Intake Manifold Injection

[George Tyler]

you won't get the mixture very lean because you don't have perfect control over it, some cylinders end up getting a leaner mixture than others as some of the the fuel follows the inlet manifold walls, if you have a colortune spark plug you can see this.
You have only lean it until to just before the leanest cylinder starts to missfire, and other cylinders will be still richer. FE helps a lot.

[Arragonis]

+1 for the Colortune, I think I mentioned it before Its worth the money.

Ed - I may "pinch" your links if/when I get time to restart my MGB GT resto and the electric MGB plans don't work out.

[EdKiefer]

Originally Posted by George Tyler

you won't get the mixture very lean because you don't have perfect control over it, some cylinders end up getting a leaner mixture than others as some of the the fuel follows the inlet manifold walls, if you have a colortune spark plug you can see this.
You have only lean it until to just before the leanest cylinder starts to missfire, and other cylinders will be still richer. FE helps a lot.

right, that was one of main advantages to fuel injection , your not limited by wet IM design and much better distribution of fuel between cylinders .

[MGB=MPG]

not only desmogged .. i have a drip to the intake manifold ,, design was for MMO[mystery marvel oil ] but i have a soup of nitromethane methenol and castor oil in there.. apparent difference is now unable to set time by *ear* ..

unable to detect ping on advance .. using previously proved methodology advanced to 60 degrees Before top dead center [BTDC] hummwho would have thought an ICE would start with 60 BTDC much less do a road run..


my target EGT is [as advised by race engine builder waldrop @ acme speed shop.com ] is 1250 .. sensor is one inch from the head ..

last i leaned 3 flats [half turn]

i want to get a lean adjust screw with a shaft brazed on it ,, attach a torque tube to it , route to cabin and adjust mixture +on the Fly+ ..

im worried about tuning mix too lean and burning holes in my head ..

am i correct in thinking that monitoring of the EGT will prevent that ?

i am approaching 30 MPG with a 60's technology 1800 CC analogue system

that w/o applying my FE driver technique ..[ie: stuffing foot to footfeed and running up to 5G RPM [90mph] is NOT condusive to FE ..
when stabilized and start trials ...

what kind of FE does modern 1800 CC equipment provide? vs my 60's technology

[MGB=MPG]

Arragonis

start the MGB GT restore either electric or classical

be sure and go to

The MG Experience: MGB, GT, V8, Midget Owners Club MGA MGC Magnette all models: Forums, Library, Registry, Repair, Restoration, Events Calendar, Cars For Sale, Free Classifieds

we be glad to see you

go register today say .. " i have a 19** MGB GT and want to convert it to an all electric..

see what they will say..

all MGB welcome there..

[George Tyler]

my 1968 Austin 1800 with the same engine got 29 mpg US at 70-80 MPH, it was using much more, then i found the aircleaner was blocked so I removed it.

[George Tyler]

chemically correct mixture will burn at the highest temperature, right? So EGT will be lower when you run lean at first, then increase when the mixture is burning so slowly that it is still burning in the exhaust, this is when you start burning valves etc. That makes the optimum EGT the lowest temperature you get?

[EdKiefer]

EGT of 1250 sound cool , would put it on rich side IMO but I never checked on carb engine .
Are these temps for only part throttle or both part WOT , unless you have EGT in each exhaust runner i am not sure how good it would be as cylinder to cylinder mixture can go wild in carb setup .
I am old school so would just read the plugs . drive vehicle in steady state that you want to test and then cut ignition an rpm, pull over and check plugs . not best but it can give decent indication of mixture and plug heat ranges .

[MGB=MPG]

im pretty old school my self..

i do *flying cuts* to check the plugs .. that is switch off on a run and then pull plugs ..

there is some discussion on aviation sites [usually only ones who worry about leaning via EGT ] about setting Lean of peak LOP or ROP rich of peak ..

lean of peak is a ,, alternative ,, one would think LOP would result in enhanced FE

aviation engines one can adjust the mixture *on the fly*


i am told if i get set too lean i will burn the valves .. i wonder [and inquire] if valve burning happens at high EGT and if close examination of EGT might prevent that ..
my EGT sensor is one inch from the head on cyl # 1..

i do not do very much WOT ,, it runs up so fast.. i set throttle by manifold vacuum ,,,, attempt no less than 10INGH ..5INHG on a hard pull up grade ..

15INHG in cruise ..

single SU HIF 44 .on a heilmholltz log .. my needle is *not right * im flowing much better than as designed ,,K&N filters and enhanced exhaust sector ,,
my last adjustment was 1/4 turn lean ..
currently seeing 1300 on the EGT and looking for the drop .. Lean of peak
i have no flippin idea where im set in the profile now

here are plug images ,, not so current but about he same i think ,,

[EdKiefer]

Little hard reading them with so much deposits (hard to tell color change on ground strap) but looks pretty good to me .
how many miles on those ?