Braeden Clark
Well-Known Member
How do I deal with that with a non adjustable valvetrain? Custom pushrods? That would really suck. This setup is supposed to work perfectly fine with stock pushrods and lifters. Maybe the lifters just aren't right
Rebuilt magnum 360 Noise
- Thread starter Braeden Clark
- Start date
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Rat Bastid
Dunamis Metron
There are way too many variables to say with certainty what will work and what won’t.
This should have been sorted out at assembly, not after it’s in the car. If it is a case of pushrod length.
That’s why I cringe when guys think you can slam a engine together and not check everything. It’s a giant ***** to sort this stuff out and fix it after it’s in the car.
And it’s cost ineffective. You have to check everything. It takes many, many hours to correctly measure and assemble and engine. It may go together 4, 5, 6 times. I’ve done engines that I had pre-assembled 12 or 15 times. On final assembly it went together and went on the dyno without an issue.
Braeden Clark
Well-Known Member
Yea I kinda just took the companies words for it when they said it will all go together with no issue. I now know for next. You live and you learn I guess. I'm only 19 and this is the first motor I've built. I'll know for next time but it sucks I've got to deal with this one
Braeden Clark
Well-Known Member
The exhaust system is the same as the old one. Same manifolds and everything. Funny thing is the other motor had a similar noise. Slightly louder but the symptoms were the exact same. Only made it holding the rpms below 2k. Two different motors. Similarish noise with the same symptoms.
TT5.9mag
Two atmospheres are better than one
I sure would be investigating the exhaust system way before pulling the pan or valvetrain. My opinion
Non adjustable from a 360?
And you put performance springs on?
And you didn't check if the rockers were hitting the springs?
I rest my case . I have seen this several times. that is why 340's even though they have the same stamped steel rockers they are machined on the spring side to make room for the springs. take a side off and see if they are hitting. There will be an evident rub mark . Its worth a free look.
Braeden Clark
Well-Known Member
Yea I will pull the valve covers. I bought these springs from hughes after many emails making sure they are a direct fit for stock rockers and a cam, but like mentioned, I should have been more careful to triple check. Thanks for the help. I'm going to check for an exhaust leak first and if my noise is still present I will dive deeper. I feel it will not be an exhuast though
Jeff Seighman
aka jeffnmo
What cam, if it has a lot more lift that the stock cam, using stock rockers, stock push rods and stock replacement lifters would put more preload on the lifters. I don't know if that would cause the noise you are describing but it's worth looking into. You would need shorter push rods or adjustable rockers.
Braeden Clark
Well-Known Member
It only has .480 lift on intake and exhuast. It'd a small cam. It's comp cams 20-744-9. I may make a trip to my machinist and have him listen too.
Jeff Seighman
aka jeffnmo
I don't know the lift of the stock Cam, so I don't know how much the new cam would add to the preload. someone here will know. Even if that's not the source of the tick it would be worth correcting.
Braeden Clark
Well-Known Member
The stock cam is smaller but hughes makes a cam that has over .500 lift and uses all the same stock stuff as I do. Or is supposed to be able handle it... maybe my lifters just can't handle the lift as well as oem lifters. Idk. I'll have to look into it
That's a fast rate of lift camshaft. You can have everything perfect and still have valve train noise. You may have to live with it. They smack the valves open and slam them shut. There's gonna be noise involved.
Who says it's "supposed to be able to handle it"? Hughes? Of course they do. That's like buying from a crack dealer and asking how good his product is.
As long as the base circle of the cam is the same and there was no other changes like a milled deck of the block or cylinder heads or a head gasket swap, it should be fine.
Braeden Clark
Well-Known Member
Yea I'm just confused as to how the noise seems to dissappear with more rpms. I mean if my engine will run fine forever with this noise, I can live with it no issues. I just don't want there to be something wrong. It also just blows my mind my old 318 had a noise under identical conditions. Here is a video of my old engines noise. Same conditions. Steady rpm under 2k.
https://youtube.com/shorts/TEndLnTh240?feature=share
It's still there at higher RPM, you cannot hear it because the frequency is too high.
I'm not sure that i sis on the Extreme Energy cams. Since they are a fast rate of lift, they might have a reduced base circle. Thing is, Comp won't tell you as if it's a CIA secret. That's something that should have been measured, just like bearing clearances and all the rest of it. .......but I'm preachin to the choir tellin you that.
Braeden Clark
Well-Known Member
Yea I've been told a few times that I should have measured. Which I now understand now that I should have. My mistake. First motor ive built. You live and you learn I guess. Will know for next time. Just at a loss as to what to do next on this motor. I guess I pull the valve covers. Just don't know exactly what I am to be measuring.
It's an unfortunate mistake people sometimes miss. We all start somewhere. Not only that, but Chrysler was terrible with machining tolerances such as deck heights too tall, which adds to the dilemma. I won't build a stone stock 318 without making SURE the lifter preload is correct. It's pretty critical, IMO. These engines ran hundreds of thousands of miles likely needing the preload corrected and even rocker shafts relocated......but that was in stock form with weak stock valve springs. Once you start a performance oriented build, all of that changes.
Braeden Clark
Well-Known Member
I'm just not understanding how to adjust preload on my setup. I have non-adjustable pedestal mount rockers. I followed the FSM for installing the rockers and tightening the rocker bolts to 21 foot pounds. But maybe with the cam being different I missed something. Damn it
I would try to find the source of the noise before you tear it all apart. Use a mechanics stethoscope. They are inexpensive and work pretty well. The one I have will let you screw the rod end off it leaving an open bell or upside down funnel shape on the end. It then works especially well for finding exhaust leaks at the manifold. It's a really handy tool. Here is one. There are many to choose from.
Lisle 52500 Lisle Mechanic's Stethoscopes | Summit Racing
Lisle 52500 Lisle Mechanic's Stethoscopes | Summit Racing
Braeden, try checking the length of the pushrod by marking the valve tip
Here's one article that describes how.
Lunati How To Verify Valvetrain Geometry
You're correct. There's no adjustment other than pushrod length. With your cam you shouldn't need to have longer pushrods.
Edit: I just read through the entire article. I cant see why you can do it with hydraulic lifters. I checked mine after getting it together.
Here's one article that describes how.
Lunati How To Verify Valvetrain Geometry
You're correct. There's no adjustment other than pushrod length. With your cam you shouldn't need to have longer pushrods.
Edit: I just read through the entire article. I cant see why you can do it with hydraulic lifters. I checked mine after getting it together.
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Braeden Clark
Well-Known Member
I will look into that. Seems simple enough. It would be nice if I could do that without pulling the intake. Maybe I should have just had a machine shop put this thing together. It was fun and a good learning experience. Until crap like this happens.
No need to pull the intake. Just pull a rocker arm, mark the valve tip, put the rocker back on, spin the engine by hand 3 times, remove the rocker and see where the marker is worn off.
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