Port and Star engines were getting to 5-7 gallons off on fill ups so I sent the injectors in. One would go max flow as soon as he started raising the pulse width. Another one dribbled a bit at idle, dirty, the rest were a little low on flow, dirty. Four years later, same thing. He said the Merc/Chev injectors are crazy expensive so he got some from a Volvo? Something like that. There's a slightly different ohm/impedance?, can't remember, but when run side by side with the other injectors they flow the same.

Other than the consumption discrepancy I didn't notice anything running.

The engines are slightly fat at idle but no soot build up, just a stumble off idle, be it 5 minute idle or an hour, trying to get on plane that clears up before I'm on plane. Then, to clean the plugs, I hammer the limiters. Mercs system kills fuel so it works great!
Haha kidding, stupid limiter design.

You're running a hot plug in a blower motor and you are worried about the heat in my engines?

The cool northeast air, col lake waters, and my 120 degree stats are my chillers I have recorded movies using tuner pro on very hot summer days on long sustained runs, no knock or timing retard, I'm ok with my set up

Split fire

Volvo on their TB injectors only were used in their highest offering 315 hp 5.7 350 GXI models back in 2001 thru 2003 or 04. They ran fuel pressure at 29 to 31 psi for that app. just some info.

Yea. Im running a hot plug in blower motor and i am worried about your set up. I know tha 250 blowers make lots of heat over 6 psi. Thats why i have chillers to keep the heat down. 250s make lots of iheat

IR temp gun, and knock sensor monitoring show no difference in the 3.5 in pulley to the 3.25 (6-8lbs). I am approaching 100 hrs with this set up, based off data I collected, not what I "heard".

When they Blow up like mine did you can REALLY wake them up- Alum heads- 509- full roller- smaller pulley- SMITH POWER and then Young Tune -- Yea Baby!

Great discussion. Thanks for all the feedback. I replaced the two bad plugs and it runs great. My engines are stock and I am running 93 non-ethanol gas, so I will probably change to the -7s in the future.

When I was tuning drag cars I always used ngk plugs to "find" the tune as they would show the heat mark earlier than any other plug. BUT they wouldn't last 20 passes in a 13:1 motor with a .038 jet in a pro fogger, so once I got it where I wanted I switched to the cross ref auto lite racing plug

Now I read this....after getting 16 new R5673-8 plugs delivered yesterday.....LOL. All joking aside I have run these plugs with the 256 blowers and now with 8-71's
I have not had any bad ones but there is always a chance of getting one. I replace the cap and rotor every year and wires every 3 years.