Blown head gasket / causes

[pastaroni34]

Rear guard is preferred.

[TulsaSpider]

Rear, ya that's what I meant.. That's what I get for posting before coffee lol

[TulsaSpider]

Quick update. I bumped up the timing to about 12 btdc and wow it really runs great! No pinging just goes waaaaaaaaaa! wohoo!

[TulsaSpider]

I found the NGK BP7ES plugs today, (one range cooler than the Champions I had been running) and installed them. I took it out for a spin and I don't think it has as much top end now. Maybe I need to re-gap them?

[TulsaSpider]

Anyone know why I would have a drop off in power?

[manoa matt]

"Anyone know why I would have a drop off in power?"

Maybe its a blown head gasket. Just kidding. Switch back to the Champions.

[TulsaSpider]

LOL so is there a reason why the power in the upper RPM range would drop off with a colder plug? The gap seemed smaller than the Champions but they always say now not to gap plugs so I didn't.

[baltobernie]

You'll drive yourself nuts trying to compare one day's performance to the next, without having real numbers. If you have a smart phone or an iPod, there are apps for 0-60 etc. using the accelerometer in the phone.

Heat range of the plugs will not change HP, until the plug being too hot or cold dissolves or clogs the gap.

[Sunracer]

Gap them, if they are too cold they might not stay as clean as the standard heat range-you should only use a colder plug if your engine needs it-higher compression ratio and other HP adders do, stockers don't. If it ran better with the champions put them back in.

[TulsaSpider]

It's definitely high C/R! I took them out and gapped them out some. I found some improvement but for some reason the Champions seem to have more kick! I'll do a little more playing with them!

[TulsaSpider]

So I put the Champions back in this evening. There is definitely a performance difference!!! However upon listening closely I could hear the slightest pinging, but man it really screams! With the NGK's there was no pinging but definately less performance. So If I put in more advance with the NGK's I wonder would I get better results performance wise with them? Any thoughts? This is intriguing!

[Sunracer]

So I put the Champions back in this evening. There is definitely a performance difference!!! However upon listening closely I could hear the slightest pinging, but man it really screams! With the NGK's there was no pinging but definately less performance. So If I put in more advance with the NGK's I wonder would I get better results performance wise with them? Any thoughts? This is intriguing!

try champions in one colder range?

[lanciahf]

Tulsa what Champions are you using? RN9 or RN8?

Thanks,
Ralph

[TulsaSpider]

Champ RN9YC The pinging is very slight, under max load, but now I'm paranoid about it!
OK maybe I should begin another thread here..?. I was talking to my buddy Kent and I realized I really didn't explain myself before, when I wrote that switching the plugs caused a drop in power.
Specifically the change was not from low RPM or take off. That seemed about the same. In the upper RPM range about 4K RPMS with the NGK's it simple did nothing. With the Champions in when I rev it in gear about 4k I get a nice surge of power. Not so with the NGK's hold it to the floor at 4K nothing, no more RPM's no more power. With the Champions in it will continue to rev to 5K. I was just at the local cruise night and had her going at 4500 RPM and mashed the gas and it lurches forward I still had plenty of power.
Kent's a pretty good mechanic. He thinks that the spark from the coil may be weak, thus the hotter plug does better at high RPMs. With the performance changes I could try get a better coil and ditch the decades old module.
Sounds logical to me especially since it has been said that the should be no performance differences in the plugs according to consensus... Opinions?

[lanciahf]

I have a motor similar to yours, 4.5 dome pistons and a 40/80 cam on the intake side. My car runs nicely to redline and beyond on NGKs so maybe its a fuel delivery issue on your car. Does it miss at high speed or just stop going?