That's correct. A longer stroke not only provides more displacement for the
same bore size, but it also provides more leverage (mechanical advantage)
for the combustion pressure to apply to the crank. It's a longer lever.
A long-stroke/small-bore motor will produce more torque than a
short-stroke/large-bore motor of the same displacement, but the short-stroke
motor will rev higher.
"Back in the day" (read mid 1960's) there was a dragster team called Starkey
& Jent (sp?) who ran a destroked Chevy small-block with a displacement of
233 ci and a GMC supercharger. They turned the thing to 10,000 rpm! At that
time, if you could get 8,000 out of a SBC, you were doing really good.
(Gawd, getting old is positively scary when I can remember things like that
but I can't remember what I had for lunch two days ago!)
And the amount of time the gas has to work on the crank is the same for any
engine at a given rpm. At 6000 revolutions per minute, that's 0.005 seconds
for half a revolution (the power stroke), regardless of bore, stroke or
anything else. Piston speed will be higher because it has to travel farther
during that time.
Gordon Glasgow
-----Original Message-----
From: datsun-roadsters-bounces@autox.team.net
[mailto:datsun-roadsters-bounces@autox.team.net] On Behalf Of Embarq
Customer
Sent: Thursday, April 09, 2009 9:57 AM
To: datsun-roadsters@autox.team.net
Subject: Re: [Roadsters] long rod (r16) stroker
The only thing that strokes the motor is a crank. Different rods and
pistons might change the angles between the rod and piston but does not
change the stroke or displacement. To change the displacement you have to
change the stroke or bore.
Andy
----- Original Message -----
From: "Stephen Wan" <steve@olsonarchitect.com>
To: datsun-roadsters@autox.team.net
Sent: Thursday, April 9, 2009 11:03:30 AM GMT -06:00 US/Canada Central
Subject: Re: [Roadsters] long rod (r16) stroker
I think its from the longer distance the piston can travel during the
combustion phase.
The longer downstroke increases the amount of time that the expanding gas
has to turn the crank before reaching BDC per combustion cycle.
Steve
70' 1600 that still needs a tranny swap.
----- Original Message -----
From: "Eddie" <eddietude@socal.rr.com>
To: "Gordon Glasgow" <gsglasgow@comcast.net>
Cc: <datsun-roadsters@autox.team.net>
Sent: Wednesday, April 08, 2009 11:23 PM
Subject: Re: [Roadsters] long rod (r16) stroker
>I thought the longer rod also pushed the piston farther "up" the
> cylinder wall, thus compressing the gas MORE... and that's where the
> power gain came from...
>
> Isn't that also the case?
>
> Eddie
You are subscribed as andycost@embarqmail.com
Datsun-roadsters mailing list
http://www.team.net/archive
http://autox.team.net/mailman/listinfo/datsun-roadsters
Datsun-roadsters mailing list
http://www.team.net/archive
http://autox.team.net/mailman/listinfo/datsun-roadsters
________________________________________
Support Team.Net http://www.team.net/donate.html
Datsun-roadsters mailing list
http://www.team.net/archive
http://autox.team.net/mailman/listinfo/datsun-roadsters
|