Gulfstream8 wrote:As far as I can remember the 84 2lt does not have stellite valve seats or bronze valve guides so if the previous owner has used GAS there is a good chance the head is worn anyway.
fistly most jap vehicles from this era had ok valve seats for LPG. i am rebuilding my 4y now and have just put it on straight lpg
i can tune it up to run better on lpg than with the asain carby but it wont match the webber though..but for what i need it will be more reliable due to angles ect ( racing)
the 4y block and heads are same just different stroke 3y is 86x86mm and 4y is 86 x 91mm from memory
straight gas can be tuned up to give excellent reliability and performance, much better that the performance on lpg when set for dual fuel...(all due to octane ratings, i can explain more if needed)
now with myset up....i had a 32/36 webber rebuilt and jetted to the max...it was again doe to race not for the street and therefore the fuel eccomony was horrible
all that i did was fit the jetted webber, extractors with a fairly open 2 1/4" pipe and tuned it all up
the webber is a fickle SOB... it breathes through the shaft so tries to suck crap in through the butterfly seals, linkages always jam ( i fixed it by greasing all the links heavily) and they are tempremental they floody and starve at times...
whilst it gives a heap of performance the reliability and ability to say climb vertically are reduced....
in my opinion,
if the vehicle will tour around straight LPG may not be ideal
straight LPG will be the most reliable fuel off road
fit the hei ( built in coil) distributor from the 3y in tarago
dont do the webber!!
and with straight gas it al;l depends on how the system is designed for fitment and how its tuned
any elec dissy gives a stronger ( high energy) spark to the plug and more is better especially with lpg
..and no points to wear out
id say it will have an asain carb on it ( with vac secondary) and yes its way more reliable..best solution is to hut for an asain with mech secondary's ..more fuel delivery and more power
as for lpg.. you can leave all the fuel stuff in if you want and not use it, just leave all as is and just get the timing advanced for lpg ( it wont run on petrol then it will just ping) the best option for straight gas is to change the system for an impco negative pressure system, it is a different convertor and mixer..bit of goofying around but better performance..
not sure how worth it it is, as it can be costly to get those bits set up... stick with the origional set up for now, throw it on a dyno for 1/2hr and get the timing set correctly fot lpg only..whilst im using impco in mine for racing, i have all the bits laying around
also as soon as thats done stick a timing light on the car and see what its set at..then if you need petrol, swing the timing down a tad and use it and then youy know where to set tit back to with out a dyno
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