Spark plugs

So I bought this street race type car with the intention of making it more streetable. The car is beautiful.
The guy passed but I was able to locate his cousin who gave me some info. Turns out the guy built the engine himself. 455 30 over 308S cam. Stage 2 SE heads . It was set up with Nitrous/Dominator on a SP1. I am replacing with Performer dual plane and 850 quick fuel. Want to use the ram air. No Nitrous. I may replace the cam but want to see how it performs for now. What I need advice on is spark plugs. Currently NGK BP5ES
Thx.

 

What compression ratio
A 5 heat range is hot on a nitrous motor.

Lots of ppl run the fr5 i lower compression aluminum heads. But I wouldn't but the bottle to it......the fr5 have the smaller her size

I run the ngk 7173 in my motor but im over 12:1. They also use the smaller 5/8 her.

I just dynoed a 383 yesterday with afr heads, stk marine cam only 9.5:1 and the fr5 look a tick warm in it

 

No two engines are alike,,period. Your better off running a slightly colder plug than hotter being you don't have any specs on engine. Is it pump gas, race gas ?? Just because some people run a certain plug doesn't mean it's correct,, those people's plugs could also be pure white showing no color, that correct also ?? No!!
If its a pump gas motor around 10.5:1 ngk recommends bkr6e. According to ngk one hest range is difference of 250 degrees in combustion chamber. Thats my recommendation, run them put some mileage on them and then look at them. The plug will tell you what the engine wants.

 

Thx Larry. I spoke to you on the phone also. Good stuff.

 

Nothing else to do. Waiting for dyno. Decided to change out all the plugs. Turns out. ( And I'm guessing that this was the problem from jump). Why the cam lobe #7 Cylinder exhaust failed in the first place. We knew that the #7 plug was loose afterwards. Thought that it was a brain fart. Turns out that the #7 plug will not tighten to specs. When the engine was IN - was a different feel i guess. Engine out - First 7 plugs np. #7 Cylinder - Turns in no problem. But when trying to tighten correctly. No good. Keeps turning. Thinking now that was the problem all along for the cam failure on #7 exhaust lobe. Thats why it was loose afterwards. . Anyhow. Now what? Can't helicoil it. My friend says that there is such a thing as a spark plug sleeve. He actually has has something like this. Anyone ever hear of such a thing for an aluminum head?

 

No problem to sleeve or heli coil....I've never been a fan of TAs plug threads....but a loose plug isn't goin to wipe a lobe

 

Ok Larry. I heard you. Sent

 

I absolutely will work this out tomorrow. Hopefully.

 

Its not unusual for aluminium heads to strip out a plug hole. Thats why they sell kits for it.

 

Never remove plugs on aluminum head motor when hot....can strip threads....at least what I have heard.
I run the 7173 (R5672A-8) NGK racing plugs.

 

I heard the same thing, I do it cold

 

My buddy had an old helicoil brand spark plug insert deal. Letting it dry overnight. Should be okay. So it's understood. When I said that I was waiting for dyno time I guess I should have explained that the engine is out of the car. So obviously cold.

 

What I did was turn the engine over until the piston was all the way down and the intake valve was closed and the exhaust valve open. We used a good tap oil (tap magic). Important. Go easy. A little at a time remove the tap and wipe off continuously. Used a very long skinny air blower both in the plug hole and the exhaust port. Actually turned the engine upside down and repeated. I'm pretty comfortable with the results. Could I have removed the head? Sure. But I honestly didn't think that it was necessary. If you're careful.

 

One other thing. A lot of people giving tips. Especially about not removing sparkplugs from a hot engine. Here's another one. NEVER try to install a sparkplug on an aluminum head by hand. ALWAYS. And I mean ALWAYS. Use a 3/8 hose. Fuel or vacuum or otherwise. To install. Never by fingertips. Trust me. It works.

 

I'm not saying it did or it didn't. Actually I should have pulled this engine like Larry told me from the start. But hard headed. I didn't. I actually was lucky that the lobe on the cam went. When I looked clocser it showed me that the engine was about to grenade. I got lucky that the cam went before the whole engine went. In any case. The Buick lives.