Blow through turbo Snowmobile

Propane, Butane, LPG, GPL, C3H8, C4H10
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Kealo
Posts: 7
Joined: Sat Jan 09, 2016 7:29 pm

Blow through turbo Snowmobile

Post by Kealo »

Hey Guys,

I have been working on this project for a year now. I just stumbled across this site and had a great read through Gerald's Dragon's Breath Drag bike. I am basically complete and the sled is running but after reading through here i think i may need a few additions or adjustments.. Let me know what you think of my set up and if there are any flaws or thing i should change. Being a snowmobile the challenges i have are dealing with cold weather below 0c for the most part.

Here is the set up

Engine is a Yamaha carbed 1000cc 4cyl out of an RX1 snowmobile (basically same eng R1 street bike)

Modified Ski doo chassis

The Turbo is a GT2560

AFR AEM

propane main parts IMPCO
200m-1-2 mixer
H420 regulator/vaporizer

Questions i have are
Spark plugs? do i need to run different plugs than with normal operation?
engine Temp. stat runs around 160f. should this be higher?
intercooler. do i need this?
cold start solenoid.. or SV. I just read about this.. i think i need but don't totally understand how it works.

this is AFR i was told to run the at with gas. a little on the rich side as i don't have timing control. from what i have read here i can prob go leaner
Idle 12.5-14.5afr, wherever it seems to idle best
Cruising not in boost 13-14 afr
Part throttle boost 12-12.3
Mid throttle boost 11.5-12
Full throttle boost 11.3-11.7

Kealo
Posts: 7
Joined: Sat Jan 09, 2016 7:29 pm

Re: Blow through turbo Snowmobile

Post by Kealo »

Here is some pics
Attachments
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Kealo
Posts: 7
Joined: Sat Jan 09, 2016 7:29 pm

Re: Blow through turbo Snowmobile

Post by Kealo »

more pics
Attachments
IMG_5162.jpg
IMG_5155.JPG
IMG_5114.jpg
IMG_5126.jpg

Kealo
Posts: 7
Joined: Sat Jan 09, 2016 7:29 pm

Re: Blow through turbo Snowmobile

Post by Kealo »

more pics
Attachments
IMG_5155.JPG
post-46307-0-64703500-1448585861.jpeg

Kealo
Posts: 7
Joined: Sat Jan 09, 2016 7:29 pm

Re: Blow through turbo Snowmobile

Post by Kealo »


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

Re: Blow through turbo Snowmobile

Post by C3H8 »

Welcome to the site. Dating myself but "Cool" machine. I am sure you will get a lot of good advice from the turbo enthusiasts on the site. I have a few observations and comments however there are many on this site with more experience the I on small engine turbo applications.

The orientation of your cylinder is not good for this type of use. 33LB forklift cylinders come in two types. One for vertical use only and one for vertical or horizontal use. The goal for your application is obviously horizontal so make sure it is for that application and make sure the cylinder is mounted with the correct orientation as there is a proper top position. The main issue with your mounting is the pick up tube is pointed to the front of the machine. Once your fuel level drops (to about 1/2 a tank) every time you accelerate or climb a hill the fuel will run to the rear and expose the pick up tube to vapour only. Accelerate long enough or climb a long enough grade and you will use up the vapour and result in a lean condition or even powering out. If possible you should turn the tank around so the bottom is at the rear of the machine. You should also install a fitting and hose on the relief valve so it vents behind the machine and does not result in any vapours getting into the engine compartment in the event it ever relieves itself.

The intercooler gives the same advantage on LPG as gasoline. The disadvantage is the added fuel that exists if an intake backfire occurs. Volume is increases with the intercooler and therefor any intake backfire will be more violent causing more damage. Maintaining and using high quality ignition components is paramount. The only other consideration is how cold is too cold. Snow mobiles typically operate at very cold temps. -25 to -30 through an intercooler might be too cold.

Depending on the scale you are reading those AFR from they might be OK. I see you have an OHG or Woodward reg. If it has the Orange spring under the secondary diaphragm it will flow fuel at -5" WC. This would result in slightly richer mixtures with the 200 mixer. Normally a 200 mixer is used at -1.5" WC which requires a blue spring under the secondary. The lighter spring may work well on a turbo application. As mentioned if your numbers are on a gasoline scale they would be OK. 15.5:1 is stoichiometric on propane. higher is leaner and lower richer. No boost and light load I would expect to see 15 to 16. If it the gasoline scale 14 to 15. You mid range load with boost is a little rich. Normally a mixer only richens beyond 80% throttle and load. Typical mixture range around
Propane scale non turbo
idle 14.5:1
Idle to 75% throttle 15.5:1 (unboosted)
WOT 13 to 14 (unboosted)

I would expect boost to change the numbers above idle approximately .5 to 1 point richer. Some of the experienced turbo guys using AFR ratio meters can probably provide more detailed numbers.

160 degree thermostat is fine depending on the capability of the engine to reach that temperature in sub zero temps. At this temp you might be best without an intercooler.

Since this is obviously not a factory engine, I would suggest you drop two ranges cooler on the plugs and adjust from there after reading them.

SV stands for start assist valve. It communicates with the secondary chamber on the regulator and sends fuel into the mixer below the gas valve. It is operated with a momentary switch or wired to the starter solenoid wire for power at crank only. In the video you start the engine and it starts very quickly. If that was a cold start you don't need an SV.

Kealo
Posts: 7
Joined: Sat Jan 09, 2016 7:29 pm

Re: Blow through turbo Snowmobile

Post by Kealo »

Thx for the reply C3H8

I have also read that the SV will provide extra fuel at WOT.. It doesn't start that quick when cold.. i have not tried starting in below 0c yet.. i did install a plug in coolant heater just in case. So basically the SV connects to the bottom part of the vaporizer with a solenoid and then to a port on the mixer.. I think i will defiantly need this. I will see if i can find the controller module. Basically a primer..

good thoughts on the tank.. this tank can be vertical or horizontal.. i just positioned it so i can read the gauge for that position. Talking about cylinders what is the rule of thumb on this? what type of cyl can i use? can i use any cyl and install the liquid pick up?.. I am using this as i can have several and they are readily available. The problem is it is too tall. i would rather have two longer smaller ones.

Kealo
Posts: 7
Joined: Sat Jan 09, 2016 7:29 pm

Re: Blow through turbo Snowmobile

Post by Kealo »

what about some kind of water injection like this?

http://www.flashlube.com/en/products/va ... r-kit.html

geraldm
Posts: 94
Joined: Sat Nov 09, 2013 4:53 pm
Location: Pump handle Saskatchewan

Re: Blow through turbo Snowmobile

Post by geraldm »

Yea I run the dragon with an ADJUSTABLE switch on the throttle at the mixer to give him a little extra at close to wot . It actually works as a cold start also all I do is turn ignition on and open throttle full for a couple of seconds that will prime you up , let it sit with the throttle open for 3or 4 seconds close the throttle hit the starter and and that should do it , you can also just use a push button switch on the left handle bar and give it a shot when ever the need . Keep in mind that propane is opposite to gasoline for rich and lean ,, on gas if you lean out the temperatures in exhaust rises , on propane if you lean out the opposite happens and you will run cooler , if you run to rich on the propane it will make it run hotter . One thing at a time , water injection seems to help me out but that was the last thing I done . I dont see why you would need a inner cooler on a sno-mo . .. Your in good hands here these members are very well informed and have helped me a ton .. geraldm.
Now how the hell did that happen ?

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

Re: Blow through turbo Snowmobile

Post by bumpstart »

nice rig. surprised at that fire up when cold. would have thought you would need a squirt of ether or a bag warmer for the bottle to help the cold start

think also that you have been given a petrol AFR scale
( ie. running LPG but reading it on a wideband that is scaled to petrol AFR )

if you convert them all to lambda ( divide by 14.7 ) and then multiply them with the LPG AFR ( 15.5 )
.. see what you get ( as read on a wideband calibrated to LPG AFR )

sometimes i guess it is better to keep things all in lambda
but AFR. like inHg and PSI is what most of us grew up with , even in the metric countries
unfortunately not all gauges will have a calibration selection for fuels other than petrol
myself use the PLX stuff as it is one of the few that do. and gives you an onscreen trend
when the going is hard, don't retard, remember your lubrication

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

Re: Blow through turbo Snowmobile

Post by bumpstart »

my thought on the SV. .. or VPV
a VPV or similar , as pointed out by gerald can operate also as an SV
.. the VPV from impco is not boost rated .. your parts will be cold and more brittle and i wouldn't like to trust one under boost

as for myself i use a HP shut off solenoid and a relay / mounted onto the vapour deck of the convertor and routed by hose to the mixer above the throttle body as a "PV" ( power valve )

unlike gerald
( who because of the entirely analog nature of his setup.. is instead running a switch near WOT on the throttle )
i use my programmable ecu to sense load or boost and open the PV solenoid, and i have an over-ride switch to make it a cold start SV
( haltech e8. also running the safety time out .. the boost control , logging , and the ignition timing )

you could do similar "load switching " instead with a hobbs pressure switch used to switch the earth side of a relay which drives the new PV solenoid
( power up the relay from the existing shutoff solenoid circuit and it will have redundancy for when safety time out shut off )

using a PV this way allows you a "three" setting for the mixer .. you have idle mixture control with the air bypass screw
you have mid range / part throttle mixture control on the main mixture screw
and you have a WOT mixture control by adjusting the size of the mig jet hole that you are using as a "pill" in the PV hose line
and the setting on the hobbs/ throttle position switch/ ecu aux flags is for when you want it to cut in and boost those mid range fuel mixes

im using around -5 inHg and 2000 rpm as my flag
( the rpm flag so it doesnt act as SV unless i earth the relay with my over-ride switch )
and i use about 6 mm hose and a mig jet stuffed in it drilled about 2.5mm ( for a 300 rwhp 13bt )
when the going is hard, don't retard, remember your lubrication

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

Re: Blow through turbo Snowmobile

Post by C3H8 »

:oops: Oops. I confess my thinking was muddled in my initial reply. For some reason my brain got stuck and read blow through as draw through. I'm with bumpstart. An SV or VPV are poor choices for blow through since they are made of plastic.

As for the cylinders. The 33 LB cylinders are pretty well the smallest diameter. The dip tubes are welded in so you just have to make sure they are suitable for horizontal use and orientate the tank correctly. I'm not aware of any smaller diameters or lengths then the 33 IL forklift tank.

Lastly the secondary chamber is the upper half of the regulator. Other then priming it is not the best practice to use the primary pressure port for fuel delivery. Primary pressure will always be 1 to 3 PSI over boost so controlling fuel out of this port could be very difficult.

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

Re: Blow through turbo Snowmobile

Post by bumpstart »

the impco VPV also uses the same secondary chamber and pill method for controlling the fuel.
it works just fine and it will err to be slightly richer as boost gets higher
because the differential between the delivery pressure and that post mixer rises with increasing boost
when the going is hard, don't retard, remember your lubrication

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