Gas Piston Dwell - Adjustment?

nbjly · June 21, 2003, 13:43

I searched all *30* pages that came up under 'Gas Piston'.......
One post mentioned gas piston dwell, which would be the gap between the piston and bolt carrier. There are a couple of ways to adjust it, if it needs it -

When assembled, my gas piston protrudes about .030.
The bolt carrier does *not* hit it, there is a raised pad on the left side of the bolt carrier that gives a little clearance.

I'm thinking....

You don't want the piston too long or it will hammer the the whole front end everytime the bolt carrier goes forward, plus keep it slightly out of full battery.
Conversely, you don't want the piston to be too short or it will hammer the bolt carrier everytime it hits it.

So - Is there a value to pursue, should I get some plasti-gauge? (JK)
or is everything just right?

About now I should say thanks for looking

**EMDII** · June 21, 2003, 14:05

Leave the plasti-gauge in the toolbox. If you have aproperly headspaced FAL it won't matter so long as you use the correct piston.

Radio · June 21, 2003, 15:10

My GOSH you must have a lot of free time!

* One, to be worried about something as esoteric as this...
* Two, to have gone through THAT many archived threads in search of this leeeetle bit of "gold".

"Fool's Gold" in this case, as the "problem" you mentioned is hardly worth the trouble. "It won't matter so long as you use the correct piston." Which, with today's aftermarket, is very easy to do.

The ONLY time "dwell" is truly something to be concerned about is "negative dwell", or the piston being too LONG, thus interfering with the carrier's full forward travel. That happens about as often as Bill Klinton was ever right about anything.

--Radio

nbjly · June 21, 2003, 15:29

*FREE* time - no such thing

I've always been a perfectionist, but I understand that perfection is an idea never realized, so I try to acheive 'GE' - good enough. It's hard though when you're not sure of the GE threshold........

But hey if you have time to respond

, please look at my para top cover post and tell me what's up wit dat so I can go shoot this thing!!!! It's the only remaining issue between me and sighting in - I hope

I was just kidding (JK) about the plasti-gauge, I ain't *that* bad

**Stoney** · June 21, 2003, 15:49

I aways thought that dwell was the time the bullet was between the gas port and the end of the barrel. i.e. shorter distance (barrel length) ment larger gas hole.

**gw11** · June 21, 2003, 17:39

Dwell? why that is what I set when I tune up my "56 Chevy"

By golly it says it right there on that E lectrical gaget thing.
Where's my fal? I'll fix er up!
gw11

Radio · June 21, 2003, 17:53

Yer showin' your age, there, gw11...

I always appreciated the "window" built into those superior GM distributors, sure made adjusting the dwell eaisier with the engine running... compared to Chrysler or (gasp) Ford... I still appreciate it on my big block '69 Camaro SS/RS.

And just to give myself legitimacy, my first car was a '67 Mustang convertible (bought it for $400) and my brother used to have a '69 Superbee with a 4bbl/440. When we built that engine we decided after many bull sessions to go with a lower compression...

ONLY 11:1.

The young kids today have no concept of 100 octane gas for 35 cents a gallon.

--Radio

**gw11** · June 21, 2003, 18:03

Radio
Actually my first car was a 1940 Cadilac Lasalle! of course that was 22 years old, but cherry. then a 55 Chevy and next came the 56 Chev with a 62 350 vet engine.
Now it's Nissans etc that I let someone else work on.
gw11

Radio · June 21, 2003, 18:12

My brother (same one) has long lamented the loss of his '56 Chevy.

The AMBULANCE with the 392 HEMI and iron-case Chrysler automatic...
the fastest 7000-lb sled you ever saw!!

When we tore that engine down, we found every compression ring had been broken. While he was in the Marines his original porcelain spark plug wires were stolen, and later he sold the engine (and his 354 and 331) 'cause he needed the money. Also sold the engineless body to a Chevy collector, hope it got a good home. That thing was so big, you could have worn a top hat in the front seat. Sure was a lot of fun, back there in the '70s.

--Radio

nbjly · June 21, 2003, 18:26

Another hijacked thread.......

No matter - it's together now - thanks to all!

Snakeshot · June 21, 2003, 18:29

nbjly,

Hijacked, yes, but there is no point in dwelling on it.

**gw11** · June 21, 2003, 18:41

nbjly
Sorry if I have offended you!
gw11

nbjly · June 21, 2003, 18:45

Offend? No way - thus the

I'm just glad to get it together and for all the help, not just on this thread.

I always thought that if someone was offended, it was their problem anyway - although I 'spose there limits.......

**gw11** · June 21, 2003, 18:52

nbjly

Quote:

I always thought that if someone was offended, it was their problem anyway - although I 'spose there limits.......

I for one, agree with you but in an effort to get along occasionally, it doesn't hurt to be polite!
Enjoy your rifle.
gw11

June 21, 2003, 13:43	#1
nbjly Registered FALaholic #: 7539 Join Date: Sep 2002 Posts: 84	Gas Piston Dwell - Adjustment? I searched all 30 pages that came up under 'Gas Piston'....... One post mentioned gas piston dwell, which would be the gap between the piston and bolt carrier. There are a couple of ways to adjust it, if it needs it - When assembled, my gas piston protrudes about .030. The bolt carrier does not hit it, there is a raised pad on the left side of the bolt carrier that gives a little clearance. I'm thinking.... You don't want the piston too long or it will hammer the the whole front end everytime the bolt carrier goes forward, plus keep it slightly out of full battery. Conversely, you don't want the piston to be too short or it will hammer the bolt carrier everytime it hits it. So - Is there a value to pursue, should I get some plasti-gauge? (JK) or is everything just right? About now I should say thanks for looking __________________ "It has been said that history turns on small hinges and so do people's lives. That is why it is worthwhile to look ahead, to set a course, to be at least partly ready when the moment of decision comes" Thomas S. Monson

June 21, 2003, 14:05	#2
EMDII Evil Moderator Silver Contributor FALaholic #: 6 Join Date: Jul 2000 Location: Kennesaw, GA Posts: 13,971	Leave the plasti-gauge in the toolbox. If you have aproperly headspaced FAL it won't matter so long as you use the correct piston. __________________ "The Spartans do not enquire how many enemy there are. The SPartans merely enquire WHERE they are." E.M. (Ted) Dannemiller II 1*

June 21, 2003, 15:10	#3
Radio Registered FALaholic #: 263 Join Date: Jul 2000 Location: Eastern Washington State Posts: 9,868	My GOSH you must have a lot of free time! * One, to be worried about something as esoteric as this... * Two, to have gone through THAT many archived threads in search of this leeeetle bit of "gold". "Fool's Gold" in this case, as the "problem" you mentioned is hardly worth the trouble. "It won't matter so long as you use the correct piston." Which, with today's aftermarket, is very easy to do. The ONLY time "dwell" is truly something to be concerned about is "negative dwell", or the piston being too LONG, thus interfering with the carrier's full forward travel. That happens about as often as Bill Klinton was ever right about anything. --Radio __________________ Train Like You Fight: Second PLace is NOT an Option. --E.M. (Ted) Dannemiller II* "You seem to fantasize about me a lot. Maybe you should tell your boyfriend? He could dress up like me or something." --*K.O.A.M.*, November 9th, 2009 "You're better off hoping she don't miss, it's quicker that way." --ce, December 15, 2009

June 21, 2003, 15:29	#4
nbjly Registered FALaholic #: 7539 Join Date: Sep 2002 Posts: 84	FREE time - no such thing I've always been a perfectionist, but I understand that perfection is an idea never realized, so I try to acheive 'GE' - good enough. It's hard though when you're not sure of the GE threshold........ But hey if you have time to respond , please look at my para top cover post and tell me what's up wit dat so I can go shoot this thing!!!! It's the only remaining issue between me and sighting in - I hope I was just kidding (JK) about the plasti-gauge, I ain't that bad __________________ "It has been said that history turns on small hinges and so do people's lives. That is why it is worthwhile to look ahead, to set a course, to be at least partly ready when the moment of decision comes" Thomas S. Monson

June 21, 2003, 15:49	#5
Stoney Former 0311 Contributor Bronze Contributor FALaholic #: 1205 Join Date: Oct 2000 Location: Brush Prairie, WA USA Posts: 3,325	I aways thought that dwell was the time the bullet was between the gas port and the end of the barrel. i.e. shorter distance (barrel length) ment larger gas hole. __________________ Stoney Bureaucracy,, taking the fun out of life one stupid rule at a time,,,, Old Viking saying: Never be more then two steps from your weapon Don't pick a fight with an old man. If he is too old to fight, he'll just kill you. Peace is that brief glorious moment in history when everybody stands around reloading. - Thomas Jefferson

June 21, 2003, 17:39	#6
gw11 Veteran Member Gold Contributor FALaholic #: 2731 Join Date: Feb 2001 Location: CT. USA Posts: 1,404	Dwell? why that is what I set when I tune up my "56 Chevy" By golly it says it right there on that E lectrical gaget thing. Where's my fal? I'll fix er up! gw11

June 21, 2003, 17:53	#7
Radio Registered FALaholic #: 263 Join Date: Jul 2000 Location: Eastern Washington State Posts: 9,868	Yer showin' your age, there, gw11... I always appreciated the "window" built into those superior GM distributors, sure made adjusting the dwell eaisier with the engine running... compared to Chrysler or (gasp) Ford... I still appreciate it on my big block '69 Camaro SS/RS. And just to give myself legitimacy, my first car was a '67 Mustang convertible (bought it for $400) and my brother used to have a '69 Superbee with a 4bbl/440. When we built that engine we decided after many bull sessions to go with a lower compression... ONLY 11:1. The young kids today have no concept of 100 octane gas for 35 cents a gallon. --Radio __________________ Train Like You Fight: Second PLace is NOT an Option. --E.M. (Ted) Dannemiller II* "You seem to fantasize about me a lot. Maybe you should tell your boyfriend? He could dress up like me or something." --*K.O.A.M.*, November 9th, 2009 "You're better off hoping she don't miss, it's quicker that way." --ce, December 15, 2009

June 21, 2003, 18:03	#8
gw11 Veteran Member Gold Contributor FALaholic #: 2731 Join Date: Feb 2001 Location: CT. USA Posts: 1,404	Radio Actually my first car was a 1940 Cadilac Lasalle! of course that was 22 years old, but cherry. then a 55 Chevy and next came the 56 Chev with a 62 350 vet engine. Now it's Nissans etc that I let someone else work on. gw11

June 21, 2003, 18:12	#9
Radio Registered FALaholic #: 263 Join Date: Jul 2000 Location: Eastern Washington State Posts: 9,868	My brother (same one) has long lamented the loss of his '56 Chevy. The AMBULANCE with the 392 HEMI and iron-case Chrysler automatic... the fastest 7000-lb sled you ever saw!! When we tore that engine down, we found every compression ring had been broken. While he was in the Marines his original porcelain spark plug wires were stolen, and later he sold the engine (and his 354 and 331) 'cause he needed the money. Also sold the engineless body to a Chevy collector, hope it got a good home. That thing was so big, you could have worn a top hat in the front seat. Sure was a lot of fun, back there in the '70s. --Radio __________________ Train Like You Fight: Second PLace is NOT an Option. --E.M. (Ted) Dannemiller II* "You seem to fantasize about me a lot. Maybe you should tell your boyfriend? He could dress up like me or something." --*K.O.A.M.*, November 9th, 2009 "You're better off hoping she don't miss, it's quicker that way." --ce, December 15, 2009

June 21, 2003, 18:26	#10
nbjly Registered FALaholic #: 7539 Join Date: Sep 2002 Posts: 84	Another hijacked thread....... No matter - it's together now - thanks to all! __________________ "It has been said that history turns on small hinges and so do people's lives. That is why it is worthwhile to look ahead, to set a course, to be at least partly ready when the moment of decision comes" Thomas S. Monson

June 21, 2003, 18:29	#11
Snakeshot Registered FALaholic #: 909 Join Date: Sep 2000 Location: Non Harry Reid Nevada Posts: 4,044	nbjly, Hijacked, yes, but there is no point in dwelling on it. __________________ "When plunder becomes a way of life for a group of men living together in society, they create for themselves in the course of time a legal system that authorizes it and a moral code that justifies it." Frederic Bastiat

June 21, 2003, 18:41	#12
gw11 Veteran Member Gold Contributor FALaholic #: 2731 Join Date: Feb 2001 Location: CT. USA Posts: 1,404	nbjly Sorry if I have offended you! gw11

June 21, 2003, 18:45	#13
nbjly Registered FALaholic #: 7539 Join Date: Sep 2002 Posts: 84	Offend? No way - thus the I'm just glad to get it together and for all the help, not just on this thread. I always thought that if someone was offended, it was their problem anyway - although I 'spose there limits....... __________________ "It has been said that history turns on small hinges and so do people's lives. That is why it is worthwhile to look ahead, to set a course, to be at least partly ready when the moment of decision comes" Thomas S. Monson

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