Heyo,
I wanna put my ZK fairlane on gas and supercharge it. ATM it has a EFI 250 crossflow with about 260km's under it belt.

I was thinking of getting another 250 crossflow and builting it up to better suit LPG and supercharger. (noting too drastic as i dont have a huge amount of $$$, but a few lil things like cam, lighter pistons, etc.)

but then i got thinking, if i'm gunna build an engine, wouldn't i be better off with something newer, like a EF or EL motor?? i figured the conversion wouldn't be too horriffic as the car would be straight gas it wouldn't need the computer and all the wiring and sensors from the EF/EL. just basically the motor.

So what would be a better option for a fairly low buget? (btw i already have the supercharger and i'd be fabricating all the brackets and stuff.) i imagine EF motors still have some value, where as the old 250 crossflows people are happy to give them to you for free to save them the trouble of taking it to sims. so i could get all the basic parts for next to nothing, and it would bolt straight in, and i already have a bellhousing to go between my T5 manual and a 250. but from what i gather the EF EL is a far superior engine (yes?) and would give a better end result.

the car is an everyday driver so cant be off the road for too long, thats why i was thinking of building an engine then doing a swap one weekend.

anyones thoughts experiences would be much appreciated.

Regards
Rene.

PS, dont anyone tempt me with a V8 (droool)

supercharging is not an option for LPG engines, cos if they happen to backfire, you can blow your top hat off! VERY EXPENSIVE.

Turbo is the best.

Heyo,

Are you sure about that? if the car backfires, in a supercharged car, it goes down and out the exhaust, in a turbo car the TURBO cops it, no?

also a roots supercharger gives a linear amount of boost rather the a turbo who's boost increases exponentialy (roughly atleast) with revs. also, i'm gunna have a boost limiter that will reduce boost above about 3.5k rpm, and run fairly high boost down low (about 10psi in 1500-3000 rpm)

i want most of the power and torque down low where I will use it.

Why would a supercharger be not suited to LPG but turbo is ok?

Regards
Rene.

dont think I've seen a supercharged LPG 250, I say go for it.

i dont see how turbo is any different? in the event of a backfire it will sit put back pressure on the turbo

Heyo,
Basically my main question was:
should i stick with a 250 x-flow (cheaper easier to fit), or use an EF/EL motor (newer, more efficient and powerful)?
Rene.

I would use the ef/el

But thats just me

Having dealt with LPG for quite a few years, you will find that any LPG fitter worth their salt will run a mile before fitting to supercharge.

A system is being developed by my company for lpg to ford turbo at the moment

250x flow motor go hard but not that hard are you sure you want to spend that kinda money ???? i'd do a re build if i was you or you mite be sorry

 

 

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Heyo,

Woah, thats nasty! i dont plan of thrashing the crap out the engine, i just want bit more go and a bit less fuel cost.

as for cost, i already have the blower and complete LPG set, just wondering about the engine...

Creeture3, i've seen a couple of setups where theres a blower and LPG and seems to be running fine, from what i've read, LPG is well suited to forced induction due to its high octan rating and cooling effect. I'm not wanting to argue with you i'm just very curious why LPG and FI would be bad?

what i had in mind was a suck thru setup ie: airintake -> air filter (pod filter maybe?) -> LPG carby -> supercharger -> engine

Regards
Rene.

i think when people say back firing on LPG, it mainly happens in the intake manifold, has a tendancy to blow open the ducting unless you take precautions and fit an expansion valve ... scot, RIP mate, told me how to make a simple one for my car, i haven't had any exploding intake manifolds since and i have had a few intake backfires happen since the valves been fitted, but no damage done to anything

just trying to picture what might happen to an engine that has other stuff in the inlet manifold area, or connected to it ... like for example a supercharger, to relieve any pressure from an induction backfire you'd need an expansion valve, might be tricky setting one up that won't vent off when you have positive pressure in your inlet manifold

supercharging it or slapping a turbo on you still have the chance of backfiring. My mate has a 250 crossflow turbo i put it on gas and it backfired on him and blew the mixer up into 3 pieces. You can do it just dont get a s**t LPG system spend the money and go Gas Research, keep it tuned and keep the mixes correct or BANG.

Yeah, def need really good LPG system to do any sort of forced induction, Gas research is the popular choice, i think some impco models are suitable

there are many 10sec X series falcons around in vic using a straight gas/turbo setup, on both the 250 blocks and later 4.0

only car i have actually ever seen LPG and supercharged was the Predator concept thingy Ford built back in the late 90's