Oil pressure gauge always pegged.

[Hipster]

I did research putting in a roller cam. Initially too expensive, for one thing, but the other thing is it seems to require special parts like a different timing chain, some kind of cam plate, different distributor gear, and IIRC, I had a hard time finding a factory spec cam. IMO, that's a lot of nonsense to go through for zero power gain.

I digress. I think it's time to get those ARP studs you mentioned. It will put my mind at ease.

I went through it with 2 different heads after going to arp studs the gm nuts were just fine. Also the nuts don't seem to do well with power tools either off or on. Impact guns, air ratchets Imho. not saying it's 100% the problem but you could thread one on the oem head if they're still laying around for a quick comparison.

 

[DeCaff2007]

Here's a vid of the headers glowing. You'll hear the TBI backfire around 2:30.

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FEI (For Everyone's Information), I am absolutely NOT firing it up 10 more times. Believe it or not, I am learning from this experience....

Time to go order parts.

 

[Hipster]

Here's a vid of the headers glowing. You'll hear the TBI backfire around 2:30.

xc_hide_links_from_guests_guests_error_hide_media

FEI (For Everyone's Information), I am absolutely NOT firing it up 10 more times. Believe it or not, I am learning from this experience....

Time to go order parts.

I'm kind of hearing some racket from the rockers. It's important that the valve adjustment is some kind of close to spot on. If you have rocker nuts backing off it's not possible.

 

[Road Trip]

Vacuum assisted. Who's GMT400 doesn't have power brakes?

As far I know, no GMT400s were built with manual brakes. (Old squarebody brake RPO code 'JB1')

My question about your brake booster was if your truck was built with a brake vacuum booster (RPO code JB#)
-or-
if it was manufactured with a hydraulic brake booster (aka: "Hydroboost") driven by the power steering pump? (RPO code JD#)

NOTE: For additional info, check out the helpful chart over HERE shared by @someotherguy. And notice how
at the very top of the GVWR rating the JB vs JD brake booster relationship gets broken?

IF you still have your original RPO sticker on the inside of your glovebox then you can see what brakes your truck
was originally built with. (driven by the GVWR that your truck was built to.) For example, my '99 C2500
has the JD7 brakes for the 8600 GVWR.

And, to be honest, I had been wondering about that. I don't really have a way to test a vacuum line that big, so plugging it for the time being might be a good idea.

It certainly won't hurt anything, and by doing so it will help us figure out if
you have a defective booster causing a large air leak into the intake manifold
or not.

****

As for your rocker arms, I just took a careful look at your photo, and I was wondering
about the orientation of those nuts?

Close-up of your photo, possibly showing the shoulders in the air?

You must be registered for see images attach

My question is, do your rocker arm nuts look exactly the same on both ends? Or, is one side flat (as seen above)
but the other side is more of a bevel or 'dome' shape? If the other side is beveled, then that is the *top* of the
nut, and these need to be turned over.

On the other hand, if both the top & bottom sides of the nut are identical, then that would lead me to believe that
these nuts don't have the self-locking feature?

To better illustrate what I'm trying to describe, here's a picture of a self-locking nut for a SBC that I just looked up
on the Advance Auto website:

You must be registered for see images attach

NOTE: There are 2 main types of self-locking nuts. The first has a plastic (nylon) insert that
provides the 'drag' (EDIT: correct term is 'prevailing torque') between nut and stud, but these are not normally used in high heat
areas. The second type is all metal, but the 'top' of the nut is purposely distorted in order
to provide the desired 'self-locking' function. The photo above is listed for the 350ci SBC
in an '88 C1500. Other brands may look a little different while still providing the same functionality.
(the 'tri-lobe' distorted nuts in @Schurkey's photo are often seen when
the valve covers are removed.)

Again, when I looked carefully at your photo I either wasn't seeing the self-locking physical attributes
- or - your self-locking nuts are inverted?

Either way, fresh (good) self-locking nuts will require noticeable effort while being run down to
the zero-lash point, even before you are working against the spring pumped up hydraulic lifter.
'Self-locking' nuts that spin down freely have lost their mojo, and is cause for immediate rejection
by the engine builder.

EDIT: I second @Hipster's recommendation to use only hand tools when working with these
self-locking nuts. Primarily with power tools you lose the ability to 'feel' the difference in effort
that it takes to run one of these down versus the others. And because of the increased speed of these
tools possibly the additional frictional heat generated helps to cause the self-locking feature to relax a bit?

In a perfect world all 16 of the nuts will take the same (noticeable) effort to be threaded down to the
zero-lash point. Also, you can only run these up and down so many times before they lose most of
their self-locking functionality.

In English, if I am doing repeated mock-ups of the valvetrain during a build (ie: sorting out cam timing
and/or verifying proper valve/piston clearances) I will use conventional nuts during
the trial phase, and then use a set of fresh self-locking nuts once for the *final* assembly. (Note:
this mimics the 'once & done' assembly during initial manufacturing.)

Let us know what you discover. Best of luck, hope this helps!

 

[Schurkey]

You must be registered for see images attach

EXACTLY what I bought from Rock Auto last time. You telling me some were randomly bad? I mean, they are nothing more than 3/8-24 locking nuts.

If those nuts, with the tapered tops are EXACTLY what you bought...where did they go? Your photo shows very different nuts, with flat tops. A couple of them appear to have the side of the nut dimpled as a self-locking feature, but the photo doesn't show it well enough for me to tell for sure.

If this is a problem with the studs--and I guess it could be--so that self-locking nuts don't lock on them, I guess you'd need new (properly-made) studs. I'd test with known-good nuts before I scrapped the studs. Whoever "manufactured" the heads ought to provide you with usable studs for free. But for that matter, they owe you usable nuts as well.

 

[DeCaff2007]

Ok so the lock nuts are inverted. I've been putting them on that way the entire time. They are the type with distorted metal. I certainly know enough not to use the nylon type in this case.

Hmm. Not sure if anyone will understand this reference, but if 2 + 1 =3 and 1 + 2 =3, What's the difference?

Meaning, why does it matter if the "shoulders" on the lock nuts are up or down?

I'm not defending nor rejecting either case, just wondering why.

Whoever "manufactured" the heads ought to provide you with usable studs for free. But for that matter, they owe you usable nuts as well.

That's never going to happen and we both know it.

All new hardware is on the way. Let's hope it shows up before the whole world feels the need to celebrate a 2-thousand-plus year old corpse.

 

[Hipster]

Ok so the lock nuts are inverted. I've been putting them on that way the entire time. They are the type with distorted metal. I certainly know enough not to use the nylon type in this case.

Hmm. Not sure if anyone will understand this reference, but if 2 + 1 =3 and 1 + 2 =3, What's the difference?

Meaning, why does it matter if the "shoulders" on the lock nuts are up or down?

I'm not defending nor rejecting either case, just wondering why.



That's never going to happen and we both know it.

All new hardware is on the way. Let's hope it shows up before the whole world feels the need to celebrate a 2-thousand-plus year old corpse.

typical with almost all fasteners the larger flat side goes toward what its holding. The locking feature whether nylock or crimped always goes at the unloaded end. Posi or poly locks are two piece jam nut set up. This question of yours is a basic rudimentary question. 2+1 is golden while 1+2 can be destructive as it's the opposite to the engineering behind it. Proper assembly and the little details matter. Lots of engineering involved with fasteners. Some is covered in the first or second chapters of most manuals and whats not there can be found in a Machinists' Handbook. By time you get to the engine building chapter it's assuming you've read and understand the basics covered previously in the book. Kind of surprised this happened or that there were no pictures/illustrations in the manual you used for reference to look at. Rule number one, it goes together with parts and pieces facing the same direction as they came apart as engineered. It's not like we don't have phone cameras to document teardowns and create our own reference.

 

[Schurkey]

I have no idea how you could even get those nuts started on the studs when they're upside-down. I thought they were distorted enough that they wouldn't thread on from the wrong end.

And then the tiny area of contact on the rocker balls should have been a clue.

the little details matter.

VERY true. DeCaff and I have had that conversation before.

 

[Hipster]

I have no idea how you could even get those nuts started on the studs when they're upside-down. I thought they were distorted enough that they wouldn't thread on from the wrong end.

And then the tiny area of contact on the rocker balls should have been a clue.


VERY true. DeCaff and I have had that conversation before.

my experience is that it's just the top few threads where they are pinched is where they really start to snug up.. I don't know how starting them upside down would go.... but they did....tapered side first like a lugnut. Comparing them to a standard locking nut , not even close. It may be my computer but not really diggin the lifter pic, but it's not very close or lit well.

 

[DeCaff2007]

my experience is that it's just the top few threads where they are pinched. I don't know how starting them upside down would go.... but they did....tapered side first like a lugnut.

It wasn't nearly as difficult as any of you may think.