[steve25]

Crank / bearing issues could stem from the fact that the motor is fitted with main studs and the line Bore was never checked?

[tom s]

I see main bolts?Tom

[steve25]

Sorry, your right!

[glhs#116]

Originally Posted by chiphead

Did you guys notice how the wear on the mains is off-center? Both #2 and #3 are off center worn down to the copper. The caps are shifted on the block just a smidge. Likely .0005" or so. Really looks to me like it needs a line hone and the crank checked for straightness.

Hey! Thanks for the insight. I did notice how both caps had the copper showing on the same side off-centre.

Originally Posted by chiphead

If it was lack of oil, all the mains would be burned and the inserts would be welded to the journal. I had serious detonation in my 400 and the mains didn't look this bad. #1 looks passable and #4 and #5 don't look half bad.

Yikes! I know detonation can be silent but I also know that I replaced plugs several times in this car. The last time not long ago. Never saw any speckles...

Originally Posted by chiphead

This is either cap misalignment or a slightly bent crank. This engine ran for awhile with the mains like that. It would hurt oil pressure, but not the cause of the total loss of oil pressure.

Oil pressure was always great. Never really fell below halfway on the gauge. In fact I was really considering the 60psi pump because I figure that 80psi pump possible overloaded the distributor gears.

Now you are reminding me of something. One thing I remember from the past few years is that I rebuilt the TH350 and put (as recommended) a new torque converter on. I always felt it was rough after that. It seemed to me that the torque converter wasn't correctly balanced but I couldn't really be sure since this all happened shortly after the crank replacement. Then, about a year ago, the transmission was starting to slip again and I knew I needed to do a proper "race" type rebuild not a stock one or the trans would keep failing. After this I replaced the torque converter again. The new one fixed that vibration confirming to me that the old TQ was not balanced properly. So, the engine ran with an off-balance torque converter on it for several years. Could that cause that sort of wear (perhaps by causing the crank to flex in a certain direction due to the imbalance)?

Originally Posted by chiphead

Crude checking for a bent crank is easy. Install #1 and #5 block inserts with oil. Sit crank in block. Zero dial indicator on #3 journal and rotate crank. More than .001" runout is possibly bent or serious journal Out Of Round.

I will do this check when I get things apart. This week is looking quite busy with non-car stuff. But maybe at some point late in the weekend.

Originally Posted by chiphead

If you can't get a line hone done, you can re-assemble #2 and #3 with looser main clearances to make up for the slight cap misalignment. .001" per inch of journal should do just fine.

Good advice.

So, as you allude to, I don't really have access to the kind of services I clearly need. There's not a machine shop here I can afford to trust. So I basically have this plan:

1. Take it all apart.
2. Clean, clean, clean
3. Replace bearings: main, rod, cam
4. Dingleball cylinders, lightly polish piston skirts, new rings
5. New distributor gear, new cam, new lifters
6. Probably 60psi Melling 54DS
7. Ye olde emory cloth polish of crank journals

One last question:

One of the main worries that I had with the crank replacement being done in such a side-of-the-road style garage was the concern that they wouldn't torque things correctly. Could you get that kind of bearing wear from wrong torque of main bolts?

When I get time to take some rod ends apart I will share what I find. I've been looking at what I can see of the cam lobes and I'm not seeing any of that slope to them. They all look pretty square in profile. It's kind of a moot point since I have to replace the cam to replace the cam distributor gear...

Sam

[glhs#116]

Judging by my improvised bore mic it looks like still standard bore. I have to order rings so I have to know. As much as I tried to line up the camera you should know that in person the end of my probe is actually about halfway between the ruler marks (looks like it is closer to the far end in the pic).



Sam

[dataway]

Pistons should say if they are oversized. Stamped on the top usually.

[chiphead]

Will an eagle crank drop-in without a balance? I wonder what bobweight Eagle uses for their 455 cranks? Is it close enough to stock 455 rods/pistons BW?

Can nobody in Qatar balance and polish a crankshaft?

[glhs#116]

Originally Posted by chiphead

Will an eagle crank drop-in without a balance? I wonder what bobweight Eagle uses for their 455 cranks? Is it close enough to stock 455 rods/pistons BW?

Can nobody in Qatar balance and polish a crankshaft?

The problem with Qatar is that you have two things and nothing in between. You have the super-mega-hyper-ultra stuff (Gucci, Lamborghini, etc) and you have ultra-bargain guys-from-the-villages-of-Pakistan unregulated dirt cheap cut-every-corner shops. The bargain shops are for sure just going to screw up your stuff. The ultra-hyper-super "Mega Custom" shops are aimed at the mega-wealthy locals and will be full of flash and hype and stupid expensive and are still probably about 50-50 on screwing up your stuff. So I don't really think I have that option. The same thoughts did bother me as well (how close to balanced is this as a drop-in?). But I don't see a way around it here. Apart from buying a rotating assembly. Which sounds quite expensive even before shipping. And somewhat wasteful seeing as it will be going into an "as-is" block with probably just a dingle-ball hone on the bores.

It's not that I like doing it this way. I'm just trying to play the hand I'm dealt, so to speak.

Sam

[n2ogpsj462]

Going to keep having problems unless you do it right. Learn that 20 yrs ago when I rebuilt my first motor. 400 with spun bearings. Decided to skip cleaning the block professionally and got about 1500 miles out of it before it started knocking. Especially on the other side of the world where you can't even find a proper cherry picker.

[glhs#116]

Originally Posted by n2ogpsj462

Going to keep having problems unless you do it right. Learn that 20 yrs ago when I rebuilt my first motor. 400 with spun bearings. Decided to skip cleaning the block professionally and got about 1500 miles out of it before it started knocking. Especially on the other side of the world where you can't even find a proper cherry picker.

Um, sure. I’m worried about that. But as I explained I don’t see any way to “do it right” available to me.

Sam

[64speed]

Save the money you would put in a crank and all the guts and then save some more until you have enough to pay the shipping and get at least a short block from Butler. I have been very impressed with dealing with them since I started my build. I can’t think of the guy I talked to last when I ordered my rocker arms but he told me that jim butlers goal was to put a Pontiac motor in the hands of anyone that wanted one. Hell they have a completely unstructured layaway plan that’s basically pay what you can when you can until it’s paid off. I was blown away by that cause NOBODY I know of is gonna give customer flexibility like that in my opinion. After the three or four conversations I have had with them I plan on buying as much of the stuff that I need that I can from them. Was gonna buy the scat rotating assembly from Summit but after talking to Butler I am ordering their rotating assembly. They ship all over the place. I’m sure they would take a crate down to UPS and stick a Qatar sticker on it as long as you paid for the ride. Once and done is less painful than two and three times of roadside rebuilds in my opinion. Your mileage may vary.

[455GRIN]

Sounds cheaper to buy one of these guys on the forum a ticket to Qatar. Have them pack some tools, and parts. Spent a week in the garage then give them the tour of the country in a T/A just cruising around enjoying the glory.

[steve25]

That's not a bad way to go 455GRIN!

Here's my thinking on this Sam.

If you get things worked out and find out what made the uneven ware in the Bearings then your 1/3rd the way home to getting the motor back up and running well.

Ball honing the cylinders and just a re-ring will if nothing else get you back to what you have said / stated to be a good level of ring seal so we can stratch that off the concern list!
In fact stepping up to gap less total seal rings is a step up when dealing with a 5/64" ring pack, so overall re-ringing could be a gain.

The first thing to do is to get the needed magnetic dial indicator so you can set your Crank back in the block on 2 upper bearing halves and check the run out on the number 3 main, so let's get to this point first.

[n2ogpsj462]

Originally Posted by glhs#116

Um, sure. I’m worried about that. But as I explained I don’t see any way to “do it right” available to me.

Sam

Plenty of good people in the Pontiac community willing to help anyone. A 70 firebird rolling thru the streets in Qatar has got to be a site to see and worth getting it back together right. Maybe we can come up with a package of donated parts to help offset getting the short block right? I have a 2802 cam and lifters cryo treated by Paul marked to the lobes I'd donate if others were interested.

[chiphead]

You can use a dial bore gauge to see if the caps are centered on the block well enough to put back together. That will confirm what condition the main tunnel is in. I expect breaking a crank made the cap dowels move around a bit.

You'll need a bore gauge and a set of mics anyway to check bearing clearances. You got ebay in Qatar?

For the crank, at least ask the question of an Eagle dealer (butler or some of the pro guys here, etc) about shelf balance? At the extreme, maybe somebody will swap cranks with you? All you need is a crank with good journals that has been balanced to factory GM tolerances if you have factory rods and pistons.

What main fasteners are used? You have mentioned ARP fasteners, but AFAIK, only ARP studs are available for main fasteners??

The rest you can do in your living room.

[glhs#116]

Originally Posted by chiphead

You can use a dial bore gauge to see if the caps are centered on the block well enough to put back together. That will confirm what condition the main tunnel is in. I expect breaking a crank made the cap dowels move around a bit.

You'll need a bore gauge and a set of mics anyway to check bearing clearances. You got ebay in Qatar?

For the crank, at least ask the question of an Eagle dealer (butler or some of the pro guys here, etc) about shelf balance? At the extreme, maybe somebody will swap cranks with you? All you need is a crank with good journals that has been balanced to factory GM tolerances if you have factory rods and pistons.

What main fasteners are used? You have mentioned ARP fasteners, but AFAIK, only ARP studs are available for main fasteners??

The rest you can do in your living room.

Ho ho! Good catch my friend. ARP main stud kit and ARP rod bolts were provided to the shop. The fact that we all see bolts tells me they were never used. Since this shop will never see another Pontiac I think it's more likely than theft that they simply figured they were the wrong part since it wasn't like what was coming out of the engine. So, yeah, I guess probaly all the factory fasteners... Eagle cast steel crankshaft 104554210.

Sam

[dataway]

Originally Posted by n2ogpsj462

Plenty of good people in the Pontiac community willing to help anyone. A 70 firebird rolling thru the streets in Qatar has got to be a site to see and worth getting it back together right. Maybe we can come up with a package of donated parts to help offset getting the short block right? I have a 2802 cam and lifters cryo treated by Paul marked to the lobes I'd donate if others were interested.

I was thinking something like this way back in the thread ... I'd throw in $20, obviously our man is not doing all this for some charity ... so he deserves some charity

[johnta1]

Sam, what oil filter were you using?

[steve25]

A big note here to those of you who have posted to this string about using Emory cloth or whatever to polish out the Crank, please look at this info out of the Federal Mogal bearing catalog.

It pertains to nodular Cranks like Pontiac factory and aftermarket cast ones.

If you think you can just polish up one of these Cranks at home your very wrong!

Also it makes you wonder how a small shop that does not cut Cranks on site can even polish one up , and to top that off even a shop that can cut Cranks that takes one in by another shop needs to know how the Crank was spun when it was cut to then know how to spin it up to repolish it!!

Also here's some info on bearing failure modes.

[glhs#116]

Set aside some time today to make some progress. The distributor gear looks exactly as expected given what the gear on the cam looked like from underneath. No big surprise. But the distributor otherwise seems quite good. End play in spec. Side play not really noticeable.

With the valve covers off I see no nasty surprises there either. All pushrods seem to be spinning based on the witness on the guide plates. The HS rockers still look good. Spark plugs came out and again all look pretty good. No sign of detonation on the plugs, decent burn, no oil.

Hopefully I'll get some time this week to get the heads and valley pan off. I already TDCed the engine on #1 compression and marked the distributor position to help when I finally get this together again.

My immediate concern is getting everything cleaned and getting the crank polished. I've appealed for help through a friend who works on the base. Hopefully he can find a Pontiac enthusiast there who can help me out. I don't trust any local shops. If it comes down to that necessity I'll probably just see what I can do at home...

I'm guessing I should at least pop out the oil gallery plugs and get new ones. How much of a pain is it popping new plugs in and getting them to stay? Yes, I've heard of tapping them for threads but that sounds like something I wouldn't trust a shop to do nor myself so I'd rather properly drive a plug and properly stake it.