408 Valve train noise??

E Satterfield

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New to Mopars. Recently installed a 408 crate engine in wife’s Duster. At first I thought there was an exhaust leak. But after checking all connections to include header flange to head

I believe the noise to be in the heads. I hear a ticking/clicking at 1800 Rpm that resembles an exhaust leak. I don’t believe it to be detonation .

Take the engine above or below that figure (1800RPM) and it becomes inaudible at least it seems

It’s a 4spd with 3.55 it spends a lot of time in this operating range on the mostly two lane roads in my area

Hot oil pressure is around 40-45psi at that RPm. I think the camshaft is Comp Cams Nostalgia Cam Type: Flat Tappet
  • .474 Intake .474 Exhaust
    233 Intake / 240 Exhaust duration
    @ .050 - 110 degree lobe separation

  • As I understand the rockers are non adjustable on magnum heads. Any ideas? Normal? Thanks ERIC.
 
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Scody21

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Ok, so LA’s sound like a sewing machine when they are running. The Magnum uses pedestal rockers like a cheby. Pull your valve covers and check the rockers and springs. May have a loose rocker, or a broken inner spring, or who know what, only one way to find out. then you may find out what you have going on…
 

Professor Fate

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Type: Flat Tappet
  • .474 Intake .474 Exhaust
    233 Intake / 240 Exhaust duration
    @ .050 - 110 degree lobe separation
Hydraulic or solid flat tappet?
As I understand they are magnum heads on an LA block.
Sounds to me like pushrod length may be suspect.
If you have a solid cam, you're trying to run it with a non-adjustable valvetrain. Custom length pushrods are required with this setup, but no matter how carefully you measure, you need adjustability built in to dial in your valve lash.
If you have a hydraulic cam, your pushrod length is critical with a non-stock head/block combination; if too short the lifters never achieve adequate preload, if too extreme you run the risk of the lifters coming apart.
Is this something you pieced together from a crate short block and Mag heads, or did you purchase the entire engine assembly? Reputable builder or EBay special?
 

Dartsun

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My blueprint crate engine is a little loud on startup in the valve train. 408 magnum heads older blueprint from 2008
 

E Satterfield

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I checked the torque on the rocker arm hold down bolts assume the torque value is 21 ftlbs ? All were ok I called and spoke with a tech at the company that builds the engines. The person was respectful and friendly but had no answers or suggestions
 
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jbc426

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Are you using Remflex gaskets? How did you check the head flange for leaks? Are you running headers or cast manifolds?
 

RustyRatRod

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What rocker arms If they are rollers, it may be normal for some noise. Also keep in mind, those nostalgia cams from Comp are ground specifically to take advantage of the Mopar .903 lifter diameter. That means that series of cams has more aggressive lobes then their standard "Chevy" style lobes. So it might be normal for that as well. Since we cannot hear it, we have nothing to go by.
 

Dan the man

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Ok, so LA’s sound like a sewing machine when they are running. The Magnum uses pedestal rockers like a cheby. Pull your valve covers and check the rockers and springs. May have a loose rocker, or a broken inner spring, or who know what, only one way to find out. then you may find out what you have going on…
If it's a xe comp cam they are noisy
 

krazykuda

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Are you sure it's valvetrain noise???

Check the torque converter to flex plate bolts....
 

E Satterfield

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1973976022, member: 3615"]Oh my, no answers or suggestions. I just don’t know what to say to that. Kim[/QUOTE]


It’s like this. I’ve been working and building GM stuff for over 40 years. I’m certainly no expert on Mopar and obviously have a lot to learn or I wouldn’t be asking for info here.

I’ve never mentioned the builder as I’m not trying to start a pissing match over these engines as it always someone who doesn’t own one making the statement of how they are junk etc etc. or some other smart *** comment about wasting money

I guess I was hoping someone might say. “ My 408 from....does the same thing and it’s been fine for 10k miles and the reason is this or that so no worries “.


I didn’t know the rockers were not adjustable. When I called the tech line and asked the guy if he knew the brand of camshaft used and did they recommend further adjustment after break in and would it void a warranty if I did try to adjust them and his response was “ We don’t have an issue with you doing it”. Tells me he knew less about that particular engine than I did

Same as the first time I called the “ Tech Line “ asking if 18-19lbs hot oil pressure with straight 30 was normal for these/Mopar small block engines. I’ve never had a Chevy/ Ford/MG/Willys that I personally rebuilt have oil pressure that low on a fresh less than 200 mile rebuild. But as stated. I’m New to Mopars but not working on automobiles

I feel the noise is valve related either lifters or rocker arm due to lifter issues. The headers are new Dougs with provided gaskets. I’ve been chasing this noise since I replaced this engine.

I replaced the header to head and collector gaskets a second time even though I saw no evidence of them leaking with new ones treated with copper silicone and have the same noise. So I don’t believe it to be exhaust

it’s a 4 speed so no flex plate issues

The rocker arms are stock stamped steel with pushrod guide plates.

I assume the camshaft is Comp? The published specs are the same as Comp/ Nostalgia. But the tech person didn’t give a definitive confirmation


Thanks to everyone for the suggestions and help. The engine is under warranty so if this becomes a real problem instead of just an annoyance I guess it will be dealt with then.
 
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Mopar73340

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My Magnum headed 408 has valve train noise also. I’m sure the Hughes hydraulic roller cam doesn’t help.
 

71GSSDemon

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So, as strange as it sounds, my dad had a ticking noise in a fresh 440. Pull the PCV valve and noise goes away. Would never believe it, but it is the case. Replace it and sound comes back. I don't know, something to try.
 

TT5.9mag

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I would be looking for collapsed lifters. Or weak check valves in lifters. Seems to be a common problem in todays hot rodding market. Pull the valve covers after shutting it off and press down on the pushrod side. They all should be fairly pumped up.
 

TT5.9mag

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@E Satterfield I commend you for not wanting to throw anyone under the bus as far as crate engine suppliers. From your previous threads I think we all know this is a blueprint engine, and I think @Johnny Mac should be brought in here. He is the mopar liaison for blueprint and can probably provide some insight.
 

E Satterfield

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Thanks ! I’m a lot of things but a trouble maker isn’t one of them. Yes it’s a BP engine. I had one rocker that seemed to have bled down more than the others when I checked the torque on the hold down bolts.


I had a set of Lunati lifters in a Chevy once that bled off so badly when the engine sat for a day it drove me nuts listening to them clatter until they pumped back up. Their response was it’s Normal. I’m not sure about all that as all the engines I ever rebuilt from the 80s onward never had this issue...So is it stuff is just made so much cheaper today or is there a legitimate reason?

If this ticking isn’t going to hurt anything with this 408 then I’ll just have to deal with it as I’m really not interested in pulling it back out of the car. But same as with the oil pressure what’s it going to be like down the road with more miles and NO warranty?
 

Johnny Mac

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@E Satterfield I commend you for not wanting to throw anyone under the bus as far as crate engine suppliers. From your previous threads I think we all know this is a blueprint engine, and I think @Johnny Mac should be brought in here. He is the mopar liaison for blueprint and can probably provide some insight.

Yup, no problem helping at all. for some reason the "tagging" feature isn't working for me but Satterfield my email is on my profile, or PM me.
in short the grind is a comp 20-670-4, and this is a stock iron magnum head, with stock rocker arms. they do have a sewing machine noise. Rocker arm stud torque is 25 ft lbs.
I honestly wouldn't worry too much about it unless it sounds like an obviously collapsed lifter, that is extremely noisy. I'd check all the pushrods, the rocker arms, rockers, etc. no you won't void a warranty checking over things like that.
for some reason i've found that pedestal mount fords, and mopars with flat tappet cams are just noisier than our roller cam/roller rocker engines.

i dont have a problem with 20 PSI of oil pressure either. it's a melling pump, and elgin lifters on this oldie build. this PN has been unchanged for alot of years.

if you do find a lifter is collapsed, we can send a set. no worries. just call with your serial #.


traveling this week for work, but will check PM and thread as i can. talk soon.
 

E Satterfield

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Thanks for the reply. I really like the engine far as that goes. It sounds good. Power is great . But I’m sure everyone on here knows what I’m talking about. Everything on your vehicle meets your own standards but you have this “ One Thing” that drives you crazy and you spend what seems like every free moment trying to correct it with no success. This is what the noise is me.

3ECB1992-B202-4333-8E8E-85DB9E0CB8C3.jpeg
 
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RustyRatRod

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Here's another angle. I don't know if those cams are ground on a reduced base circle or not. If they are, you could possibly need some longer pushrods. Non adjustable valve trains plus reduced base circle cams = longer pushrods. But you won't know that answer unless you actually measure.
 

TT5.9mag

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Thanks ! I’m a lot of things but a trouble maker isn’t one of them. Yes it’s a BP engine. I had one rocker that seemed to have bled down more than the others when I checked the torque on the hold down bolts.


I had a set of Lunati lifters in a Chevy once that bled off so badly when the engine sat for a day it drove me nuts listening to them clatter until they pumped back up. Their response was it’s Normal. I’m not sure about all that as all the engines I ever rebuilt from the 80s onward never had this issue...So is it stuff is just made so much cheaper today or is there a legitimate reason?

If this ticking isn’t going to hurt anything with this 408 then I’ll just have to deal with it as I’m really not interested in pulling it back out of the car. But same as with the oil pressure what’s it going to be like down the road with more miles and NO warranty?
That one lifter that “bled down more than the others” would be where I would start. Could be trash in the check valve and I would be pulling the intake and at the very least, disassembling and cleaning that lifter. Possibly all 16.
 
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