Rod knock on an engine with 4000 miles??????

[highperf4x4]

Originally Posted by americanmusc1e

to thin down 4 quarts of 20w50 (which i run because i have a flat tappet camshaft)

Your oil is only 20w. It's never any thicker than that unless it's extremely cold outside. That 50 only means that when it's "hot" is "equivalent" to straight 50w that's also hot. They use "fillers" to keep the 20w050 from thinning down much as it heats up. You sacrifice some lubrication for it.

I run straight 30w.

Also, thicker oil doesn't help a flat tappet cam. Lubrication and heat reduction does. A multi-grade oil has less lubrication than a straight weight oil. You can use a zinc additive if you're worried about the camshaft.

[americanmusc1e]

Originally Posted by special-K

It could be alot of things.But low oil pressure points away from most.Was the oil pump replaced?
I based my other remarks on the 4,000 mile statement.i guess it`s been knocking for awhile?
I wish I could check it out.I hope it`s not too serious.

oil pump was replaced with mellings m55 standard volume.

I started this thread when the problem started. The rocker arms have been giving me a problem for a while. at first I had 'em too tight and killed a lobe on #2 exhaust for sure, now I've been having a problem keeping them tight

[Rudy67chevy]

sounds like my 02 chevy silverado

[highperf4x4]

Originally Posted by americanmusc1e

oil pump was replaced with mellings m55 standard volume.

I started this thread when the problem started. The rocker arms have been giving me a problem for a while. at first I had 'em too tight and killed a lobe on #2 exhaust for sure, now I've been having a problem keeping them tight

Setting the lifters too "tight" won't kill a lobe. It only makes the engine run bad since the valves won't close.



1. if you lost a lobe then you should have pulled it immediately. It's throwing metal shavings everywhere!!!!!!!

2 If you have other rockers that are getting alot of lash in them, then you're killing more than one lobe.

3. sounds like you didn't break the cam in right.

When you first put the motor in the truck how did you break in the cam and how did you set the lifters? It's as easy as pie with hydraulic lifters and you shouldn't have to touch them again once they're set. If you had to adjust them after you ran the engine then your cam didn't get broke in right.

[highperf4x4]

I can tell by now that your engine is in bad shape. Even if it was a new build with fresh machine work, it's toast now. I can gaurantee you that you're out a cam and set of lifters for sure. If you keep driving it and you have stamped steel rockers then you're out a set of rockers and pushrods too. The beefier rockers like rollers or roller "tipped" might hold up longer but you'll probably find a pushrod or two trying to go through a rocker right now. I am gonna say this though, that knocking noise you think you hear is probably coming from the lifters. Still, as much metal as you've circulated through the motor now, I'd turn the crank again. If it isn't smoking yet then the cylinders are ok.

I'd pull the intake off the motor right now and see how many pushrods have slack in them and then run your finger around in the oil laying in the lifter valley and see if you find "copper" shavings in it. If so, your mains and rods are shot.

[highperf4x4]

Oh btw, just for the record, any pickup and especially a performance motor should have a high volume oil pump. In fact, even if I do a stock rebuild, I use a high volume pump.

[americanmusc1e]

OK, I pulled the intake, I definitely have a flat lobe on #2 exhaust, but the lifter was not worn through. couldn't find any copper looking stuff in the intake valley (copper is not an easy color to look for in a red intake valley), did find some oil with metal in it sitting in the intake valley, but the oil itself looks pretty good. I haven't inspected it yet(that's next).

could the problems I'm having be coming from the valvetrain (even the low oil pressure???)????

[highperf4x4]

The low oil pressure would be coming from the crankshaft. Mostly the mains but the rods too.

The oil will look good. It's still fresh oil it's just full of metal shavings so now it's more like sandpaper than a lubricant.

If you took your finger and smeared it around in the oil laying in the lifter valley (especially the low spots) then the copper shavings will be on the end of your finger. You'll be able to tell the difference between copper and any other metallic flake in the motor. It looks copper, the rest look silver.

I swear to freakin god you just told me that your lifter valley was painted red!!!!!!!!!!!!!!!!! Someone needs to be shot. Either you or your engine builder.

NEVER UNDER ANY CIRCUMSTANCE PAINT ANY INTERNAL AREA OF ANY ENGINE. If you meant something else ( I can't imagine what) by "it's red" then my bad, otherwise....

[highperf4x4]

Btw, that cylinder with the flat cam lobe would be making a knocking sound for a couple of reasons, 1. MAJOR valve lash 2. The exhaust can't get out if the valve doesn't open far enough. It will pop when the intake opens.

[highperf4x4]

Originally Posted by americanmusc1e

could the problems I'm having be coming from the valvetrain (even the low oil pressure???)????

Dude, your engine is shot. Period. There is nothing else I can tell you. It has to come out and you have to start from square one. Goodluck.

[americanmusc1e]

OK I'm really depressed, tried to adjust the valves and my #2 intake pushrod disappeared. pulled the intake back off and found it in two pieces. My Engine looks like its shot, but I don't have enough money to rebuild it.

[special-K]

Glycol is red.

Man,I was hoping for the best.I`m real sorry to hear this.

[highperf4x4]

That sucks dude but it is what it is. Just get headed in the direction of another build. Jerk it out, tear it down, see what can be re-used. Toss the cam, the lifters, the pushrods, AND the rocker arms in the trash.

Check your crank for grooves in the rod and main journals and check the bearings as well. If you see any grooves in the crank or your bearings are showing copper then you probably need to turn the crank again. Pistons/Rings and cylinders should be fine if you're strapped for cash but new rings wouldn't hurt. Cam bearings should be ok. Timing chain should be okay too. You will need to flush the heads really good and have the block vatted to get all the metal shavings out of the tight spots.

It won't cost you nearly as much as a new build would mainly because you don't need to do any machine work.

[highperf4x4]

Originally Posted by special-K

Glycol is red.

hahaha, antifreeze in the lifter valley???!!!!

Dude, don't jinx him. He's suffered enough already.

[chevymad]

I think special K meant glyptol, which is an acceptable coating for the inside of a motor. If a cam lobe is flat, and theres metal in the oil, all the bearings will most likely be shot. Been there. Cam bearings will need to come out too, they'll be worn AND they'll be hiding metal shavings behind them. High volume pump is almost never needed in a sb chevy unless you've set your bearing clearances waaay too loose.

I was able to re-use my timing set, crank, pistons/rods, and heads when I lost my cam. Everything else was a loss. 50k mile motor running mobil 1. This new oil spec is crap!

You'll want to run rifle brushes through every oil galley in that block, or the metal thats in there will tear up the motor again.

Sucks, I know, did this all last year myself.

[special-K]

Yeah,that`s what I meant.I forgot to remember the name.

Is this a large journal steel crank 327?Hoping the crank stood up w/o needing down another notch.

Just in January one coldass morning my crate motor blew.A main web cracked at a cap bolt,cap was loose,and crank broke.50,000 miles out of $8,600...it hurts.I feel your pain,Sometimes even doing the right thing isn`t enough.Go figure...

[highperf4x4]

Originally Posted by chevymad

I think special K meant glyptol, which is an acceptable coating for the inside of a motor. If a cam lobe is flat, and theres metal in the oil, all the bearings will most likely be shot. Been there. Cam bearings will need to come out too, they'll be worn AND they'll be hiding metal shavings behind them. High volume pump is almost never needed in a sb chevy unless you've set your bearing clearances waaay too loose.

I was able to re-use my timing set, crank, pistons/rods, and heads when I lost my cam. Everything else was a loss. 50k mile motor running mobil 1. This new oil spec is crap!

You'll want to run rifle brushes through every oil galley in that block, or the metal thats in there will tear up the motor again.

Sucks, I know, did this all last year myself.

Actually it's Glyptal with an "a" but I still don't use it. I believe it changes heat reduction in the iron as it "insulates" it from the oil, but that's my own opinion. If you're going to use it you need to do it right after the engine is vatted or bead blasted or it doesn't stick.

As for the bearings, (main's/rods) I would NEVER re-use them no matter what the circumstances are. However an "inspection" of their condition (grooves or showing copper core) can tell you whether or not the crank needs to be turned again. However, if your crank is at .040/.040 already then look for another one if it's damaged.

The cam bearings are a different story. They don't need to be replaced unless you can see something wrong with one of them. Once the block is disassembled get your mirror and flashlight and have a look. The engine I built for my 4x4 2 years ago has cam bearings that have been through 4 different cams. The engine was originally in my old 76 chevy and I only changed the cam bearings when I built it for that truck. And yes, one of those cams was a failed break-in. I've been there too.

As for cleaning the metal out of the block, I'd leave that to the machine shop when they vat it. It's impossible to get it all yourself.

[highperf4x4]

Originally Posted by special-K

Just in January one coldass morning my crate motor blew.A main web cracked at a cap bolt,cap was loose,and crank broke.50,000 miles out of $8,600...it hurts.I feel your pain,Sometimes even doing the right thing isn`t enough.Go figure...

Now THAT....... would suck!

[highperf4x4]

One more note, any motor, small block or not that isn't "stock" or is being used in a pickup/van/suv should have a high volume oil pump. Extra heat is generated by the crankshaft under heavy load or high rpm and caps/bolts will expand/stretch. You need the extra pressure to keep plenty of oil in those journals.

[monte0185]

So far everything I have read is mostly true but I have to add a couple things. If you put the block in a VAT at a machine shop they HAVE to pull the cam bearings and replace them. Main reason for this is that the acid in the vat will melt anything that is not steel or Iron. 2nd is I never do a rebuild without replacing cam bearing cause this is the first place you will loose oil pressure. Oil pumps high volume or not if its not a performance rebuild and your not turning 6k rpm's on a regular basis a standard oil pump is just fine.

Oh and the reason I know these things is I have worked at a machine shop for a couple years on the side for some extra money. I still have the same guy do all my engine work cause i know and trust him. Of course everything about cars is open to interpretation.

[chevymad]

I've got a standard volume pump that keeps 85psi of cold pressure at 1200rpm. Which is actually too high. Its 40psi hot idle. I'm using 10w30 royal purple. Oil pressure was actually higher with mobil 1. If you want pressure change the pump spring, you only need volume when you have large bearing clearances.

I know I won't change your mind, but putting the info out there.

And vatting the block will not remove the metal from inside the galleys. And most machine shops won't do it either. You need to take it yourself and wash/brush out every galley.

Another reason for changing the cam bearings, the same oil that is full of metal, that ate the mains/rods, also went through the cam bearings. Even looking ok, have you measured the clearance?

[highperf4x4]

Guys I'm gonna back out of this one. It looks to me like we're just headed for an argument in the middle of this dudes thread and that's only going to confuse him. I've been building performance engines for over 20 years so I'm pretty thick headed about my opinions.

Best of luck to everyone though. We do it because we love it.

americanmuscle, if you need any help or just want to ask a question pm me ok?

[americanmusc1e]

thanks guys, I called the machinist that did the motor and he agreed that the motor was probably gone. but he said occasionally you can change the cam and the oil and the bearings will be fine. Just for grins, I'm gonna stick a used lifter and pushrod in it and see if the the oil pressure improves. probably not, but if it does, I'll stick a new cam in it and see how it does.

If it needs a rebuild. I'm not gonna reuse the crank, I'm gonna put a SCAT 3.75" 9000series crank, good rods and forged pistons in it. (I know it will cost more but I wanted to do this last time and didn't do it, then I kicked myself for not building a 383)

Hopefully my vortec heads will not need any work

[highperf4x4]

You got spunk! I like that!

[monte0185]

Good luck!! Sounds like its gonna be a fun build. A 383 is gonna be my next build think im going with twin turbo's though.

highperf4x4
I just wanted to say that you sound like you know what your talking about and I pretty much agree with everything you say. We all have our difference of opinions on the way things are done but that dosent mean any one of them is wrong just different. Please feel free to add your opinion as not all of us are experts and all of us have something to learn that we might not have know previously. I know I appreciate it. just didnt want anyone to think I'm not open to advice.