Any Ford Master Mechanics on here
- Thread starter eminence1963
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Why on a Ford 3.8 Liter motor the No3 Piston stroke is shorter than the other 5 cylinders?
I goggle it and cant find the answer
Why on a Ford 3.8 Liter motor the No3 Piston stroke is shorter than the other 5 cylinders?
I goggle it and cant find the answer
Anybody played with the components previously? Piston or rod? Let us know what you find out.
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Maybe you should use a simple search term and go from there.
https://www.google.com/search?q=Ford+3.8+liter+engine
I do not know why that cylinder's stroke would be different, but I also would ask Scorpion8 (member here too) and Shotwell (he's a member but only a post or two) on TH.
Are you having head gasket problems? This engine seems to be notorious for that. They can go like hell when you stand on them, I DO know that as I watched a guy in a later Taurus wagon just about hit Mach .5 and didn't even toss much gravel on takeoff in a lot a few years ago...didn't need a Hemi.
But you haven't even gotten very deep into why you have it apart...would be nice to know.
I would look to see if this is a truncated small V-8 like a few other prominent V-6 engines.
https://www.google.com/search?q=Ford+3.8+liter+engine
I do not know why that cylinder's stroke would be different, but I also would ask Scorpion8 (member here too) and Shotwell (he's a member but only a post or two) on TH.
Are you having head gasket problems? This engine seems to be notorious for that. They can go like hell when you stand on them, I DO know that as I watched a guy in a later Taurus wagon just about hit Mach .5 and didn't even toss much gravel on takeoff in a lot a few years ago...didn't need a Hemi.
But you haven't even gotten very deep into why you have it apart...would be nice to know.
I would look to see if this is a truncated small V-8 like a few other prominent V-6 engines.
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Is this a rebuilt engine? I would pull one of the piston/rod assemblies from one of the cylinders that you know reaches
TDC and compare rod journal c/l distance to piston pin c/l to the one that is in question. Sounds like a difference in
piston pin location.
You could put number 1 assembly in hole number 3 (just to test TDC) and see what you come up with for
crank stroke on that journal with number 1 assembly.
I can't fiqure why you would want less compression in number 3 ?? Strange for sure.
TDC and compare rod journal c/l distance to piston pin c/l to the one that is in question. Sounds like a difference in
piston pin location.
You could put number 1 assembly in hole number 3 (just to test TDC) and see what you come up with for
crank stroke on that journal with number 1 assembly.
I can't fiqure why you would want less compression in number 3 ?? Strange for sure.
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I am not the original owner of the van. But it has been driving fine up until I discovered a slight head gasket leak on that same No 3 cylinder. This is why I have it apart to replace the head gasket. I have had the van now for 2 years, passed the emission test with no problems. The van has plenty of power as well, no rough idle. Just wanted to replace the head gasket and water pump as that was bad too. There is nothing knocking when it ran. So that would exempt it from having a bad bearing or bad wrist pin. Discovered the bad head gasket from changing out the spark plug and there was oil mixed in with the coolant. Never overheated the engine either.
Well the blown head gasket has nothing to do with why this piston is not at full tdc. Did you rotate the crank to make sure
that that cylinder is at full stroke? It looks like about .125 from reaching deck height. A worn bearing or pin would not
have such a difference in stroke.
There were 3 different cu. in motors available, so if rebuilt, parts could have been mixed. I have seen some weird shit in reman motors.
I would not worry about it much. If your head is still true, slap a new gasket on here and be done with it. Don't forget
to change the oil
that that cylinder is at full stroke? It looks like about .125 from reaching deck height. A worn bearing or pin would not
have such a difference in stroke.
There were 3 different cu. in motors available, so if rebuilt, parts could have been mixed. I have seen some weird shit in reman motors.
I would not worry about it much. If your head is still true, slap a new gasket on here and be done with it. Don't forget
to change the oil
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Well the blown head gasket has nothing to do with why this piston is not at full tdc. Did you rotate the crank to make sure
that that cylinder is at full stroke? It looks like about .125 from reaching deck height. A worn bearing or pin would not
have such a difference in stroke.
There were 3 different cu. in motors available, so if rebuilt, parts could have been mixed. I have seen some weird shit in reman motors.
I would not worry about it much. If your head is still true, slap a new gasket on here and be done with it. Don't forget
to change the oil
that that cylinder is at full stroke? It looks like about .125 from reaching deck height. A worn bearing or pin would not
have such a difference in stroke.
There were 3 different cu. in motors available, so if rebuilt, parts could have been mixed. I have seen some weird shit in reman motors.
I would not worry about it much. If your head is still true, slap a new gasket on here and be done with it. Don't forget
to change the oil
Yea I did do that rotate the crank 2 revolutions just to make sure I was not seeing things. Its 3 quarters thickness in the gap. Heads are at the machine shop being tanked and resurfaced. I just don't jam another gasket on without that getting done. I don't roll that way. Its either do it right the first time or I am not doing it at all. I am so OCD all bolts and all hardware is getting replaced as well. I'll be calling my local ford dealer ship in the am to see if there was a service bulletin on this. One thing I did notice is that the piston in question has number stamped on to the other are smooth.
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Perhaps, the clue is in picture of the #3 piston-top. Looks like the service part # and possibly an arrow pointing in the direction of the piston's proper orientation in the cylinder bore. It's possible a different piston than the other five was installed. I agree with Mike: the crankshaft rod journal may not be the difference in piston height, but where the piston pin is oriented on the piston could be.
Nando.
Nando.
So do 5 of the 6 pistons come up flush with the deck, or does only one come up flush and the other 5 are below deck a bit? I'd expect them to be slightly below deck height if its typical with other Ford motors. The one thats up flush looks like its had a lot of detonation issues, which would go with the higher compression in that cylinder. I'd have to second the notion that someone did a HA rebuild on it and used some mismatched parts.
I don't know the 3.8 particularly, but its something of a troublesome engine. If you change the coolant annually, they don't have gasket problems but nobody does that. It has to do with the aluminum heads and the iron block. The coolant becomes an electrolyte and the gasket ends up as a sacrificial material.
I don't know the 3.8 particularly, but its something of a troublesome engine. If you change the coolant annually, they don't have gasket problems but nobody does that. It has to do with the aluminum heads and the iron block. The coolant becomes an electrolyte and the gasket ends up as a sacrificial material.
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