[shermanator2]

Originally Posted by 78w72

it says "engine balance: external" thats what i was referring to about terminology, pontiac engines aren't external balanced by the definition i have always understood. i didnt mean to open a can of worms regarding what the proper terms are, but i hope firebird central confirmed this is the correct flywheel for your pontiac engine that should be internally balanced.

I have to disagree with you. Internally balanced means that rotating assembly is in balance without the external components (flywheel and harmonic damper). No production traditional Pontiac V-8 left that factory this way as far as I have read. To be in balance, the flywheel/flexplate (an external component) had to be attached. This means a factory Pontiac engine is externally balanced. With a SBC of 350 CID or less, the rotating assembly is in balance without the flywheel or damper attached. That is why the say is is internally balanced.

If the OP is replacing a stock flywheel, then the one he selected (externally balanced) is correct. If his engine was balanced with an aftermarket neutral balanced flywheel, then he would want an "internal balance" version.

[bhill86]

Thanks for the help on the flywheel guys. I am replacing a stock so I should be good with the one I posted it seems.

Maybe a hint of good news today. Pulled the pan and found what appears to be a coating of some sort inside coming off. I have no clue about this pan other than it was on the car when I got it. The coating coming off looks very much the same as the flakes I found in my filter. Picture of it and what it looks like in my hand. What do you think? The picture don’t reflect it well, possibly from the lifting, but in my hand, one side looks brass colored and the other lighter.

[bhill86]

Next observation leading to a question….the oil pump pickup has some crud on the bottom. Is this normal or should I be raising an eyebrow? The pickup also is welded in place but appears to not be horizontal, or parallel, with the bottom of the pan. You can see a partial outline in the bottom of the pan. Is that ok?

That leads me to, what might I be looking for when I pull the oil pump? I know there isn’t much to them but do you expect if there is trash holding the check ball open that I’ll find something or will it be easy to miss? What else might I look for with regard to the pump? I wanted to ask that before I went diving into it.

I also opted to not dig any further tonight till I get a dial indicator gauge. I want to check the crank end play before I mess with anything. That said…..

I plan on pulling at least the main caps but I’d like your advice as to where to start. Can I leave the rear main alone for now since it doesn’t leak? I don’t know what kind of seal it currently has. And should I plan to check the rods as well? Again, the top end is assembled and I’d like to not mess with it if possible. I know it may not be they typical preferred method but I hoped to leave the pistons and rods in place. Can I do that and safely check those bearings or am I risking too much?

[PunchT37]

I would leave the rear main alone right now. Pull a few rod caps 1’st. See if they show copper. Then maybe the number 1 main. If they are ok, the problem is prolly in the pump or pickup.

[tooski]

From the first pic of the pickup/screen, the pickup was installed incorrectly. The edge of the screen should be on the other side of the bottom plate. There is a little relief in the pump body casting at that corner where the edge of the pickup normally fits into. When that is done it would also slightly change the angle of the pickup.

[West Coast GTO]

This pick up had so much crud and silicon pieces in/on it that you could barely see any screen and it still showed 15 pounds at idle and 60 at 3000 rpm.

[25stevem]

Indeed that pick up is too low.

It needs to be between 3/8" and 1/2" off the bottom of the pan.

In terms of the pickups position in relation to the pump body there should be a dimple cast into the body that stops the pick up from going to close in the direction of the windage tray when the pump is bolted onto the block.

The outer lip of the pickup should be right up against that cast on dimple.

[78w72]

Originally Posted by shermanator2

I have to disagree with you. Internally balanced means that rotating assembly is in balance without the external components (flywheel and harmonic damper). No production traditional Pontiac V-8 left that factory this way as far as I have read. To be in balance, the flywheel/flexplate (an external component) had to be attached. This means a factory Pontiac engine is externally balanced. With a SBC of 350 CID or less, the rotating assembly is in balance without the flywheel or damper attached. That is why the say is is internally balanced.

If the OP is replacing a stock flywheel, then the one he selected (externally balanced) is correct. If his engine was balanced with an aftermarket neutral balanced flywheel, then he would want an "internal balance" version.

thats fine if you disagree, i wasnt trying to argue or state either term was right or wrong, was just replying to the OP asking about the 301 balance & wanted to provide my experiences of what i was told by butler & my machinist as to which flexplate/flywheel to buy for my rebuilt pontiac engines, they were all called neutral/internal balanced & were not used as part of the balancing of the engines... the butler supplied eagle rotating kits come pre balanced & they say no further balancing is needed & that you can use any aftermarket neutral/internal balanced flexplate/flywheel.

the OP said this engine is rebuilt so its very possible it was balanced internally, just suggesting to confirm what the engine needs before buying a flywheel that could be the wrong balance type.

[tom s]

Check the #2 and #4 mains.That should give you a good clue of the mains.Tom

[bhill86]

Will do on checking the rods and #2 and 4 on the mains to start. Fingers crossed.

As for the pump, I’ll have to take a look at it again when I’m able. Maybe tonight after work, if not, likely tomorrow. Am I correct in assuming with the pickup tacked in an improper position I’m best off picking up another pump to at least correct that?

Curious if anyone has an opinion on that coating inside the pan. Does that pan look aftermarket which would’ve had some sort of coating inside? I wouldn’t expect a stock pan to but what do I know?

Lastly, going back to the flywheel, I’m replacing a stock one which I hadn’t had any issues with balance wise. I don’t recall the builder having checked any balance on anything nor do I remember him even having the flywheel and clutch assembly but he may have. I did notice an area where it looks like the pressure plate and flywheel were marked with zeros to maintain alignment so maybe that was from him. I just can’t remember.

[tom s]

Have the balanced checked on your flywheel and have the new one set to it.Tom

[78w72]

Originally Posted by bhill86

Lastly, going back to the flywheel, I’m replacing a stock one which I hadn’t had any issues with balance wise. I don’t recall the builder having checked any balance on anything nor do I remember him even having the flywheel and clutch assembly but he may have. I did notice an area where it looks like the pressure plate and flywheel were marked with zeros to maintain alignment so maybe that was from him. I just can’t remember.

i didnt mean to cause you any worries on the flywheel, just suggesting you confirm you are buying the correct flywheel based on how the engine was balanced when it was rebuilt. the machine shop should have a record of what they did on that engine or the builder should be able to say how he would have balanced the engine.

after the other posts on balancing i think it is an issue with what terms some people use for how a pontiac engine is balanced when rebuilt & how the aftermarket refers to their flexplates & flywheels balance. always a good idea to confirm you buy the right parts based on how t he engine was built/balanced.

[25stevem]

In regards to the rod bearings with the Pontiac Oil system number 2 rod is the last one to get oil.
That looks good then you may get away fine.

[bhill86]

78w73, no worries. I take all of this as a learning experience. I did find the paperwork from my build but it only specifies the crank balance was checked and no changes. The more I think about it, I may have sent the flywheel off with the engine but I can be sure. Tom s’s idea of having the old and new checked is a good one. I would think since it said “balance checked and no changes” it would be balanced the same as factory.

25stevem, thanks for the tip on the #2 rod. I will start there

[bhill86]

Well, got enough time today to get to #2 rod and #4 main. I’m guessing this is not what I want to see. I’m fast I know the top half of #2 isn’t. I measured my crank endplay last night too which came out to .010”. From what I’ve found that’s at the limit, if not slightly beyond, what’s considered acceptable. Am I correct in my assumption that seeing copper on the thrust surface is a bad thing? According to the paperwork I have from the builder the endplay measured at .009” at that time.

To reiterate, this engine has around 4700miles on it over 5 years.

[bhill86]

Also, I noticed this scoring on a couple piston skirts I could see. Normal or concerning?

[25stevem]

That scoring is from crap in the motor, but the piston can be reused.

That rod bearing was ready to spin on you and likely then take the whole motor out!

You did the right thing by biting the Bullet and yanking it out of the car, so pat yourself on the back for good judgment!

[bhill86]

Yea, I’m glad I pulled it. Now begs the question, was it debris of some sort that caused the bearing to fail and where do I go from here? I know I only pulled the one cap and that one rod so far but should that crank be polished or could I get away with new bearings, check for good clearances, replace the pump if necessary and run it?

Dependent on what else I find with the other bearings of course.

[25stevem]

If it where me I would pull out the oil galley plugs and see how much gunk might be in there.
If the block was not cleaned well on the last rebuild then crap may still be in there or even crap from the current failure could be hanging out in that gunk only to come loose and eat up the motor again.
The same with the oil passages in the crank, they must be flushed out with the needed size long brush.

[Verdoro 68]

Found myself in a similar spot recently when I pulled my engine so I definitely feel your pain. Mine looked worse than yours, but it's helpful to see what other engines look like. Early on in my engine's life, the valve stem retainers destroyed the stem seals which sent trash everywhere and killed the bearings. It never had a chance.

https://forums.maxperformanceinc.com...5888&p=6309978

Although it sucks, it's best to pull it all apart, clean it thoroughly (then clean it again and again) and take your time to rebuild it correctly.