I have stumbled upon a CAT 3408 that is set up to run on natural gas. I know it would be very expensive to convert to a diesel. But what I'm wondering is, could it be configured to burn gasoline? It's in a compressor that I have come across. I have to scrap the whole unit, but am thinking of grabbing the engine. Don't know what I can do with it but I can't bring myself to scrap it. Any ideas?
unless that eng has gaping holes in it don`t scrap it, if it runs on nat.gas it will run on propane as well. have never heard of one converted to gas
Generator engines that burn propane usually run on the same settings for gasoline. But natural usually has timing advanced and compression ratio higher in non-boosted engines. I am sure it could be made to work. But what do you want to do with it?
I don't have a need for it at all. I just can't get used to the idea of scrapping it. Maybe I'll make a log splitter out of it.
I"m betting that compressor was a gas line booster and ran off the line fuel. Build a propane rat rod.
Correct. Do you know about them?
Not the 3408, but I seem to recall the compression ratio in an NG engine would be high enough to possibly self destruct in gasoline. So how did they run the 3408 on NG? spark plugs and distributor? Magneto? Sounds pretty interesting.
Post up the engine Serial Number and let's have a look how it's specced..........
Years ago worked at a place that built gas compressors and other gas and oil equipment. They made a few units with 3412 natural gas engines but what surprised me was seeing spark plugs in an engine that big. HP ratings were lower too, I'm guessing for longer life.
When I worked offshore, we had some Cat engines converted to natural gas, a 3412 and a 3306 both on gas compressors. Long time ago but as I recall the block and heads were the same as diesel, they had adaptors that fit the spark plugs to the injector hole and thick plates between the block and head to reduce the compression. Natural gas and propane are both very slow burning fuels and they offset that by advancing the timing to around 35 BTDC. These engines last a long time on natural gas. I heard of some 3400 series cats running 100 K hours on natural gas before any work was done on the bottom end, so you might have a very good block there for someone who's 3408 diesel is worn out. I wouldn't think of converting it to gasoline. Maybe you can find a worn out scrap diesel 3408. Horsepower ratings are way less than diesel, many gas compressors run 24 hours a day, 365 days a year for decades. Also they are usually set up for 900 to 1200 RPM. They had magnetos. Mostly we had Waukesha engines and many went 60K hours on the bottom end, valve jobs only 15000 hours.
Garbage trucks running diesels converted to CNG for many years now! Frito Lay, UPS and others doing now too!
Well I check on a site that has a formula for determining the size of carb(s) needed for a gasoline engine and running the numbers looks like a 3408 would need just two 750 Holleys if run naturally aspirated at a max of 5,500 rpm. Not sure if a 3408 will take running up to 5,500 rpm.
Two for each cylinder?
Not sure how accurate the formula is cause it did sound a little low for an engine of over 1,098 Cubic Inches! But then I did check out a couple sites about what carb would be good for a 472 c.i. Cadillac engine and a guy said he had contacted Edelbrock and they said a 750 carb. So two 750's might not be too far off for a 1,098 c.i. engine.
Six different Serial Number prefixes for a G3408. Need to know which one it is. First option I looked at only had options of either 9.5 or 9.7:1 compression ratio ........
We have dairies in this area with manure to gas generators running huge engines making electricity. I got a tour of one place up by Lynden, WA that had converted MTU diesels running 24/7. The only hold back for them was the amount of exhaust from the cows sometimes couldn't keep up with the engines. The other issue is that type of gas is extremely corrosive and can cause problems in the engines if not processes correctly. Land fill co-generation plants might be a market for your extra engine.
Check out this link describing use of small reciprocating engines to supplement power for wind and solar applications. https://insights.globalspec.com/art...3894&et_mid=83831207&frmtrk=newsletter&cid=nl
Tough to read but I got this off of it. Tell you anything? 6NB02258
How's this for a start?
Does this engine have value, is the question.
Well I guess it all depends on if you need one! I also guess one could start looking at what parts of it might be the same as used in say a diesel engine in a 988B or a 769C or one of many other diesel applications for a 3408.
Does it have value as a diesel engine? I would say no. Does it have value as an engine that runs on some kind of vapor gas? I would say yes. If nothing else it is likely a core. Call a Cat dealer and ask about a replacement cost and then ask for the core charge. That should give you an idea of what it might be worth.
I'm going to put it on CL or Ebay. Would be hard for me to lose. Thanks for your input.
Iam thinking that would make a cool engine for a rat rod I have not built one in 10 years but the crank and block has value they run them in a D8 L also in diesel yhat is. Back when I used to build them for the gold mine cranks were hard to come by
Well you could pass that file of the "AS Built" information to anyone interested! But that means I get a commission on the selling price, right?
Ebay https://www.ebay.com/sch/i.html?_fr...leDesc=0&_osacat=0&_odkw=cat+3408+block+crank
That gas engine “as is” ought to be worth at least $40k of anybody’s money.... IMHO
Is it a gas compressor package? It might be worth more than the engine to oil field folks. $$$ https://fuelled.com/cat/compressor-packacges
I would be interested in hearing about it when you sell it. Keep us informed.
Here's what might swing the calculation a bit. The crank from that engine is a 1W-5009. It is used in no less than 269 different models of 3408 engine, even up to 3408HEUI which was the last iteration of the 3400 engine before the C-Seires took over. The block with liners is a 1W-5081, used in 175 different 3408 engines. Now replaced by 122-2245. New crank - $10,000 New block - $18,200 Cylinder heads, camshafts, & pistons are specific to the gas engine. The rods will fit anything 3408. As many other posters have pointed out if you could get someone in the LNG industry interested the complete engine might be worth more than the sum of its parts.
What percentage of new would you use for an asking price on the uses engine? What percentage of new would you figure is the bottom dollar you would take for it? How much is the crank worth in the block? How much money would it take to rebuild the engine to current state? Hypothetically, how much money money would you offer for this engine of unknown history and condition? Is the engine worth $5,000, $15,000, $25,000 or more?
It might be a case of individual parts being more saleable than the complete engine in its current arrangement. However IMO both options (sell complete unit vs sell certain parts piecemeal) should be looked at.