Propane 3.8 Draw Thru

[Freddie's Buick]

Yo Freddie. Propane Gas is what is used most with these type conversions. I see many people term "LPG" in their posts, but when you read through...turns out it's regular propane. I'm still not %100 on what LPG is or means.

LPG is a generic term and covers all liqufiable petroleum gases. Low grade propane, (BBQ), may not be as as pure as the auto standard HD-5.

Any Details on the system you narrowed too? looks like twin Impco 425 mixers & twin regulators is required from my research. Either a custom Side mount mixer to turbo compressor manifold, or a hole in the hood.

The simple reply is that it's all bolted on. All that is needed is one CT425 mixer, (in place of the carb), with an adapter bolted onto a Q-jet throttle plate. The other necessities are a lock-off, a vaporizer and a converter. All easily fit in the engine bay. I haven't measured it's total height yet but if it's too tall I may have to make the bulged hood functional. The project is temporally on hold, (still searching for a tank).

 

[dr_frankenstein]

wow....... seen some big names in here...... supprised that we get that much reading here in B4B .....

Propane works great, but in my experiance (deep well pump engines) I have found that propane is too dry for alot of boost. it eats up the top end, particularly the valves and seats. need a bit of marvel to keep the top end wet. but i was working on industrial motors holding 25lbs of boost for like 48hrs nonstop.

 

[Ashley]

Charlie, I've been looking at aftermarket distributors and MSD box, seems like the easiest and most cost effective way to go. Briefly looked into Coil on plug conversions, but even if I had found a solution for our engines...comparables are spendy as hell, and toe-to-toe with an aftermarket HEI distributors and a MSD box...six in one half a dozen in the other. 750CFM looks to be more than most of us will ever ring out of the Q-Jet. The carb should be good for whatever we can throw at it...no? Still have to do some forum Searching on the turbo side, I read through the 301 hybrid and saw how involved it was...not to mention the last 301 turbo I saw on E-bay (a couple months back) was starting bid of $900.00 or so :/ Need to find the thread on the Grand national hybrid turbo. Would deffinately consider the 301 hybrid if the price was right for the turbo, but I'd like to see how it stacks up against the GN Hybrid first.

Freddie, from all I've read, even to rev within the stock powerband, one CT425 mixer isn't gonna cut it. It maxes at 460 CFM of Airflow. Two CT425's are needed. One CT225 mixer maxes at 329 CFM. Two CT425 @ 920 max CFM Vs. Two CT225 @ 658 max CFM. I'd rather go over than under personally. To keep from chopping the hood up, you would have to mount them both sideways (a fringe benefit of gas) via a custom sidedraft Mixer-to-turbo manifold.

Frank(enstein), are you just refering to the exhaust side? If so, In addition to hardened seats, would brass valve guides and a ceramic type coating help on the exhaust side? Your referring to Marvel Mystery Oil...right? what is the interval?

I fully plan on building the 81 Monte Carlo around Gasoline first. Cars been sitting for 20 years, so it's gonna need some work. Engine is gonna get some attention, so hardened valve seats will be installed when it's rebuilt to make way fr Propane if I decide to go their once it's done. For me, this is a lifetime car, and one I plan to enact, finally, all the knowledge I've learned about cars on paper....so I'm going at it methodically. Converting to propane before it's fully dialed in, and reliable on gas, is asking for a pile of headaches.

 

[charlief1]

A Q-jet can flow as much as 1100 CFM by doing new throttle plates and some cleaning up of the barrels. I've actually have 1 of the stock 800 CFM units here that I need to clean up some. With just cleaning up the barrels I can get about 860 CFM out of it. With the new turbo it's about the same CFM but the newest version will need more than a stock carb.

 

[Freddie's Buick]

...Freddie, from all I've read, even to rev within the stock powerband, one CT425 mixer isn't gonna cut it. It maxes at 460 CFM of Airflow. Two CT425's are needed. One CT225 mixer maxes at 329 CFM. Two CT425 @ 920 max CFM Vs. Two CT225 @ 658 max CFM. I'd rather go over than under personally. To keep from chopping the hood up, you would have to mount them both sideways (a fringe benefit of gas) via a custom sidedraft Mixer-to-turbo manifold....

Ashley, I'm not sure were your headed with that info. But keep this in mind: The stock air flow, ("powerband"), on the .231 engine at best, even with an OEM high performance well tuned engine is somewhere in the neighborhood of 370 CFM@5500 RPM, (WOT). And that is with 100% volumetric efficiency, (turbo). Stock carburetor CFM ranges are from 227 CFM, (the Duel-Jet which was the most common carburetor used on the .231), to 750 CFM, (the Quadra-jet used on the turbos and .252 engines).

It is virtually impossible for the OEM V6 to pump any more air than 370 CFM maximum without modifying it well beyond the scope of what it was designed for, (which is a given here at this website). Those modifications in general are racing goals which are not my objective.

With that in mind, you can safely say that one CT425 which is rated at 460 CFM should easily handle .231 turbo and .252 engines.

 

[Freddie's Buick]

..Propane works great, but in my experiance (deep well pump engines) I have found that propane is too dry for alot of boost. it eats up the top end, particularly the valves and seats. need a bit of marvel to keep the top end wet .but i was working on industrial motors holding 25lbs of boost for like 48hrs nonstop....

LOL...wow Doc! That is a bit extreme. But good to know. I think that that is why LPG is rated at different grades, (similar to gasoline. For example Chevron has Techron which does keep the top end very clean). But yer right....there's nothing better than M.M. oil for that.

 

[Ashley]

It is virtually impossible for the OEM V6 to pump any more air than 370 CFM maximum without modifying it well beyond the scope of what it was designed for, (which is a given here at this website). Those modifications in general are racing goals which are not my objective.

Awesome Freddie, that's the info I needed. I was going off an assumption based on the Q-Jet rating, which is my bad to begin with. Makes packaging the system a stock affair.

Judging by other posts, fuel deatomising & puddling at the turbo neck is a big restriction with this design (Rich/lean carb tuning). With the propane being gaseous, that problem is solved. how far do you think this set-up can be safely taken compared to Gasoline?

 

[Freddie's Buick]

I've been researching for several years now and I've studied some of the the engineering criteria as well. I've concluded that it is a 100% safe alternative fuel and regulated by ASME standards. The Canadian standards are far more regulated and I strive to achieve their safety standards which exceed USA's. This car, (Turbo Buick), in particular as it is designed is a perfect candidate and to my knowledge no one has done it yet. But As I noted before there are issues of availability and insurance in a lot of states.

Our govt is idiotic and still has not seen the light of a future without foreign oil dependence. T. Boone Pickens has been battling our govt but to no avail. They're hell bent on electric which is too far into the future. This technology is here, readily available and with an American infrastructure. And just about any experienced DIY'er can handle it. Plenty of third world countries in Latin America already use this technology as their main fuel source, (taxi's and tractor trailers) and they are OPEC producers! LPG being a by-product of gasoline makes it cheaper and more abundant than gasoline so they sell their gasoline to us and we are still using it as our main source of fuel. Go figure...our govt is severely stupid.

 

[mikemcvaney]

Getting away from propane for a moment and back on over to petrol, though still relevant in context. The thing that captivates me about this engine is it's static nature. Your stuck with the intake manifold it came with, pretty much stuck with the turbo (besides 301 hybrid), stuck with the Quadrajet, mostly stuck with the ignition system, and have very few cam choices. The great equalizer on this engine?...The Turbo. The Turbo is the bottleneck, and it's operating parameters are basically set in stone. The improvements have to be made around it and mostly with existing systems (I'm not talking add on injected liquids or full Drag set-ups here). A perfect test bed to implement a couple different "why bother, just turn up the boost" efficiency modifications at once, and to see the improvements based solely off better design at equal or lower boost. Below are the ancillary modifications that add to efficiency:


Modifying/porting the Quadrajet

Porting: Heads (aftermarket or stock), Turbo housing, Intake manifold, Gasket matching, Port matching,

Turbo exhaust Theory based upon pulse/back pressure/scavenging: Equal length manifolds and their optimal diameter, straight conical diffuser of 7-12° included angle downpipe (at least a mandrel bent pipe in the factory design), Divided wastegate downpipe either vented to atmosphere (screamer pipe) or spliced back in 12"-18" later downstream, and exhaust design with minimal sharp bends.

A modern cold air intake to enclosed filter.

Coatings: Thermal Barrier, Heat shedding, liquid shedding, and low friction.



Read these three many times over:

http://www.tercelreference.com/tercel_info/turbo_exhaust_theory/turbo_exhaust_theory.html

http://www.myturbodiesel.com/1000q/turbocharging.htm

http://www.myturbodiesel.com/1000q/turbochargingpage2.htm

Disagree with you r statemant my car has an upgraded turbo thats not a 301 set up and it is running a holley 3310 _780cfm squrebore you are only stuck with stock stuff if you let it happen. Think outside the box Mike

 

[COOPER12]

Has anyone tried Hydrogen? I have seen a few kits floating around. claiming better fuel economy and longer engine life.
My father in law is claiming about 10 miles per gallon better on a v8 buick newer model.
Not real sure about it all. sorry to chime in on the propane post but figured we are talking alternative fuel