62 Fuelie Mods for Percolation prevention
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Drifting
Joined: Apr 2004
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From: Allen Park Mi
62 Fuelie Mods for Percolation prevention
hey all, i know this is out there somewhere but i'm having trouble today finding who sells and/or recommends what.
I have a driver 62 - 340hp car - actually bought it for my wife to drive - which she does quite regularly.
I acquired a 62 FI unit that (along with a Lt1 cam to replace the 097) will be going on that car - its got the wider ratio T10 and 3.70s so it should be pretty fun to drive.
I've read about the anti-siphon solenoid and a few other tricks but...
1) are there (other than running straight AV gas or Racefuel) any known addatives that when combined with pump 92 will keep percolation down to a minimum on these FIs?
and
2) does anyone sell a complete kit for modding the spider with the solenoid
Finally, who sells good CCVs for these - or can the perc mods be done to elminate the CCV as well, as on the 64/5 Units?
Thanks i advance
Aaron
I have a driver 62 - 340hp car - actually bought it for my wife to drive - which she does quite regularly.
I acquired a 62 FI unit that (along with a Lt1 cam to replace the 097) will be going on that car - its got the wider ratio T10 and 3.70s so it should be pretty fun to drive.
I've read about the anti-siphon solenoid and a few other tricks but...
1) are there (other than running straight AV gas or Racefuel) any known addatives that when combined with pump 92 will keep percolation down to a minimum on these FIs?
and
2) does anyone sell a complete kit for modding the spider with the solenoid
Finally, who sells good CCVs for these - or can the perc mods be done to elminate the CCV as well, as on the 64/5 Units?
Thanks i advance
Aaron
Race Director
Joined: Feb 2007
Posts: 15,479
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From: northern california
C2 of Year Finalist (track prepared) 2019
This is the definitive thread on dealing with FI fuel perc problems:
FI fuel perc mitigation - click here
Postings #5 and #7 discuss the current state of the art.
FI fuel perc mitigation - click here
Postings #5 and #7 discuss the current state of the art.
Last edited by jim lockwood; Today at 12:02 PM.
Intermediate
Joined: Dec 2025
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aaronz28: Thinking if you run straight AV Gas(100LL) your problems will go away. But you need to
get all the old gas out first. It took me 3-4 fill ups to finally get my tank to have all 100-% Av Gas(100LL).
The articles all agreed that the higher the octane rating on fuel the less volatiles (evaporative qualities) it has and to us that means less vapor lock. The engine runs best with a slow even burning of the fuel. Octane ratings are an indication of the burn or flash rate of fuel. Even if you do not need
all of the octane the big benefit will be the shelf life of the av gas is so much better then and pump
gas (ethanol or non-ethanol). It will not gum up like the gas from the pump. DO NOT MIX THE AV
GAS WITH ANYTHING AS IT DOES NOT TAKE MUCH TO CHANGE THE CHARACTERISTICS OF THE AV GAS. JMHO-LARRY P.S. I assuming that your engine is mostly stock and not overly modified.
get all the old gas out first. It took me 3-4 fill ups to finally get my tank to have all 100-% Av Gas(100LL).
The articles all agreed that the higher the octane rating on fuel the less volatiles (evaporative qualities) it has and to us that means less vapor lock. The engine runs best with a slow even burning of the fuel. Octane ratings are an indication of the burn or flash rate of fuel. Even if you do not need
all of the octane the big benefit will be the shelf life of the av gas is so much better then and pump
gas (ethanol or non-ethanol). It will not gum up like the gas from the pump. DO NOT MIX THE AV
GAS WITH ANYTHING AS IT DOES NOT TAKE MUCH TO CHANGE THE CHARACTERISTICS OF THE AV GAS. JMHO-LARRY P.S. I assuming that your engine is mostly stock and not overly modified.
Race Director
Joined: Feb 2007
Posts: 15,479
Likes: 8,957
From: northern california
C2 of Year Finalist (track prepared) 2019
The big advantage of AvGas or racing gas is that its distillation profile is radically different from that of pump gas. That's what accounts for the reduction in fuel perc when used in Rochester FI.
I've never read anything which suggests a correlation between octane and fuel perc.
I've never read anything which suggests a correlation between octane and fuel perc.
