390 noise
Thread Starter
|
Tuned
Joined: Apr 2017
Posts: 266
Likes: 7
390 noise
I have a 1970 F100. It has a 390 with 3spd/OD column shift transmission. The engine was rebuilt roughly 8 thousand miles ago by Terry Walters Precision engine in Roanoke VA. The engine runs great, although it has a chatter noise when the engine is fully warmed up and hot from driving it around. It's not like a lifter tap, but rather just a chattering noise. When the engine is cold and warming up is sounds like a sewing machine though. The paperwork from the shop said that the rocker shafts were reconditioned. Whatever that means. I'm just not sure what I'm hearing. Do I need new rocker shaft assemblies that are adjustable? Do I need to measure for longer pushrods? Weak lifters? Oil flow? Or is it anything that I even need to be concerned with. I had a 65 Merc with a 390 that didn't sound like this. Any help is always much appreciated. Thanks and here's a link to the video of it so you can hear what I'm referring to.
Super Moderator
Joined: Apr 2004
Posts: 34,499
Likes: 2,811
Any oil getting to the rocker shafts?
Sounds like a solid lifter engine badly in need of adjustment.
Something is worn and/or not fitted correctly--too short of a pushrod perhaps?
Somehow I put our 390 back together for our dad and had no trouble......
Sounds like a solid lifter engine badly in need of adjustment.
Something is worn and/or not fitted correctly--too short of a pushrod perhaps?
Somehow I put our 390 back together for our dad and had no trouble......
FTE Leadership Emeritus
Joined: Jul 2002
Posts: 42,561
Likes: 423
From: Long Island USA
Yeah, a hydraulic-lifter engine shouldn't sound like that. But then, even solid lifters shouldn't do that.
Like 85e150 said, pull the valve covers, and see if the rockers are getting oil. While there, pull the coil wire (and put it near the engine block so the spark has somewhere to go), and turn it over with the starter. Make sure all the rockers are moving the same amount.
I hate to say it, but it sounds like a wiped cam lobe.
Like 85e150 said, pull the valve covers, and see if the rockers are getting oil. While there, pull the coil wire (and put it near the engine block so the spark has somewhere to go), and turn it over with the starter. Make sure all the rockers are moving the same amount.
I hate to say it, but it sounds like a wiped cam lobe.
Thread Starter
|
Tuned
Joined: Apr 2017
Posts: 266
Likes: 7
Yeah Krewat, that's kind of what I was thinking also on the cam lobes. I was not the one that had the engine rebuilt. The PO did and from what I could gather he is a dumb B#$tard and probably didn't break the engine in right because it has done that since I've owned it. Is that something that I would notice at operating temp and not on a cold engine?
Anyway, no comp cam that I know of. Thanks for the replies
Anyway, no comp cam that I know of. Thanks for the replies
Thread Starter
|
Tuned
Joined: Apr 2017
Posts: 266
Likes: 7
Also, Dave you mentioned a possible problem with the Comp Cam XE cams. May I ask what it is? What kind of cam would you recommend? Currently it has a run of the mill cam in it with a 204/214 duration according to the engine paperwork. Thanks
Cargo Master
Joined: Oct 2020
Posts: 2,676
Likes: 785
The older Comp Cams High Energy and Magnum lobes don't have this problem neither do the Engine Power grinds which are available everywhere. In flat tappet hydraulic applications normally I use the Reed Torque Master flat tappet grinds which also don't have noise problems. I get them ground for my by Steve Demos, Demos' Cams Jefferson GA.
Trending Topics
Fleet Mechanic
Joined: Feb 2007
Posts: 1,652
Likes: 79
From: Mooresville, NC
FEs, FTs don't sound like that --- this one sounds like CHIT.............likely upper end, but ---> I'd get a 3-4 ft length of rubber hose, "attach" one end to your favorite (already attached) Mark 1 Ear Piece, the other end as a probe.
Ditto what Dave McClain said -- real, actual CHIT coming out of the (combined) Edelbrock / Comp Cams bunch lately.
Ditto what Dave McClain said -- real, actual CHIT coming out of the (combined) Edelbrock / Comp Cams bunch lately.
Last edited by F350 1990; Apr 18, 2021 at 10:27 AM.
FTE Stories
Ford Trucks for Ford Truck Enthusiasts
10 Things Every Truck Owner NEEDS (2026 Edition)
Michael S. Palmer
Rezvani's Latest Post-Apocalyptic Monster Is a Ford F-150 Raptor Underneath
Verdad Gallardo
Top 10 Most Expensive Ford Trucks Ever Sold on Bring a Trailer
Joe Kucinski
2027 Ford Super Duty Buyer's Guide (Every Model, Engine, & Package)
Brett Foote
Top 10 Ford Truck Tragedies
Joe Kucinski
AEV FXL Super Duty - the Super Duty Raptor Ford Doesn't Make
Brett Foote
Lobo Vs Lobo: Proof the F-150 Lobo Should Be Even Lower!
Michael S. Palmer
Ford's 2001 Explorer Sportsman Concept Looks For a New Home
Verdad Gallardo
10 Best Ford Truck Engines We Miss the Most!
Joe Kucinski
Thread Starter
|
Tuned
Joined: Apr 2017
Posts: 266
Likes: 7
FEs, FTs don't sound like that --- this one sounds like CHIT.............likely upper end, but ---> I'd get a 3-4 ft length of rubber hose, "attach" one end to your favorite (already attached) Mark 1 Ear Piece, the other end as a probe.
Ditto what Dave McClain said -- real, actual CHIT coming out of the (combined) Edelbrock / Comp Cams bunch lately.
Ditto what Dave McClain said -- real, actual CHIT coming out of the (combined) Edelbrock / Comp Cams bunch lately.
Cross-Country
Joined: May 2006
Posts: 75
Likes: 15
What is your oil pressure when the engine is hot?
Low pressure can also cause lifter noise.
We have comp cam lifters and had a similar noise to yours when hot. Had to preload the lifters more than you do typical lifters. Your typical lifter is preloaded about 1/2 a turn. These had to be preloaded about 1 turn. We have adjustable rockers on an aftermarket system..
If you do not have adjustable rockers, only way to add more preload is use a longer pushrods.
Low pressure can also cause lifter noise.
We have comp cam lifters and had a similar noise to yours when hot. Had to preload the lifters more than you do typical lifters. Your typical lifter is preloaded about 1/2 a turn. These had to be preloaded about 1 turn. We have adjustable rockers on an aftermarket system..
If you do not have adjustable rockers, only way to add more preload is use a longer pushrods.
Last edited by dcm0123; Apr 22, 2021 at 10:06 PM.
Thread Starter
|
Tuned
Joined: Apr 2017
Posts: 266
Likes: 7
What is your oil pressure when the engine is hot?
Low pressure can also cause lifter noise.
We have comp cam lifters and had a similar noise to yours when hot. Had to preload the lifters more than you do typical lifters. Your typical lifter is preloaded about 1/2 a turn. These had to be preloaded about 1 turn. We have adjustable rockers on an aftermarket system..
If you do not have adjustable rockers, only way to add more preload is use a longer pushrods.
Low pressure can also cause lifter noise.
We have comp cam lifters and had a similar noise to yours when hot. Had to preload the lifters more than you do typical lifters. Your typical lifter is preloaded about 1/2 a turn. These had to be preloaded about 1 turn. We have adjustable rockers on an aftermarket system..
If you do not have adjustable rockers, only way to add more preload is use a longer pushrods.
Cross-Country
Joined: May 2006
Posts: 75
Likes: 15
Comp cam "changed" the preload instructions for High Energy™ & Hi-Tech™ lifters. If these are the lifters you have I suggest you call Comp Cam, explain your situation and ask them for the recommended preload.
We initially set our 1/2, had the same noise and found out they changed the instructions per the instructions above so we reset for more preload and the noise went away..
There are reasonable priced sources for custom length push rods if you need them. You need to make sure you order the proper ball diameter to fit the lifter and the rocker arm. My recollection was the lifters provided by Comp Cam did not take the same diameter push rod as the OEM.
We initially set our 1/2, had the same noise and found out they changed the instructions per the instructions above so we reset for more preload and the noise went away..
There are reasonable priced sources for custom length push rods if you need them. You need to make sure you order the proper ball diameter to fit the lifter and the rocker arm. My recollection was the lifters provided by Comp Cam did not take the same diameter push rod as the OEM.
Cargo Master
Joined: Oct 2020
Posts: 2,676
Likes: 785
As long as there is some preload I don't see how adding more will make the valve train any quieter unless you've got the lifter adjusted to be nearly bottomed out and if the lifter is very leaky(poor quality); instead of leaking down the expected .006 is actually leaking much more maybe .020. If the lifter was adjusted to be only .006 from the bottom and it couldn't bleed of any more than that amount it would be quieter.
The valvetrain probably would also run quieter if solid lifters where used and set to have a lash that's .006 X the rocker ratio.
The valvetrain probably would also run quieter if solid lifters where used and set to have a lash that's .006 X the rocker ratio.
Cross-Country
Joined: May 2006
Posts: 75
Likes: 15
As long as there is some preload I don't see how adding more will make the valve train any quieter unless you've got the lifter adjusted to be nearly bottomed out and if the lifter is very leaky(poor quality); instead of leaking down the expected .006 is actually leaking much more maybe .020. If the lifter was adjusted to be only .006 from the bottom and it couldn't bleed of any more than that amount it would be quieter.
The valvetrain probably would also run quieter if solid lifters where used and set to have a lash that's .006 X the rocker ratio.
The valvetrain probably would also run quieter if solid lifters where used and set to have a lash that's .006 X the rocker ratio.
My son said the cam is a high lift cam. I remember in my younger years there were hydraulic lifters advertised as "lifters which click" to help idle when you had a high lift cam. Maybe this is a variation of that.
Cross-Country
Joined: May 2006
Posts: 75
Likes: 15
As long as there is some preload I don't see how adding more will make the valve train any quieter unless you've got the lifter adjusted to be nearly bottomed out and if the lifter is very leaky(poor quality); instead of leaking down the expected .006 is actually leaking much more maybe .020. If the lifter was adjusted to be only .006 from the bottom and it couldn't bleed of any more than that amount it would be quieter.
The valvetrain probably would also run quieter if solid lifters where used and set to have a lash that's .006 X the rocker ratio.
The valvetrain probably would also run quieter if solid lifters where used and set to have a lash that's .006 X the rocker ratio.