| Author |
Message |
    
johnny
New member
Username: johnny
Post Number: 2
Registered: 03-2006
| | Posted on Monday, March 06, 2006 - 09:10 am: | 
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Hello everyone,
I have a question for who ever is knowledgeable on Detroit Marine Engines. First I would like to say that I have been collecting and restoring antique stationary engines sense about 1980 and worked on engines sense I was a teenager. So I didn't just fall off the turnup truck yesterday. To my knowledge the Detroit marine engines used low pressure fuel injection system with a valve contolling the air intake and fuel pressure OR a few different types of carburetors. The fuel injection system injected fuel directly into the cylinder. My question is on the marine carburetor type engines was the fuel sucked up from the carburetor in the intake port into the cylinder? or sucked up from the carburetor into the crank case up the intake port then into the cylinder?
Thank you..
John
P.S...Check out my website for literature,photo's and info on Detroit Engine Works and related engines.
http://www.antiquengines.com |
johnny
Member
Username: johnny
Post Number: 5
Registered: 03-2006
| | Posted on Monday, March 20, 2006 - 09:26 am: |
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Wow! No one knows if the fuel is going into the crank case? or is it going into the cylinder? I do not own a marine engine so I don't know this answer. I would guess the fuel is going into the cylinder and not in the crank case but I'm not sure. I'm trying to put together some information on my website to help fellow collectors and restores. I know how the Stationary Detroits work but I have never worked on the marine engines that use carburetors. Help! |
richarddurgee
Senior Member
Username: richarddurgee
Post Number: 1048
Registered: 11-2001
| | Posted on Monday, March 20, 2006 - 10:15 am: |
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Go to Search above type in word "Detroit"
First one should be Titled One and Two Cylinder gas inboards- Sandow by Detroit.
scroll down illustration and explanation there ! |
johnny
Member
Username: johnny
Post Number: 6
Registered: 03-2006
| | Posted on Monday, March 20, 2006 - 07:51 pm: |
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Richard,
Thanks for the reply, I have the cross view diagram of the engine explaining how the low pressure fuel injection works. I understand it completly.
All I wanted to know was if the Detroit marine engines using carburetors sucked the fuel into the crank case or was it sucked directly into the cylinder passage? Some of the literature I have shows the carburetor mounted down low. Also what type of reed or valve did they use in front of the carb to keep crank case pressure from escaping out through the carb? |
jb_castagnos
Senior Member
Username: jb_castagnos
Post Number: 103
Registered: 07-2002
| | Posted on Monday, March 20, 2006 - 09:06 pm: |
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Johnny, a two cycle pulls air into the crankcase as the piston moves up. If it's a carburetted engine the fuel is going to go with the air, no matter where the carb is mounted. Mounting the carb high on the cylinder was popular to gain cylinder heat and help vaporize the fuel. On the down stroke the air fuel charge is compressed and enters the cylinder when the ports open. Early engines with a Lunkenheimer mixer didn't need a seperate check valve. Later engines had a valve cage with a four bolt square mounting pattern, the automotive type valve faced straight in towards the engine, a light spring on the outside to pull it closed. Below the valve was a cast in elbow, internal threads that the carb screwed into. |
johnny
Member
Username: johnny
Post Number: 7
Registered: 03-2006
| | Posted on Tuesday, March 21, 2006 - 02:29 pm: |
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Ok let me try this one more time.
Jb, I understand the basics of how a 2 cycle engine works. The question I ask is:
Do the Detroit marine engines using carburetors suck the fuel into the crank case or was it sucked directly into the port or cylinder passage? The literature I have on Detroit carb engines does not show clearly where the carb is mounted. The Krice carb, Schebler carb,etc.. These carbs didn't use any kind of check valve or reed valve? What keeped the crank case pressure from escaping? |
jb_castagnos
Senior Member
Username: jb_castagnos
Post Number: 104
Registered: 07-2002
| | Posted on Tuesday, March 21, 2006 - 08:30 pm: |
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It doesn't matter where the carb is mounted, the fuel is going with the air into the crankcase and then into the transfer port to the cylinder. With the fuel injector the air only was drawn into the crankcase through the air valve, fuel was injected into the cylinder when the pressure dropped. A two port motor needs a check valve, a three port uses the piston as a valve. I think the Detroits were all two port, but maybe someone else knows for sure. |
johnny
Member
Username: johnny
Post Number: 8
Registered: 03-2006
| | Posted on Wednesday, March 22, 2006 - 08:30 am: |
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Jb,
I'm not trying to be rude but it does matter to me where the carb is mounted because thats what I'm trying to find out. Where does the fuel enter into the engine? through the crank case or through the transfer port? I'm assumming there is a threaded hole or something where the carb mounts on to the engine. Does the carb mount on the crank case or on the outside wall of the transfer port. I'm talking about the carburetor engines only.
You said you thought Detroits were 2 port engines and they would need a check valve. I believe this is correct. Then do the carburetors have check valves built into them or is the check valve some how built into the area where the carb mounts to the engine? |
jb_castagnos
Senior Member
Username: jb_castagnos
Post Number: 107
Registered: 07-2002
| | Posted on Friday, March 24, 2006 - 08:33 am: |
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Johnny, there was a misunderstanding, you asked where the fuel was sucked in, I think you wanted to know the carburetor location. I have an ad for Detroit marine engines showing a Lunkenheimer mixer mounted on the tranfer port. I tried to post it but don't know how to reduce it, I emailed it to Richard, if he recieves it maybe he can post it. |
richarddurgee
Senior Member
Username: richarddurgee
Post Number: 1060
Registered: 11-2001
| | Posted on Friday, March 24, 2006 - 07:29 pm: |
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JB
I'll be back home on Monday, will post Detroit
ad then ! |
ernie
Senior Member
Username: ernie
Post Number: 376
Registered: 01-2002
| | Posted on Friday, March 24, 2006 - 07:46 pm: |
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JB If you want send it up here and I will post it for you. |
johnny
Member
Username: johnny
Post Number: 9
Registered: 03-2006
| | Posted on Friday, March 24, 2006 - 09:24 pm: |
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JB,
If the carb is mounted at the crank case I would imagine the fuel would be entering into the crank case? If the carb is mounted on the cylinder at the transfer port I would think the fuel would be entering into the transfer port?
Do all Detroit's with a original factory carburetor despence fuel directly into the transfer port or do they despence fuel into the crank case then up the transfer port or maybe they do either or. I need to know this information to post on my website to help people that are restoring Detroit marine engines. I want to post all the different types of carbs that were used on Detroit two cycle marine engines. Also the location of where the carb mounted on the engine. I have all the low pressure fuel reservoir/injectors posted already.
Any help would be grateful.
Thanks...
John
http://www.antiquengines.com |
ernie
Senior Member
Username: ernie
Post Number: 377
Registered: 01-2002
| | Posted on Sunday, March 26, 2006 - 08:09 am: |
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Here is the add from JB
 |
johnny
Member
Username: johnny
Post Number: 10
Registered: 03-2006
| | Posted on Sunday, March 26, 2006 - 09:09 pm: |
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Sorry Guy's,
That is a different engine company then Detroit Engine Works or Detroit Motor Car Supply Company.
Thanks anyways...
John |
gregoryan
Member
Username: gregoryan
Post Number: 8
Registered: 09-2004
| | Posted on Thursday, June 08, 2006 - 08:29 am: |
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The fuel/air mix enters the crankcase {on all the 2 stroke gasoline engines that i know) reguardless of if the carb is mounted on the cylinder casting or the crankcase it's self! *Cylinder mounted carb only leads to the underside of the piston, the mixture is prevented from escaping back out when the piston covers the port.
* Crankcase mounted carb has a check valve.
* Transfer port is seperated in either type.
Greg |
johnny
Senior Member
Username: johnny
Post Number: 619
Registered: 03-2006
| | Posted on Friday, August 23, 2019 - 11:38 am: |
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Come across this post from back in 2006 when I didn't even own a marine engine. Funny now looking back on it and reading. I now have to many DEW marine engines and have worked on many. The answer I was looking for back then was, Most all of the factory DEW marine engines that have carbs or mixers dispense the fuel in the transfer port on the side of the cylinder. They do not dispense the fuel in to the crankcase. Also the Detroit engines that use a carb or mixer need a inline check valve to keep the compression from escaping unless the carb or mixer has it's own built in check valve. The fuel injected DEW marine engines dispenses the fuel directly into the cylinder. So if you are using a gas & oil mix only on a DEW marine engine with a carb, mixer or fuel injection your probably not going to get much lubrication to the lower end connecting rod bearing unless you have one of the early DEW engines that has a greaser on the end of the crankshaft. On the later model DEW engines recommended you use the drip oiler that feeds the lower & upper end bearing's. |
