[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.

[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

[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]

Well, it seemed to run ok before. You have that going for you.

Put a new stock harmonic balancer on it and fix the piston issues as soon as you can. That piston should fixed be right now, but if you can’t, you can’t.

[TRADERMIKE 2012]

Originally Posted by Jay S

Well, it seemed to run ok before. You have that going for you.

Put a new stock harmonic balancer on it and fix the piston issues as soon as you can. That piston should be fixed right now, but if you can’t, you can’t.

Thank you for the help, we put the Heads on tonight and all went well.

[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

[Cliff R]

.078" quench is HORRIBLE in one of these engines, even worse using factory iron heads with their flat chamber floors/machined combustion chambers.

Good thing you have a RAIV cam in it, or it would pound the rod bearings out of it in a week due to detonation. The RAIV cam saves the day here as it bleeds off a LOT of cylinder pressure and pushed peak VE high in the RPM range. Put a 10 degree smaller cam @ .050" in this build on a 110LSA and it wouldn't last a month......IMHO....

+2 on moving the heads away from the pistons to increase valve to piston clearance. These engines have a BUTT-LOAD of that right to start with with factory "low lift" cams in them.

The only Pontiac engine I ever had close for piston to valve clearance was a 455 with forged TRW Super Duty pistons in it (2 small valve reliefs). With a 276/284 @ .050" cam with .750" lift it still had just under .040" piston to valve bumping it thru without a head gasket in place. The heads were CNC ported early round port E-heads at 330cfm with 72 cc chambers (milled to .068cc).

So basically, without writing a book here on building these engines and checking critical areas during the process, piston to valve with the cam you are using shouldn't even be on the list of things to worry about........FWIW........

[Jay S]

Butler’s composite gaskets crush to around .042”. to .044” thick.

Blue felpro crush to about .045”, most cheaper head gaskets crush to .045” also.

I assume the cam is still using the comp 9 way timing set using full advance 4th key yet, as reported earlier. Could be just a miscommunication on my end. I will reiterate it though, the 4th key should be 8* advanced, each key changes the advance 2*. Using the extreme 4th key ends up at roughly 105.5* if it started at 113.5*.

Like Cliff said, quench is marginal to bad, if the cam is advanced to far, you”ll wish you never touched the cam timing. If your convinced all is good though, carry on.

There is plenty of valve to piston clearance with the SPC-8 cam and 1.5 rockers. No reason to bother checking that. Should be good unless the install is really messed up.

[78w72]

Originally Posted by Jay S

Butler’s composite gaskets crush to around .042”. to .044” thick.

Blue felpro crush to about .045”, most cheaper head gaskets crush to .045” also.

Aren't the felpro head gaskets .039? not much of a difference, but thats what the specs show for the cheaper blue & the better permatorq ones with the metal ring.

https://www.summitracing.com/parts/f...6/make/pontiac

[Cliff R]

One thing I've tested that most folks haven't is moving cams around then street testing, followed by track testing.

Another "myth" about advancing cams is "making more low end torque". You may see of "feel" a shift in power but may not make as much power anywhere as before the move. When I advanced the cam in my first 455 from 109ICL to 107ICL it KILLED it at the track at every point on the run including 60' time. I also moved it to 111ICL, and on up to 113ICL.

It was a TURD at 107 and again at 113, if you went by the track times, but superficially "felt" pretty peppy at 107ICL and made a little tiny bit more vacuum at idle.. Remarkably the car ran almost the same at 109 and 111ICL, just fuzz-nut quicker in 60' at 109 than 111.

In any case I would NEVER just advance a cam just to improve low end power, street manners or compensating for chain stretch, or following random advice on the NET from someone who probably Googled up their information instead of actually trying it out.......and, IF your chain is going to stretch out that much, buy a better timing set......FWIW.........

[Stan Weiss]

To many pages and I have a bad memory. What CR does he have and what thickness head gasket was that figured with. As the head gasket get thinner for better quench it will also be increasing his CR.

Stan

[Jay S]

Originally Posted by 78w72

Aren't the felpro head gaskets .039? not much of a difference, but thats what the specs show for the cheaper blue & the better permatorq ones with the metal ring.

https://www.summitracing.com/parts/f...6/make/pontiac

I think your right on that, I was thinking the blue gaskets don’t crush quite as far as the 1016s, but the blue I think do crush to less than .045”, hard to measure also. The 1016s crush to .039. I have both here, if I remember I will double check.

[Jay S]

Originally Posted by Stan Weiss

To many pages and I have a bad memory. What CR does he have and what thickness head gasket was that figured with. As the head gasket get thinner for better quench it will also be increasing his CR.

Stan

LOL, yes, I am with you, too many pages to go look or recall that stuff. I remember not seeing any part number or oversized stamps on the piston photos, and do not recall anything mentioned on that. ??

Doesn’t sound like it matters anyhow, heads are back on.

[PAUL K]

One could pull the engine and fix it in less time than it takes to read this entire thread.... Normally I'm all for "trying to learn" but a lot of words have been typed trying to justify mistakes that just need to be corrected or lived with. You can discuss this as long as you want but nothing will change the outcome unless something is "actually done" or its decided to live with the situation at hand.... It's that simple.

[78w72]

Originally Posted by Jay S

I think your right on that, I was thinking the blue gaskets don’t crush quite as far as the 1016s, but the blue I think do crush to less than .045”, hard to measure also. The 1016s crush to .039. I have both here, if I remember I will double check.

Just wanted to mention what felpro states the compressed thickness is for their pontiac head gaskets, edelbrocks are also .039. Thats the spec i used when calculating compression for my recent stroker build.

[TRADERMIKE 2012]

Originally Posted by Stan Weiss

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

You guys got to tell me that stuff in advance, the Head mechanic took some material off the Head to surface them, but I did not ask him how much. That clay idea is good, thank you, just a little late I am afraid, bummer. We know that the Piston is .023" lower than the Deck, given the stock Valve clearance to deck with this new Gasket at a thickness of .057 un-crushed and crushed could be about .050 like the used one that came off, how much possible clearance could there be? The Heads are installed and the Timing cover is installed. Do you want me to pull some timing out now while I can? I went to the 4th notch, so I could pull it back a notch to be safe, if you want. Each notch at the Crank is 2 degrees = 8 degrees, according to the directions, at the crank and that is 4 degrees advanced at the Cam. I am at 109.5 advanced timing at the Cam presently. The original straight -up Cam Timing from Melling through Butler, has 1.5 degrees built into the Cam = 103.5 - 4 degrees = 109.5 now. Since the Cam specs. all work out perfect and the motor is now degreed properly will I be safe if I leave everything alone, remember the timing cover is installed as well as the water pump?

[TRADERMIKE 2012]

Originally Posted by Cliff R

.078" quench is HORRIBLE in one of these engines, even worse using factory iron heads with their flat chamber floors/machined combustion chambers.

Good thing you have a RAIV Cam in the motor or it would pound the rod bearings right out of it, in a week, due to detonation. The RAIV cam saves the day here, as it bleeds off a LOT of cylinder pressure and pushes peak VE high in the RPM range. Put a 10-degree smaller cam @ .050" in this build on a 110LSA and it wouldn't last a month......IMHO....

+2 on moving the heads away from the pistons to increase valve to piston clearance. These engines have a BUTT-LOAD of that right to start with factory "low lift" cams in them.

The only Pontiac engine I ever had close for piston to valve clearance was a 455 with forged TRW Super Duty pistons in it (2 small valve reliefs). With a 276/284 @ .050" cam with .750" lift it still had just under .040" piston to valve bumping it through without a head gasket in place. The heads were CNC ported early round port E-heads at 330cfm with 72 cc chambers (milled to .068cc).

So basically, without writing a book here on building these engines and checking critical areas during the process, piston to valve with the cam you are using shouldn't even be on the list of things to worry about........FWIW........

YAAAA, I lucked out there, since I don't have dish Pistons to lower the compression ratio.

You said:

"The RAIV cam saves the day here, as it bleeds off a LOT of cylinder pressure and pushes peak VE high in the RPM range. Put a 10-degree smaller cam @ .050" in this build on a 110LSA and it wouldn't last a month"......IMHO....

Mikes reply: How close are those specs., that you mention above, to my original # 886 Cam. The Tri-Power one, that ran like a raped ape, when the Cam lobes were worn down and I was bending push rods, because the Rocker arm bolt mounted on the Rocker stud was cracked, that I found out, while testing and tuning at 130 mph, simultaneously, ruining the new Cooper tires, that I later discovered, where rated for 80 mph.

Note, I don't know whether or not the worn lobes, not giving the correct lift, that the used Cam was intended to have, works in your favor or not, considering your statement, both ways?