Have you ever seen anything like this before?-gctid360203

[Guest]

Have you ever seen anything like this before? There was nothing in the cylinder when I took the head off..No chunks or foreign nothing.. But yet the pistons are beat to hell and burned.. No... melted is more like it.The valves are fine no dents cracks or burning. The head gasket was blown, but not yet to the water jacket..(see pic) No water in the oil. Now I did not do this.. It was that way when I got the boat.. Believe it or notit ran semi ok except it had a light miss that I could not track down until I took a compression test. ThenI sent a scope in the plug hole and seen the problem.. But I did not think it was in 3 cylinders so I onlylook at number 4. When the head was pulled I seen it was in 3 cylinders. I am still dismayed how wellit ran in this condition.. Anyway I'm rippen it apart and going to rebuild it to have a few more ponies.Now I will have 2 fresh rebuilt Cone Clutch King Cobra and a new engine..If any one has ideas of what type pistons, cam, etc to use I'm all ears'Continued on next post

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[Guest]

If the engine runs too lean it will overheat and burn valves and pistons. That black stuff, is that carbon or oxidized aluminum? What about cylinder sleeves? Are they smooth to touch or do they have burn marks and scuffs? I have used aftermarket WISECO pistons http://www.wiseco.com/ to rebuild my old outboard, it worked better than original. Use their online catalog to match pistons for your engine. You will want to order a set of bearings for the rod assembly as well.

By the way, did you take compression readings before taking it apart? Bad reading means valves are not sealing or piston ring damage.

[Guest]

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[Guest]

Looks like chunk of ring came off or some other metallic object that caused damage. Take out the block and examine the cylinder walls. If you have deep scuffs, the blocks will have to be machined to next size over. That will determine the proper size of pistons you will need. If the sleeves are relatively unharmed, simple honing will do with new pistons you should be able to get mid 130 psi compression.

[Guest]

GrindKore wrote:
Looks like chunk of ring came off or some other metallic object that caused damage. Take out the block and examine the cylinder walls. If you have deep scuffs, the blocks will have to be machined to next size over. That will determine the proper size of pistons you will need. If the sleeves are relatively unharmed, simple honing will do with new pistons you should be able to get mid 130 psi compression.

Yea, I am going to have it punched out .30 over.. With new pistons.. New cam, new crank, maybe new rods.. Just about all internals will be new..

I will be taking it out this weekend and sending it to the machine shop..

[Guest]

GrindKore wrote:
If the engine runs too lean it will overheat and burn valves and pistons. That black stuff, is that carbon or oxidized aluminum? What about cylinder sleeves? Are they smooth to touch or do they have burn marks and scuffs? I have used aftermarket WISECO pistons http://www.wiseco.com/ to rebuild my old outboard, it worked better than original. Use their online catalog to match pistons for your engine. You will want to order a set of bearings for the rod assembly as well.

By the way, did you take compression readings before taking it apart? Bad reading means valves are not sealing or piston ring damage.

Yes I did do a compression test on it.. Thats whot got me lookin at the inside.. ( I have the numbers if you want to see them) I pulled a plug and put a scope down the hole..

The walls are smooth as if nothing is wrong.. The never got toughed.. Like I said it ran real good for having this type of damage..

[Guest]

While waiting for machine shop, get your carburetor rebuild. Often bad air/fuel mixture issues start there and go unnoticed till engine damage occurs. And good luck with the rebuild, take lots of pictures and update this thread. If you have tools and motivation, it can be fun.

[Guest]

GrindKore wrote:
If the engine runs too lean it will overheat and burn valves and pistons. That black stuff, is that carbon or oxidized aluminum? What about cylinder sleeves? Are they smooth to touch or do they have burn marks and scuffs? I have used aftermarket WISECO pistons http://www.wiseco.com/ to rebuild my old outboard, it worked better than original. Use their online catalog to match pistons for your engine. You will want to order a set of bearings for the rod assembly as well.

By the way, did you take compression readings before taking it apart? Bad reading means valves are not sealing or piston ring damage.

I went to the site you suggested and it seems they only have outboard stuff..

[Guest]

Giddy-Up wrote:
Yes I did do a compression test on it.. Thats whot got me lookin at the inside.. ( I have the numbers if you want to see them) I pulled a plug and put a scope down the hole..The walls are smooth as if nothing is wrong.. The never got toughed.. Like I said it ran real good for having this type of damage..

You be surprised in what condition engines can still run. Few years ago I had a running engine, however it was weak and rough idling. After a compression check one cylinder barely pulled 67psi others 117 and 130. It still ran.

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[2850Bounty]

The answer is yes.... I certainly have!

The dark color may be from the aluminum... I'm not sure.

The several pistons that have ring landing damage is pretty typical of Detonation Damage.

Overall, certainly looks like Detonation damage from either a lean scenario or ignition induced.

This is the Stbd bank... correct?

#2 has ring landing damage very likely due to detonation.

#4 has deep scoring markings that are probably from piston ring pieces.

#6 has burned cleaner, but also has ring landing damage.

#8 has ring landing damage, and also probably tossed ring pieces around inside causing the markings.

#1... Whatever you do, DO NOT go back together with those Full Dished pistons! Those have NO place in a SBC Marine build! rod

#2... Do not let an automotive exclusive machine shop make your component decisions for you.

#3... Read Dennis Moore's Small Block Chevy Marine Performance book.

#4... I'll have to think up a #4.

#5... Read what you can re; a quench effect build, and take advantage of the wedge combustion chamber design.

We've had many discussions re; building the SBC correctly for Marine use. Do a BOC search.... you'll find many threads on this topic.

Keep the C/R within reasonable limits. The quench style pistons allow for this. Don't let anyone tell you differently.

The cost to do a quench build is peanuts on the larger scope, compared to the benefits.

And equally as important, watch your Ignition TA and F/A ratio when you get it up and running again.

Try to find out what caused the engine to detonate in the first place.

When/if you guys suspect that there's severe damage like this, and when/if you can, run the engine and look at your ignition TA numbers while you have the chance to.

You don't want to build a new engine, and have this very same thing happen again from a malfunctioning ignition system.

[Chief_Alen]

Wish i could write as well as Rick does. I totally agree.

You were running the correct plugs?

[Guest]

2850Bounty wrote:
The answer is yes.... I certainly have!

The dark color may be from the aluminum... I'm not sure.

The several pistons that have ring landing damage is pretty typical of Detonation Damage.

Overall, certainly looks like Detonation damage from either a lean scenario or ignition induced.

This is the Stbd bank... correct?

#2 has ring landing damage very likely due to detonation.

#4 has deep scoring markings that are probably from piston ring pieces.

#6 has burned cleaner, but also has ring landing damage.

#8 has ring landing damage, and also probably tossed ring pieces around inside causing the markings.

#1... Whatever you do, DO NOT go back together with those Full Dished pistons! Those have NO place in a SBC Marine build! rod

#2... Do not let an automotive exclusive machine shop make your component decisions for you.

#3... Read Dennis Moore's Small Block Chevy Marine Performance book.

#4... I'll have to think up a #4.

#5... Read what you can re; a quench effect build, and take advantage of the wedge combustion chamber design.

We've had many discussions re; building the SBC correctly for Marine use. Do a BOC search.... you'll find many threads on this topic.

Keep the C/R within reasonable limits. The quench style pistons allow for this. Don't let anyone tell you differently.

The cost to do a quench build is peanuts on the larger scope, compared to the benefits.

And equally as important, watch your Ignition TA and F/A ratio when you get it up and running again.

Try to find out what caused the engine to detonate in the first place.

When/if you guys suspect that there's severe damage like this, and when/if you can, run the engine and look at your ignition TA numbers while you have the chance to.

You don't want to build a new engine, and have this very same thing happen again from a malfunctioning ignition system.

[SIZE]3 wrote:
[COLOR]#000000 wrote:
[FONT]Calibri wrote:
Yes it is the starboard side.. [/FONT][/COLOR][/SIZE]

[FONT]Calibri wrote:
[SIZE]3 wrote:
[COLOR]#000000 wrote:
[/COLOR][/SIZE][/FONT]

[SIZE]3 wrote:
[COLOR]#000000 wrote:
[FONT]Calibri wrote:
From what I can see the rings are not broke.. This is the reason I think it ran as well as it did.. Only one cylinder was below 100 pounds. I think it was [/FONT][/COLOR][/SIZE]

[SIZE]3 wrote:
[COLOR]#000000 wrote:
[FONT]Calibri wrote:
at 72 pounds.. I also think the guy that sold it to me took it apart and cleaned the peace's out then put it back to together with the old head gasket..[/FONT][/COLOR][/SIZE]

[SIZE]3 wrote:
[COLOR]#000000 wrote:
[FONT]Calibri wrote:
The head gaskets were of two different types. Felpro was on the port side.. Starboard I don't know what that is.. The intake gaskets and valve cover [/FONT][/COLOR][/SIZE]

[SIZE]3 wrote:
[COLOR]#000000 wrote:
[FONT]Calibri wrote:
were also felpro and new looking. The port side of the engine looks good and all cylinders were over 150 pounds. But I must say that one of the intake valves had deep [/FONT][/COLOR][/SIZE]

[SIZE]3 wrote:
[COLOR]#000000 wrote:
[FONT]Calibri wrote:
pitting on it. As if maybe it was a used but serviceable.. (see pic of port side bank).[/FONT][/COLOR][/SIZE]

[FONT]Calibri wrote:
[SIZE]3 wrote:
[COLOR]#000000 wrote:
[/COLOR][/SIZE][/FONT]

[SIZE]3 wrote:
[COLOR]#000000 wrote:
[FONT]Calibri wrote:
All the machine shop is going to do is clean, inspect and bore the block. Then clean and inspect the heads. Install valve guides etc. [/FONT][/COLOR][/SIZE]

[FONT]Calibri wrote:
[SIZE]3 wrote:
[COLOR]#000000 wrote:
[/COLOR][/SIZE][/FONT]

[SIZE]3 wrote:
[COLOR]#000000 wrote:
[FONT]Calibri wrote:
I have heard of the " quench effect" before but did not pay much attention at the time.. (thought my days of "mechanicing" were through) So can you please[/FONT][/COLOR][/SIZE]

[SIZE]3 wrote:
[COLOR]#000000 wrote:
[FONT]Calibri wrote:
Elaborate on this a little for me? I have also been hearing a lot about hydrostatic pistons.. What are these? And why are the different.[/FONT][/COLOR][/SIZE]

[FONT]Calibri wrote:
[SIZE]3 wrote:
[COLOR]#000000 wrote:
[/COLOR][/SIZE][/FONT]

[SIZE]3 wrote:
[COLOR]#000000 wrote:
[FONT]Calibri wrote:
What cause all of this I could only guess. But I think your right about the detonation.. I also seen that the previous owner had put in a protronic [/FONT][/COLOR][/SIZE][SIZE]3 wrote:
[COLOR]#000000 wrote:
[FONT]Calibri wrote:
Ignition system. You know the thing they put in the distributor going from points to electronic system. That may not have timed it right after[/FONT][/COLOR][/SIZE][SIZE]3 wrote:
[COLOR]#000000 wrote:
[FONT]Calibri wrote:
they put that in. Also maybe some lower octane gas.[/FONT][/COLOR][/SIZE][SIZE]3 wrote:
[COLOR]#000000 wrote:
[FONT]Calibri wrote:
I am an old school mechanic, hopefully some of that will come in handy for this job. [/FONT][/COLOR][/SIZE][FONT]Calibri wrote:
[SIZE]3 wrote:
[COLOR]#000000 wrote:
[/COLOR][/SIZE][/FONT][SIZE]3 wrote:
[COLOR]#000000 wrote:
[FONT]Calibri wrote:
Do you have a preference on pistons and valves.. I have been looking at SS valves.. Also cam choice. I want to keep this build under[/FONT][/COLOR][/SIZE][SIZE]3 wrote:
[COLOR]#000000 wrote:
[FONT]Calibri wrote:
Say $1200 to $1500 for parts. I got this boat in 2010 and have been working on it since. I bought an extra king cobra cone clutch drive because I heard so much [/FONT][/COLOR][/SIZE][SIZE]3 wrote:
[COLOR]#000000 wrote:
[FONT]Calibri wrote:
About how hard it was to get pats. That was 2200 hundred bucks Had the one that came with the boat rebuilt for 1100 bucks. [/FONT][/COLOR][/SIZE][SIZE]3 wrote:
[COLOR]#000000 wrote:
[FONT]Calibri wrote:
I bought an engine for it on eBay a few months back and the person selling was running a scam.. I got my money back but decided right then that will build my own engine. [/FONT][/COLOR][/SIZE][FONT]Calibri wrote:
[SIZE]3 wrote:
[COLOR]#000000 wrote:
[/COLOR][/SIZE][/FONT][SIZE]3 wrote:
[COLOR]#000000 wrote:
[FONT]Calibri wrote:
Ok.. Any and all suggestion are welcomed and appreciated..

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[Guest]

Chief Alen wrote:
Wish i could write as well as Rick does. I totally agree.

You were running the correct plugs?

I do not know.. I am not the one who did this.. I bought it that way..

I did put in new plugs trying to fix the miss that it had..

[2850Bounty]

Chief Alen wrote:
Wish i could write as well as Rick does. I totally agree.

Thank you, Chief. Verbose, yes.... but I try to cover the bases.

Giddy-Up wrote:
All the machine shop is going to do is clean, inspect and bore the block. Then clean and inspect the heads. Install valve guides etc.

[COLOR]"#0000FF" wrote:
You may as well have the shop look at the crankshaft and see if the rods should be re-sized, etc. [/COLOR]

I have heard of the " quench effect" before but did not pay much attention at the time.. (thought my days of "mechanicing" were through) So can you please

Elaborate on this a little for me? I have also been hearing a lot about hydrostatic pistons.. What are these? And why are the different.

[COLOR]"#0000FF" wrote:
See below.[/COLOR]

What cause all of this I could only guess. But I think your right about the detonation.. I also seen that the previous owner had put in a protronic

Ignition system. You know the thing they put in the distributor going from points to electronic system. That may not have timed it right after

they put that in. Also maybe some lower octane gas.

I am an old school mechanic, hopefully some of that will come in handy for this job.

[COLOR]"#0000FF" wrote:
Yes... likey detonation.... and yes, your skills will come in handy.[/COLOR]

Do you have a preference on pistons and valves.. I have been looking at SS valves.. Also cam choice. I want to keep this build under

Say $1200 to $1500 for parts.

[COLOR]"#0000FF" wrote:
I rarely feel comfortable suggesting things like this. Too many Chefs in the stew, and................... well, you know!

What I will say..... all components must compliment one another.

Piston selection is influenced by cylinder head chamber volume. Can't choose a head until you know which pistons will be used.

Can't choose a piston until you know which head will be used.

Your knowns are:

4.030" bore if this will be first over.

Stroke will be 3.480"

Chamber volume is likely 64cc since I see the full dished pistons used.

So those are a few of your perameters that will lead you to the correct parts.

[/COLOR]

First of all..... what a shame, whatever the cause was. My money is still on detonation. Check your ignition system before re-using it.

Here are just a few random images of detonation damage. These are not necessarily SBC pistons.

Detonation causes:

High cylinder pressures and high engine loads.

Lean F/A mixture.

Too much ignition lead per engine rpm and load.







The quench effect is simple to achieve and not all that costly.

Nut shelling this:

SBC cylinder head has a flat wedge area to the upper side of the combustion chamber. (likewise w/ the 335 series Fords and Chrysler wedge head engines)

This is a rather crude image..... the piston deck and cylinder head wedge would actually be within .040" of each other.



The Full Dished piston (as it comes up underneath the wedge area) leaves a portion of the dish volume open and a place for part of the flame front to hide.

This can cause a secondary burn and severe shock waves within the combustion chamber.

This is a quench or squish style piston that still offers a dish volume, but is not a Full Dish.



A piston that brings up a flat surface underneath the wedge creates a squish or quench zone. Note how the piston deck mirrors the wedge area.

Any dish volume is limited to underneath the combustion chamber area.

The flame front has no area to hide.

continued

.

[2850Bounty]

D-dish that works well with your pre-Vortec chambers.



Low Compression Quench piston that works well with the Vortec chamber.

(wrong skirt length shown.... but the piston deck is very similar)

(example only)



You can play around with some of the numbers yourself with this Static C/R calculator.

http://cleanandsober.741.com/CompressionCalculator.html

Go back to post #14 and look at the squish band image for piston deck and compressed head gasket thickness locations.

Talk to your machinist for piston deck height..... probably around .015".

Shoot for .038" -.040" total quench band (this is best for the SBC Marine) which makes the compressed gasket thickness about .025" +/-.

The Automotive Hot Rod guys perfer a squish/quench dimension that is greater.... but do not use a larger dimension.

Plug in the following info:

Piston block deck height, the compressed head gasket thickness, the bore (4.030") /stroke (3.480"), the combustion chamber volume (probably 64cc but varify), the piston dish volume (just try a bunch of them) and see what C/R range you come up with.

You probably don't want to exceed 9.4:1 or so......, and that's only if you do the squish/quench build.

Pistons:

This style piston should be available in any material... cast, forged, hypereutectic, just as the full dished pistons are. Hypereutectic is a higher silicone content aluminum alloy that is very durable. (probably one of the better choices)

With exception to the cost of Forged Pistons, the cast or hypereutectic quench style pistons won't break the bank.

Any major piston manufacturer or suppier should be able to supply these.

For the correct pistons, your machine shop person needs to know your perameters... bore/stroke/cylinder head chamber volume, desired C/R, yada yada yada.

He then makes a phone call to his prefered and knowledgeble piston manufacturer's sales rep, and asks questions.

Or... when your decision for Quench or NO Quench has been made, and when you are clear as to your parameters, call a reputable piston manufacturer/supplier yourself.

Benefits:

Better combustion, more ignition lead w/ less chance of Detonation, opportunity to gain a few more points on C/R (w/o risk of detonation), more low end torque.

You may encounter a few of the usual Nah Sayers regarding the quench build, telling you that it's not necessary.

I can tell you that these guys are mainly building auto SBC's, and are not aware of Marine engine loads, nor the benefits of a quench build for a Marine SBC.

In which case I'd say, "move on to another shop!"

.