Methanol

[dfhotlm33c]

Strange question, why is methanol not used in late models? Is it strictly due to its corrosiveness and requirements to run more fuel ini the cell that burns off faster and changes handling more drastically over a shorter race?

I ask because my engine of lower power than many ini my field, but a boost with running methanol could help me be more competitive. Just curious if it's an avenue to really pursue

[MasterSbilt_Racer]

Strange question, why is methanol not used in late models? Is it strictly due to its corrosiveness and requirements to run more fuel ini the cell that burns off faster and changes handling more drastically over a shorter race?

I ask because my engine of lower power than many ini my field, but a boost with running methanol could help me be more competitive. Just curious if it's an avenue to really pursue

I have experience running it as recently as this season. The only downfall is the burnoff, IMO. The burnoff can be a huge deal. The big plus is that you will not overheat. Even if the radiator has some junk in it.

[Jking24]

In my area we run it in steel blocks and most run it vs gas. We have switched from gas to methanol mid season and saw no major change in our setup needs in races under thirty laps. If you have a stock type head rule it can be a real advantage. If you run every week you really don't have to do anything real different with fuel system maintenance but it's not a bad to pull the plugs during the week so the cylinders can dry out. If you switch make sure you change your fuel filter and know that some fuel cell bladders cannot be filled with methanol without damage. One in particular is atl standard bladders

[TheJet-09]

I drove a couple cars for a buddy of mine, 20 years ago and again just this summer, each on Alcohol. I had the same feeling this time around as I did back then, that when the track slicks off they just don't seem very "smooth" at lower RPM off the corner. Obviously things like the cam and engine as a whole would (or should) affect that, but I just summed it up as a difference in the fuel (without knowing any better).

But before 18* stuff came around, many guys ran alcohol...certainly in Modifieds, so I guess it can't be that bad. It was never my thing, though.

[fastford]

you would be amazed at how quick a cylinder will oxidize , i like a quick connect at the carb and run a quart of racing gas through it when im done

[Krooser]

you would be amazed at how quick a cylinder will oxidize , i like a quick connect at the carb and run a quart of racing gas through it when im done

A lot of guys do that... back in the day we just shut off the main line from the cell and ran it dry... then fired it. up with gas dripping in the carb for 30 seconds or so.

I'd determined to get my ride out in 2020... I have an ancient alky BG 750 that I rebuilt but I'm thinking I may need an 830-850 now... and a bit more modern carb.

[MasterSbilt_Racer]

A lot of guys do that... back in the day we just shut off the main line from the cell and ran it dry... then fired it. up with gas dripping in the carb for 30 seconds or so.

I'd determined to get my ride out in 2020... I have an ancient alky BG 750 that I rebuilt but I'm thinking I may need an 830-850 now... and a bit more modern carb.

Krooser, carburetor technology peaked decades ago. I don't care how super their bowls are, the new stuff isn't gonna make a difference. Use what you have.

[fastford]

i 100% agree with masterSbilt , i have run BG carbs for years , ever since he left holley and started his own company , you can call them and talk to there circle track rep and gain a lot , i mean a lot of info . the only other carb i have run in last 20 years was a C&S , which also has very good customer support . also , that 750 is plenty big enough IMO , it will out perform a 850 off the corner.......

[Jim11h]

Setup the #1 reason everyone switched to gas. There's been dyno tests done that show no distinct advantage or disadvantage between the 2. Think alky gave slightest of slight torque increase. I can tell you that on 1/3 mile track I run with 2 barrel on alky I burn about 15 gallons in feature so your talking half tank. Hotlaps, heat race 10 laps, feature 20 laps I figure 20-25 gallons a night. At just over $2/gal. I kill $40-50, but if was gas I'd be looking 7-8 gal roughly for whole night at $7/gal, but I can now place the weight where I want it!

[Jking24]

Setup the #1 reason everyone switched to gas. There's been dyno tests done that show no distinct advantage or disadvantage between the 2. Think alky gave slightest of slight torque increase. I can tell you that on 1/3 mile track I run with 2 barrel on alky I burn about 15 gallons in feature so your talking half tank. Hotlaps, heat race 10 laps, feature 20 laps I figure 20-25 gallons a night. At just over $2/gal. I kill $40-50, but if was gas I'd be looking 7-8 gal roughly for whole night at $7/gal, but I can now place the weight where I want it!

If your burning that much alcohol to gas then you are way too rich. We burn 16-17 gallons in a feature on a half mile track running 25 laps. But on the same track we 10-12 gallons of gas

[Jking24]

Also the worse the head is that you have to run the bigger the advantage is on alcohol. For example if you have to run a world products sportsman 2 head sometimes called the io37 head and 60cc chambers with flat tops. Methanol is almost a must if allowed their is a distinct advantage to running it. Maybe not peak hp but under the curve it makes alot of low end.

[MasterSbilt_Racer]

My experience is you burn about 1.8x as much by volume. That comes out to nearly double the weight burned off. In short races, not a big deal. But at some point, it starts being a big deal.

[dfhotlm33c]

I rarely run a race longer than 25 laps at Eriez Speedway, which is basically 1/3 mile. I run with the back of the pack and have been doing well staying with those guys, especially since I'm a steel block 23 degree guy with a very old chassis that is down about 100hp from most of these guys. Looking to see if I can move up a bit with a bump in power. I'm running a mechanical fuel pump. (I know I should run a belt driven so I can have variable fuel pressure, but there is only so much money) I know I need a different one that is compatible with methanol. Is it true I want about 8.5 psi? I plan to get a Quick Fuel methanol carb. Anything else I need to know? Best top lube?
Thanks!

[fastford]

i really dont understand why any one would use methanol any more , to me , E85 is the way to go , its cheaper and less burn off , i do not know the exact ratio , all i know is what i put in the tank and it falls some where in between gas and methanol.....

[MasterSbilt_Racer]

i really dont understand why any one would use methanol any more , to me , E85 is the way to go , its cheaper and less burn off , i do not know the exact ratio , all i know is what i put in the tank and it falls some where in between gas and methanol.....

It should be about 1.3x gas burn rate by volume. If I had to buy a carb, that's the route I would go to.

OP, I'm not sure you are going to get a noticeable power gain. I think you'd pick up more speed getting your nose down on the track by raising your crossmember if you have an old, unupdated car.

[billetbirdcage]

I rarely run a race longer than 25 laps at Eriez Speedway, which is basically 1/3 mile. I run with the back of the pack and have been doing well staying with those guys, especially since I'm a steel block 23 degree guy with a very old chassis that is down about 100hp from most of these guys. Looking to see if I can move up a bit with a bump in power. I'm running a mechanical fuel pump. (I know I should run a belt driven so I can have variable fuel pressure, but there is only so much money) I know I need a different one that is compatible with methanol. Is it true I want about 8.5 psi? I plan to get a Quick Fuel methanol carb. Anything else I need to know? Best top lube?
Thanks!

Everyone has their own opinion and experience so. . .

Now I really haven't messed or built motors in a fairly long time but a while back I did and have my own dyno so I'm not completely stupid.

1. Even with low compression engines alky gained about 20/30# or torque on average even with low HP (down to about 450ish) even on lower compression claimer or street type engines (as low as 10:1). I rarely ever saw any gain in total peak power just torque increase at below torque peak.

2. Most of the older alky carbs where extremely rich, especially the box stock Holley alky carbs. They came with a .125 hole above the metering block and a #80 Jet, Best power was almost always with a #46 to 52 Jet. If it was a newer carb with no hole above the jet, something in the .146 to .162 Jet size was best (least with the carbs I used - doesn't mean it can't vary from that for sure)

3. The old Holley alky mechanical fuel pump that was the smaller one (3 valve vs 6 valve - IIRC) and wasn't the super high pressure one (Thinking 7 to 9 PSI with out regulator) was only good for about 550 HP and it would run out of fuel on the dyno. You couldn't hear it, it just layed down on the top end and was down about 50 HP vs the electric pump system I had on the dyno cell.

4. Fuel pressure, What the carb can handle is directly related to the needle and seats the cabs has. A .150 window N/S can't take as much pressure as a smaller one (say .110 like a gas N/S), it's pressure vs square inches of needle/seat area. Many will over flow as early at 6 to 7 PSI and others can take 9 sometimes. Since generally the N/S is the restriction in getting the fuel in bowls (large lines and ETC), the smaller the N/S the more pressure required to flow a certain volume so with a large N/S it doesn't need anywhere near the pressure to flow the same amount. I see way to many people run way too much pressure and not large enough N/S and this causes the carb to flood over on decel and you hear the carb stutter in the middle of the corner when they pick up the throttle.

5. Small N/S and high pressure: This just Aerates the fuel more and causes more problems, think a 1" garden hose flowing fuel into a bucket. Sure you get some aeration but nothing like that same hose with you finger over it simulating a small needle and seat with higher pressure. I never used over 6.5 PSI, if done correctly you can feed a 500HP with as little as 5 PSI with the right set up and never fight float/flooding issues. I never was a fan of the high pressure stuff (over 7 PSI and especially the regulators that where throttle controlled and bumped pressure up really high at wide open throttle.


Hope this helps

On a side note, for what you spend on a new carb (maybe you need a new one anyways) you could have some simple port work done on the heads and pick up more power then you will get from a new carb by a long shot. There are lots of good small head porters out there that do good work for not a ton of money (not a full port job). I'm sort of guessing on your motor/heads to make this statement

[dfhotlm33c]

Thanks so much for the information. This is a 406, Mahle piston, Dart block, Callies rods, Scat Ultralite crank, 13.5:1 Brodix -10 SP heads ported to all heck, 2.125 valves, matched 2925 intake. Sounds like I have a lot to think about.

[billetbirdcage]

Sorry on the porting as figured you was running a more limited engine and maybe had as cast heads.

I will ask another question: I know nothing about that class or track there, but are you sure your really needing more power? I've seen it time and time again where a crate car can be really competitive against supers on smaller tracks when they aren't hammer down and your talking way less power then you should have right now.

Just an honest question

[fastford]

i agree with billet,s last statement , i was thinking a 350 with iron heads , with your combo and everything right , you should have more than enough power , especially in the slick.....

[Krooser]

Lots of good info here...

My old BG has the holes drilled above the Jets...it has the older style metering blocks with the smaller Jets vs. the newer style.

I prefer to have all the fuel coming thru the Jets to avaid any chance of fuel levels going under those small holes. I will likely use jet extensions on the rear bowl.

I bought a newer 850 a couple days ago. I'll look it over and see how good it is. A good deal @ $200.00. A new kit and some tlc may be all it needs.

As far as methanol use I don't think we've been pouring 15 to 18 gallons of fuel in my friends super..it's a 362 spec motor, Brodix heads, Willy's s 750
He runs it over 8k on Shawano's paperclip 1/2 mile. 35 laps per night plus hot laps.