High Compression motor - looking for the right fuel setup

Energy One
XTREEME

XTREEME

Active Member
I've been doing a lot of research on this lately, including what some of you guys have tried here, and what I came up with is that I have at least two options available to me, based on my new 10.5:1 comp, carb'd, with open baffled race pipe.

Both involve pump gas and this Lucas fuel treatment some of you have mentioned:
Lucas Fuel Treatment : Lucas Oil

The 3rd item in the mix is either an octane boost like Justice Bros, or the 110 racing gas.

Option 1:
4 gallons premium unleaded pump gas
3 oz JB Octane Boost
1 oz Lucas Fuel Treatment


Option 2:
3 gallons premium unleaded pump gas
1 gallon 110 leaded race gas
1 oz Lucas Fuel Treatment


I'm trying option 1 right now. Seems to run a lot smoother, and less backfiring as well. But some of that might have to to with the cooler weather.

I'm still not convinced that mixing lead and unlead is a good thing to do, although I do see people doing it.

I suppose I could simply go with the race gas by itself, but I am concerned about the longterm affects on the motor with this one.

Why am I bothering to do this extra work? The quality of pump gas by itself around here is constantly going downhill. The higher comp motor is really affected by this.
 
Black Dawg

Black Dawg

Active Member
Out in Phoenix we have the worst gas in the country with premium only 91 octane.

With my zero deck I'm at 10.5:1 and can have an issue on 91 octane if it's a little hot or I get into it at a low rpm.

The good news is 100 octane no lead and 110 octane leaded is available at a few pumps here locally. The last time I check it was north of $6/gal, but if I mix 1 gal. 110 octane with 3 gal. 91 I'll have 96 octane mixed. Sometimes I'll run a stronger mix too. The bike loves it. The leaded gas isn't a problem since these carbed bikes don't use O2 sensors.

I don't believe in octane boosters or fuel treatments, mostly snake oil.
 
scubaman15

scubaman15

Well-Known Member
I know I don't have a modified 117 just stock ...but I know mixing the 110 and 96 ..works !!!!! the bike has never run better ,I know all about compression ratios and octane usage ,still I know the motor runs better. Also I like to use the Lucas fuel treatment with the mix I think it helps with the compression rings ,think about how a two stroke engine works ?? Snake oil ? All I know is that using lucas fuel mileage numbers go up !! Try it and you will see .
 
Black Dawg

Black Dawg

Active Member
Hey, if it works for you that's all that matters. Probably doesn't hurt anything either. Though two strokes and four stokes are worlds apart on what they like and how they operate.
 
scubaman15

scubaman15

Well-Known Member
True but think a min about what goes on in a engine... Trying to get oil past the oil control rings and then the compression ring to get lub to the first compression ring ? what is oiling the first compression ring ...fuel?
I'm not saying you should mix two stroke oil in with the gas , but using Lucas has a positive effect on fuel mileage ...its cheep and it works , so if it works what's going on ...?? More power from the same amount of fuel ? or less friction? ... or both? Anyway I respect your views and I look fwd to your posts ." I think you have a bad ass bike ...I'm still going to get a LSR one day soon . Also as soon as my warranty is up I plan on doing the zero deck mod I'm still struggling with my clutch , going to rip into it this week for the 3ed time !:bang: I would love to hear your bike !!!! I did the washer baffle mod on a set of Mean Mothers ,that came off a K9 and found out the pipes were not the same ..even after buying the correct bracket from Nelson. But I only have 175.00 in the whole deal and they seem to work great!!! NO decell pop and run's great ...now just get the clutch right! Ron

 
XTREEME

XTREEME

Active Member
Man, these Dogs are a blast to ride when they are running properly. :choppersmiley:

A freshly updated motor, a nice cold day (57 degrees today) and some 110 race gas makes for nice combination.

What a great aroma that burned leaded fuel creates. Reminds me of the old days racing snowmobiles.
 
Black Dawg

Black Dawg

Active Member
scubaman15 said:
True but think a min about what goes on in a engine... Trying to get oil past the oil control rings and then the compression ring to get lub to the first compression ring ? what is oiling the first compression ring ...fuel?
I'm not saying you should mix two stroke oil in with the gas , but using Lucas has a positive effect on fuel mileage ...its cheep and it works , so if it works what's going on ...?? More power from the same amount of fuel ? or less friction? ... or both? Anyway I respect your views and I look fwd to your posts ." I think you have a bad ass bike ...I'm still going to get a LSR one day soon . Also as soon as my warranty is up I plan on doing the zero deck mod I'm still struggling with my clutch , going to rip into it this week for the 3ed time ! I would love to hear your bike !!!! I did the washer baffle mod on a set of Mean Mothers ,that came off a K9 and found out the pipes were not the same ..even after buying the correct bracket from Nelson. But I only have 175.00 in the whole deal and they seem to work great!!! NO decell pop and run's great ...now just get the clutch right! Ron
Click to expand...
The top ring is still being lubed by the engine oil, it doesn't need much to be ok. The cylinder walls are coated in oil.

Maybe I'll try some of that fuel treatment, it'll at least give the carb a nice internal cleaning.

You'll like the LSR pipe, it gives the bike a good muscle sound without being obnoxiously loud. Though it barks pretty good when you get into the throttle. But you'll really like the big bump in power.
 
Cutter

Cutter

Well-Known Member
Black Dawg said:
Maybe I'll try some of that fuel treatment, it'll at least give the carb a nice internal cleaning.
Click to expand...
I like it... the people behind you may not like the smell, it gives off a stronger odor, not horrible...
... although PigPen doesn't like it :lol:
 
05ridgeback

05ridgeback

Active Member
i have 10.5.1 comp / woods 650 cam/

1 gallon vp110
3 gallons 93
1 oz. lucas fuel treatment

davinci G carb with 31/80 jets
 
scubaman15

scubaman15

Well-Known Member
1 gallon vp110
3 gallons 93
1 oz. lucas fuel treatment

Thats right ... good stuff
UPPER CYLINDER LUBRICANT
 
barhopper

barhopper

Another round please
1extremeskier said:
I can get 100 Chevron locally in LA, Unleaded Just 100 at Pump for 6-7$ gal. thoughts?
Click to expand...
No reason to. I run 91 from union 76. Runs great. Unless you have gobs of money to spend and just want to say " I run 100 octane and you don't". I even tried the octane boost, made no difference.
 
TCALZ06

TCALZ06

Well-Known Member
Black Dawg said:
Out in Phoenix we have the worst gas in the country with premium only 91 octane.

With my zero deck I'm at 10.5:1 and can have an issue on 91 octane if it's a little hot or I get into it at a low rpm.

The good news is 100 octane no lead and 110 octane leaded is available at a few pumps here locally. The last time I check it was north of $6/gal, but if I mix 1 gal. 110 octane with 3 gal. 91 I'll have 96 octane mixed. Sometimes I'll run a stronger mix too. The bike loves it. The leaded gas isn't a problem since these carbed bikes don't use O2 sensors.

I don't believe in octane boosters or fuel treatments, mostly snake oil.
Click to expand...
Damn, this isn't what I wanted to hear. I was planning on going to 10.5 with at least a 600 cam this fall.

I'd been told by bourget here in phoenix that a lot of their bikes run 10.5 in AZ on pump gas with zero problems
 
V

Vegas

Well-Known Member
There is an octane booster called Kemco that the ATV guys swear by. It's a leaded booster than can raise your octane up to 14 points. I haven't tried it personally since I still run VP 110 in my quad but if it gets scarce, I'll be trying the Kemco additive.
 
john sachs

john sachs

Well-Known Member
FWIW,
The compression ratio # is just that,a #.Really doesn't mean as much as the cold cranking compression on the compression gauge.:D
You can have 12:1,and after factoring in the cam timing,you may only wind up with 190 cold cranking....fine for most 91 0r 92 octane fuels.
Using additives and/or leaded fuel,will coat the living shit out of valves,and combustion chambers.The build up of residue on the backside of the valves will CERTAINLY hurt power.(race motors are o/hauled often,so they don't have the above issues).:angry:
I have several customers with Aerocharged turbo bikes that we run high boost in.There's no getting away from leaded race gas.I usually have to replace the valves,and chisel the crap off the pistons,and chambers at 4,000 mi.
Of course if you like the smell of it,then be prepared to replace parts that wouldn't need replacing if you used pump gas.
10.50:1 with a WT TC46 cam should give you NO problems at all.I run even higher on motors I use that cam in.:up:
John
 
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