[78w72]

One member asked about how oil clearance on the rod bearings were measured, then oil psi at certain engine temps was posted, oil temps are not the same as engine coolant temps.

Nobody questioned the rod length, they mentioned how the pistons should be at or above the deck in that arrangement, they are stock rods so of course they are stock length.

.035 pistons below deck seems rather low, anyone care to comment on that? Most builds try to get a lot tighter or even zero decked for optimum quench, .035 is far from ideal & no "racer" would do that if they were trying to get extra power.

Ive seen plenty of balancers with cracked hubs that, 1- werent caused by damage to the trans, just time & wear &/or internal engine balance problems over time. 2- didnt make any noises or vibrations with a cracked but not completely failed hub and the crank bolt was still tight.

I hope youre right on that theory but my 2 cents on the "ghost" noise is it wasnt from the balancer or the first claim of using 4" dryer duct on the exhaust, you said you tested the car for awhile after the trans rebuild, so if the balancer is what made that noise from being cracked... logic & reason would say it should have done it right away on first start up.

Just trying to provide some other perspective on this ordeal, guessing & assumptions are kinda pointless... with all this effort & money on fixing the heads, a few hundred more dollars & some time would be well worth it to inspect &/or fix the bottom end issues with pistons & rods. Why put that off now when everything is already apart only to hope you fixed the unknown noise but still have wacky pistons/rods.. then have to tear it all down or remove the engine again & buy hundreds of dollars in gaskets, again?

Best of luck on your plan but common sense says to do it now the right way.

[TRADERMIKE 2012]

You said:

"You said you tested the car for a while after the trans. rebuild, so if the balancer is what made that noise from being cracked... logic & reason would say it should have done it right away on first start up."

Upon repairing the Trans. I was fighting the Modulator Issue. I was between the Modulator and Govenor or a number of other after build things that come up, especially being my first Trans. rebuild. I was concentrating Soley on the Trans. at that moment. As I passed the Trans. issue, that is found that the Modulator was the culprit, once repaired on testing and tuning for longer distances and moving faster than the Ghost noise reared its ugly face. Once we were driving at higher speeds on I-95 in south Florida this had everything to do with noticing the Ghost noise. First, we turned off the AC unit compressor to look for a difference in sound, but it was still there. Then we put some rubber between the Electric fan and the AC condenser unit, thinking it was the vibration and it was not. Then we did not use the AC at all, drove the vehicle with all Trans. issues resolved, but the vibration Ghost noise was still there. We pulled the Heads, good thing and finally found the smoking gun, the Harmonic Balancer is cracked!

I am not prepared to go any further than this, time to test and tune to see if I have found today's problem. As rite as everyone is that I should take the next step and go for the entire rebuild, I need to satisfy my curiosity to whether or not I have diagnosed the current problem. True I was told to rebuild the Trans. and I had to check out every other possibility first, and I mean I learned a lot and better understand Trans. 101 because of my diligence. Otherwise, how will I ever learn this mechanic stuff? Remember I am a student of Auto mechanics not a pro like some of you.

[Jay S]

As long as you measured and checked the cam timing properly and it is coming in at 109.5 I would expect it to be fine.

Don’t assume that the corresponding keys work right according to the instructions. They often do not. Always measure and check when using those keys.

Here a quote from someone that did a lot more cams than I have. It can be true for 9 way set too, even though the instruction all say the cam timing is moved half that. The instructions are actually wrong, the key way are in 4* increments at the crank, and only move the cam timing 2*. I have never actually seen a timing set that works like the instruction say. Just like this Joe Sherman quote:

[TRADERMIKE 2012]

Originally Posted by Jay S

As long as you measured and checked the cam timing properly and it is coming in at 109.5 I would expect it to be fine.

Don’t assume that the corresponding keys work right according to the instructions. They often do not. Always measure and check when using those keys.

Here is a quote from someone that did a lot more cams than I have. It can be true for 9 ways set too, even though the instruction all say the cam timing is moved half that. The instructions are actually wrong, the key way is in 4* increments at the crank, and only move the cam timing 2*. I have never actually seen a timing set that works like the instruction say. Just like this Joe Sherman quote:

I agree totally with that statement!

[Cliff R]

Guys, I already provided DIRECT experience with an engine assembled with offset factory type pistons installed in the WRONG direction. 10,000 miles of grief, noise (piston slap) or "rocking" as they cross TDC, and it never sealed up well....it went on deaf ears

My engine was removed without knowing what the problem was, discovered the problem, corrected the problem and 90,000 more miles without any issues whatsoever including getting rid of the "odd" noise it made from the moment you started it up that you just couldn't nail down a cause for. It never went completely away, and got bad enough toward the end it forced pulling the engine to find out what it was.

Anytime you have something right in front of you, problems are discovered, it's within easy reach to correct them, it needs to be done. Anything less just doesn't cut it in this game. Even worse here connecting rod orientation isn't known. When I installed 8 pistons in the wrong direction ALL of my connecting rods were in the right orientation, flats running together and chamfers to the outside.

Here steps weren't even taken to know if the rods are in backwards, or not, and even worse 7 out of 8 pistons in backwards and one facing the right direction is likely to cause issues with harmonics as things wear on.

I must have missed the part about the pistons being .035" or WAY down in the holes at TDC. That NEVER works out well either when teamed up with a .050" thick head gasket. Pontiac engines using factory heads with flat chamber floors are more sensitive to that deal than others I've worked with over the years. No engine here ever goes together with more than .040" quench for any reason. I've worked on enough piss poor running Pontiac engines builds in my time to know better. One common denominator with every single running hot, overheating and pinging on pump gas Pontiac build I've been asked to assist with has had WAY too much quench in it, no exceptions........FWIW......

[Formulajones]

.035 below deck doesn't surprise me. Even though the method of measurement probably wasn't super precise, it's still pretty typical of stock OEM engines.

[Cliff R]

Most I've checked before taking them apart have been closer to .015-.018" unless they were using aftermarket pistons. Most 400 replacement pistons with the eight valve reliefs were in the .035-.050" range below the deck at TDC. They also lower the compression ratio over half a point. I've NEVER had a good experience with one of these engines with that much quench in them, especially if the "short" pistons were teamed up with later heads with huge combustion chambers in them, and why NOTHING goes together here with more than .040" quench distance for any reason.

I've been following this thread and trying to help, but my suggestions have been ignored for some reason. It appears the OP talks himself into alternate methods of repair to keep as much money in the wallet as possible. I certainly get that. WAY back when I installed 8 pistons backwards I had to fart in my pocket to have a cent. It was very difficult to accept the fact that I messed up the build and had to remove the engine and spend more money on it. I was raising my kids and pretty much check to check at that time. Even so I bit the bullet and did it the right way, then was nicely rewarded with a PERFECT end result, even though it was pretty painful on the bank account at that time........FWIW......

[Stan Weiss]

Originally Posted by Cliff R

Most I've checked before taking them apart have been closer to .015-.018" unless they were using aftermarket pistons. Most 400 replacement pistons with the eight valve reliefs were in the .035-.050" range below the deck at TDC. They also lower the compression ratio over half a point. I've NEVER had a good experience with one of these engines with that much quench in them, especially if the "short" pistons were teamed up with later heads with huge combustion chambers in them, and why NOTHING goes together here with more than .040" quench distance for any reason.

I've been following this thread and trying to help, but my suggestions have been ignored for some reason. It appears the OP talks himself into alternate methods of repair to keep as much money in the wallet as possible. I certainly get that. WAY back when I installed 8 pistons backwards I had to fart in my pocket to have a cent. It was very difficult to accept the fact that I messed up the build and had to remove the engine and spend more money on it. I was raising my kids and pretty much check to check at that time. Even so I bit the bullet and did it the right way, then was nicely rewarded with a PERFECT end result, even though it was pretty painful on the bank account at that time........FWIW......

Maybe he likes other peoples ideas about what to do better than yours.

Stan

[Cliff R]

Like STOOPID suggestions to leave the 7 pistons in backwards and one in the right direction...........

[Stan Weiss]

Originally Posted by Stan Weiss

I have no problem with the pistons in backwards. I would turn the 8th one around (backward) make sure the rods are correct direction on the crank and call it a day.

Stan

Originally Posted by Cliff R

Like STOOPID suggestions to leave the 7 pistons in backwards and one in the right direction...........

While not in a Pontiac I have not had the same problems as you running pistons backward.

Seem some others have not had the same problems as you running pistons backwards in a Pontiac.

Installing pistons backwards
https://firstgenfirebird.org/forums/...32&type=thread

Stan

[TRADERMIKE 2012]

Originally Posted by Stan Weiss

While not in a Pontiac I have not had the same problems as you running pistons backward.

Seem some others have not had the same problems as you running pistons backwards in a Pontiac.

Installing pistons backwards
https://firstgenfirebird.org/forums/...32&type=thread

Stan

I compare Mechanics to Doctors and Medicine, because of the cause and effects on the body and the various treatments, trying to get the best treatment and medication best suited for each problem a patient comes in with.

Now, Mike has a problem with his Engine, there are many things happening, the more I dig deeper into this Engine.

I decided to repair the Cracked and damaged parts that I see today, only. There is no doubt that the unknown bottom end is not going anywhere so, it will be addressed in due time, regardless of anyone being disappointed with me, thank God you people care so much about the Pontiac Auto s continuation to survive.

Here is where we are at, it turns out that the Intake Valve seats were the ones that were milled down to accept positive seals, I stand corrected on that one, most likely done from the factory, from what you say.

As far as the Exhaust seat bosses are concerned, the Head Mechanic elected to use the black type Umbrella seals (with no lip on top) that fit tightly over the boss, rather than milling the Exhaust Bosses down for the positive seals. The Head Mechanic used the Umbrella type seal shown in the photo (posted in an earlier thread) that was black and had "no" upper lip to grab the Valve stem, unlike the Umbrella seal that I used, that stuck to the Valve stem.

In addition, one Exhaust Valve, that is located between the center of the "D"-port center area, where it is written "670" has 3 hairline cracks on the side facing the Piston. These same two Exhaust Valves received the new hardened Valve seats. Thus, it is a good thing we are performing the Pontiac cooling mod. with the 421-cooling mod.
Lou, my roommate is in the kitchen drilling the last 2 holes, one in each Head for the final part of the operation. We drill slowly with oil and work our way up in size until we are just short of the hole in the Head gasket, the last drill is to debur the cooling jacket hole.

The Stroke was measured using a depth gauge and caliper, inside the cylinder, as the piston was down in the bore.

Number one cyl. @ TDC to Deck clearance is +/- 0.023"
The thickness of the new Butler innovated metal ringed Head gasket un-crushed is 0.057".

The Deck is uncut and the letters used to denote the Pistons for that particular cylinder are easily read.

One member asked how the oil clearance on the Rod clearance was read? Ans: Using a feeler gauge from side-to-side play. We did "not" remove the Main Bearings nor the Piston Caps.

The reason for this thread being used is because it had not been used in a while. So, I elected to continue it with my information since I started this thread in the first place. I like to be able to share my information with others so that they can get the most of the internet experience without jumping around all over the place. Plus, it is good for me to remind myself if I need to.

All Ideas are welcome, different or not, I only learn from the ones that know more than myself. I absorb everything you say and you are all correct in what you believe in your own experiences, I take every word in stride.

The motor is going back together, the Heads are back, we are drilling the 421 mod. holes tonight and just finished them. One Exhaust Valve is un-usable and was replaced, due to 3 hairline fractures in the Valve face. There was too much heat I would say, in the center port area that is shared by two Exhaust Valves adjacent to one other. The 421 mod should clear up that problem, since the two cooling hole jackets merge with the new holes that we made; we inserted a long wire through them to prove it will work, by the way.

Question: I need solving, moving on past the Pistons of course, is what Harmonic Dampener to purchase.

(A)I am looking into 1967 HB Summit, PQX-2438940, $209.87, SFI rating, 18.1, Billet steel in black epoxy.

(B)Gimmick or not? FLUID GEL DAMPERS SFI RATED 254550 $222.87 in black epoxy,

I wonder what crankshaft pully hole = 3, effects installing it on my 428 Motor on both A and B means.

(C) eBay: # 265577079296 Pioneer DA 4551 $78.26

(D) Jegs ATI $111.68 085 - 916500

(E) Butler SUPER DAMPER ATI 916500 $159 95
AVAILABLE IN ALUMINUM OR STEEL.

I wonder if aluminum unsprung wait on the internal moving reciprocal parts would be worth having for takeoff reasons vs. steels strength for longevity, since the Harmonic Balancer already cracked in this area, is it worth anything?


(F) OPG(G240633) $247.99 Hub and Dampener SFI
Balancer, 2 pc, 1960-67 Pontiac
ORIGINAL PARTS GROUP.

[TRADERMIKE 2012]

Originally Posted by TRADERMIKE 2012

I compare Mechanics to Doctors and Medicine, because of the cause and effects on the body and the various treatments, trying to get the best treatment and medication best suited for each problem a patient comes in with.

Now, Mike has a problem with his Engine, there are many things happening, the more I dig deeper into this Engine.

I decided to repair the Cracked and damaged parts that I see today, only. There is no doubt that the unknown bottom end is not going anywhere so, it will be addressed in due time, regardless of anyone being disappointed with me, thank God you people care so much about the Pontiac Auto s continuation to survive.

Here is where we are at, it turns out that the Intake Valve seats were the ones that were milled down to accept positive seals, I stand corrected on that one, most likely done from the factory, from what you say.

As far as the Exhaust seat bosses are concerned, the Head Mechanic elected to use the black type Umbrella seals (with no lip on top) that fit tightly over the boss, rather than milling the Exhaust Bosses down for the positive seals. The Head Mechanic used the Umbrella type seal shown in the photo (posted in an earlier thread) that was black and had "no" upper lip to grab the Valve stem, unlike the Umbrella seal that I used, that stuck to the Valve stem.

In addition, one Exhaust Valve, that is located between the center of the "D"-port center area, where it is written "670" has 3 hairline cracks on the side facing the Piston. These same two Exhaust Valves received the new hardened Valve seats. Thus, it is a good thing we are performing the Pontiac cooling mod. with the 421-cooling mod.
Lou, my roommate is in the kitchen drilling the last 2 holes, one in each Head for the final part of the operation. We drill slowly with oil and work our way up in size until we are just short of the hole in the Head gasket, the last drill is to debur the cooling jacket hole.

The Stroke was measured using a depth gauge and caliper, inside the cylinder, as the piston was down in the bore.

Number one cyl. @ TDC to Deck clearance is +/- 0.023"
The thickness of the new Butler innovated metal ringed Head gasket un-crushed is 0.057".

The Deck is uncut and the letters used to denote the Pistons for that particular cylinder are easily read.

One member asked how the oil clearance on the Rod clearance was read? Ans: Using a feeler gauge from side-to-side play. We did "not" remove the Main Bearings nor the Piston Caps.

The reason for this thread being used is because it had not been used in a while. So, I elected to continue it with my information since I started this thread in the first place. I like to be able to share my information with others so that they can get the most of the internet experience without jumping around all over the place. Plus, it is good for me to remind myself if I need to.

All Ideas are welcome, different or not, I only learn from the ones that know more than myself. I absorb everything you say and you are all correct in what you believe in your own experiences, I take every word in stride.

The motor is going back together, the Heads are back, we are drilling the 421 mod. holes tonight and just finished them. One Exhaust Valve is un-usable and was replaced, due to 3 hairline fractures in the Valve face. There was too much heat I would say, in the center port area that is shared by two Exhaust Valves adjacent to one other. The 421 mod should clear up that problem, since the two cooling hole jackets merge with the new holes that we made; we inserted a long wire through them to prove it will work, by the way.

Question: I need solving, moving on past the Pistons of course, is what Harmonic Dampener to purchase.

(A)I am looking into 1967 HB Summit, PQX-2438940, $209.87, SFI rating, 18.1, Billet steel in black epoxy.

(B)Gimmick or not? FLUID GEL DAMPERS SFI RATED 254550 $222.87 in black epoxy,

I wonder what crankshaft pully hole = 3, effects installing it on my 428 Motor on both A and B means.

(C) eBay: # 265577079296 Pioneer DA 4551 $78.26

(D) Jegs ATI $111.68 085 - 916500

(E) Butler SUPER DAMPER ATI 916500 $159 95
AVAILABLE IN ALUMINUM OR STEEL.

I wonder if aluminum unsprung wait on the internal moving reciprocal parts would be worth having for takeoff reasons vs. steels strength for longevity, since the Harmonic Balancer already cracked in this area, is it worth anything?


(F) OPG(G240633) $247.99 Hub and Dampener SFI
Balancer, 2 pc, 1960-67 Pontiac
ORIGINAL PARTS GROUP.

We measured the (old used) Head gasket thickness crushed, to be : .050" + .023" Piston to Deck height = .078" Quench. This should be enough Quench to leave the Valve from ever hitting the Piston at 4 advanced degrees @ the Cam?

[Stan Weiss]

Originally Posted by TRADERMIKE 2012

We measured the (old used) Head gasket thickness crushed, to be : .050" + .023" Piston to Deck height = .078" Quench. This should be enough Quench to leave the Valve from ever hitting the Piston at 4 advanced degrees @ the Cam?

If you don't have the tools to check piston to valve clearance. You had the heads off. You could have checked piston to valve clearance with nothing more than a piece of clay. You don't adjust quench clearance to set piston to valve clearance.

Stan

[steve25]

I would like to request a whole new thread be started to better reference how things and issues have shifted since at this point it’s dam far from being about the cam any more!

[TRADERMIKE 2012]

Installing pistons backwards
Posted By: trauschu Installing pistons backwards - 10/08/04 12:20 AM
Has anyone heard of installing pistons backwards in a poncho 400 rebuild, so that the arrow on the dish points to the back, instead of the front of the block?

What is this supposed to accomplish, if anything?
Posted By: P. M. I. USA Re: Installing pistons backwards - 10/08/04 02:34 AM
Check the location of the oil spurt hole in the rod. The hole points to the opposite cylinder bank.
Posted By: TOHCan Re: Installing pistons backwards - 10/09/04 08:46 AM
This changes the direction of the pin offset in the piston. The manufacturers use pin offset to lessen piston slap noise. By installing the piston, the other way 'round, the connecting rod and the crankshaft throw form a different angle at and around TDC that makes the engine act like it has a longer rod. This has to do with the location of the piston at each degree of crank movement. One of the more important effects is the change in dwell time around TDC, and another is the rate of acceleration change around BDC. Most of this to say that, most noticeably on an engine that is induction limited, when reversing the piston pin offset by installing the pistons backwards, the general effect is an improvement in output and efficiency on either side of the torque peak.

I have assembled several street engines and a few race engines over the years this way and have been hard pressed to detect any additional noise when cold or hot. I have, however, detected an increase in output and fuel economy. The longest I have driven one of these engines was around 50,000 kms before I sold the vehicle and found no adverse effects.

A fair percentage of race pistons are machined with no offset to reduce the number of different pistons needed (by half). Most "street" pistons have a .060" offset.

Circle Track magazine did a dyno test on this a few years ago, using pistons that had .100" offset, I think. The results were illuminating, and confirmed what I had been feeling from my test engines. Every time I do an engine the "normal" way to recheck this effect, I regret not reversing the pistons!

P.S. If the rod has a squirt hole, it has to be facing the correct direction, so the piston must be intentionally installed backwards on the Rod.


You said from this article:


P.S. If the rod has a squirt hole, it has to be facing the correct direction, so the piston must be intentionally installed backwards on the Rod.

Mike wants to know if this is why my Piston number two with the only correct orientation is installed so, maybe?


Installing pistons backwards
https://firstgenfirebird.org/forums/...32&type=thread

Stan



Mikes reply:

What if all 7 of my pistons have the oil hole on the Rod, forcing them to be installed facing rear and the number two Piston had to be assembled correctly (factory like) because of lack of the oil hole

[Kenth]

You'll never know what was going through the mind of the moron who put your engine together before, but with everything you've found out in this thread, it shouldn't be impossible for you to fix everything without thinking about trivialities continuously.

JMHO

[Jay S]

I attached the instructions for Comps 9 way timing set instruction, those instructions are pretty much the same no matter who’s timing set you buy.

The problem is the instruction are often wrong on timing sets, the key moves the crank twice as much at the crank than the number indicates (each key changes it 4* at the crank, not 2*). The keys are often not all that accurate either. Could be this timing set is different though, I am mentioning it incase your assuming the instruction are correct, and didn’t bother rechecking the cam timing after using the multi key timing set..

If you degreed the cam in after you used those keys and it worked, don’t take the timing cover off, it should be correct.

If you assumed the instruction are correct and did not degree the cam timing. Then take the timing cover off and degree it in and make sure. Every multi key timing set I have had so far would have advanced it 8*, not 4*.

.

[Cliff R]

Kenth, do to the way the Pontiac engine is layed out it's more common than you think to find problems with piston orientation and problems with assembly. In most other V-8's the forward most piston in the block is #1. This requires pistons used on that bank of the engine to be installed with the notches on the pistons forward and chamfers on the rods facing the rear of the block, flat sides forward. IF you install those four pistons notches forward and chamfers on the rods to the rear, the other four should automatically be correct when they are installed.

The BIG flag that goes up here is that one piston is running in the block with the notch on the piston facing forward like it should, but seven are wrong....hum? Considering the machine shop should have pressed four pistons in one direction on the rods and four the other direction, it makes me wonder how many rods are in this engine without the flat sides facing each other?

Machine shops even get confused and make mistakes pressing pistons on for them. So between that issue and "builders" assembling them not paying close attention it's pretty easy to make mistakes in that area of the build.

For this build in particular having 7 wrong and one right throws up some flags for me. Plus the OP is complaining about unusual noises. Pistons installed with the offset in the wrong direction is a DIRECT contributor to piston "slap". Piston "slap" never gets better as with the engine I built back in the 1980's with the pistons facing the wrong direction. Mine had an "odd" sound to it from day one, and it got bad enough by 10,000 miles it had to come out. So bottom line here is, that no matter how many folks recommend installing pistons with the offset in the wrong direction, it is NOT a good idea unless you are willing to deal with some of the negatives involved with that move........FWIW......

[TRADERMIKE 2012]

Originally Posted by Cliff R

Kenth, do to the way the Pontiac engine is layed out it's more common than you think to find problems with piston orientation and problems with assembly. In most other V-8's the forward most piston in the block is #1. This requires pistons used on that bank of the engine to be installed with the notches on the pistons forward and chamfers on the rods facing the rear of the block, flat sides forward. IF you install those four pistons notches forward and chamfers on the rods to the rear, the other four should automatically be correct when they are installed.

The BIG flag that goes up here is that one piston is running in the block with the notch on the piston facing forward like it should, but seven are wrong....hum? Considering the machine shop should have pressed four pistons in one direction on the rods and four the other direction, it makes me wonder how many rods are in this engine without the flat sides facing each other?

Machine shops even get confused and make mistakes pressing pistons on for them. So between that issue and "builders" assembling them not paying close attention it's pretty easy to make mistakes in that area of the build.

For this build in particular having 7 wrong and one right throws up some flags for me. Plus the OP is complaining about unusual noises. Pistons installed with the offset in the wrong direction is a DIRECT contributor to piston "slap". Piston "slap" never gets better as with the engine I built back in the 1980's with the pistons facing the wrong direction. Mine had an "odd" sound to it from day one, and it got bad enough by 10,000 miles it had to come out. So bottom line here is, that no matter how many folks recommend installing pistons with the offset in the wrong direction, it is NOT a good idea unless you are willing to deal with some of the negatives involved with that move........FWIW......

It is a given that I did not build this motor, for if I did, as I built my first Engine, a chevy 327 ci, I would have taken it into the machine shop and let them build the bottom end completely. It is a shame that a machine shop could build an Engine wrong. It is the reason I do all my own work, by the book today. Let's see how the Engine works after this repair and there was never a mention of a piston slap by me, as far as I am concerned it has a unknown vibration and sounds in the upper end that turned out to be in the Heads and the vibration is in the Harmonic Balancer. This being the only problems at this time and are being delt with as we speak. The cooling mods. should help the Heads to last longer and a well-built Dampener is the main topic here. Help me figure out the one best suited in my application, please, I know nothing about the upgraded ones.

[Jay S]

I think Cliff said it best when he said even experienced builder’s mess up with those multi key timing set! Easy to do when the instruction are crap!

I have had a cloyes 3 way timing set move cam timing 8*, which means the 2 different crank keys changed it 16*. Instructions said it would move it 4*, or 2* at the cam…Freaking ridiculous!