Mixing leaded and unleaded?

[jwyche]

My new 347 has 10.5 compression. I can easily get LEADED race fuel. What I'm wondering is can I mix 110 leaded with 93 unleaded and not screw up my motor? Has anyone ever done that?
Thanks,
Jim

[svtlx]

i don't see how it would hurt..i ran 110 leaded..but i was run'n e7 heads...the high octane don't really help with lower compression (e7te), but u should notice a differnce maybe with yours...i mix it..doesnt really help horse, i just like the smell...my buddy runs 100% 110 leaded in his stang for the past 3 1/2 years with a kenne brown (?) twin screw blower on e7 heads...no problems there either....i don't know how he affords it...dat shit was $5.50 a gallon last summer....dat's all he puts in his stang....i only put a couple of gallons in mine for the odor so those honda kids back off when they smell it at a light.

[matthews.stang]

Quote: Originally Posted by Gasoline, Wikipedia From January 1, 1996, the Clean Air Act banned the sale of leaded fuel for use in on-road vehicles. Possession and use of leaded gasoline in a regular on-road vehicle now carries a maximum $10,000 fine in the United States. However, fuel containing lead may continue to be sold for off-road uses, including aircraft, racing cars, farm equipment, and marine engines until 2008.

[jimmy_beaner]

what fun is that... I like to play with them. Pace them until first is half up... then laugh and floor it. The expression is priceless. Of course, a good portion of the Honda boys now hate me.

[svtlx]

yea, but let's admit it...racing most of those guys is a waist of gas...granted there are some 300hp civics were i live and a 400hp neon (hate dat guy!!!) and another guy with turboed cavalier...that's y i bought a 9lbs. blower over the winter. when i got waxed by an integra, from rolling start @ 100mph...left me like i was sittin at a light...i was like wtf!?!? every other souped up honda i've raced run outa power @ 90 mph. never,never,never, do i get stomped on top end by a 4 banger...these ricer kids have some big budgets where i live.

[jwyche]

SVTLX,

There's a good possibility that I solved my problem. I was getting some detonation and a valve train "rattling". Someone suggested I try some race gas to see if it would go away. Here's how I got a partial answer to my problem...

After posting something about blending leaded race fuel and unleaded 93 (btw, Sunoco 110 octane leaded is $5.85 and 100 octane unleaded is $11.95 per gallon locally). Someone asked why I wanted to blend fuels that 10.5:1 should be fine with 93 octane and I told them that we might have a detonation problem. This is my answer to them after a bunch of suggestions:

I think I may have found out what my problem was. I have a 3 position Diablo chip that was in for the 302. We set the timing at the base setting of 10 degrees advance and had never clicked into the other two settings. The computer may have altered our 10 degree setting.

I got to talking with a Chevy builder who told me his 408 stroker detonated at normal settings so he ran it at 28 degrees retarded on the street and 0 on the strip with race gas. I'd never heard anything like that but right now I'm asking little old ladies in the check out at Wal-Mart what their opinion was on my car. The Chevy guy suggested that I retard the timing and see how it went.

Got to thinking that one of the settings on the computer was for 5 degrees advance. I started the car in the "Nitrous" setting, which is the 5 degrees advanced. It was a miracle! The knocking sound almost disappeared. I then set it to the "street" setting, 14 degrees advance, and the knocking stayed gone. Be aware that I’d dumped two bottles of 104 octane booster into a full tank.

I'm guessing the computer goofed something on the base/default setting. When set on one of the other positions, the computer took over and got it right.

The X303 with 1.7 RR seems to be a bit noisier than the E303 was with it...kind of a sewing machine sound. That's not a problem for me. The knocking sound scared me.

Joe Dirt was right, the 10.5 seems to be fine now with pump gas and a bottle of 104.

I also got this feedback from someone on a forum and, like so many other things, it was an education for me...

“When questioning which fuels to run, always remember that an engine will make it most power on the lowest octane fuel that can used without detonation. I think you should stay away from it unless you are looking for that nice smell of race fuel when pulling into the car shows. Just to put your mind at ease, when I built my Fairlane engine to run in the PHR Pump gas drags, I wound up with 13.2:1 compression and ran it on 93 octane with 175 HP shot of nitrous as well. This was no strip only car either, I drove it all over the place like this. I just kept an eye on things such as spark plugs and cooling systems so I knew when I was running a little close to the edge.”

Driving the car around this afternoon the “knocking sound” seemed greatly reduced but not completely eliminated. At the 14 degrees there seemed to be no detonation, pinging, or clattering of the valves. And it felt pretty strong.

Any further thoughts?
Thanks,
Jim

[PureVenom]

You could always run torco instead of race gas as well. I intend to get a pallet or two when I install the whipple...and will run a 32 oz can per fill up to get around 102-104 octane when filling up with 93.

[lowflyn]

To answer the original question clearly, you can mix the two without any ill effects.

For those with cats however, leaded fuel will foul out a cat faster than dumping a gallon of gas through it. Do not run any leaded gas through a car equipped with cats EVER.

[silverstangboy]

well, I agree that 10.5:1 should run fine with 93 and aluminum heads...
maybe a trip back to the dyno is in order.

to the original question, it wouldn't hurt a thing, other than what matthew stated, being illegal. putting unleaded fuel in an early model car before the use of stainless valves would be a very bad thing however

[PureVenom]

However, torco would solve your problems and be legal.

In case you haven't heard of it, here it is: Torco Racing Fuels

There is a cheaper distributer than buying direct...but that is the info on it.

[svtlx]

jim, i glad u got it figured out...i've never owned any high compression heads but was told that the cam2 (110 race) doesnt help my horse, basicaly wut your joe dirt buddy said. everyone kept ask'n me...why u run'n ported stock when u can get some reasonable gt40's? answer..cause i knew i was get'n a blower, and u can run more advance on lower compression heads without detonation...however, with the current gas prices...i'm seriously considering dropping back down to 1.6 rr or putting back on my 1.65's...or smaller throttlebody...i dunno...but before i tore my motor down, i was get'n 11mph on the highway. i droped down to a set of e6te heads..the intake ports already match the gasket unlike the e7te...but i had to remove almost double the material from the exhaust ports than i did with the e7...the e6 are supposed to be the high swirl heads..i will let yall know how it did with the blower...some ford mechanics told me that my gas mileage will improve since i upgraded to 24lbs. inj. since i was push'n 68lbs. of fuel through 19lbs. inj. the injectors wouldn't cycle correctly at low rpm..too much pressure on the springs (in the injectors)...i guesse they say rule of thumb is that if u need more than 50lbs. of fuel, u need to move up an injector size. we shall see

[silverstangboy]

you shouldn't be tuning from fuel pressure anyways, thats a very bad old school trick that never has died down like it should..

[svtlx]

well not necessarily tunig from fuel pressure, just realizing the problems of too much fuel pressure...with not enough fuel all at the same time. to get the mixture right i have max out the fuel pressure which makes the injectors not cycle properly at idle...injector springs cant close fast enough cause of high fuel pressure.. i went round and round with the tps and mass air..in the end it ended up being too much fuel pressure..i borrowed some 24lbs. inj. and it idled fine with enough fuel at the top end...had to give the injectors back now, i got my own 24lbs. inj.

[bullitt482]

I run 16 degrees base timing all the time, on 93 octane .

And like brad said, never run it with cats. They will get hot, crack, fall apart, and then clog up your exhaust system.

[bullitt482]

Quote: Originally Posted by svtlx jim, i glad u got it figured out...i've never owned any high compression heads but was told that the cam2 (110 race) doesnt help my horse, basicaly wut your joe dirt buddy said. everyone kept ask'n me...why u run'n ported stock when u can get some reasonable gt40's? answer..cause i knew i was get'n a blower, and u can run more advance on lower compression heads without detonation...however, with the current gas prices...i'm seriously considering dropping back down to 1.6 rr or putting back on my 1.65's...or smaller throttlebody...i dunno...but before i tore my motor down, i was get'n 11mph on the highway. i droped down to a set of e6te heads..the intake ports already match the gasket unlike the e7te...but i had to remove almost double the material from the exhaust ports than i did with the e7...the e6 are supposed to be the high swirl heads..i will let yall know how it did with the blower...some ford mechanics told me that my gas mileage will improve since i upgraded to 24lbs. inj. since i was push'n 68lbs. of fuel through 19lbs. inj. the injectors wouldn't cycle correctly at low rpm..too much pressure on the springs (in the injectors)...i guesse they say rule of thumb is that if u need more than 50lbs. of fuel, u need to move up an injector size. we shall see

Several things, I say again:

1. E6's are junk

2. Why in the hell would you need 68 psi of fuel?????? I've heard of several guys running aftermarket higher flowing heads(trickflow, holley, RHS) and stickin with the stock 19 lb injectors. I'm running a full Trick Flow setup, 190 lph pump and only 42 lbs of pressure, and it's running pig rich right now and get 17 mph in the city and 19.7 on it's latest highway venture(not all highway though).

3. Compression has little do with the head. It depends on the combustion chamber size and how far up the piston goes in the cylinder. In your case, I would rather run a higher compression head(smaller combustion chamber) with less boost than run those shitty E6's and a blower with more boost. Besides boost is just an end result of a bottle neck in the system anyway. You can run the same amount of "boost" on two different motors and have two different numbers.

[svtlx]

hay bullit482,
seververal things i will say again, i like stock parts. secondly, as far as fuel psi.....i dunno..dat's y i'm ask'n u..lol..my heads are very heavily ported...the car wouldn't do more than idle when i stuck the heads on. & 1.65rr, & .e-cam..acted like fuel pump was bad, put adj. reg on it, ran great....then later added some 1.7rr dat's when i really had to crank the fuel psi..btw, 70ml. t.b., typhoon intake.....i thought the excessive fuel consumption was cause of excessive blow-by....changed bottom end with tighter piston/cylinder "no blow-by"..on this block....still used alot of fuel...just got alot more power out of it....it made alot of power on top end...i talked to a friend that is a pro racer..alcohol pro street?...his car is fiberglass, but not a funny car...if i'm make'n any sense. anyway he said that i went alil wild on the intake porting which is why it uses so much fuel, but also y it makes good high rpm power....he was like u and was wanted to know why the hell i need so much fuel psi. for e7's...so i let him play with it. and he said, wow, u musta ported the shit outa these things......long story short, ima broke ass, i only got like $20 in the heads. the top end power i got with stock heads was awsome...and i dusted off a few stangs with high dollar heads, and some chiped up 4.6's with gears. so i'm pretty satisfied with the results, verses the money i have invested in it. @ 140mph on the rear bumper of the porche carrera (rated @ 355h.p.)....like i said before, says alot about stock heads....i wish i had dyno'd it before disassembling it, cause all u guys think i'm full of shit...i can tell u that there is dyno'd proof that u can get 40 h.p. outa ported e7's....and i followed the instructions to a "t"...

[bullitt482]

You can find GT40's out of wrecked explorer for practically the same price as that 20 bucks you put into those e6's and with correct port work can flow as much as some out of the box trick flows.

My other advice to you is pretty much what blue said. I wouldn't recommend "tuning" with FPR. Go to a tuner and have them take a look at it. As much as I know you don't want to spend money, to have a semi fast car it still takes money to make horsepower. You can only get so much power for free.

[svtlx]

Quote: Originally Posted by bullitt482 You can find GT40's out of wrecked explorer for practically the same price as that 20 bucks you put into those e6's and with correct port work can flow as much as some out of the box trick flows. My other advice to you is pretty much what blue said. I wouldn't recommend "tuning" with FPR. Go to a tuner and have them take a look at it. As much as I know you don't want to spend money, to have a semi fast car it still takes money to make horsepower. You can only get so much power for free.

tru dat, tru dat homey...and i haven't found any g.t.40's for quite that cheap...i been look'n though. actualy i was want'n to wait till i put my blower on, and then get it professionaly tuned on a dyno (not me tuning it..lol), and possibly get the ecm re-burned...all around $250...the alcohol racer i was tell'n u bout has a speed shop in patascala and specializes in stangs..(mostly 4.6 stuff).....don't get me wrong, i totaly understand wut u r say'n...anyone who talks to me for more than 5 min. will quickly realize how limited my knowledge is. i found a set of gt40 for $100 @ "ford swap meet" here in columbus...i'm glad i looked hard...someone had cut into the water-jackets on the exhaust side, just alil over-porting i guesse..a.k.a. being greedy. obviuosly they didn't us a cut-out maps that show u were the water jackets r. u know, i think they should have an underprivilaged street rodder fund for guys like me on a realy tight budget dat wanna go fast "poor kid play'n rich kid games..lol"...i started as a chevy guy "f-body fanatic". grow'n up watch'n these guys make superfast cars outa junk yard parts...the only new shit they bought was bearings and gaskets. they knew wut 3 motors to rub together to make one bad ass motor...pop the hood...rusty iron motor, with very shiny carb. i guesse i will get my shit together eventualy.