Help me evaluate these photos. Chamber and Piston

[want-a-be]

Even the Pro Stock guys are seeking higher RPMs. RPM=MPH all there is to it.

[user-9274568]

Even the Pro Stock guys are seeking higher RPMs. RPM=MPH all there is to it.

can I get a AMEN!!!!!!!

[Keith Morganstein]

4 Cylinders?, RPM's ?

Just look a the 4cylinder motorcycle engines if you want to see RPM's.

[Keith Morganstein]

Chad,
If you use a reduced Radial thickness ring at top, example .135 radial size and a little bit thickr 2nd ring exaample .145 radial and whatever oil ring size turns you on in a std tension ring . the overall drag will not be much and the radial tension on those two top rings will be slicker'n snot. Use the gas ports for your wall tension of that top ring.


Ed

This is interesting and it makes me think more about thin rings in general.

Should we consider gas porting mandatory whenever a thin and/OR reduced radial thickness ring is used?

[Strange Magic]

I'm having a hard time with is this. Every single time I've personally or witnessed someone raising their peak hp, it's went faster (ET) I witnessed a friend pick up 300 rpm in peak and it ran .05 faster. Why? Because IMO, RPM is ET.

You are correct. The ability to raise the torque curve will mathematically produce higher hp figures. It is also important to remember that you do not go down a race track at one given single engine rpm. The broadness of the curve plays more of a factor in the ability to kill an et clock than the actual peak number. The more gears to row the less likely it will suffer when elevating torque numbers even with a loss of torque curve under that peak figure. I don't believe your rowing 5 gears like a pro stock so be very careful not to hurt the average when making attempts to elevate your peak torque numbers higher in the rpm.

[MaxFlow]

i guess if your not afraid of the piston speed then just keep throwing gear at it til it slows down. What's VE telling you to do with this combo? I haven't paid any attention to those numbers here.

However, if your going to do that, I'm sure the ringseal issue will need fixed.

[Ed-vancedEngines]

Kieth,
Remeber your source. It is only from me, not a big name shop or builder.

Now here is my theory and this is seeming to work pretty well on onlly normal aspirated engines. Everyone is wanting the light tension and reduced oil ring backages to cut down on ring drag on the cylinder walls. Some guys have gone as far as not only reducing oil ring tension but have eliminted the second ring and then use a Ackerly and chils or a Hell Fire top ring, which in my opinion has more outward radial tension than just about anything else available.

My theory is when using gas ports let most of the top ring radial outward tension be generated by those gas ports. I know if your piston is cut for it that the .135 radial top ring is much less radial tension. Less drag with no reduction of top ring cylinder seal should be a plus plus with less weight and less drag. The second ring has no gas port and is like a secondary oil wiper ring, so use the .145 radial thickness for less weight with less side tension but with the Napier Wiping design. The letting bit of extra outward wall tension that will be with the standrd tension oil rings has been more than equaled or surpassed by the cut back first and secong rings. Now you have a nice lightweight top ring package light wall tension but better oil control using stanrd pil rings with the Napier designed second.

This will hold up and will give better oil control with less over all drag.

Can I be poitive about this? No, Just like most anything else I have done, I have no way to do any official testing of the results. I can say that on dyno pulls there is no oil or moisture from vacuum pump during dyno. I can say the cars seem to be ok in the pwer dept.

I have no proof to show anyone abiut most things I have done, but at least consider the possibilites.

Ed

[user-9274568]

One more thing. With all this 4 cylinder talk, watch this video. TURN UP YOUR SPEAKERS!! It was from a few years ago, but it's a sweet sound!!

http://www.youtube.com/watch?v=FeCWVMYbhok

[user-9274568]

Well, I pulled a piston. I posted a photo. It's not very good photo, I was having a hard time. Tell me what to look for.

Thanks guys

http://www.speierautosales.com/sb2.htm

[Andrew Starr]

The walls seem really shiney to me.

I really think you hit on an important observation. I noticed the shiny walls also. Regardless of engine vacuum, ring width or radial tension, RPM etc, if the walls are unable to hold the required oil film then the rings will do nothing more than "hydroplane". This can explain a number of problems. The oil coming from the gas ports(what a great observation!), the vacuum loss at RPM, etc. All this oil will also lead you to believe the engine is "tight" with a leak down test also.

The first thing I check when I see shiny walls is the second ring. If the ring has more than a thin sliver of wear , typically on the bottom for most second rings, then it is an indication that it is scrubbing the wall from lack of oil retention. If the whole face is wiped clean then you will for certain found your problem.

You might have mentioned what block you are using and I am sorry I missed it if you did, but each type of block, due to the density of the material, requires a different honing technique. Harder aftermarket blocks will typically require more aggressive honing techniques to insure you are not tearing and folding the material in the bore. When this happens a shiny bore is the result as oil is wiped off the surface allowing the ring to remove what ever finish you had on the walls. The second ring is the key.

I recommend contacting your ring manufacture to verify if proper honing technique was used, and it it isn't Total Seal...just call them directly instead.

Best of luck on your search....