Subject: [Healeys] Lightened Flywheels

From: Bob Spidell <[email-masked]> gA2WgI/M78YiIwHZiAIKv+mweIux/+VjTnTvfsGt/dPscCpyDZ8On9vKeNEFKIOJY7J3SuaaUPxNP8+KvBepzTitW/4R5DZwPuo=
Date: Tue, 18 Jun 2024 09:46:15 -0700

Listers,

I know this one has been discussed--well, beat to death--but it looks 
like I'll have to pull my BJ8's gearbox/OD to replace a leaky front 
seal, so I'm thinking of installing a lightened flywheel while I'm at 
it. My main reason for considering it is to stop some pretty significant 
run-on ('dieseling,' which I get on my BN2 as well). I'm not totally 
comfortable with dropping the clutch in gear to stop it, and any 
performance improvements would be a plus. It just so happens I just 
caught an episode of 'Engine Masters' on MotorTrend TV, where they 
seriously reduced the rotating mass of an engine--an SBC, which is what 
they mostly do--and got some interesting results: more HP and torque, as 
measured on a topnotch dyno. The gains were shown primarily on 
acceleration which, intuitively I suppose, were greater when RPM was 
raised at 300RPM/minute vs. 600. Any constant speed increases weren't 
addressed as far as I could tell.

The late, great Gary Andersen, who raced, said the main benefit was 
faster spin-up for rev-matching downshifts; anyone noted any other 
significant benefits? The 'Dyno Master' on EM said he'd seen timing 
chain failures with lightened flywheels; my main concern for both my 
Healeys has been reliability, with minimal maintenance required, but if 
it stops/minimizes the run-on I'd be happy. Anyone know how far you can 
go lightening without adverse effects?

TIA,
Bob
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From: Hank Leach via Healeys <[email-masked]>
Date: Tue, 18 Jun 2024 18:10:50 +0000 wMBbzTqpL42knUDHyaqsVpDHoaL5LIQ++Sswu4AeA3A0SmY9FgXeMQKLKRSbJfDXPxV3TxPCjzHEalEIFhOWIGIXl/Le3j/U9d/IbKlFebEYxECAVBIa3RuI

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<div>The best way to stop run on is foot on brake, car in gear-It's not =
hurting anything and is recommended by the likes of Geoff Healey and others=
. Denotation has a worse effect on the engine.</div>
<div>The downside of the lightened flywheel is a heavier clutch engagement.=
 That said the heaviest part I ever picked up is a 100 flywheel.&nbsp; Egad=
, what a hunk of metal!<br>-However the issues with the flywheel/cracked =
crankshaft can be traced to a lack of a front pulley dampener and that =
might be the better solution to the issue.&nbsp; It may in fact make =
dumping the clutch easier on the drivetrain, but not proven. Since your =
problem is with the front of the engine, I would address the seal =
replacement -felt if you are a purest -or yes, the modern solution fancy =
cover to stop drips on the floor. I collect my Healey oil in a small =
swimming pool I constructed to hold leaks, while in storage. Then some =
kerosene quickly cleans up the mess when the car is moved. Since they no =
longer oil the roadways, think of the benifit you are supplying to the =
asphalt in longer life. Hank-------------------&nbsp;<br><br>From: "Bob =
Spidell" &lt;[email-masked]&gt; <br>To: "Healeys" &lt;healeys@autox.=
team.net&gt; <br>Sent: June 18, 2024 at 10:03 AM PDT <br>Subject: [Healeys]=
 Lightened Flywheels <br>Listers,<br>I know this one has been =
discussed--well, beat to death--but it looks like I'll have to pull my =
BJ8's gearbox/OD to replace a leaky front seal, so I'm thinking of =
installing a lightened flywheel while I'm at it. My main reason for =
considering it is to stop some pretty significant run-on ('dieseling,' =
which I get on my BN2 as well). I'm not totally comfortable with dropping =
the clutch in gear to stop it, and any performance improvements would be a =
plus. It just so happens I just caught an episode of 'Engine Masters' on =
MotorTrend TV, where they seriously reduced the rotating mass of an =
engine--an SBC, which is what they mostly do--and got some interesting =
results: more HP and torque, as measured on a topnotch dyno. The gains were=
 shown primarily on acceleration which, intuitively I suppose, were greater=
 when RPM was raised at 300RPM/minute vs. 600. Any constant speed increases=
 weren't addressed as far as I could tell. The late, great Gary Andersen, =
who raced, said the main benefit was faster spin-up for rev-matching =
downshifts; anyone noted any other significant benefits? The 'Dyno Master' =
on EM said he'd seen timing chain failures with lightened flywheels; my =
main concern for both my Healeys has been reliability, with minimal =
maintenance required, but if it stops/minimizes the run-on I'd be happy. =
Anyone know how far you can go lightening without adverse effects? TIA, Bob=
 _______________________________________________ Support Team.Net =
http://www.team.net/pipermail/healeys http://autox.team.net/archive/healeys=
 [email-masked] http://autox.team.net/mailman/listinfo/healeys =
harter.net</div>

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From: Hank Leach via Healeys <[email-masked]>
Date: Tue, 18 Jun 2024 18:57:12 +0000 2TAP9aqp0udywdLLPR6EQOhgALTO6n4e8PV10rszZkrV4U2t2JIFDgiv/iF02zkcBcEIyohUbT92UocE7Bg0/7UbjDlIJWvEs8YkvXfVu6Tq1w6QLqRUXOr9

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<div>OK BJ8 issue...that is a lighter flywheel.&nbsp; I still recommend =
dumping the clutch to stop any run-on. Might check your timing with a light=
 and set it to 17 degrees to compensate for the lousy fuel we get today. =
That appears to tbe the magic number for most of the old British iron- used=
 to 95+ octane fuels. When those cars were built there was no corn in the =
fuel. Sad that many of our classics are now running on volts and amps.=
</div>
<div>An aside-on the old 100 gearbox, with just rifling for a seal, =
I add an o-ring to the input shaft to "contain the spinout. =
Hank<br>-------------------- <br><br>From: "Bob Spidell" =
&lt;[email-masked]&gt; <br>To: &lt;[email-masked]&gt;, "Healeys"=
 &lt;[email-masked]&gt; <br>Sent: June 18, 2024 at 11:46 AM PDT =
<br>Subject: Re: [Healeys] Lightened Flywheels <br>Thanks, Hank. To clarify=
, the seal I need to replace is at the front of the gearbox; i.e. the input=
 shaft seal on my BJ8 gearbox. I'm pretty sure that's the source of the =
leak--disappointing, since the rebuild only a few years ago--because it =
smells like the MT-90 I use in my gearboxes (I know, syn leaks, but this =
box probably has 10K miles on it before it erupted). I also spent time and =
effort sealing the O/D drain, since I initially assumed it was the source =
of the leak. Makes me wonder if seal quality has suffered, like a lot of =
things. Pretty sure I checked the input shaft for wear.<br>I'm about =
(re-convinced) to forgo a lightened flywheel, since it apparently causes no=
 harm (just have to remember to do it). I've heard it can actually cause an=
 engine to run backwards, which would be all kinds of bad. bs On 6/18/2024 =
11:10 AM, Hank Leach wrote: &gt; The best way to stop run on is foot on =
brake, car in gear-It's not &gt; hurting anything and is recommended by the=
 likes of Geoff Healey and &gt; others. Denotation has a worse effect on =
the engine. &gt; The downside of the lightened flywheel is a heavier clutch=
 engagement. &gt; That said the heaviest part I ever picked up is a 100 =
flywheel.&nbsp; Egad, &gt; what a hunk of metal! &gt; -However the issues =
with the flywheel/cracked crankshaft can be traced &gt; to a lack of a =
front pulley dampener and that might be the better &gt; solution to the =
issue.&nbsp; It may in fact make dumping the clutch easier &gt; on the =
drivetrain, but not proven. Since your problem is with the &gt; front of =
the engine, I would address the seal replacement -felt if you &gt; are a =
purest -or yes, the modern solution fancy cover to stop drips on &gt; the =
floor. I collect my Healey oil in a small swimming pool I &gt; constructed =
to hold leaks, while in storage. Then some kerosene &gt; quickly cleans up =
the mess when the car is moved. Since they no longer &gt; oil the roadways,=
 think of the benifit you are supplying to the &gt; asphalt in longer life.=
 Hank------------------- &gt; &gt; From: "Bob Spidell" &lt;bspidell@comcast=
.net&gt; &gt; To: "Healeys" &lt;[email-masked]&gt; &gt; Sent: June =
18, 2024 at 10:03 AM PDT &gt; Subject: [Healeys] Lightened Flywheels &gt; =
Listers, &gt; I know this one has been discussed--well, beat to death--but =
it looks &gt; like I'll have to pull my BJ8's gearbox/OD to replace a leaky=
 front &gt; seal, so I'm thinking of installing a lightened flywheel while =
I'm at &gt; it. My main reason for considering it is to stop some pretty =
&gt; significant run-on ('dieseling,' which I get on my BN2 as well). I'm =
&gt; not totally comfortable with dropping the clutch in gear to stop it, =
&gt; and any performance improvements would be a plus. It just so happens I=
 &gt; just caught an episode of 'Engine Masters' on MotorTrend TV, where =
&gt; they seriously reduced the rotating mass of an engine--an SBC, which =
&gt; is what they mostly do--and got some interesting results: more HP and =
&gt; torque, as measured on a topnotch dyno. The gains were shown primarily=
 &gt; on acceleration which, intuitively I suppose, were greater when RPM =
&gt; was raised at 300RPM/minute vs. 600. Any constant speed increases &gt;=
 weren't addressed as far as I could tell. The late, great Gary &gt; =
Andersen, who raced, said the main benefit was faster spin-up for &gt; =
rev-matching downshifts; anyone noted any other significant benefits? &gt; =
The 'Dyno Master' on EM said he'd seen timing chain failures with &gt; =
lightened flywheels; my main concern for both my Healeys has been &gt; =
reliability, with minimal maintenance required, but if it &gt; =
stops/minimizes the run-on I'd be happy. Anyone know how far you can &gt; =
go lightening without adverse effects? TIA, Bob &gt; =
_______________________________________________ Support Team.Net &gt; =
Archive: http://www.team.net/pipermail/healeys &gt; http://autox.team.=
net/archive/healeys [email-masked] &gt; http://autox.team.=
net/mailman/listinfo/healeys Unsubscribe/Manage: &gt; http://autox.team.=
net/mailman/options/healeys/gradea1@charter.=
net</div>

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