I am in the process of gathering parts for my Nonvtec B20 build for a Drag test and tune/ weekend fun car. I am confused as to which may be best for my build to help out an already handicapped setup when compared to vtec engines. Please don't ask why don't I build an LSV, because the answer is simple, because I don't want to, I want a challenge, and prefer nonvtec.


I was watching "Power Nation" on Spiketv this past weekend. On "Engine Power" there was an 427 being build that the hosts mirror polished the tops of the pistons, mirror polished the combustion chambers, and used low tension piston rings.

I have removed all of the sharp edges on the tips of my pistons, and sanded the tips to a slight haze, as that's what most threads on the forum said to do. I planned to mirror polish the combustion chambers, and I am planning to use a knife edged crank(OEM one I have has a knick on the journal), lightweight rods, ATI damper, and fully balance the rotating assembly. I can't really find too many posts about Honda engines using low tension rings, but I know some members do use them.

So on to the questions:

1. Is it better to fully mirror polish, or leave a haze on the piston tops? And please elaborate on your choice please.

2. Is a mirror polished combustion chamber an asset or hindrance for flame control/travel, and detonation prevention

3. Is polishing a piston top OK if not polishing the combustion chamber, and vice versa? Which is better?

4. What are your thoughts on low tension piston rings? What type of ring life should I expect, assuming that the rings are properly seated after build is completed?

Yes I have done research, and not only on this forum. I see a lot of contradicting information, and the few threads I have found are old, and I have a couple more questions than what was included in previously posted threads, hence me starting a new one.

All opinions and help is greatly appreciated.

 

The questions listed are really beyond the knowledge of most forum members here, and are very broad considering all the different applications.

Very few, except oe engineers or high budget, competitive race teams have done back to back repeatable tests in repeatable environments to reach a conclusion on the questons you brought up. Hence the reason web searches reveal endless contradictions and opinions with little to no info or data to back them up. Most people I have seen that do things like polish piston tops simply because it feels good or they saw it somewhere else.

I try my own little things here or there but dont get too excited or convinced that what I did serves the purpose I think it may have. The best reference is to look at what the manufacturers do during each new engine design. Friction reduction, rigidity increases, surface finish, port angles and on and on. There is certainly more left on the table due to short comings of mass production but it leads you in the right direction of a little here and a little there to increase output.

 

Don't over-think it brother. Keep it simple. You should put your focus on tuning and learning to drive the car, both of those will get you more HP and better track times.
What many don't consider when looking into all of this polishing and what-not is it goes on an application to application basis. Piston dome shape, combustion chamber shape, etc all plays a vital roll.
I would focus on the head porting a valve job aspects to extract extra hp.

 

spark plugs

 

^^lol tru

 

Get a good valve job, un-shroud the valves, clean up the bowls etc. Then get some decent cams and valvetrain. The flow characteristics of the cylinder head have the biggest impact on HP. That is why the LS-VTEC conversion is so popular.

 

I am planning to get Laskey racing to port my P8R head, I have Crower 62405A camshafts and appropriate valvetrain, and pistons to put my compression around 13:1 compression ratio depending on how much I decide to have the head milled, I plan to degree in the cams, and make timing adjustments if there is more power left on the table. The reason I didn't ask about deshrouding valves, port work, and spark plugs is because I have done the research on those topics, and understand the ins and outs as far as they are concerned. I just figured there were engine builders/racers in the "A/M N/A" who wouldn't mind commenting on things that they found made power, or was pointless to do. I'm not asking for the more experienced guys to tell me all of their tricks, just to comment on the questions I am wondering about.


I'm sure I am over thinking this build, but I just want a very strong nonvtec engine. I have a vtec head, I just choose not to use it, as it doesn't interest me to. Yes I get that I may spend more/make less power and torque, and honestly that doesn't bother me, I'm not looking for 300hp nonvtec, just something to have people talking.

 

The Old One - Energy Dynamics : Articles


I believe that is what you were asking about.

 

Yes, I've read their articles a few times, but still doesn't help me understand why some people semi polish their pistons and combustion chambers, and others mirror polish them. Or which is better, but I just may be over thinking a simple build. So I guess it's best to let this thread die off

 

You don't want to polish them, you want to remove the sharp edges. The only thing I've ever read about polishing pistons or chambers was to "reduce carbon buildup", which is a load of bullshit.

Just sand down the rough edges and you're good to go.

 

Doing this will free up alot of ponnies. Trust me, works every time.

Open Wide!

 

Yea, I've done that, the removal of sharp edges to prevent detonation is one of the few things related to my questions I understand haha.

Is there any use for low tension rings? Or just snakes oil for the power level I'm going to be in?

 

Low tension rings with the correct finished bore AND engine oil will reduce friction on very high RPM application. Very measurable friction.

 

I think the low tension rings are mainly because in a racing engine, you are going to be running hotter temperatures then a street engine, and the rings will expand with heat, oil control is important, but not as important as on a street engine that has to last a lot longer. A lot of race engines you will hear some piston slap when they first start, but once they warm up and everything gets toasty that goes away. The tolerances need to be a little looser then a street engine, if you ran standard friction rings, they may expand enough for you to get some scuffing

 

So I'd be better off just using standard rings in my build? As I plan to occasionally drive it on the street. I'm not worried about piston slap, that's just the nature of forged pistons, but obviously with proper tolerances less piston slap can be had.


And by the way, I appreciate the comments guys.

 

I've ran multiple sets of forged pistons and have never experienced actual 'piston slap'. My hatch does blow a little smoke until it warms up though.

I'd just run the regular rings and call it a day.

 

I'm just not good at "splaining" things over the net, OP what type of racing are you doing again? circle track? In prolonged high RPM racig standard rings can expand too much from the heat and cause some scuffing, thats the primary reason for low tension rings, that and less friction in general, you are compensating for the extra ring expansion by running them

 

Test and tune nights at the drag strip, and the occasional weekend/weeknight drive.

 

I dont think it will make a huge difference at the drag strip, some reduction in friction, but for a car thats street driven, just use your standard rings, it would be more for prolonged high rpm racing,such as circle track, that they would be more useful

 

How will be this compared to something like a WPC treatment?

 

Honestly I have no idea, I've never used anything WPC treated. I looked it up, it seems like it changes the molecular structure of the metal? I'm not sure I didn't spend a long time looking at it.

Maybe someone else can chime in.

 

WPC is a pretty simple concept. Just blast tiny particles at the metal, and it forms the metal on the molecular level to fill in the microscopic holes left by the manufacturing process. A very tiny improvement that could prove very beneficial

http://www.wpctreatment.com/about.htm