[rick38]

Thanks Perfect

[TRADERMIKE 2012]

Originally Posted by JSchmitz

Yes, I think I understand it pretty well. Piston slap is bad. It causes ring wear, sounds bad, etc. The offset is their help eliminate this. Are you saying that his knock isn't from improper assembly?

I know that my dad owned a 1969 Chevy pickup. He had the engine rebuilt. The guy put the pistons in backward. Guess what, it had a strange knock.

[QUOTE=JSchmitz;6469943] I would say that the piston installation didn't break any laws of physics. They are merely complying with the laws. The laws dictate that the pressures and angles act on the pistons in a certain manner. The engineers that designed the pistons understood this better than anyone in this discussion. They designed an offset to minimize unwanted movements of the pistons and maximize efficiency. Choosing to go against this is most likely causing the noises in this engine.

Mikes Reply:

We are putting the Trans. back to the Engine now, I will let you know when we run the Motor. I am not holding my breath though, that this noise has disappeared. Perhaps the noise was always there, I just did not hear it until the Heads were remanufactured, causing new Harmonics resonance within this Engine.

The Pistons are backwards except for #2, Why. The racers reversed the Pistons for a reason, we know why.

The #6 Rod is backward, and maybe more. Not good.

The Pictures in the 1967 Pontiac service Manual are confusing at best.

People made mistakes rebuilding these engines over the years and it seems that I have one of them.

Let's see what happens when we get the Vehicle running again.

I bought the Stethoscope, with the long rod on the end, we can now listen better, to isolate said noise, if it is still there.

Mike out, thank you all for your help.


Also, to find out that my Pistons are closer to TDC because they are installed backwards, is ironic since I spent all that time with the degree wheel just to find true TDC.

[TRADERMIKE 2012]

Originally Posted by Cliff R

"If you ever run into that cam card I would be interested in the advertised duration. How aggressive was it?
I Had Tim at Bullet specially take some of the aggressiveness out of my roller cam for safety.
It might cost me 10-12 HP but it's better than a mangled mess."

"Sadly, I lost quite a few cam cards and dyno charts when my last PC Hard Drive took a chit. I had a "mirror" drive installed in the computer and it was supposed to have everything saved on it but I'm computer "stupid" and never once performed or set the computer up to perform the operations needed to make that happen. Well, sadly you just have to pick and choose your career path and for sure electronics HATE me so I stay as far away from them as humanly possible!

The 455 we "lunched" had a long history. I got involved with it back around 1999-2000 when it was topped with stock #48 heads and Comp 292 Magnum cam. In a 3400lb car it was running 12.0's at that time. It's backed by a TH350 and 3.73 12 bolt.

Wanting more power, the owner had KRE port the #48's and supplied a 260/260 @ .050" flat solid cam for it. That put it solidly into the 10's, but not good enough. Next went on 330cfm Edelbrock heads and roller Cam about .650" lift and not overly "aggressive" lobes. That moved it down to the really low 10's, but after a short stint still hot good enough so the last time we "freshened" up the engine it got more cam (very aggressive profile) and 13 runs in BOOM!

The writing was on the wall anyhow as the last time I was in it there was a main cap dowel at the bottom of the pan. Looking back on it and the evolution of the engine and increased power and vehicle performance we simply reached and were exceeding the capabilities of a 1974 455 block....IMHO. As with self-destruct things, at the top end of the track around 6400rpms it is difficult to isolate a single cause or basically what came first, the chicken or the egg? I suspect the lifter bore failure or a piston nudged a valve, just hard enough to start that snow ball rolling.

Matters not in the end as with those things you basically lift on the intake and carb and throw the rest in the scrap pile!

It was all replaced with a KRE complete 505cid engine package with High-Port heads up near the 750hp mark. That put the car solidly into the 9's at 135-136mph where it still runs today, nearly 20 years later. That engine has only been out once for rod bearings, new valve springs, timing chain and replacing a set of cracked Scorpion roller rockers with Crower Enduro's........

Mikes reply:

I agree to build a motor from the start the correct way, when you can.

[TRADERMIKE 2012]

Originally Posted by mgarblik

SD=Rod and piston pics: Couldn't get them posted fast enough. Sorry for the double post.

Mikes reply:

From what I read, they had to raise the oil pressure up to around 60-80 psi on the SD engines, Nunzi had something to do with the repair with the factory reps. Or so have read?

[TRADERMIKE 2012]

Originally Posted by Jay S

Maybe you could check and see if the SD pistons have holes drilled through the oil ring, instead of the long slots, like the other OEM pistons? I could show some pictures, if you don’t follow what I mean. If the SD pistons were designed by TRW and run that much piston too wall clearance, I bet they are the VMS-75 alloy. Which is closer to a 4032, but the design of the skirt expands a bunch and needs a lot of piston to wall clearance. If they had that skirt design, with the small holes under the oil ring, they would have quite a bit of piston slap, cold no matter what the offset is from that (.006-.007”) piston to wall needed for the extra skirt expansion.

Just a side note, and I really don’t care one way or the other, if someone wants to make a different case for piston offset. It seems like I have been the only one so far that has built some Pontiacs with the stock type pistons in backward. I have not done a Pontiac with reverse hanging pistons for years. But with their long factory pistons skirts, tall decks, and good rod to stroke ratios, the cold piston slap noise was less than what I hear today with newer LS engines. Some have mentioned some problems with SBC’s and reverse pistons, and that could very well be. I know a lot of people that did that in the circle track world, and on stroker SBC to get more rod to block clearances on some SBC’s. I think the SBC 400 and even a SBC 350 can do some funky stuff with the pistons reverse hung, the 400 only had a 5.565” long rod, with a 3.75” crank, in a short 9.123” block. The strokers or SBC with a 6” rod did better, but the 400 with the 5.656” rod almost pulls the piston pin out of the bottom of the cylinder, and does not take much to unseal the rings or make noise. Joe Sherman used to claim 15 to 30 HP from reversing pistons on some SBC’s. Engine masters could find any difference on one of their tests. Smokey Yunick supposedly had some equation that maximized what he thought should be the best piston offset for making power at certain RPMs. Kind of what I remember is he was not on board with the keeping the same offset or no offset, he seemed to think it should vary. He claimed that most of the Nascar teams were running their pistons backwards in that era, offset was run in factory backed cars. I have no idea what Pontiac or any of the teams did. Tom Hoover, a Chrysler backed drag racer, who was also an Engineer for Chrysler ran the piston is backwards and did some seminars back in the day, for direct connection where he talked about piston offset. He more or less said the reverse offset gained some low-end torque and added some extra ring wear. Most of the time it does very little and just adds some noise in cold start-ups. As mentioned, nothing a good stereo can't cure. Lol

Mikes reply:

Thank you for that information, good to know that others have their Pistons in backwards beside me and why.

[Dragncar]

Originally Posted by TRADERMIKE 2012

Mikes reply:

I agree to build a motor from the start the correct way, when you can.

I do not think that post was about building a engine "the correct way".
Its about stock blocks only being able to take so much power, so much cam even if they are build right.
Point is not pushing the limits of a stock block, just buy aftermarket and let it live a long happy life.

[TRADERMIKE 2012]

It was questionable that after the remanufactured Heads were installed, this latest noise occurred.

Not to discount that the Piston slap is the answer to this current noise, questionable is why do we all of a sudden hear it.

My roommate and I discussed the current noise issue recently and we now think that the Heads, using the new gasket with the metal rings around the Piston area on both sides for sealing purposes, is also causing the noise or allowing us to hear the existing noise.

We theorize that adding metal to the gasket, at the Piston surrounding areas, on both sides of the gasket, acts like an Acoustical Coupler, thereby enhancing the existing Piston slap noise so that we can now hear it.

It is Kind of like using the Stethoscope with the rod on the end, that we just bought from Harbor freight, that is meant to touch the Block, so one can hear the internal noises of the motor and where they are located?

What are your thoughts?

We got the car to run, however we need to get rid of an exhaust leak and oil leak, before we can take it down and road test it, this week.

[TRADERMIKE 2012]

Originally Posted by Dragncar

I do not think that post was about building an engine "the correct way".
It's about stock blocks only being able to take so much power, so much cam even if they are built right.
Point is not pushing the limits of a stock block, just buy aftermarket and let it live a long happy life.

I agree with that too, I had mentioned in a former post, that I would rather build this Motor back up stock and sell it and use that money toward the purchase of a 700-1000 hp modern Pontiac Block.

[steve25]

Before you build a motor up that will produce that high level of power take advantage of what others have found in hindsight, that being set the car up for it first !

[steve25]

I forget what cam lift your running, but now that I see a picture of your heads and the fact that the springs still have the oil splash shields on them that could make for interference.
I need to dig out my notes, but above a certain amount of lift those shields need to not be used and then the tops of the valve guides need to get cut for positive type valve seals.

[TRADERMIKE 2012]

Originally Posted by steve25

Before you build a motor up that will produce that high level of power take advantage of what others have found in hindsight, that being set the car up for it first!

Mikes reply:

What would be a realistic- body limit Vs HP range? I have sub-frame connectors, Herb Adams suspension and full roll bar. I do plan on enhancing the trans. and rear end to suit the Motor build. I am also keeping it as a street car. Keep in mind this is just a futuristic goal.

[TRADERMIKE 2012]

Originally Posted by steve25

I forget what cam lift your running, but now that I see a picture of your heads and the fact that the springs still have the oil splash shields on them that could make for interference.
I need to dig out my notes, but above a certain amount of lift those shields need to not be used and then the tops of the valve guides need to get cut for positive type valve seals.

I would be going with an aftermarket Block and E- Heads, for sure.

[steve25]

This comment of mine from post 750( yikes!!!!!) was in regards to your noise issue, not anything dealing with a future build.

[tom s]

If he keeps it a street car he won’t need a aftermarket block,It would take a solid roller cam and duration of 200 @ 200 lift to need one.IMHO,Tom

[tom s]

If he keeps it a street car he won’t need a aftermarket block,It would take a solid roller cam and duration of 200 @ 200 lift to need one.IMHO,Tom

[Cliff R]

"We theorize that adding metal to the gasket, at the Piston surrounding areas, on both sides of the gasket, acts like an Acoustical Coupler, thereby enhancing the existing Piston slap noise so that we can now hear it."



EGADZE! Did I read that correctly?

Whatever you and your roomate are smoking I want some of it!

[TRADERMIKE 2012]

Originally Posted by tom s

If he keeps it a street car he won’t need an aftermarket block, it would take a solid roller cam and duration of 200 @ 200 lift to need one. IMHO, Tom

Why can't I have a street car with a big motor, some day?

Although I could call it a street-strip car instead!

[TRADERMIKE 2012]

Originally Posted by Cliff R

"We theorize that adding metal to the gasket, at the Piston surrounding areas, on both sides of the gasket, acts like an Acoustical Coupler, thereby enhancing the existing Piston slap noise so that we can now hear it."



EGADZE! Did I read that correctly?

Whatever you and your roommate are smoking I want some of it! beerchug:

Florida has the best; I can attest to that!

Seriously, I want a reason why we can't be affected by the metal on the gaskets, Acoustical coupling amplifying the Piston slap, that you say is in my Engine.

ANYBODY, HAVE EXPERIENCE WITH NOISE OCCURING WHEN USING HEAD GASKETS WITH METAL AROUND THE PISTON AREA, THIS IS MY FIRST TIME USING THEM.

[Gach]

Originally Posted by tom s

If he keeps it a street car he won’t need a aftermarket block,It would take a solid roller cam and duration of 200 @ 200 lift to need one.IMHO,Tom

Exactly the comp roller I’ve used in stock blocks is 195 @ 200 lift with total lift of .730 never a issue in stock block’s.

[TRADERMIKE 2012]

Originally Posted by TRADERMIKE 2012

It was questionable that after the remanufactured Heads were installed, this latest noise occurred.

Not to discount that the Piston slap is the answer to this current noise, questionable is why do we all of a sudden hear it.

My roommate and I discussed the current noise issue recently and we now think that the Heads, using the new gasket with the metal rings around the Piston area on both sides for sealing purposes, is also causing the noise or allowing us to hear the existing noise.

We theorize that adding metal to the gasket, at the Piston surrounding areas, on both sides of the gasket, acts like an Acoustical Coupler, thereby enhancing the existing Piston slap noise so that we can now hear it.

It is Kind of like using the Stethoscope with the rod on the end, that we just bought from Harbor freight, that is meant to touch the Block, so one can hear the internal noises of the motor and where they are located?

What are your thoughts?

We got the car to run, however we need to get rid of an exhaust leak and oil leak, before we can take it down and road test it, this week.

I AM ASKING THE FORUM FIRST: "HAVE YOU HAD ANY NOISE ISSUES, AFTER YOU INSTALLED ONE OF THESE HEAD GASKETS WITH METAL AROUND THE PISTON HOLES?"