Slant *        6        Forum
Home Home Home
The Place to Go for Slant Six Info!
Click here to help support the Slant Six Forum!
It is currently Mon Oct 27, 2025 2:01 am

All times are UTC-07:00




Post new topic  Reply to topic  [ 28 posts ]  Go to page 1 2 Next
Author Message
 Post subject: New motor noise
PostPosted: Sat Aug 27, 2022 9:37 pm 
Offline
Board Sponsor
User avatar

Joined: Sat Feb 08, 2003 2:37 pm
Posts: 4194
Location: CA
Car Model:
I’ve had a shop built motor sitting upside down on my garage covered. Been maybe 2-3 years since it was done and hasn’t been touched since.

I put a few squirts of oil down the plug holes and was able to turn it by hand. It’s an assembled long block at this point but no plugs. Turns fine but at certain spots it’s making a higher pitched squeak noise at the same spots in the rotation. I think it’s the guides/springs/valves… by trial and error I put my hand on one of the valve springs and while rotating it back and forth through the squeak I can feel the vibration.

I tried squirting oil through the spring at the stem but it didn’t help. It uses positive type valve seals so I don’t think much oil will get to the guide from the top. I thought about maybe holding an oil saturated rag/sponge against the valve through the manifold port.

I think it’s affecting at least one other valve because I heard it on at least one other part of the rotation. Should I be worried, or is this normal and just needs some breaking in?


Top
   
 Post subject: Re: New motor noise
PostPosted: Tue Aug 30, 2022 4:39 am 
Offline
EFI Slant 6

Joined: Mon May 26, 2014 4:02 pm
Posts: 442
Location: Vermont
Car Model: Slant Six M37
If this is on the engine stand, can you turn the engine sideways or upside down, and then hit the open valve with some oil? If it is not then penetrating oil might help out.

I would try not to bar the engine over too much as the cam lube will be wiped off prior to break in..


Top
   
 Post subject: Re: New motor noise
PostPosted: Tue Aug 30, 2022 7:35 am 
Offline
Board Sponsor
User avatar

Joined: Sat Feb 08, 2003 2:37 pm
Posts: 4194
Location: CA
Car Model:
I’ve took the pan off and soaked the cylinders and cam from the bottom (and top through plug holes) and made no difference

I pulled the rocker shaft - bottom ends quiet. I’m thinking stems/guides or seals. Hunch is the positive seals are too tight or dried out. I’m going to replace them… just trying to decide whether it’s with other positive seals or umbrella type


Top
   
 Post subject: Re: New motor noise
PostPosted: Tue Aug 30, 2022 8:24 am 
Offline
Board Sponsor
User avatar

Joined: Sat Feb 08, 2003 2:37 pm
Posts: 4194
Location: CA
Car Model:
Sorry… yes, I did get a bunch of oil through the springs onto the valves and seals using an oil can with a little shooter at the end. Didn’t help. I don’t think that made much a difference as the seal wipes it all away.


Top
   
 Post subject: Re: New motor noise
PostPosted: Sat Sep 03, 2022 9:00 am 
Offline
Board Sponsor
User avatar

Joined: Sat Feb 08, 2003 2:37 pm
Posts: 4194
Location: CA
Car Model:
Well.. the saga continues. I removed all the seals and put it back together. No change, same noise

So it’s valve train related, but only happens when it’s under pressure of the springs. What’s left, cam bearings themselves may have gone dry? I squirted oil over the lobes but none probably got in the bearings.


Top
   
 Post subject: Re: New motor noise
PostPosted: Sat Sep 03, 2022 12:48 pm 
Offline
Board Sponsor
User avatar

Joined: Sat Feb 08, 2003 2:37 pm
Posts: 4194
Location: CA
Car Model:
Well I know I’m a rookie at engine engine internals but I’m pretty sure a front cam bearing isn’t supposed to look like this


Attachments:
1F8E83FE-7C44-440E-A693-A364D5F4022E.jpeg
1F8E83FE-7C44-440E-A693-A364D5F4022E.jpeg [ 96.83 KiB | Viewed 1686 times ]
Top
   
 Post subject: Re: New motor noise
PostPosted: Sat Sep 03, 2022 1:34 pm 
Offline
Board Sponsor & Moderator
User avatar

Joined: Mon Oct 21, 2002 11:08 am
Posts: 17167
Location: Blacksburg, VA
Car Model:
I doubt that cam bearing will give you any trouble. Different engines make weird noises sometimes. I wonder if you could be bottoming out the springs, if you have a non-stock cam? I would probably put it in a car and run it for a while and see how the noise goes. Hard to diagnose things on an engine that is not running.

My 2 cents, YMMV...

Lou

_________________
Home of Slant6-powered fun machines since 1988


Top
   
 Post subject: Re: New motor noise
PostPosted: Sat Sep 03, 2022 2:07 pm 
Offline
Board Sponsor
User avatar

Joined: Sat Feb 08, 2003 2:37 pm
Posts: 4194
Location: CA
Car Model:
You’d run a cam bearing that looks as bad as what’s attached above??? It looks like it was pecked at by a chicken.

It’s an rv15rdp cam. I don’t think they are stock springs… I want to say 318 or 340 springs maybe? Don’t remember it was long ago. Not stock valves either. I believe 1.70/1.44 stainless ones from enginebuilder


Top
   
 Post subject: Re: New motor noise
PostPosted: Sat Sep 03, 2022 3:08 pm 
Offline
Supercharged
User avatar

Joined: Wed Oct 12, 2005 9:00 pm
Posts: 3035
Location: kankakee IL
Car Model: 80 volare, 78 fury 2 dr, 85 D150
I can't tell completely by the picture but it doesn't look that bad without seeing it in person for myself.
It looks more "stained" than anything. Can you catch a fingernail on it?
That being said, when I was buying parts to build my engine I took the first set of mains out of their box and they had "chunks" out of them, like some kind of coating, I'd posted pix asking what the members that be, thought at the time// and decided that for what they cost me, to just order another set and put these aside as they were cheap in the overall scope of the cost of an overhaul, not to take a chance on them.
Looking at yours being that some shop built it, I'm guessing they build all brands of engines and probably mostly V8's. I'm hoping it wasn't their first rodeo.
That said a bad cam bearing is a bad cam bearing /no matter what brand of engine. If I were assembling an engine and saw that I would have questioned it as soon as I saw it, whether out of the box or upon installation at worst. From what I see, other than that they apparently didn't lube anything on installing the cam, (which isn't real keen anyway) it doesn't look that bad.
Now, a cam bearing install tool isn't something the average guy has, but I happen to have one. It isn't hard to do, just gotta be careful lining up the oil holes correctly upon the install. And drive them in straight and square.
As long as you did tear down the engine that far for what they cost I'd probably change it but I doubt that is your noise. I'd be looking closely at the head and valves. It's very possible that once everything gets moving and oil starts getting pumped around the noise would be gone.


Top
   
 Post subject: Re: New motor noise
PostPosted: Sat Sep 03, 2022 3:15 pm 
Offline
Supercharged
User avatar

Joined: Wed Oct 12, 2005 9:00 pm
Posts: 3035
Location: kankakee IL
Car Model: 80 volare, 78 fury 2 dr, 85 D150
What brand of bearings are/were they? In my case I'd bought new but very old stock "TRW" brand which in their day were top dog.
That set that I put aside, the box was marked "made in England" and we're packaged better than any other set of engine bearings I had seen before so I was quite surprised to open them and see what I did.
That set had a "v" in a circle stamped in by the part number which I believe they were (something like) Vanderwell, Vandervelde, etc made "for" TRW back in the day. I've since seen this brand advertised for sale in their own packaging in various places. But being from England and from probably (judging by packaging) made in the late 70s/early 80s, I wouldn't have expected a problem with parts from "over there". They ain't china after all

The 2nd set I ordered were also TRW, but this box was marked "made in USA" and looked nothing like the suspect parts did.


Top
   
 Post subject: Re: New motor noise
PostPosted: Sat Sep 03, 2022 3:50 pm 
Offline
Board Sponsor
User avatar

Joined: Sat Feb 08, 2003 2:37 pm
Posts: 4194
Location: CA
Car Model:
Yes to catch a nail. It’s bad.

Maybe it’s the picture. I’ll try to take a better one. I popped out the rear cam seal plug. The rear bearing has the same polished stain but doesn’t have the pecking marks.

Not sure what brand bearings they are as the shop supplied them. If they had a million miles on them ok… but for a new build that’s only been turned by hand ….

Ok, so bad bearings but not source of squeak. But vibration can be felt on cam gear during squeak. Back to valves? Yes running it could spread the oil out that it goes away or it could be catastrophic and make something go boom.


Top
   
 Post subject: Re: New motor noise
PostPosted: Sat Sep 03, 2022 6:30 pm 
Offline
Board Sponsor & SL6 Racer

Joined: Wed Oct 23, 2002 7:57 pm
Posts: 9022
Location: Waynesboro, Pa.
Car Model: 65 Valiant 2Dr Post
Does the cam insert easily and turn freely?

Am I reading right that this is a new never run engine? Any way you look at it those don't appear to be new cam bearings to me. That being said I doubt they are your noise.

_________________
2 Mopars come with Spark plug tubes. One is a world class, racing machine. The other is a 426 CI. boat anchor!
Image
12.70 @ 104.6
Image


Top
   
 Post subject: Re: New motor noise
PostPosted: Sat Sep 03, 2022 6:46 pm 
Offline
Board Sponsor
User avatar

Joined: Sat Feb 08, 2003 2:37 pm
Posts: 4194
Location: CA
Car Model:
Correct, never ran, sat on stand for a few years after rebuilt and just now getting to it.

Cam goes In freely except for last say 1/4” then needs a gentle tap. It will spin with a 6-8” wrench. It will not spin by hand if I put one finger on the bolt and the other on the gear locating pin

That front journal looked dry to me. I’m thinking next step is to lube the journals, put it in, maybe without the chain, and see…

Only thing left if it’s not the bearings is the valve/guides.


Top
   
 Post subject: Re: New motor noise
PostPosted: Sat Sep 03, 2022 8:23 pm 
Offline
Board Sponsor & Moderator
User avatar

Joined: Thu Oct 17, 2002 7:27 pm
Posts: 14723
Location: Park Forest, Illinoisy
Car Model: 68 Valiant
I've had dry rockers sqeak/squeal until oil got go them.

_________________
Official Cookie and Mater Tormentor.


Top
   
 Post subject: Re: New motor noise
PostPosted: Sat Sep 03, 2022 9:00 pm 
Offline
Board Sponsor
User avatar

Joined: Sat Feb 08, 2003 2:37 pm
Posts: 4194
Location: CA
Car Model:
Quote:
I've had dry rockers sqeak/squeal until oil got go them.
Noted. I oiled the shaft from the top but next go around I’ll take apart all the rockers, spacers etc and use assembly lube on them.


Top
   
Display posts from previous:  Sort by  
Post new topic  Reply to topic  [ 28 posts ]  Go to page 1 2 Next

All times are UTC-07:00


Who is online

Users browsing this forum: Bing [Bot], Google [Bot] and 4 guests


You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum
You cannot post attachments in this forum

Search for:
Jump to:  
Powered by phpBB® Forum Software © phpBB Limited