CamaroSS30thAnn

I'm running trick flow heads on a 355 lt1 with 11 to 1 compression and a 23*/24* cam.
What are the spark plug recommendation for this setup.
I do not like that the trick flow tech have me part numbers for tr5/tr6 bc they are tapered and the heads need a gasket seat.

if I cross reference the tr6 with autolite i get AR103.
The plug that has the same description as AR 103 except gasket seat is AR3923.
Should I go with the 3923. I want a projected tip for tuning N/A and then run a non projected tip for nitrous.

Thanks a lot
Bobby

CamaroSS30thAnn

It helps as I planned on using one step colder than the recommended plug in the directions.

Injuneer

Some info of limited value, but reflects one experience. The information I have is from the shop that built my engine, and spent hours tuning on an engine dyno, then on a chassis dyno, and then on the track. I don’t have TF heads. In this case it’s well ported factory LT4 heads (so you'll have to determine the equivalent gasketed plug), somewhere around 10.9:1 static CR, mild solid roller cam 230/242 114 LSA 0.590/0.590” @ 0.050, actually capable of meeting NJ rolling emissions.

Straight motor - 496 HP at the flywheel - Autolite 104 (my understanding is this is 1 full step colder than stock LT1, and I questioned this in the spark plug thread in the N2O forum). Tuned for Sunoco 94 (r+m)/2.

+125 HP (1 stage) N2O - Autolite 103 (2 steps colder than stock). Tuned for 100 (r+m)/2 unleaded.

+300 HP (total both stages N2O) - an ice cold Champion race plug, (I would have to look up the number in my notes). This plug was so cold that it would not tolerate much in the way of idling, it’s for track only. Tuned for a blend of VP Fuels C16 and Air Race.

A caution - my engine has no knock sensor. They don’t work with the clatter of a solid lifter cam. Hence the max amount of time on the dyno, a specific fuel, and repeated studies of all 8 plugs of various heat ranges, to identify if there was incipient knock. The tuner did all the work...when I happened to be present he repeatedly showed me the fire ring on the insulator with a lighted, magnifying plug inspection tool. I honestly could not see what he said he saw.

If you are going to start with a hot plug, have a real time scanner that shows knock retard. If you can't do that, or if the knock sensor circuit has been desensitized, or the max retard reduced significantly in the tune, start on the cold side. If it’s too cold it fouls, but does no damage to the engine. If you start on the hot side, an error can result in engine damage.

CamaroSS30thAnn

1995_LR

I run TrickFlow heads in my 383. I run higher compression than you and I'm two heat ranges cooler. Saw loads of knock at one step cooler.