sbc operating temps/spark plug

[Guest zfan]

I have a 4 bolt 350 sbc 30 over. The motor is 10.3 to 1, hydr. roller cam, RPM aluminum heads, weiand stealth dual plain intake, Holley 750 double pumper, Msd distributor, 6a box and blaster coil.

 

I was recently told to go with NgkTR5's for spark plugs gapped at 44. I ran Champion rc12yc plugs gapped at 40 to 44.

 

I also was told I am running my motor too cold. I run the temp at 180-185 with a 180 thermostat. I was told to run a 195 and the car will run better at 195-205 operating temps.

 

Several of the newer performance cars run at these temps or even higher.

 

I swapped plugs just as mentioned above and noticed no difference if anything the car is a little more sluggish than before. Several Hot Rod buddies of mine dog Champion plugs but Edelbrock states that they are the recommended plug for this application.

 

Does anyone have any suggestions or comments to plug changes and raising the temp issues.

 

Thanks Mike

[grumpyvette]

you NEED to get your oil temp to about 215 degrees (F) to allow it to burn off the moisture and lubericate CORRECTLY.

you will make the best power on almost all engines with the water temp in the 180-210 degree range and the air as cold and dense as you can get it. oil temps MUST go above about 215 degs (F) to remove all water from the oil that forms when the engine cools and the moisture in the air trapped in the engine condenses that otherwise would form acids in the engine from combustion byproducts. next point is that as engine temps are raised the vapor formed as fuel hits hot surfaces becomes easier to hold in the port air flow and the smaller the fuel particals are the faster and more completely they burn.

SMOKEY YUNICK did alot of testing for G.M. for the NASCAR GUYS , heres some quotes from him on the subject, on coolent temps "running an engine at 180 degs will drop the overall hp by 2%-3%, for max power the coolent temp. should be at least 200 degs on oil temps...."the operateing temp of the oil is one of the most important aspects of racing engine operation.....the oil temp must be between 230f and 260f degs...but 260F degs is about the safe upper limit if your useing mineral base oil.. now concidering how much G.M. payed in dyno time to find that out!!!!!! use the info!!! it takes 212 degs to boil water and at 213 degs PLUS any water mixed in the oil can,t remain in a liquid state at sea level air pressure and will boil out of the oil as its heated and sprayed around on the hot interior engine surfaces.

now a little trick Ive been useing is to use a 195 deg thermostat but I drill about 8 3/32" holes in the perimmeter flange, this alows a steady but restricted flow of coolent over booth sides of the thermostat and no chance of an air pocket insulating the thermostat delaying its openning responce time, this tends to keep the engine coolent temps at about 190 degrees and rock steady except while seriously racing and even then they rise slower, a good oil cooler and a 7-9 qt oil pan will also help keep temps stable. and one of these,

is a cheap effective way to drop oil temps about 10 degrees

 

 

http://www.jegs.com/cgi-bin/ncommerce3/ProductDisplay?prrfnbr=1734&prmenbr=361

 

 

[This message has been

[zthis]

Why would you use a TR5 (Taper Seat and colder)plug isn't the FR4 (Gasket Seat )the correct replacement for a Champion RC12YC ?

[Guest zfan]

To be honest with you I really do not know that much about spark plugs. That's why I asked. I kept my Champions and may just clean them up and re install them.

 

Chalk it up to learning experience.

 

Grumpy, I think I will follow your lead and put the 195 thermostat in and drill it out as well.

 

Thanks, Mike

[QWKDTSN]

Let me ask you guys if this is normal... I can start up my car in the garage and with the fan on and the hood closed, it'll idle forever at an indicated 180 degrees. However, as soon as I start driving and put the engine under load, the temp goes right up to an indicated 210 and sometimes touches an indicated 250 (though at this point I usually slow down or coast...). As soon as I put the motor in neutral and coast or sit at a light, the temperature gently descends to 180-190. Is this normal?? The motor's still breaking in with around 40 miles on it...

[pparaska]

Nion,

Sounds like the water temp sensor is getting uncovered as you drive. Make sure all the air is out of the system. Drill an 1/8" hole in the thermostat, and park on a hill, nose pointed uphill and fill the radiator.

[Guest zfan]

The newer fuel injected sbc motors are running temps in the 200 to 210 temp range. I know Grumpy has said it is better to run in this area of temp range.

 

My question is it too hot a temp range for the old school carburated engines? Is the high temp going to give us carb guys fuel problems? Heat related of course!

 

One other question I cannot seem to get answered. Is the NGK TR5 plug a hotter or colder plug than the Champion rc12yc?

 

Thanks Mike

[zthis]

The correct cross reference for a Champion RC12YC

to NGK is FR4 (Washer on sparkplug). TR5 IS A COLDER PLUG AND ALSO A TAPER SEAT TYPE . If you want a colder plug you should really use the FR5. with NGK higher number means colder plug

[Guest zfan]

Thank you zthis I will try the FR4.

 

Mike

[zthis]

Please let me know if you find any difference

with the NGK i have the same heads as you and

plan to switch to FR4s in the spring myself