit and no replacement was available.  It seems that a certain amount of rattle should be expected from the compensator and VPC  (not sure if you have a VPC, but I do).

the knock on my engine comes out both sides of the engine quite clearly at hot idle.  I have not restarted it cold to see if it's gone, but it wasn't there during the heat cycles.

have you played with your tune at all?
At the moment it's tuned quite well and as far as playing with the tune, with 120 different edits and loads, I guess the answer is yes. I've dropped the timing and the noise remained so put it back to base map, then later settled on 19* for the best idle for my engine. For me, I've ruled out the comp 100% as the noise, so it's comming from someplace else. At least I don't feel all alone with my knock now since you have the same thing. Hopefully somebody has been through this and found the cause. Right side seems louder than the left, but the horn etc could be shrouding the sound or reflecting it more to the right. By chance, did you notice how much rocking you had on the front rod at the wrist pin?
Ron
I came over to the Dark Side. They have chocolate kisses.

Offline splitting_lanes

  • Site Supporter
  • Full Member
  • *****
  • Posts: 659
  • Country: us
  • Nor Cal
Re: Rod Knock Sound Only At Hot Idle
« Reply #13 on: Monday, April 26, 2010. 12:39:03 PM. »
Ron -

I've got the same crank/rods setup as you in my 117 that I just rode last night for the first time -- and I noticed a loud, dull rod knock at hot idle.  I came to the forums and found this thread...  so I'm working on an issue that sounds the same as yours.

I'm going to do some vtunes -- I had a starter map that seemed good on my ride, but my engine did get rather warm.  We'll see if the noise changes with tunes.

I am running the stock compensator, as the SE unit that was shipped to me got broken in transit and no replacement was available.  It seems that a certain amount of rattle should be expected from the compensator and VPC  (not sure if you have a VPC, but I do).

the knock on my engine comes out both sides of the engine quite clearly at hot idle.  I have not restarted it cold to see if it's gone, but it wasn't there during the heat cycles.

have you played with your tune at all?
At the moment it's tuned quite well and as far as playing with the tune, with 120 different edits and loads, I guess the answer is yes. I've dropped the timing and the noise remained so put it back to base map, then later settled on 19* for the best idle for my engine. For me, I've ruled out the comp 100% as the noise, so it's comming from someplace else. At least I don't feel all alone with my knock now since you have the same thing. Hopefully somebody has been through this and found the cause. Right side seems louder than the left, but the horn etc could be shrouding the sound or reflecting it more to the right. By chance, did you notice how much rocking you had on the front rod at the wrist pin?
Ron
I did not notice any rocking, but I did not specifically check it.

One thing that dawned on me from all the V-8 engines i've worked on -- rod knocks get louder with RPM, main bearing knocks go away.
« Last Edit: Monday, April 26, 2010. 01:35:54 PM. by splitting_lanes »

Offline Max Headflow

  • Site Supporter
  • Full Member
  • *****
  • Posts: 18478
  • Country: tr
  • Not Admin
Re: Rod Knock Sound Only At Hot Idle
« Reply #14 on: Monday, April 26, 2010. 12:48:42 PM. »
Quote
Still keep coming back to the bottom of the skirts as the most reasonable explanation, over everything else.

Yep could be hitting if it wasn't checked.. IIRC someone saw this on a similar build.. Might have been a 117 though.. Pistons were CP IIRC.

Quote
That leaves the rod clearances. While the stock 07 rod fit was quite snug the Hoban cranks rods had a rocking movement of 1/16" total at the wristpin. The rear has 1/32".

If this this pins in the rods you got problems. If it is side to side while holding the rod over to one side of the flywheel.. the The front is good but the rear you should feel almost none.

Max
Aka Mousinator, Another Wasted Minute With Max,
No Collar to the Bone

Offline 05FLHTC

  • Full Member
  • Posts: 4633
Re: Rod Knock Sound Only At Hot Idle
« Reply #15 on: Monday, April 26, 2010. 01:06:43 PM. »
Oval / egg shaped cylinders?
Illinois the Corruption Capitol of USA

Offline hotroadking

  • Full Member
  • Posts: 3870
Re: Rod Knock Sound Only At Hot Idle
« Reply #16 on: Monday, April 26, 2010. 01:10:51 PM. »
Got a 113 Elbruto that has that sound, hollow popping kind of sound, mostly heard at idle when warm.. I"m thinking pistons as well as they bored the cyl out to the max and put in new pistons...


Offline rbabos

  • Full Member
  • Posts: 7936
  • Country: ca
Re: Rod Knock Sound Only At Hot Idle
« Reply #17 on: Monday, April 26, 2010. 01:56:23 PM. »
Quote
Still keep coming back to the bottom of the skirts as the most reasonable explanation, over everything else.

Yep could be hitting if it wasn't checked.. IIRC someone saw this on a similar build.. Might have been a 117 though.. Pistons were CP IIRC.

Quote
That leaves the rod clearances. While the stock 07 rod fit was quite snug the Hoban cranks rods had a rocking movement of 1/16" total at the wristpin. The rear has 1/32".

If this this pins in the rods you got problems. If it is side to side while holding the rod over to one side of the flywheel.. the The front is good but the rear you should feel almost none.

Max
Max: Not sure about your reply and I may have confused the issie. Taking my thumb and finger and placing them on each side of the wrist pin hole of the rod, the front will move left and right a total of 1/16 at the wrist pin hole. Rear forked is 1/32 indicating bearing clearances. Thrust clearances appeared fine. While I could only read .0005 of bearing clearance with the dial indicator at the crankpin, this should not translate to 1/16" movement side to side at the wristpin. I don't know what the width of the front rod is at the big end, otherwise I could take that 1/16 over the length of the rod to find how much clearance is needed at the rod big end at a certain width to actually produce the 1/16" play. Reverse math engineering if you will. There is a point where actual rod knock can be heard, but I should be a long ways from there. Interstingly enough a filter cut at 800 miles showed less metal than the stock 96 did. No bronze, only a few expected small alum and steel flakes. Stocker was always making bronze flakes right up to 5k at which point they diminished and I quit looking, since my eyes were set on this better 113 :banghead:
Ron
I came over to the Dark Side. They have chocolate kisses.

Offline rbabos

  • Full Member
  • Posts: 7936
  • Country: ca
Re: Rod Knock Sound Only At Hot Idle
« Reply #18 on: Monday, April 26, 2010. 01:59:40 PM. »
Oval / egg shaped cylinders?
I agree, that could be a source but HQ's takes the Harley oval cyls and hones them to .005 over and supplies CP pistons to fit. I did bore gauge the cyls on the bench without torque plates and they were very good. Piston clearance was what CP called for as well.
Ron
I came over to the Dark Side. They have chocolate kisses.

Offline REED

  • Full Member
  • Posts: 124
Re: Rod Knock Sound Only At Hot Idle
« Reply #19 on: Monday, April 26, 2010. 03:36:00 PM. »
a frind had a noise sounded just like this, turned out to be that his rocker boxes wern't clearanced enough, a little more work with the die grinder the noise went away.  It was almosst impossible to see where the contact area was.
just a suggestion  REED

Offline rbabos

  • Full Member
  • Posts: 7936
  • Country: ca
Re: Rod Knock Sound Only At Hot Idle
« Reply #20 on: Monday, April 26, 2010. 04:08:28 PM. »
a frind had a noise sounded just like this, turned out to be that his rocker boxes wern't clearanced enough, a little more work with the die grinder the noise went away.  It was almosst impossible to see where the contact area was.
just a suggestion  REED
Interesting. I have more noise on the front exhaust valve only when hot according to the steth. Both the knock and the clack occur at the same temp. Could it be echoing in the cyl to cause the rod knock sound, even though each has it's own unique sound. Even though the 575 cams require no special clearancing I did look things over and there seemed to be plenty of clearance. I will inquire about this at HQ to see if it could be an issue. There is something quite not right with that valve as far as sound.
Ron
I came over to the Dark Side. They have chocolate kisses.

Offline Ajayrk

  • Site Supporter
  • Full Member
  • *****
  • Posts: 1048
  • Country: us
Re: Rod Knock Sound Only At Hot Idle
« Reply #21 on: Monday, April 26, 2010. 04:13:55 PM. »
rbabos

Does it sound like a diesel motor?  CP pistons 2618 alloy have heard this noise in a Ford V-8 with CP pistons.

Changed to Aris or JE (don't remember brand) but still 2618 alloy.  Also knock knock.

Change to Mahle 4032 alloy.  Now quite as stock.

I think it's piston noise.  Could be collapsed skirts.
« Last Edit: Monday, April 26, 2010. 04:18:18 PM. by Ajayrk »
AJ

Offline rbabos

  • Full Member
  • Posts: 7936
  • Country: ca
Re: Rod Knock Sound Only At Hot Idle
« Reply #22 on: Monday, April 26, 2010. 05:05:14 PM. »
rbabos

Does it sound like a diesel motor?  CP pistons 2618 alloy have heard this noise in a Ford V-8 with CP pistons.

Changed to Aris or JE (don't remember brand) but still 2618 alloy.  Also knock knock.

Change to Mahle 4032 alloy.  Now quite as stock.

I think it's piston noise.  Could be collapsed skirts.
Maybe, but what about the fact it's silent when cold, when the piston should be at it's loosest state. Not as loud as a diesel. :hyst:
Ron
I came over to the Dark Side. They have chocolate kisses.

Offline Ajayrk

  • Site Supporter
  • Full Member
  • *****
  • Posts: 1048
  • Country: us
Re: Rod Knock Sound Only At Hot Idle
« Reply #23 on: Monday, April 26, 2010. 06:39:11 PM. »
I'm going to grab at another straw.  Exhaust leak @ front cylinder.  Did you use S/E gaskets or the stock tapered gaskets.  I had an exhaust leak with the S/E gaskets that sounded like a knock.  The TC-88 uses the EVO exhaust dimensions, but the head is wider and the counter bore for the gasket is deeper and the flange can some times bottom out before the gasket is crushed.
AJ

Offline FSG

  • BrisVegas in Oz
  • Administrator
  • Full Member
  • *****
  • Posts: 11597
  • Country: au
  • BrisVegas
Re: Rod Knock Sound Only At Hot Idle
« Reply #24 on: Monday, April 26, 2010. 07:12:11 PM. »
Quote
  and the flange can some times bottom out before the gasket is crushed.

Which is why I use two clips per pipe.