Polishing Pistons

[RSVDon]

Should I? I've got some Tropicare car wax that might work well. Or I could just use Mother's. I'm thinking the more polish on the piston the more the fuel will bead up evenly causing a complete and equal burn across the surface of the piston.

[schmuckingham]

Should I? I've got some Tropicare car wax that might work well. Or I could just use Mother's. I'm thinking the more polish on the piston the more the fuel will bead up evenly causing a complete and equal burn across the surface of the piston.

I hate you

[ReconRat]

Put a tiny little computer fan on each piston, to keep the fuel-air mixed up proper.

[RSVDon]

Hey, good idea! Think I should put the fan before the valve or just drill and tap it straight into the piston surface. Wiring would be a bitch, but hey, I might be able to use VP Racing Q16 if I do it right!

[NinjaNick]

[jbot]

don't be a bish, get a turbonator, son!

[schmuckingham]

I have a port and polish kit in a sack right here, just tear and dump and VWALA..... results

[RSVDon]

Does it come with snake oil that cures cancer? If so, I'm in!

Anyways, aside from being a bit of a troll, I made this thread because I was bored and laughing at a friend. One of the scorpion rocker arms on his GTO broke and dropped bits into the lifter tray so he took it apart and being the anal motherfucker that he is, he polished his pistons up with carb clean and a toothbrush!

[Dweezel]

Actually Polishing the piston top/combustion chamber is a good idea. you don't have to go crazy and get it mirror smooth but a smooth surface does several things, eliminates peaks that hold heat and could cause pre-combustion (knocking), allows air to flow more smoothly (which in a 4v head is good because their flow characteristics suck ass anyways, as with all 4v heads) and makes it harder for carbon deposits to build up.

NOW, in a carb setup you need to leave a rough surface on the intake ports, and intake manifold to cause turbulance to keep the fuel in suspension, and should also have the intake manifold floor about 1/16th of an inch above the cylinder head floor to induce turbulance at a key point.

End of lesson

edit, also equal burn across the piston is a character of combustion chamber design mainly, unless of course you have high dome pistons (bad idea) and ideally the spark plug should be on the high outside of the chamber (such as in 2 valve heads) where the most turbulence is taking place, and the worst place for it to be is in the top dead center of the chamber (where it is on a 4v head and hemi heads) where there is little to no movement. 4v heads inheriantly have shit for swirl. Not knocking any brand schmuck so keep your panties on, just a plain old fact, look it up.

[chevysoldier]

Does it come with snake oil that cures cancer? If so, I'm in!

Anyways, aside from being a bit of a troll, I made this thread because I was bored and laughing at a friend. One of the scorpion rocker arms on his GTO broke and dropped bits into the lifter tray so he took it apart and being the anal motherfucker that he is, he polished his pistons up with carb clean and a toothbrush!

Too Funny LOL

[RSVDon]

Actually Polishing the piston top/combustion chamber is a good idea.

Way to be all serious.... Nice info.

[schmuckingham]

Actually Polishing the piston top/combustion chamber is a good idea. you don't have to go crazy and get it mirror smooth but a smooth surface does several things, eliminates peaks that hold heat and could cause pre-combustion (knocking), allows air to flow more smoothly (which in a 4v head is good because their flow characteristics suck ass anyways, as with all 4v heads) and makes it harder for carbon deposits to build up.

NOW, in a carb setup you need to leave a rough surface on the intake ports, and intake manifold to cause turbulance to keep the fuel in suspension, and should also have the intake manifold floor about 1/16th of an inch above the cylinder head floor to induce turbulance at a key point.

End of lesson

edit, also equal burn across the piston is a character of combustion chamber design mainly, unless of course you have high dome pistons (bad idea) and ideally the spark plug should be on the high outside of the chamber (such as in 2 valve heads) where the most turbulence is taking place, and the worst place for it to be is in the top dead center of the chamber (where it is on a 4v head and hemi heads) where there is little to no movement. 4v heads inheriantly have shit for swirl. Not knocking any brand schmuck so keep your panties on, just a plain old fact, look it up.

coated pistons > polished pistons- better heat resistance and heat transfer is less into the piston and its a hotter burn.

4v> 2v- 4v have the plug placed in the center to start the burn from the center and work its way out causing a full, even combustion. 4v heads are meant to swirl they are meant to tumble, 2v heads need swirl to use up the space provided by the cylinder.

intakes can be ported fairly smooth for carb cars, something around a 60-80 grit. Mostly due to better castings/ intake ports/ fuel

[Dweezel]

coated pistons > polished pistons- better heat resistance and heat transfer is less into the piston and its a hotter burn.

Nobody asked about coated pistons did they? huh? didn't think so.

4v> 2v- 4v have the plug placed in the center to start the burn from the center and work its way out causing a full, even combustion. 4v heads are meant to swirl they are meant to tumble, 2v heads need swirl to use up the space provided by the cylinder.

2v heads promote swirl, swirl is important to filling at low speeds Educate yourself and don't just be a Ferd nutswinger.

http://www.gofastnews.com/board/technical-articles/281-polyquad-new-four-valve-power-concept.html

theres a stupid amount of info on that site, check it out.

intakes can be ported fairly smooth for carb cars, something around a 60-80 grit. Mostly due to better castings/ intake ports/ fuel

Sorry I'll give exact specs next time. 80 grit is still pretty rough, let me repaint your hood and stop sanding with 80 grit? Deal?

[Dweezel]

Not unreasonably a first inclination would be to assume that both types of mixture motion would work equally well. Up to a point they do but as the piston nears the top of it’s stroke these two forms of mixture motion diverges in characteristics. The tumbling charge motion breaks down to small tumbling eddies where as the swirl, as it gets compacted in the chamber can speed up while still retaining it’s swirling motion form. This swirling motion in conjunction with a well placed spark does a good job of effectively and rapidly burning the charge. On the other hand the tumbling action seen most often in four valve engines tends not to produce enough charge motion at low speed to produce as good results as the two valve engine swirl. Also tumble can be almost cancelled out when high compression ratio’s are used.

In addition to the lower combustion speed the inclined valve four valve heads tendency to allow the fresh incoming charge to cross flow out of the exhaust during overlap also cuts the low speed torque as well as increasing fuel consumption and emissions. With the appropriate proportioning of valves and bore/stroke, a two valve engine, with a well designed cylinder head, can out-perform a four valve engine to about 4000 rpm.

Just to save you the trouble there's something like the 2, 3rd paragraph. Nutswinger.

It seems your attn span is limited so I highlighted the extra important parts for ya.

[schmuckingham]

1. As your info states the 2v makes better power at lower speeds, great for around town and big blocks.

2. valve overlap is common in 4v setups to draw in fresh air and make things work less, the 2v swirl actually has to force air in so at higher speeds its less effective.

3. no one in this thread asked for your technical ideas so me addding the piston coating isnt out of line

4. What does painting the hood of my car have anything to do with intake porting, each has its varying idea of smooth and rough and 80 is pretty smooth for an intake not a car hood.

5. You assume I am speaking of a Ford 4v head, which in reality i speak of any 4v head. So your bad for assuming.

6. I have flowed enough heads to know I want a 4 or even a 3 valve head on top of my motor if possible.

7. You need to realize your not always right and peoples OPINIONS vary, I know there are plenty of 2v cars out there that perform very well but you never see anyone swaping 4v heads for 2v heads unless its meeting a class requirement.

[Dweezel]

1. As your info states the 2v makes better power at lower speeds, great for around town and big blocks.

2. valve overlap is common in 4v setups to draw in fresh air and make things work less, the 2v swirl actually has to force air in so at higher speeds its less effective.

3. no one in this thread asked for your technical ideas so me addding the piston coating isnt out of line

4. What does painting the hood of my car have anything to do with intake porting, each has its varying idea of smooth and rough and 80 is pretty smooth for an intake not a car hood.

5. You assume I am speaking of a Ford 4v head, which in reality i speak of any 4v head. So your bad for assuming.

6. I have flowed enough heads to know I want a 4 or even a 3 valve head on top of my motor if possible.

7. You need to realize your not always right and peoples OPINIONS vary, I know there are plenty of 2v cars out there that perform very well but you never see anyone swaping 4v heads for 2v heads unless its meeting a class requirement.

.....LS1tech.com is also full of people dropping LSx motors into mustangs, I have yet to see anyone drop a mod motor into a GM product... I did see a guy drop a 460 into an old GenI Camaro though, said he had the motor sitting around and it did make very decent numbers.

You also see millions of people building engines who have no business using a microwave, let alone building a motor.

If you've flowed enough heads then you'll have no agruements when I say it's a hard fact that GM's LS7, and I'm pretty sure the first gen LS6 head out flows Fords best 4v head, or allot of 4v heads in general. or haven't you flowed any GM heads? The new heads on the ZR1 and G8 are ignorant. They're getting mid/high lift numbers on stock heads that were high end big block numbers not 10 years ago.

LS7 head

Lift Intake Exhaust

.300 246 cfm 174 cfm

.400 302 cfm 200 cfm

.500 343 cfm 211 cfm

.550 358 cfm 216 cfm

.600 360 cfm 220 cfm

.650 379 cfm 224 cfm

Just to be fair since the STOCK LS7 heads are 'cnc' ported I dug up some CNC ported 4v heads to compare them with.

CNC ported 4v head

4v 5 axis CNC heads:

.300 .400 .450 .500 .550

I - 241 293 303 315 324

E - 219 249 257 264 270

[RSVDon]

Holy fuck! Those flow numbers and downright damn ridiculous.

[schmuckingham]

So know your basing this on one head from GM and I am a nutswinger......... I previously said this isnt a Ford Vs GM thing but you continously make this one.

So the LS7 heads you posted barely outflow the 4v at low end intake like its supposed to and the list you posted for the 4v stops at .550 while the exhaust is WAAY better on the 4v, so i guess this argument is mute

[schmuckingham]

Before this turns into a GM Vs Ford debacle, I will say this now. I didnt intend this to be what others have made it. I preference the 4v and find it superior to the 2v, now this isnt taking anything away from any 2v. My Lightning was a 2v, my Mustang was a 2v and my Dads Vette is a 2v. I am not taking anything away from any LSx engine because they perform hella spectacular. Many guys swap the LSx engine into a Fox platform or SN car but they are wanting a better suspension and lighter car but guys have put V8s into lawn mowers. I get a little heated over guys who think the LSx is gods gift to man but whatever floats your boat I guess.

As far as I am concerned this discussion is over and each side has made their points.

[zerocrash]

So I'm confused, who likes Ford and who likes GM?? :confused:

Sorry... couldn't resist..

[dustinsn3485]

I'm a Dodge guy

[zerocrash]

I'm a Dodge guy

Be careful bro, you may have just opened a whole new... you know.

[schmuckingham]

I'm a Dodge guy

Good friend of mine interned at SRT and now works at Heffners performance in Bradenton FL as their fabricator. He is a die hard turbo 2.2l guy from the old Daytona Shleby's and such.