Methanol Injection 11:1 350
Thread Starter
Instructor
Joined: Apr 2010
Posts: 177
Likes: 0
From: Fairview PA
Methanol Injection 11:1 350
Have a rebuilt 69 350 - 350hp. Did roller heads and is 30 over. Also a little more aggressive cam. My question, has anyone put in a meth system in a setup like this? Just wondering if this may be a good alt to running cam2 etc... The motor has not been started yet since the rebuild... Other side notes... Eldbrock Performer Intake and 650 carb as well... Replaced the point with a Pertronix kit and went 45000 on the coil.
Team Owner
Joined: Oct 2004
Posts: 81,241
Likes: 3,063
From: altered state
St. Jude Donor '05
Water injection system perhaps? (they help)
Pure meth-wouldnt run it on a carbed car.
Depending on your cam specs you may not need anything.
Which heads, iron alum, or?
need more info
Running 11.5:1 on 91. Possible to do it if the cam specs/tune is right on
Pure meth-wouldnt run it on a carbed car.
Depending on your cam specs you may not need anything.
Which heads, iron alum, or?
need more info
Running 11.5:1 on 91. Possible to do it if the cam specs/tune is right on
Team Owner
Joined: Apr 1999
Posts: 21,953
Likes: 1,445
From: Reno Nevada
2024 C3 of the Year Finalist- Modified
My question would be is: Do you really have 11-1 in a 355 ci? Like did you install domed pistons and small cc heads?
If run a big enough cam and have aluminum heads all you need is super unleaded
If run a big enough cam and have aluminum heads all you need is super unleaded
Burning Brakes
Joined: Sep 2011
Posts: 896
Likes: 7
Snow makes an NA kit and so does alky control. Ive been researching the same issue for my next motor. Everything Ive read leads me to believe that meth 50/50 will help performance and fuel efficiency. I just havnt found any threads on LS1 tech, etc. referencing meth in an NA motor. If you decide to run a kit, please let us know the results.
There is one article on the internet where a high compression NA car was tuned and dyno'd for race gas, and then dyno'd with pump gas/meth. The car made more power on the pump gas/meth combo. The article didnt evaluate fuel efficiency.
From my research of meth on all of the various FI forums and threads, is that meth should work well for high compression NA as long as nothing too extreme is used. Pump failure on the meth kits do happen. If the engine's compression and tune factor in that possibility, then NA/meth should be ok.
My thoughts are to run a nitrous plate but use it for meth injection. For your application that method might eliminate meth 50/50 from interfering with your carb.
There is one article on the internet where a high compression NA car was tuned and dyno'd for race gas, and then dyno'd with pump gas/meth. The car made more power on the pump gas/meth combo. The article didnt evaluate fuel efficiency.
From my research of meth on all of the various FI forums and threads, is that meth should work well for high compression NA as long as nothing too extreme is used. Pump failure on the meth kits do happen. If the engine's compression and tune factor in that possibility, then NA/meth should be ok.
My thoughts are to run a nitrous plate but use it for meth injection. For your application that method might eliminate meth 50/50 from interfering with your carb.
Last edited by uxojerry; Nov 15, 2012 at 01:36 AM.
Heel & Toe
Joined: Sep 2012
Posts: 17
Likes: 0
just my .02
unless you replace all gaskets,o-rings seals etc. alky will destroy it. ive been running it in my bird now for about 6 yrs. (i actually like the stuff),but had to change my entire fuel system to make it compatable with alkynow keep in mind that i run pure meth/alky with top end lube. still have to replace floats every year anddont even think about a paper fuel filter (itll eat the sh*t up). we have tried to run a 50/50 mix in my brothers blazer, tore that edelbrock carb up the first year, even though we didnt run it all the time. had to rebuild the fuel pump also. if you do try to experiment...make sure anything aluminum is annodised(that spelled right?) or you wont get it apart. these are just some of my experiences, right, wrong, good, bad and indifferent.but, 130 octane rating for about $2.50 per gallon aint all bad.
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Safety Car
Joined: Mar 2007
Posts: 3,652
Likes: 49
From: Bridgewater nj
I ran an 11:1 427 on 93 oct.pump gas with no problem. Cam choose will make or break the build on pump gas. I would back the timing down or use stiffer springs on the advance. Then if I got my hands on some race fuel, just bump it up or replace the springs and hold on!!!
Race Director
Joined: Apr 2000
Posts: 17,676
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From: Who says "Nothing is impossible" ? I've been doing nothing for years.
11:1 cr with aluminum heads should run OK as long as the cam is big enough. 93 octane and if it pings retard the timing a few degrees. I am not wearing a flame suit and don't care but I wouldn't run a vacuum advance that will put your timing above 50degs. in certain situations. 
Melting Slicks
Joined: Oct 2002
Posts: 2,317
Likes: 111
From: St Louis MO
I've used water/METHANOL (not meth) injection for years on high compression (11.5:1) and triggered it with an old Spearco water injection unit when manifold vacuum went below 5" Hg. I've had no problems with the fluid as I use blue windshield washer fluid which is close to a 50-50 mix of methanol and water. One doesn't need the detonation suppression of water/methanol injection at cruise, but only at near WOT.
Unless you really have 11:1 compression ratio, iron heads, and a cam duration of less than 235 degrees at .050 lifter rise, you probably don't need it.
Unless you really have 11:1 compression ratio, iron heads, and a cam duration of less than 235 degrees at .050 lifter rise, you probably don't need it.