...and E85 fuel (yes, I'm a fool for doing both at the same time).

Well, as usual, these things aren't completely straight-forward. I was running 73/83 jets with gasoline and the old cam, which a straight 147% conversion for E85 only translated to 82/95 jets. Since the power circuit is not improved just by rejetting, I added a little to compensate for it, or 84/95, and headed for test & tune with very little street time to see how the fuel change would affect things (and still not idling properly - I put a kit in the carb and opened up the secondary stop a little when doing the E85 conversion, but it didn't help much).

The weather for T&T was really crappy (rain in early morning, 30 mph head winds, 8400' density altitude). For reference, the previous best of 13.485/99.49 MPH was last fall with 6700' DA, calm wind, and the front passenger seat removed (and a little less weight in the driver's seat). Typical with the old cam was in the 13.80's at 97-98 MPH.

For the first run, it was okay when I would first hit it, but as RPMs started to rise, it was obviously lacking, producing a 13.76 @ 96. So, I went to 87/95 jets (for some reason, my kit only had one 86 jet), and it was still weak although it moved into the 13.50's/100.46 as the wind died down (first 100 mph time slip at altitude). Next step was 90/95, much better but still not crisp through the RPM range, wind back up but it hit 13.49 (the wind seemed calm at the launch, but at about 1000' it gusted so hard that I thought something had fallen off the car). For the last run of the day I went up to 90/97 jets, still seemed a little flat in the mid-range. The result was best at altitude ET, 13.40 @ 99 with about a 15 mph head wind.

I also had a best-ever-at-any-altitude 60', 1.708. Previous altitude 60's were in the 1.85 range, sea level 1.75. However, that 1.708 was the first run, the engine temp was about 190 degrees (I always ran at 160 with gas, any higher than 170 and it was DOA), but that was also the first run and the worst ET & MPH of the day (and the strongest head wind). I'd blame the wind, but it was obviously laboring to gain RPMs in 1st gear before wind would become a factor. After that, I fell back into old habits and had it around 160-170 degrees, and 60's were consistent 1.85-1.86. If I can get it through my head that ethanol likes heat, perhaps the 60' will drop back down there.

I still haven't matched that '57 Nomad 383 with his 13.33/102's, but he's got 4.88 gears and 4000 stall, with a cam that he shifts at 6800. But, I'm sure with a little more shake-out, I'll catch him. If I just switch back to 91 pump gas, I'd probably be there, but I think I'll try to sort it out with the E85.

Now, get the idle straightened out, and I'll really be feeling good . . .

 

Well, you've got quite the little project going. That's a pretty bold step, and commendable. You're treading on fresh turf and may actually be making some paths for the rest of us.

Doing both at the same time is just a bit more of a challenge, but one I'm sure you'll overcome. I do know that ethanol likes heat and compression pressure. I'm not sure how that cam traps air, but if the VE is good and quench is snug, the ethanol will like it a little better than gasoline.

Are you using the E85 straight from the pump or adding 2-cycle oil at about 100:1? I don't know if that would help in your situation or not, but it does make enough extra BTU and carbon to satisfy an oxygen sensor on EFI setups in daily driving.

Too bad the winds were complicating the results. Obviously, the luxury of a dyno would be ideal, but your "pavement dyno" should be a good metric IF you can get stable and consistent conditions. I'm guessing the rain on the track altered the first few runs, too. Even with the addition of barrels of VHT, the RH on the track had to be different. It looks as if your traction in the first run wasn't a problem, but that may have been due to some reduced power as well.

Just a few "dumb-guy" questions, so bear with me:

1. Are you using the slotted/windowed PV or the drilled one? That might alter PV liquid fuel flows despite the jetting.
2. You've probably already discovered this through your trials, but my gut tells me that a bit weaker secondary diaphragm spring than you would use for gasoline would be appropriate. Just a hunch.
3. Did you alter the timing curve/base? Even against race gas, the heat-sucking ability of the corn liquor could probably stand some more advance degrees. Again, I'm guessing you've been there. Then again, you're the one walking hte tightrope between temperature and timing.
4. Have you done anything with the idle air bleeds? Depending on your carb, whether you have air bleed screws and/or mixture rate screws, the idle mix may be out of control. Changing the total volume at the fixed rate versus the throttle opening is another balancing act. Not like I'm telling you anything new.

I warned you they were Dumb-Guy questions.


Three things: Intake heat, Intake heat, and Intake heat.

From what little I can find about the IRL/CART cars, they are using the 90/10 methanol/ethanol mixture with positive results, and the switch to 100 ethanol in 2007 will make some real changes. I can bet the engineering teams are already well into the R&D for the full switch, but precious little is being leaked out. The methanol they've been using already likes the boost heat, but requires a lot of liquid flow. Unfortunately for you, they're all using Motorola or Delphi EFI and big injectors, so tuning is less of a problem with them. Still, if you could find some general info on what they're doing to alter for ethanol, weighted against the widely available data on methanol, then comparing that to the changes needed for methanol versus gasoline, it might point you in a direction. Then again, you may already be well beyond that.

You're on some rare turf. Keep us posted, please.

 

I use an AMSOIL gas additive called PI, which is a detergent/upper cylinder lube. I doubt it would alter overall characterists like 100:1 two-cycle oil would.

CR is about 10:1. Deck height is stock, using a shim head gasket.

The D-G questions:
1. Regular slotted PV. I understood the power circuit metering is accomplished by the metering block, not the PV.
2. It's a double pumper.
3. I set it at 38 degrees total mechanical, as before. Tritle's experience indicated it doesn't help to advance the timing, but a) he's running a Mopar, and b) I'm running a new damper with verified TDC for the first time, so who knows for sure what I was really running before? I think I'll bump it up a couple and see what happens.
4. I haven't touched the air bleeds. I couldn't get it to idle properly with gasoline after getting it running with the new cam, I thought putting a kit in it and cleaning it all up might help - it didn't. I was advised elsewhere to leave the bleeds alone and open up the secondary blades via the stop - I did that a little while it was apart, but if that's the problem, I didn't open them up enough.

As for Ih, Ih, Ih - wouldn't you know, I went with an RPM Air Gap manifold last fall. Should have done the Stealth or Victor Jr., I guess, or gapless RPM.

That first run 60' has me wondering. The easiest test would be to stage at 190 degrees again. With that 60', all other things being equal, that should have been a 12-sec timeslip. It was still quicker than 90% of my runs last year. The car was also about 100 lbs heavier this weekend than it was for my previous best last year - a combination of removing the front passenger seat for the runs last year, and having a bit more weight in the driver's seat this year.

 

The cam results look promising I dont know if I would have made the maiden run on staright E-85 but that just me. Did you ever consider putting the 57 on a fiber diet? The only good reason I can thinik of for not having that car running 12's consistantly is the weight issue but it's a classic.

Ive been getting mixed results with my E-85 tests. It seems the Q-jet runs better then the holley with the corn juice but I'm chasing the idle around too much to really get anywhere. Moday I had the truck nailed down to a real nice tune on corn juice but tuesday it started to act really funny and die out. For some odd reason I had to crank the throttle plate screw one full turn more to keep it running but it ran perfect the previous day. Not to mention the corn juice likes alot of advance. Im now running 38 total mechanical also but it just seems to want more but that runs into some other issues I'm not ready to deal with yet.

Keep us all posted especially when you find the magic E-85 setup because I'm about to give up on it.

 

It's running 12's consistently now (sea level, anyway). The only reason I haven't gone with lightweight bodyparts is $'s.

I messed with it some more today (after changing oil in two other cars, and changing the starter solenoid on the Camaro). I discovered my memory was as bad as the weather last weekend - the primaries were jetted at 89, not 90. I played with the timing (didn't help), opened up the secondary stop (helped a little), then finally figured out the PVC hose was hitting the Holley heat shield, causing a vacuum leak. Since heat control isn't the name of the game anymore, the shield is gone, the carb mounts flat to the base again, and it will idle at 1200 RPMs when fully warmed. The 89 jets were causing horrible cruise, so I jumped up to 92's. Sounds much better. I think it really needs 4-corner idle, though.

Oh, put jet extensions on the secondaries as well. Just in case.

Hopefully I'll get out to T&T again Saturday and see what we can do.