quote:

Originally posted by Ron C.:

quote:

Originally posted by Mike Rietow:

quote:

Originally posted by 62Galaxie:
Going from race gas to alky...is it IMPERATIVE to change plugs, i.e., colder? 10.8 to 1, sbf, 480 HP. Up to now, 3924 Autolites are working just fine. Nice tan color and never a problem. Why should I change?

Colder plug makes for a larger window to advance the timing

.....I would have a different opinion on that.

Do you run a cooling system? Radiator

quote:

Originally posted by Ron C.:
.......Wrong direction...

Ron, could you elaborate on why running the coldest plug that will still fire the mixture is the wrong direction? Also on the tuning window thing?

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Originally posted by Coloradoracer:

quote:

Originally posted by Ron C.:
.......Wrong direction...

Ron, could you elaborate on why running the coldest plug that will still fire the mixture is the wrong direction? Also on the tuning window thing?

If you're not running a magneto with a Super Charger, I can see where cold plugs and tight spark plug gaps would make sense.

I have a suspicion Ron C. is running a magneto, you're not.

I don't run a mag on my car, but we do run a mag on my sons conventional blown alcohol motor. The only reason to run the narrow gap with a mag is for starting unless your running very high boost pressure, I'm talking well over 40 psi into the 50's and beyound. With today's 16v battery's and geared staters starting has been seriously improved for mags. My son and I run the same plugs and same gap (.025-28) in both engines. We also Crew Chief two Street Outlaw cars with big inch BBC with 14-71 HH blowers and run the same plugs and gap. Plug gap is a function of ignitions ability to deliver enough energy to jump a gap under a given cylinder pressure. If the gap is narrowed,...it will only build up enough energy to jump that gap. So if you set the gap at say .018 and your ignition is up to the task of jumping the gap at say .026, it will deliver a larger flame kurnal because the ignition had to rise up to that level. But,...watch your distributor cap inside for tracking. The spark is looking for a ground and it will find it in the path of least resistance. But most bracket racers will not encounter that kind of cylinder pressure to overcome. Always run the hottest plug your engine will tolerate. To cold a plug gives false readings. That's my thoughts and experience anyways.

I said if you're not running a mag with a supercharger, meaning a lot of boost. I could see running a tight spark plug gap and a cold plug making sense, meaning to not lose spark.

If I wasn't running a cooling system, Radiator on methanol. I can see where a hot plug could make sense.

Do you run a cooling system?

quote:

Originally posted by Mike Rietow:
I said if you're not running a mag with a supercharger, meaning a lot of boost. I could see running a tight spark plug gap and a cold plug making sense, meaning to not lose spark.

If I wasn't running a cooling system, Radiator on methanol. I can see where a hot plug could make sense.

Do you run a cooling system?

....When I was running blown gas ( no intercooler) at 42 psi boost I also ran a # 9 plug most of the time. Summer months would run # 10. Water in block and heads.

quote:

Originally posted by Mike Rietow:
I said if you're not running a mag with a supercharger, meaning a lot of boost. I could see running a tight spark plug gap and a cold plug making sense, meaning to not lose spark.

If I wasn't running a cooling system, Radiator on methanol. I can see where a hot plug could make sense.

Do you run a cooling system?

....Actually running a cooling system (Radiator) would make a cold plug react even colder. Heat transfer ( which is what plug heat ranges are all about) rate would be increased due to the greater Delta T. Besides....water weights 8.34 lbs per gallon, easy way to drop weight off the front end.

That's it, a cold plug is a better heat exchanger transferring heat to the cooling system to manage the vaporization of the fuel driving the car from and to the pit area, due to methanol's high latent heat.

You can run a little more ignition timing with a cold plug as well.

quote:

Originally posted by Mike Rietow:
That's it, a cold plug is a better heat exchanger transferring heat to the cooling system to manage the vaporization of the fuel driving the car from and to the pit area, due to methanol's high latent heat.

You can run a little more ignition timing with a cold plug as well.

...LOL....your trying real hard for it to mean something different than what I said. A water cooled head will actually make it worse on what your doing. If you get the tune up far enough off, you can get anyway with adding more timing than usual because your not making power ( heat) enough for it to matter. If that's making you content,...go for it. But your thinking is flawed for a proper potential tune up.

Alright so we're just down to the timing, we've already agreed a colder plug is better heat ex-changer transferring heat to the cooling system.

You can take a hot plug out of the cylinder head of any given tuneup with the metal annealing mark on the strap where ever you prefer it to be.

Screw in a colder plug, and you'll have to add timing to duplicate the same metal annealing mark on the strap. Same reasoning for using a colder plug with nitrous, more ignition timing more power.

quote:

Originally posted by Mike Rietow:
Alright so we're just down to the timing, we've already agreed a colder plug is better heat ex-changer transferring heat to the cooling system.

You can take a hot plug out the cylinder head of any given tuneup with the metal annealing mark on the strap where ever you prefer it to be.

Screw in a colder plug, and you'll have to add timing to duplicate the same metal annealing mark on the strap. Same reasoning for using a colder plug with nitrous, more ignition timing more power.

...your misunderstanding engine tune ups for power. If your tune up is far enough off you could get away with the timing thing, but it an't making potential power. You do whatever makes you happy. But your giving bad advice.

No advice, You and I have already agreed a cold plug is a better heat ex-changer transferring heat from the plug to the cooling system.


I'll say again, you can take your best tuneup using a hot plug, the mixture and metal annealing mark on the strap where you prefer it. Unscrew the hot plugs and screw in cold and you'll have to add a degree or two of timing in order to duplicate the metal annealing mark of the hot plug.

These are fundamental reasons to run a cold plug on methanol in conjunction with a cooling system bracket racing, not advise. I don't give advise. Although I might suggest a fundamental for anyone who reads it to do their own due diligence in confirming. I'm still waiting on the OP to say what fuel he used to produce the plug reading he based his original question on, before I come to any definitive conclusion.

quote:

Originally posted by Mike Rietow:
No advice, You and I have already agreed a cold plug is a better heat ex-changer transferring heat from the plug to the cooling system.


I'll say again, you can take your best tuneup using a hot plug, the mixture and metal annealing mark on the strap where you prefer it. Unscrew the hot plugs and screw in cold and you'll have to add a degree or two of timing in order to duplicate the metal annealing mark of the hot plug.

These are fundamental reasons to run a cold plug on methanol in conjunction with a cooling system bracket racing, not advise. I don't give advise. Although I might suggest a fundamental for anyone who reads it to do their own due diligence in confirming. I'm still waiting on the OP to say what fuel he used to produce the plug reading he based his original question on, before I come to any definitive conclusion.

....Again, I did NOT agree, your implying an untruth. If you really think your idea is good,...then let's all just switch to # 12 plugs, bump the timing to 50 degrees and let it rip. The proper heat range plug will always make more power and tune properly. To cold a plug will read richer than it is. So don't say that I agree with your tune up practice because I don't.

Where have I spoke of my tune up practice? The question from the OP is whether or not he should go with a colder plug. I'm supplying fundamental performance scenario's based on your best tuneup for the OP or anyone following along to come to their own conclusions.

If you and I can't agree a cold plug is a better heat ex-changer than a hot plug for transferring heat to the cooling system for better vaporization driving to and from the pits to the starting line, it's a waste of time continuing. Everyone I'm sure understands it is the design of cold plugs to transfer more heat to the cooling system and everyone on methanol driving through the pits to and from the starting line is trying to keep heat in the engine.

Good luck buddy, I'm out.

Ron he will do this until the cows come home. I’ve seen hundreds of pages of it on Yellowbullet. Don’t waste any more of your time. And here we go. LOL

quote:

Originally posted by CURTIS REED:
Ron he will do this until the cows come home. I’ve seen hundreds of pages of it on Yellowbullet. Don’t waste any more of your time. And here we go. LOL

...Thanks Curtis,....individuals like this hurt those that are trying to learn something or get help. His anology is like praising how great it is to jump off a tall building and the great feeling of like flying,.....all while completely ignoring the final outcome.

No worry's guys, but I am gonna stick with my 8 block heaters (heat ex-changers) I have screwed into my cylinder heads (cold spark plugs) to aid getting the coolant system as hot as I can, every chance I get, as odd as that may sound!

But enough about my oddity for a hot cooling system to keep the oil nice and dark green!.

However we do have one question yet to be answered that may give us hints on whether the OP already is running a cold spark plug, relatively speaking of course. What fuel was the OP running on his low compression engine to produce the plug reading his question is based on!

Good luck OP, hopefully something in here helped ya!

My head hurts now......

Thanks for the explanation Ron. I'm running -9's now, and they seem to be ok. I have some -11's but that's for when I turn on the bottle...I need to use up the plugs I have before I get any more new ones, but unless something just doesn't look right, I'm gonna guess that -9s will be good for most of what I do. I'll see how it goes when I turn the bottle on

The only way to give an objective answer to the OP on whether or not he'll need a colder or hotter spark plug, is to qualify the plug cold or hot he has in play currently, relative to the fuel he is switching to. Methanol

I've never seen first hand or heard of any fundamental for hi-performance drag racing that says you automatically go to a hotter spark plug when switching to methanol. Never - Ever. Before qualifying what you're working with.

62galaxie, If I didn't know what plug you ran before I would suggest a NGK -7 heat range plug for your lower compression milder combo.

Anyone who asks me I tell them to run the same plug as they did on gasoline (assuming it was close to the correct heat range plug) just make sure the gap is around 030 (assuming a CD ignition).

Going from a perfect tune up with the perfect plug heat range to a colder plug and then increasing the timing or taking away fuel just to get the plug to "look" the same or "right" does not mean it will make more power. In my opinion it will probably make less and be hard on parts.

Let's say you have the perfect amount of fuel and the perfect timing and the plug looks perfect. Now you change to a hotter plug or a colder plug. The different heat exhange rate means the plug will read differently and may make a person change the fuel or timing to get the plug to look right. But all that does is take the engine out of it's optimum operating parameters. Timing and fuel requirements are determined by the engines design parameters not the plugs heat range.

Scott