[Donovan]

I've read the common knowledge out on converting a carb or fuel injection to accommodate E85 for volume and safety.

I haven't seen much of anything on using the QUADRAJET specifically.

I have a 79 800cfm TTA qjet I could look at running as well as a service replacement 68 style 750cfm qjet.
I even have a Holley 4011 800cfm spreadbore that may go in the ring. (this seems like it would be simple to use so it is a backup plan) This is a marine carb so it may be a great idea.

To address fuel needs I'll run an in-tank electric fuel pump and a proper regulator with an evap/return line.

Anyone on the forum running a qjet in the real world with E85?

[77 TRASHCAN]

Yo, Cliff, where are you...

[WARPed]

A Q-Jet has enough problems just getting the volume of fuel in it as it is - let alone trying to get another 30-40% going to E85. I sure would like to see what Cliff as to say.

[455firebird1969]

I have communicated with PY member "Thumping455_GTO" who claims to run E-85 through his Q-jet successfully. He does not race, so he does not have any ET's for his car. I see a big difference between getting it to work on a street car, and getting it to work on a drag car. I would go back to a Q-jet on my drag race car, if I could make it work on E-85 and I plan to pursue a E-85 Q-jet by testing what "Thumping455_GTO" suggested, but I haven't taken any action to date. I'm still using a Holley 850DP to meter my ethanol based fuel.

I suggest you PM Thumpin455_GTO for his input, as he was willing to share info, and maybe he has made more progress.

[WARPed]

Curious what kind of power level he actually has with that Q-Jet/E85

[Cliff R]

Good topic and questions.

Right to start with, the 1968 Service carb would be the WORST choice for an E-85 project.

Those early carburetors have a piss-poor hinge pin location (not enough leverage on the needle), float is too large, and minimal bowl volume. They are a PITA to keep full past about 450hp if you have everything else going on correctly. Those early carbs are the biggest reason folks run from q-jets in the first place, as they gave the entire line a bad reputation back in the 1960's. The later units are far superior to those, fine with high fuel pressure, small floats, big needle seat assemblies and EASILY keep up with big power levels.

A 1976 or later q-jet would be my first choice for an E-85 build.

The parts we are using currently hold up fine in ethanol at any percentage, so that part is easy.

I've supplied many parts and kits for E-85 conversions, and calculated tuning parts with pretty good accuracy. I have quite a few customers using it for racing applications, both drag strip and circle track. Even with that said, we don't get a lot of feedback (unless things go horribly wrong), and this E-85 stuff is relatively new.

We supply a larger fuel inlet seat, small float, and tuning parts based on the carburetor number. So far not one single complaint about anyone running the bowl dry on hard runs, but all of those folks are also running PLENTY of fuel pump and large lines from a sump or fuel cell.

I really can't say what limitations there would be keeping a q-jet full as far as power level and vehicle performance for drag racing. I don't have it available to me here, so haven't done any testing in that area.

My engine would be the perfect candidate for the upgrade, 11 to 1 compression with very tight quench, and it runs low to mid 11's in full street trim with ease.

Just kind of typing out loud here, but a Q-jet for an E-85 project would be easy to at least 550hp, if not 600. Beyond that it may take a garden hose for fuel delivery to keep up. I have quite a few customers running over 700hp with q-jets on race gas, but not sure where the point of no return would be using one needle/seat assembly and needing 30 percent MORE fuel for any particular power level?

What I have heard from a few folks who have switched to E-85, no matter what type of carb they are using, is that their engines work better well heat soaked, and can/will run poorly unless they get plenty of heat in them, and keep plenty of heat in them throughout the day when bracket racing......Cliff

[455firebird1969]

Originally Posted by Cliff R

Good topic and questions.

How many Q-jets
I've supplied many parts and kits for E-85 conversions, and calculated tuning parts with pretty good accuracy. I have quite a few customers using it for racing applications, both drag strip and circle track. Even with that said, we don't get a lot of feedback (unless things go horribly wrong), and this E-85 stuff is relatively new.

We supply a larger fuel inlet seat, small float, and tuning parts based on the carburetor number. So far not one single complaint about anyone running the bowl dry on hard runs, but all of those folks are also running PLENTY of fuel pump and large lines from a sump or fuel cell.

Just kind of typing out loud here, but a Q-jet for an E-85 project would be easy to at least 550hp, if not 600. Beyond that it may take a garden hose for fuel delivery to keep up. I have quite a few customers running over 700hp with q-jets on race gas, but not sure where the point of no return would be using one needle/seat assembly and needing 30 percent MORE fuel for any particular power level?

Cliff

Do you have customers running a Q-jet burning E-85?

My last engine was close to 600 hp. My new engine, should be closer to 625-650 HP. If you are interested in building a E-85 Q-jet for me, I'll upgrade the fuel system to make it work. I'll post all feedback right here so everyone can learn. I'm in no hurry. I probably won't have my car track ready for at least a month or two, and when it is ready I'm planning on using my 850PD.

I'd love to go back it a Q-jet!

[Donovan]

Thanks guys for the dialog!

Originally Posted by Cliff R

Good topic and questions.

What I have heard from a few folks who have switched to E-85, no matter what type of carb they are using, is that their engines work better well heat soaked, and can/will run poorly unless they get plenty of heat in them, and keep plenty of heat in them throughout the day when bracket racing......Cliff

Many thanks on the comments Cliff. To run with what your saying on the heat, this observation is common when you start to read from many of the communities...

For a Pontiac V8, it may be best to run a cast iron intake with a working exhaust crossover. A modified or blocked off unit, or a factory HO intake may not keep heat in the plenum based on design.

Sound right?

Or perhaps heat in the engine is enough. So working counter intuitive to old hot rodding norms, running a 190-210 stat could be a part of the 'E85 kit.' Cardboard in front of the radiator like a trucker.
Sounds like some fun stuff to try on some test and tune sessions!

[Cliff R]

The intake will heat soak enough to keep any of the incoming fuel from coming out of suspension. Just make sure to keep heat in the engine, which can be difficult at times in early rounds when there are a lot of cars at any particular event.

My own engine is a bit sensitive to a cold intake, and requires some heat-soaking for best track numbers.

I have NOT built any q-jets specifically for E-85 to date, not enough interest, and I haven't done any direct testing with it. I have had folks supply me with a carburetor part number, then I sent them everything required to build the carb for E-85, and all of them ran at least as quick or quicker than what they did on pump gas.

455firebird1969, setting one up for E-85 would be easy for me, and I could hit the initial calibration pretty close, but all testing would have to be done on the user end at this time. For drag racing I can understand why you'd want a q-jet, they are just super-easy to tune between rounds if needed, changing metering rods takes seconds and no fuel bowl(s) to R & R.....Cliff

[455firebird1969]

Originally Posted by Donovan

Anyone on the forum running a qjet in the real world with E85?

The above question remains unanswered.

I discussed a member who claims to be running E-85 in a street application. Cliff says he is supplying customers who are using E-85 successfully, however; not one person has stepped into the conversation claiming any actual results. Based on what has been posted , I'm inclined to believe successful E-85 conversions of the Q-jet with track results (drag racing) have yet to be produced.

[Cliff R]

That's really not surprising to hear, as there really isn't enough interest at this time for E-85 for anyone doing this to spend a lot of time/funds in that area.

Only a handful of folks with full race Pontiac set-ups have made the swap to E-85 (that I know of). Seems to be working pretty well for most of them, once you get thru the learning curve with it.

There are some risks involved with it's use, much like running alcohol. Corrosive properties for one, absorbing water, and potential lube oil dilution.

I'm not a big fan of using it in a vented system, as the benefits could outweigh the savings in long term use. If it becomes easily available here, I'll still step up and build a carb for it at some point, but I'm not going to drive nearly 100 miles round trip to stock up on the stuff and test it, when we only have half a dozen or so requests a year for carbs or parts for folks using it.

To date the most interest has been for circle track racing, at least for q-jets. It's working just fine for all of those customers far as I know. In this business you seldom, if ever hear much or get much feedback, unless the entire deal is a total disaster, then you get to hear about it a couple of hundred times!.....FWIW.....Cliff

[77 TRASHCAN]

I keep wondering how much longer the gov'ment is going to subsidize the E-85 deal.

It would be outrageously priced w/o the gov. deal.....

Never seen a station in Oklahoma w/ E85, of course we are in the oil belt...

[455firebird1969]

Originally Posted by Cliff R

There are some risks involved with it's use, much like running alcohol. Corrosive properties for one, absorbing water, and potential lube oil dilution. Cliff

I've quoted the statement above, because it lumps E-85 (ethanol) and methanol together. These two different forms of alcohol have very different characteristics, and should be considered different. They are not the same.

Alcohol in the context quoted above, is methanol. Methanol is corrosive, methanol users do not deny its corrosive characteristics, unlike E-85 users.

After running E-85 for three years, I have not had any corrosion problems. I have never had one oil dilution problem (never milked the oil once). I do keep my ethanol fuel drum capped, and fuel cell capped, (vent is open) to avoid water absorption, and I always did that with race too.

I have never heard of an E-85 user with the corrosive problems common to methanol usage.

I look forward to first-hand E-85 in a Q-jet drag racing success.

[455firebird1969]

Originally Posted by 77 TRASHCAN

I keep wondering how much longer the gov'ment is going to subsidize the E-85 deal.

It would be outrageously priced w/o the gov. deal.....

Never seen a station in Oklahoma w/ E85, of course we are in the oil belt...

Good point, lack of support from our tax dollars would be a game changer.