turbo propane set up

Propane, Butane, LPG, GPL, C3H8, C4H10
gearhead
Posts: 28
Joined: Wed Dec 16, 2015 1:58 am

turbo propane set up

Post by gearhead »

Hey!
So, i'm new to propane powered vehicles so i'd like to pick your collective brains as i'm planning to build a propane powered project for a daily driver. I am, however, not new to building complex projects or to turning wrenches. I'm a ticketed commercial transport mechanic(diesel mechanic) and I've got several projects under my belt. I've built a twin turbo 4bt cummins engine so i'm knowledgeable with turbo's and diesel fuel systems.
I've owned several turbo charged vehicles and I would like a small v6 diesel that can make a bit of power, but there really is no such thing. Gasoline is 1.30 per litre for premium and that is too rich for my blood. So propane is 69 cents per litre and is high octane so that's why I'm thinking i'd like to try propane!

So my plan is to drop a for 3.8 v6 into a Volvo wagon and turbo charge it. my goal is 300 whp(the factory 3.8 v6 makes 190 hp) and i'm wondering how realistic this goal is if i'm trying to do a draw thru propane carb'd system. or is fuel injection a better way to go?
I've been searching around the internet about diagrams and info on how to do this and i'm wondering if anyone can point me in the right direction. There just isn't much info on older propane systems and I don't have any real experience in working on them.

storm
Posts: 796
Joined: Wed Jan 10, 2007 10:10 pm
Location: NSW, Australia

Re: turbo propane set up

Post by storm »

By the prices you have written for the prices of fuel I'm assuming you are in Australia somewhere, it helps if you put this information in your profile.

With regards to the V6 (ecotec?) into a Volvo you have a couple of options. You could install a GRA kit (I'd be going for an S510 throttle body if your looking for 300hp). I also think you will find running draw through will cause a restriction that will be a hassle in the long run. Because you are considering draw through I'd be more inclined to go for a Prins VSI setup which keeps the LPG down near the valves and not up in the turbo (I have concerns with LPG inside turbos especially on wasted spark ignition systems).

What I'd think about doing is either a blow through with the GRA mounted on the manifold or a draw through with Prins (Keihin) injectors mounted at the base of the manifold runners but using an LS1 or LS2 throttle body to ease the restriction which inevitably occurs when running a draw through system. You can get an LS throttle body adaptor through MACE

The links are based on the assumption you're in Australia.
Fuel flow requirements calculations
Engine air flow requirement calculation: CFM = Cubic Inches x RPM x Volumetric Efficiency (VE) ÷ 3456

gearhead
Posts: 28
Joined: Wed Dec 16, 2015 1:58 am

Re: turbo propane set up

Post by gearhead »

Thanks for the info! I'm actually in British Columbia Canada! Near the US border. I'll check over ur links. One question tho, why do you not like draw through set up's? Propane self ignites around 900 degrees F, compressor temps would never reach that, especially with propane as a fuel. Or could the compressor wheel cause a spark?
could one run dual mixers on draw through to eliminate the restriction?
anyway just some thoughts!
thanks again!

storm
Posts: 796
Joined: Wed Jan 10, 2007 10:10 pm
Location: NSW, Australia

Re: turbo propane set up

Post by storm »

gearhead wrote:Thanks for the info! I'm actually in British Columbia Canada! Near the US border. I'll check over ur links.
C3H8 is the man to answer your questions then he is in Canada and knows what is relevant to your situation.
gearhead wrote:One question tho, why do you not like draw through set up's? Propane self ignites around 900 degrees F, compressor temps would never reach that, especially with propane as a fuel. Or could the compressor wheel cause a spark?
I have seen the end result of an LPG backfire on a turbo.
gearhead wrote:could one run dual mixers on draw through to eliminate the restriction?
Yes but to my mind, others probably think differently, that adds complexity and another item that has to be maintained.
Fuel flow requirements calculations
Engine air flow requirement calculation: CFM = Cubic Inches x RPM x Volumetric Efficiency (VE) ÷ 3456

bumpstart
Posts: 133
Joined: Wed Jan 20, 2010 9:09 pm

Re: turbo propane set up

Post by bumpstart »

a draw through mixer has to be sized correctly for the flow it will make at WOT and revs and will be so large as to make part throttle responses poor

there also needs to be front encapsulated seal on the turbo as there is the possibilty that the gas fuel can enter and contaminate the turbo oiling system through the front dynamic type seal

then you also have a short turbo life as shut throttle on a draw though and it creates massive axial thrusting forces that rapidly destroy front thrust bearings

blow though .. or EFI is the way to go

have one of each in driveway ATM on rx7 13b turbos

for efi the prinz injectors are limited to around 50 rwhp each . you need at least 2 a pot . and you probs will be wanting sequential control on them should you wish idle quality

( EG.. one injector runs up to a point where it is at about 80 % duty and holds at that and the second injector then opens up on a new map to keep fuel up to that cylinder )

they fit and gang pretty easily and the new EFI regulator/ vapouriser is very small in the bay
the decision on which ecu should run it isnt so easy. some offering piggy back off the back of the original GMH ecu signals
and have full OBD compliance
.. and there is others like profire where the software and config and mapping is 100% user definable., but setup is much more involved and protracted.

else there is blow through mixer .
these are VERY simple systems to setup .. there is already impco feedback 225 and modle E convertors setups avail and passed for the GM 3.8 v6
all you have to do is fit one of these . and then add a reference line from the hat on the mixer ( or the i/c pipes ) to the reg/vaporiser

it is that simple.

model E is rated for about 330 hp. continuous .. . or just shy of your target at 300 rwhp . but will make that peak power in bursts
and the impco 225 will be flowing an easy 300 rwhp at around 15 psi
( it is rated for about 7 psi but they will take 15 and more if you do a few mods like replace the hat bolt for a stud )
and will go further if you build a girdle for the top of the modle E to prevent distortion on the lid under boost )

i have run 20 psi with just the stud mod ( though i have an extra modle L convertor to be sure that i have a reliable 300 + worth of flow )

personally i vouch for the impco stuff. it is designed to work together without a need to be cheating the safety interlocks
while there is the GRA stuff that has the potential to flow more without a pressure drop .. it isnt designed to work with regs that flow at under atmospheric pressure . and therefore has questionable leakdown after shutdown.

the pressure drop of a impco mixer is meaningless in the context where you must also include the loses through piping and an intercooler
// i use a bar plate intercooler with less losses and so the total sum of my restriction is possibly equal or less than the GRA guy with a tube fin i/C
when the going is hard, don't retard, remember your lubrication

storm
Posts: 796
Joined: Wed Jan 10, 2007 10:10 pm
Location: NSW, Australia

Re: turbo propane set up

Post by storm »

bumpstart wrote:for efi the prinz injectors are limited to around 50 rwhp each . you need at least 2 a pot . and you probs will be wanting sequential control on them should you wish idle quality
6 x 50 = 300 why will he need 2 50 rwhp injectors in each cylinder to get 300 hp? 300rwhp is close to 400 flywheel hp which is 100 hp over the desired 300 hp.
Fuel flow requirements calculations
Engine air flow requirement calculation: CFM = Cubic Inches x RPM x Volumetric Efficiency (VE) ÷ 3456

bumpstart
Posts: 133
Joined: Wed Jan 20, 2010 9:09 pm

Re: turbo propane set up

Post by bumpstart »

because you dont build an efi system so it runs at continuously at high duty.
OP wants 300 whp .. prinz is 6 x 50 whp
( best case scenario . clearly less efficient motors or those needing richer mix to get combustion stability will be less than this )
and you are running the injector at high duty cycles ( the rating is usually at 90 % duty )
and there is no reserve with erratic injector response expected if the engine overboosts and the injection map demands more
not a good scenario to be in on a turbo engine and even on performance petrol turbo setups it is the norm to significantly overbuild injector and fuel pump sizes

the same motor with sequential control and 2 injectors per cylinder is at 45% duty . or if stage hold setup.
one at 66% and the other at 20 something %
( 66% what a factory FD rx7 does. and mazda have been doing sequential for almost 2 decades before anyone else )
or one at 80% and the other at 10 %.. or anything in between as on a profire it is user definable

this leaves plenty of margin to push his AFR mixture where he wants it in relation to exhaust temps and ignition stability

the profire guys i had a chat with last month openly discussed the boost mixtures and timing results within the platforms they had been racing
( rx7. boosted 307 . and ford 4.0 turbo . 2jz supra )
and in there was a revelation for keeping the exhaust temps , valve recession ( where applicable ) and the detonation under control by keeping within a sweet band of mixtures that was different on each platform

some of those are as rich ( for LPG ) as 12:1 ( though myself in the rx7 run much leaner under boost )
and for that reason alone you really dont want to run an LPG system right on the limits of the injectors under boost

stuff like profire ecu comes with 8 drivers. and expands to 16 for fuel injectors . the ignition side will cover a wastespark v8 ( 4 outs )
that should tell you that even they consider that it is prudent to double up on the injectors and run them sequentially so idle and low speed isnt effected


and as for bhp/ whp .. on a modern manual you have about 20% losses and the common number for an auto is 30%
that makes 300 whp. 360 bhp ( manual ) .. or 390 ( auto ) bhp
.. 360 bhp makes the 330 bhp model E .. just shy
//

which bring me to an interesting point.. model E and L are quiet large.. to have enough heated surface area to bring the vapour down to atmospheric pressure for 330/300 bhp worth of gas
the EFI vapour gas reg is quite small in comparison. it only has to let down to 40-60 psi .
and thus is has less of a job to do and it is good for 450 bhp

it could be reasonable enough to expect.( though i havent seen it demonstrated )
that a model E reg if running at 15 psi boost reference pressure is also delivering vapour gas at just over 15 psi
and thus its 330 bhp rating should infact increase towards 350 bhp

food for thought
when the going is hard, don't retard, remember your lubrication

gearhead
Posts: 28
Joined: Wed Dec 16, 2015 1:58 am

Re: turbo propane set up

Post by gearhead »

thanks again guys! sounds like you guys have played around with this stuff for some time!

Fuel injection would probabily work pretty good, but i'm looking to do carb'd mixer stuff. For simplicity sake and budget sake!
so blow through is the way to go then. you recommend a impco 225 E, but what about a impco 425? can it hold boost?
the reason I say this is because the 225 I saw was a single barrel mount and my engine I can get 2 and 4 barrel manifolds for. Also the impco 425 flows more fuel 287 vs 237 hp(unless i'm looking at the wrong model)

storm
Posts: 796
Joined: Wed Jan 10, 2007 10:10 pm
Location: NSW, Australia

Re: turbo propane set up

Post by storm »

bumpstart wrote:OP wants 300 whp
didn't see that until just now. :oops:
Fuel flow requirements calculations
Engine air flow requirement calculation: CFM = Cubic Inches x RPM x Volumetric Efficiency (VE) ÷ 3456

storm
Posts: 796
Joined: Wed Jan 10, 2007 10:10 pm
Location: NSW, Australia

Re: turbo propane set up

Post by storm »

bumpstart wrote:OP wants 300 whp
didn't see that until just now. :oops:
gearhead wrote:you recommend a impco 225 E,
In Australia the non-factory and early factory conversions were Impco 225s (we have never had a turbo V6 here though). They are common as chips on the V6.
gearhead wrote:but what about a impco 425? can it hold boost?
Yep but don't go crazy on it.
gearhead wrote:the reason I say this is because the 225 I saw was a single barrel mount and my engine I can get 2 and 4 barrel manifolds for. Also the impco 425 flows more fuel 287 vs 237 hp(unless i'm looking at the wrong model)
287 vs 237 naturally aspirated HP. when you turbo something you raise the output by the pressure increase. 237 HP @14.7 naturally aspirated psi can turn into a theoretical 474 HP @1 bar (which is 14.7 psi more).

Just out of interest sake what V6 is it exactly? Do you have a pic?
Fuel flow requirements calculations
Engine air flow requirement calculation: CFM = Cubic Inches x RPM x Volumetric Efficiency (VE) ÷ 3456

bumpstart
Posts: 133
Joined: Wed Jan 20, 2010 9:09 pm

Re: turbo propane set up

Post by bumpstart »

my thoughts are the 225 is inherently designed to take boost and will flow more than enough for the v6
( it is also common as mud to have the 225 setup on the end of the TB hoses for the GM 3.8 v6 in oz .. not too many 425 setups though )
you just sit it upstream of the stock TB ( i have this on mine in front of the complicated 2 stage mazda throttle body )
and you take a vac /boost line from the mixer hat and run it to the balance port on the model E// that is it
factory timing and knock control should suffice at low boost though the engine will prefer more timing down low and about the same timing up top as the petrol version
typically you can pull 0.8 to 1 degree timing for every psi into boost
( in case you have programmable ignition control )

PS
if you look above in the readers rides threads you will see gerald has a similar setup on his 13b drag bike .
though he has used the impco 200 for its compact right angle inlet on top of the 2 barrel holley throttle plate

they just work out of the box without a lot of fiddling , feedback system and not ..
if you are anticipating mixture control issues then it is clever to set it up with an external idle air bypass
by closing off the idle air bypass on the mixer and add your own auxillery unit around the TB on a hose
( EG . via a needle valve for fine control of the bypass idle air )

though i dont expect this is necessary for a GM v6 setup provided you have selected the feedback diaphragm for a feedback system, and a non FB diaphragm in a non FB system
the feedback system used in the day on the oz versions was typically the CDP-02 controller
which used a deliberately rich jetting combined with a lambda control unit that increased pulsewith to a fast acting control solenoid
that would in effect feed a higher engine vacuum source ( as distinct from the mixer hat source ) to the convertor top
this would lean down the fuel mixture by subtle altering of the delivery pressure

it isnt entirely necessary //mostly of those that have emission laws.. but it does work reasonably well and increases economy .. though its inclusion often demands you also setup a impco VPV or equivelent to act for throttle movement enrichment
when the going is hard, don't retard, remember your lubrication

bumpstart
Posts: 133
Joined: Wed Jan 20, 2010 9:09 pm

Re: turbo propane set up

Post by bumpstart »

PS

in lieu of a VPV..( vacuum power valve ) . i needed something i would trust into boost
( VPV not rated for boost though it may survive for a time or may/ may not work with an NRV installed in the hose )
i instead use a HP lockoff solenoid . mounted off the LP side of the convertor .. through a pill in the hose ( a mig jet drilled to 2.5 mm ) that feeds into the side of the mixer ( actually just behind it, but meh )
and i switch it from my ecu ( haltech programmable )

though in your instance . an adjustable hobbs pressure switch would do the same . as would the level switch from any washing machine

this works great both as a cold start assist valve and as my "throttle pump" and i can adjust the setpoint where it turns on
( on an ECU you can also include flags for rpm etc ) and i can adjust the volume through the pill ( with a drill bit )
when the going is hard, don't retard, remember your lubrication

gearhead
Posts: 28
Joined: Wed Dec 16, 2015 1:58 am

Re: turbo propane set up

Post by gearhead »

apparently you guys know what your talking about! I'm gonna get lost here with all the info.
Ok, so the engine I've chosen is a 3.8 v6 from a 1999 mustang. 190 hp stock. Gonna run a manual mazda built transmission.
Gonna build the engine with low comp pistons, rv cam, mild port job on heads and intake, boost rated head gaskets and turn the boost up till I achieve my goal(within reason, 12-15 psi)
Not sure how to post pics here yet, type that car in google and have a look. the engines also come in ford tarus, windstar van and thunderbird.
So what your saying is an impco 225 E mixer is enough (when boosted) to flow 360(as per ur drivetrain calculation loss) hp at the crank and make 300 whp? And it can handle 15 psi with modifications?

So there is a few names for different parts floating around, so can someone set me straight.
the propane flows from the tanks into a vacuum fuel lock/filter mounted under the car, then goes to the Converter (two-stage
regulator and vaporizer) and then finally to the mixer(or propane carb). Do I have things right?

So I need a impco 225 mixer, that's the model, no other variations?
and the model e is the converter? That's what I order? Reading an impco catalog says the model PE is made for positive pressure, i'm assuming boost?

Explain to me the vpv again and what it does?

In BC Canada there are currently no "air care" emissions testing. So most efficient way of doing things is ok, don't have to pass a test. Plus, instead of doing a Volvo, I got my hands on a 1964 Plymouth Valiant, so even if emissions came back, i'd only have to make it as good emissions wise as the car was factory.

lol, sorry for all the questions! thanks again guys, Dug through many forums for my projects over the years, you guys are by far the most knowledgeable!

C3H8
Posts: 1129
Joined: Fri Sep 09, 2005 11:23 pm
Location: Winnipeg, Canada

Re: turbo propane set up

Post by C3H8 »

Glad to see you found the forum after we talked. Thanks for the plug storm, however as I pointed out to gearhead I felt he could get some good advice by joining the forum. My "hands on" experience with turbo's is limited to large industrial engines. You and many of the others on the forum have a lot of hands on experience which I know gearhead can benefit from.

To the questions in the last post. There are several versions of 200 mixers. The 200 is the same as a 225 with the difference being the 200 has various size openings to accommodate a remote air cleaner. The 200 and 225 use the same internal parts. The 200 opening is sized to match the outlet of common air cleaners and is casted with a 90 degree opening. Check the IMPCO catalog in the 200 mixer section to see the difference in design. The 225 is made basically for mounting on a throttle body and receives its air vertically. For attaching to a turbo with blow through I would suggest the 200's. It eliminates the weak point of a 225 that would require an add on hose adaptor which requires a gasket between the mixer body and adaptor. I don't think that gasket would hold up to high boost pressures very well.

You are correct about the set up. Tank/lockoff filter/regulator (vapourizer)/mixer (carb).

I would suggest an electric lock off over a vacuum lock off on a turbo unless you go with the draw through. A vacuum lockoff has to be carefully balanced to ensure it stays open with boost pressure on a push through. An electric does not care about boost. It only requires a module to power the lockoff with key on. The module meets the safety requirement to shut off the lockoff if the engine is not started or stalls.

The VPV is a Vacuum Power Valve. It is a normally open valve screwed into the secondary chamber on the side of the model E. The valve is closed at any engine vacuum above 3". When you crank the engine it provides an automatic prime. As soon as the engine starts the valve closes. It will open again at WOT as soon as vacuum drops below 3" mercury to richen WOT mixtures. There is an adjuster to change the vacuum it opens at The use of a VPV would be restricted to a draw through application since it requires vacuum to operate correctly.

As you stated "Aircare" should not be a problem on an older vehicle and it only carries out testing in the lower mainland as far as I am aware. A propane vehicle will not have any issue meeting the standards anyways on older vehicles.

storm
Posts: 796
Joined: Wed Jan 10, 2007 10:10 pm
Location: NSW, Australia

Re: turbo propane set up

Post by storm »

gearhead wrote:apparently you guys know what your talking about! I'm gonna get lost here with all the info.
None of us know everything so we generally post what we know and others fill in what we don't know. Franz (who hasn't been around for a while) and C3H8 are brilliant technical minds and both have contacts within the North American industry. Bumpstart knows turbos, I work on n/a (or supercharged) street style engines, and Steptoe knows alot about old engines. We all have our preferences.
gearhead wrote:Ok, so the engine I've chosen is a 3.8 v6 from a 1999 mustang. 190 hp stock. Gonna run a manual mazda built transmission.
Gonna build the engine with low comp pistons, rv cam, mild port job on heads and intake, boost rated head gaskets and turn the boost up till I achieve my goal(within reason, 12-15 psi)
Ok is that the British Essex engine that Ford Europe used to run in cars like the Capri?
gearhead wrote:Not sure how to post pics here yet, type that car in google and have a look. the engines also come in ford tarus, windstar van and thunderbird.
Underneath the text area where you type up your post is another section with 2 tabs 1 being options the other being attachments. Click on attachments, click on add files, find the file you want to add and then click ok or whatever is showing.
Fuel flow requirements calculations
Engine air flow requirement calculation: CFM = Cubic Inches x RPM x Volumetric Efficiency (VE) ÷ 3456

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