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Octane boost x plug heat range ?

SMack

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I’m running a 511 6 pack alum heads roller motor in my Bee. Dyno tuned with 100 octane it put out 650 HP. Using race gas octane boost on the street with 90-93 octane. I’m killing spark plugs. NGK BCPR5EY. I know it’s the octane booster but I’m trying to maintain the 100 point octane so that being said any thoughts on a different heat range plug? And if so cold or hot.
I read mixed reviews.
Thanks in advance for the feedback.
 
Healthy Motor like that why skimp on boasters and just use race gas or 100 octane? Your baby deserves the best and I’m guessing not a daily driver so why not?
 
Healthy Motor like that why skimp on boasters and just use race gas or 100 octane? Your baby deserves the best and I’m guessing not a daily driver so why not?
Good point birdLover. Thanks for the feedback. At 25$ a can for boost and 6$ a gal at the pump I’d probably be a wash anyway. Yep. Good point…
 
I’m running a 511 6 pack alum heads roller motor in my Bee. Dyno tuned with 100 octane it put out 650 HP. Using race gas octane boost on the street with 90-93 octane. I’m killing spark plugs. NGK BCPR5EY. I know it’s the octane booster but I’m trying to maintain the 100 point octane so that being said any thoughts on a different heat range plug? And if so cold or hot.
I read mixed reviews.
Thanks in advance for the feedback.
What’s the details of the combo? Why are you running a 5 heat range plug?
 
What’s the details of the combo? Why are you running a 5 heat range plug?
The engine tuner at the dyno shop who is an old school mopar 6 pack guy and still runs a nostalgic rail used them.
 
The engine tuner at the dyno shop who is an old school mopar 6 pack guy and still runs a nostalgic rail used them.
Post the details of the combo and a good picture of a used plug.
 
Post the details of the combo and a good picture of a used plug.

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I don’t think your dyno guy tuned anything unless it was just WOT which is typical for a dyno guy. Hard to tell from that plug picture. It definitely needs a bunch of fuel removed. Difficult part is determining where and how much. Start with idle. Clean that up and it’ll make a huge difference. Then work on drive ability and transition fueling and proceed to WOT.
 
I don’t think your dyno guy tuned anything unless it was just WOT which is typical for a dyno guy. Hard to tell from that plug picture. It definitely needs a bunch of fuel removed. Difficult part is determining where and how much. Start with idle. Clean that up and it’ll make a huge difference. Then work on drive ability and transition fueling and proceed to WOT.
So that being said would you stay with the 5 heat range plugs?
 
So that being said would you stay with the 5 heat range plugs?
Shooting in the dark without knowing the CR, cam intake closing point, cylinder head, etc. at this point, correct heat range is your last concern.
 
Those plugs look like the ones out of the dual quad 383 before I pulled a bunch of fuel out of it. WAY FAT.
 
You don't mention what compression ratio the engine is - that is important for heat range selection.
Assuming it is say 10.5 I would run colder plugs. It is better to foul a plug than hole a piston.
And I agree with the other guys it appears to rich or the rings have not bedded in.
Octane booster makes it hard to read plugs as it leaves them that rusty brown colour.
 
You don't mention what compression ratio the engine is - that is important for heat range selection.
Assuming it is say 10.5 I would run colder plugs. It is better to foul a plug than hole a piston.
And I agree with the other guys it appears to rich or the rings have not bedded in.
Octane booster makes it hard to read plugs as it leaves them that rusty brown colour.
That’s the problem steve340 the octane boost. 10.5 motor by the way. I was thinking I need the octane boost so to combat the crusty build up one step hotter plug but not sure. So looking for feedback. Much appreciated
 
3 carburettors is a pain in the *** it only needs one of them to have a problem and you have 3 places to look.
Good luck.
 
That’s the problem steve340 the octane boost. 10.5 motor by the way. I was thinking I need the octane boost so to combat the crusty build up one step hotter plug but not sure. So looking for feedback. Much appreciated
Go buy 10 gallons of a quality VP race fuel. It doesn’t leave the residue that an octane booster or pump gas will both leave. I find it much easier to tune on that fuel.
 
3 carburettors is a pain in the *** it only needs one of them to have a problem and you have 3 places to look.
Good luck.
Right on. Was running awesome. Then started to stumble. Pulled the plugs and found the brown crust. So thought a heat range change might help. Which lead to the post. Always good feedback from the people on here so again I appreciate you guys.
 
Go buy 10 gallons of a quality VP race fuel. It doesn’t leave the residue that an octane booster or pump gas will both leave. I find it much easier to tune on that fuel.
I have to agree that the blend of race gas is more consistent than pump gases of your choice
 
NGK 5 is the correct heat range. This is the heat range that NGK specified for Mopar V8s & 6 cyl. Rarely is there a reason to deviate from this unless the engine is under continuous load [ motor home, truck, circle track racing ] Doubt you would need octane booster with 10.5 CR. Alum heads run cooler than iron, & if anything, would need a hotter plug, not a colder plug to maintain tip temperature.
It is running rich, which is why the plugs are fouling.
 
NGK 5 is the correct heat range. This is the heat range that NGK specified for Mopar V8s & 6 cyl. Rarely is there a reason to deviate from this unless the engine is under continuous load [ motor home, truck, circle track racing ] Doubt you would need octane booster with 10.5 CR. Alum heads run cooler than iron, & if anything, would need a hotter plug, not a colder plug to maintain tip temperature.
It is running rich, which is why the plugs are fouling.
Thanks Geoff
 
NGK 5 is the correct heat range. This is the heat range that NGK specified for Mopar V8s & 6 cyl. Rarely is there a reason to deviate from this unless the engine is under continuous load [ motor home, truck, circle track racing ] Doubt you would need octane booster with 10.5 CR. Alum heads run cooler than iron, & if anything, would need a hotter plug, not a colder plug to maintain tip temperature.
It is running rich, which is why the plugs are fouling.
That’s what I love about alum. heads and for me big compression
 
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