Spark Plug Heat ranges, what gains have you made?
 

I run a turbo car with a enhanced tune.
Boost is 16.5psi now from 14.1psi.

I have tried all variations of VP UNLEADED RACE fuel.

I find it difficult to see a performance difference in any as opposed to Costco fuel with VP octane booster.

I do have data that leans toward when I use VP C9 or MS101 AND BRACKET RACE THE CAR IS MORE CONSISTANT, EASIER TO DIAL.

I digress, my goal is to gain more from a colder plug than standard plug.

The NGK codest plug is 3 heat ranges colder than my stock plug.

I think it will be worth a tenth in my vehicle.

Thanks in advance for your input.

Re: Spark Plug Heat ranges, what gains have you made?
 

You think there is a tenth only from the plug change?



This may not be the best forum for a turbo charged question but there are a bunch of really smart guys on here.

Re: Spark Plug Heat ranges, what gains have you made?
 

Enlighten me.
I'm not up on boost terms, but what is an enhanced tune?

Re: Spark Plug Heat ranges, what gains have you made?
 

I think there may be a small improvement in performance
if the engine is running in or on the edge of detonation.

Re: Spark Plug Heat ranges, what gains have you made?
 

All reason to go faster with correct plug on nitrous is having the wrong plug and torching electrode.

Re: Spark Plug Heat ranges, what gains have you made?
 

Enhanced tune for my vehicle is, running ignition Timing right on the edge of pre ignition.

Re: Spark Plug Heat ranges, what gains have you made?
 

I also forgot to mention the colder plugs vs the standard plugs give me a full CC less combustion chamber volume.
This increases static combustion ratio, almost always positive.

I feel like stockers should be able to submit their own spark plugs to compliment the shape of their combustion chambers, just like people submitting their own piston variations in Stock.

Btw...
Has anybody been caught moving their piston pin offset/location in Stock yet?

Re: Spark Plug Heat ranges, what gains have you made?
 

A wrist pin offset normally is 0.060" to 0.080". When people reverse the wrist pin offset (do people still do this in stock?) this moves the pin center line 0.120" to 0.160" they may see a very small difference. Lets look at a 0.060" reverse and we a talking a little under 1 degree change in Piston TDC to crank journal TDC

Bore = 4.0 Stroke = 3.25 Rod Length = 5.7
Actual Piston Stroke 3.25019600382
Cylinder Volume 40.843168 CI 669.299602 cc
Engine Size 326.745340 CI 5354.396814 cc

Wrist Pin Offset = 0.06
Crank Angle Piston TDC -0.46932221356 Piston BDC 179.15635067565

Wrist Pin Offset = -0.06
Crank Angle Piston TDC 0.46932221356 Piston BDC 180.84364932435

Where you can really see a difference is with an inline motorcycle engine where the crank line has been moved 10 mm.

Stan

Re: Spark Plug Heat ranges, what gains have you made?
 

I honestly don't think NHRA ever checks wrist pin offset in Stock or any other class. It's a gray area. Maybe that's why nobody has ever been bounced for it.

Thank you for your math on the v8 engine offset.

The initial wrist pin offset was to make engines quieter in early days, that particilar offset was the opposite of centerline direction that the offset used to gain leverage and ultimately Horsepower.

It's always been a gray area and until someone comes forward with "they've been bounced for this, then anything goes in my opinion.

Re: Spark Plug Heat ranges, what gains have you made?
 

NHRA DOES check wrist pin location. Ask David Walther or Tom West. 1972 winners of div race at Muncie, IN until getting tossed for have stocker pistons in backwards. It's all been tried. Nothing new.

Re: Spark Plug Heat ranges, what gains have you made?
 

Thank you for some clarity.

Why isn't the stock offset listest in accepted pistion?

Re: Spark Plug Heat ranges, what gains have you made?
 

Probably because it might not be a checking point now. Not sure. Need to ask Tech. Back in 1972 you couldn't run replacment pistons. Had to run OEM.

Re: Spark Plug Heat ranges, what gains have you made?
 

Thank you for some clarity.

Why isn't the stock offset listed in accepted pistons?

Re: Spark Plug Heat ranges, what gains have you made?
 

Pin offset is no longer an issue that Tech is concerned.

Re: Spark Plug Heat ranges, what gains have you made?
 

It ain't 1972 anymore.

Re: Spark Plug Heat ranges, what gains have you made?
 

David Frieburger (might be spelled wrong) from Hot Rod magazine, engine masters, road kill ect ect. Just posted within the last couple of days that they tried the reverse piston trick on a 360. They saw no changes on the Dyno.

Re: Spark Plug Heat ranges, what gains have you made?
 

Yep. Back then they HAD TECH.

Re: Spark Plug Heat ranges, what gains have you made?
 

I now for a fact on the Boss 302 it was worth 10 hp as I was at Dyno the night we run it.

Re: Spark Plug Heat ranges, what gains have you made?
 

Ralph,
Do you happen to know how much offset that piston has?


Bore = 4.0 Stroke = 3.0 Rod Length = 5.155
Wrist Pin Offset = 0.06
Actual Piston Stroke 3.00022203042
Cylinder Volume 37.701902 CI 617.823481 cc
Engine Size 301.615216 CI 4942.587850 cc
Crank Angle Piston TDC -0.51657300450 Piston BDC 179.05939775907



Stan

Re: Spark Plug Heat ranges, what gains have you made?
 

Thats approximately 2.5% gain?

There is more potential HP in a corrected Piston pin offset.

I'm glad we all know now that NHRA DOES NOT TECH THIS FEATURE.

Re: Spark Plug Heat ranges, what gains have you made?
 

Remember it is not one size does the same for all. This is a 426 ci Chrysler with the same 0.06" offset.

Bore = 4.25 Stroke = 3.75 Rod Length = 6.768 RPM = 6500
Wrist Pin Offset = 0.06
Actual Piston Stroke 3.75015962277
Cylinder Volume 53.200718 CI 871.803575 cc
Engine Size 425.605745 CI 6974.428599 cc
Crank Angle Piston TDC -0.39775244513 Piston BDC 179.29739772523

Stan

Re: Spark Plug Heat ranges, what gains have you made?
 

Wasn't the Boss 302 a dome piston? Can't put that in backwards.

Re: Spark Plug Heat ranges, what gains have you made?
 

No need to do that, any stocker can Submit their own piston for the class.

Re: Spark Plug Heat ranges, what gains have you made?
 

Fryburger....hahahahaha.

Re: Spark Plug Heat ranges, what gains have you made?
 

"on the edge of pre ignition" ?? Detonation and pre ignition are two very different things. Pretty sure you meant detonation.

Re: Spark Plug Heat ranges, what gains have you made?
 

No Bruce, it's a TURBO car, high Combustion pressure.

Turbo cars have a tendency to have low speed Pre ignition with much higher Combustion pressure....

But, I am here to gather ideas and have looked further into detonation.
I can see how they can be confused with one another.
Thank you for the response.

I do look forward to the NGK heat range 9 plug to test.

Re: Spark Plug Heat ranges, what gains have you made?
 

Help us slow ones out a little bit. What exactly am I looking at and how would it affect power?


Rick Thomason
GTOMayhem

Re: Spark Plug Heat ranges, what gains have you made?
 

When you add wrist pin offset a number of thinks happen. The piston and the crank rod journal are not ATDC and BBDC at the same time. Now based on which way you have the offset decides if piston TDC is before or after crank rod journal TDC. Another thing that happens is all 4 cycle are not long 90 degrees each. 2 become less and 2 become more. Again which 2 do what is based on where the offset was placed.The is also a very very small change in stroke and displacement. (For inline engines where you can move / offset the crank center line these can be larger).


Stan

Re: Spark Plug Heat ranges, what gains have you made?
 

In light of all this study of the laws of physics, what does the installation of an offset pin piston have on piston to valve clearance ? Sounds like a way to close up excessive clearance on one valve while opening it up on others. Or, like so many things out there, is it significant or just one more gnat to swat at?

Re: Spark Plug Heat ranges, what gains have you made?
 

Within a normal range of piston pin offset the piston travel curve does not change very much from centered. So if you are using piston TDC there should be almost no difference in VTP clearance because of wrist pin offset.


Stan


PS Above I am talking about if you degree the cam. If someone just installs the cam dot to dot (crank rod journal TDC?) There will be more of a change in VTP clearance from the offset over centered pin.


Stan

Re: Spark Plug Heat ranges, what gains have you made?
 

Did not think of this. Could you run just 4 pistons with offset? Don't know if it is worth anything as I understood using offset helps with side thrust on bore.

Re: Spark Plug Heat ranges, what gains have you made?
 

I believe it slows the piston down more at top of cylinder helping capture more usefule cylinder pressure. There are many different functional aspects of using offset Piston pins. Maybe this is a competition eliminator question since anything goes just as like STOCK Eliminator Piston pin offsets.