pop, pop, pop noise at High load.

Johnny1

Johnny1

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Apr 25, 2014
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Well, ive asked about a sum of 10 or so maybe more knowlegeable people about this noise i get when i am romping on it with the converter locked IE max engine load. it changes sometimes, gets louder, softer and it doesnt seem to do it at higher altitudes. it does it bad when im in OD and i spool up and then slam it, it pops and bangs, its really hard to describe the exact noise.
:charger:

i sounds sometimes like a hammer hitting the firewall, and other times like a turbo surge, a surge though not from withdrawel of the throttle just compressor cant hold the boost.

Ive been told it could be turbo surge - i have twins 60m over 75
draining the rail- i now have twin cp3s
injector rattle
head gasket letting go. i have 625s.
and too much timing. 30 degrees at the higher revs.

I have efi tunes from anarchy diesel.
Anyone have any ideas????


any one have any ideas???? please :ft::ft: no one is help on cummins forum about this.
 
Has anarchy seen the data logs? Your post is so incredibly vague and under informing lol. I know that's all you know about it as well but the better you can describe it and the more definitive you can be the more we can help.

My first random guess would be turbo piping (hot or cold) hitting the firewall when the engine is torqueing over in full song.

Can you tell exactly where it's coming from? Do you lose any power when it happens? Are you sure it isn't something in the transmission?
 
Your head is lifting under high boost and it is escaping through the multi layer gasket. I have experienced the same thing years ago.
 
I knew it! I thought long and hard about it. And that would make sense for, it sounds like surge, but it's too mechanical. And I just blew my 3rd gasket...... So it's obvious now. How does one solve it!???


I'm sorry I'm so vague, it changes though the sound as it does it more and more. Sous like air goes through one of the layers and when it decompresses it pops.
 
You have a good setup. My guess is the surface on the head isn't fine enough or you have a stud stretched, 625's and stock gasket have held north of 100 psi and 1200 hp.
 
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Howling said:
Your head is lifting under high boost and it is escaping through the multi layer gasket. I have experienced the same thing years ago.
Click to expand...

im not running any wastegates..


How does one solve this issue?
 
What are you tourquing the head to? Hot or cold retourque? Are you having the head resurfaced? if so what spec are they surfacing it to?
 
re-torquing them after heat cycle, after this last headgasket failure. we re-torqued them 3 times in 3 days after a heat cycle to stone cold. got block and head surfaced, to what ever the machine shop does.
 
Surface finish is the key to a MLS gasket, 50 RA or finer. Most gas engine builders/machine shop never go that fine. I hope that isn't your issue, so you don't have to pull engine again.
 
U really can't u need a fine and level plain to run a properly calibrated dial indicator accross the surface of the block then head.. fyi u cant buy a cheap indicator to get those levels ur looking at starrett or mitutoyo
 
mybigturbo said:
U really can't u need a fine and level plain to run a properly calibrated dial indicator accross the surface of the block then head.. fyi u cant buy a cheap indicator to get those levels ur looking at starrett or mitutoyo
Click to expand...

press 1 for English, newb
 
Surface roughness gauge, same thing I used when honing cylinders at Rolls-Royce for Bergen Diesels, I don't know if many machine shops would have one to check the surfaces.
However, that may only tell the surface condition if checking before surfacing, need to check the roughness AND the flatness of the sealing surface.
Possible, but unlikely to have a milled surface at 50ra to be be warped.
 
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I'm having trouble understanding how RA, which controls gasket displacement (horizontal motion) is coming into play in a situation where the educated guess was that the MLS gasket was delaminating and fluttering, a vertical motion. Not flaming. Learning.
 
so i purchased a JGS gate and such, and i have a gate plate, should i just cut a opening in the manifold collector or install the gate plate?
 
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