Lightened flywheel when I re-build my engine?

We take off about 25 to 28#.

Big savings on the center and rear mains.

I wouldn't even think about driving a Model A with out a lightened flywheel.

Purdy's right, not one downside.

We have put lots on.
 
usually most seem to remove as much from the flywheel as the counter weights add to the crankshaft. This only keeps it status quo. If you want to gain quicker throttle response and acceleration, you will have to remove more. Model B engines and model A engines with heavier counter balanced crankshafts rev and accelerate slower unless other mods are made. I'm running an 18 pound lighter flywheel with an un counter balanced crankshaft. I run several mods and they all work together . My roadster is very peppy and will run faster uphill than most stock engines with a heavy flywheel will run on flat ground.
 
In Ranking I'm just above the rank novice. I've raced a little (On the street, not track) but little means very little. I've rebuilt a couple of SBCs and a few Y blocks, and a few Hercules 105s, I've repaired a few more. So if anyone with any experience says I'm wrong, I shut up and sit down and listen. But On this subject, I feel I was misunderstood. When I said "It frees up some HP" I was not referring to the top end. A 40hp motor will be a 40HP at the top end, regardless of whether or you have a twenty lb FW or a hundred Lb FW. However, The heavier FW will exert more drag on the engine during acceleration. The lighter one, less drag! That's what I meant by "Freeing up HP" It doesn't create more HP, It just doesn't use so much to get up to speed. The HP is free to go do some real work. The heavier FWs were more of a neccessity back in the day. Dirt roads, Hills, bumps, ruts, bad fuel had to be gotten over or around. You needed that huge energy storage container. But today's conditions will allow less stored energy and more available HP. If a heavier FW was so great and stored energy was so wonderful, we'd be making them heavier. And it feels great!
Terry
 
I would sure consider using the V-8 clutch and pressure plate at the same time. I did the lightened flywheel, along with the V-8 clutch...what a difference...much less pedal pressure. I drove a friends stock clutch recently and could not believe the difference. I also agree the lightened flywheel gives a little quicker response and makes shifting slightly easier, as well as helping the mains. Mine also still idles well and also stills well at low speed. Can think of no down sides...........
 
28ACoupe said:
Facts:

1) a lightened flywheel will not create any more power. To do so requires energy to be converted and this is not what a flywheel does.
2) A heavy flywheel stores energy which can be released when needed in the form of more pulling power on a hill or other such situations.
3) A lightened flywheel will allow an engine to rev faster if, and only if the engine is capable of gaining speed at all under that particular load.

On flat ground, yes, you will get to speed a little faster. However, there is a price to pay for this.

These are facts as required by the laws of physics. If you want to go faster in your Model A, you need to modify the entire system the same as any other engine. Just changing one thing might make you feel better, but you won't gain much.

This reminds me of the guys who go out and buy an aftermarket intake and huge carb for their engines and then think they are somehow going to go faster. It doesn't work that way.
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Re #2. But only for a VERY short interval of time.

The heavy flywheel makes for slower idle is mainly because the engine won't idle smooth with no flywheel due to poor tuning.
I have demonstrated several times that a stock engine with NO flywheel can be made to idle smooth at 400 rpm.
On many of the modified street engines I built, I used an 11 lb small block Chev aluminum flywheel and an 9 inch aluminum clutch cover from a flathead Ford V8. The clutch cover weighs about 10 lb.
Even with a 404A radius lifter racing cam, these engines will idle at 600 rpm with just a slight lope.
Those that saw me at the 2002 Riverside MAFCA national meet can attest to this.

I love the signature someone on here uses that pertains to all this.

"Just because you don't believe in the laws of physics doesn't mean they don't apply to you."
 
Pete - there are a lot of key points in your statement:

1) yes you can make an engine idle just fine without a flywheel. However, as you pointed out, you pretty much have to get it dialed in to get it smooth.

2) You mentioned using an 11lb flywheel on a Modified engine. Again, if you are going to alter the system, you need to alter the whole system to accommodate it or there will be issues not the least of which could be no real difference.

It's your cars guys. If you want to waste money on stuff like this, go for it. You won't get any more top end speed out of the engine unless you see to other parts of the system as well and you will be out the money on your mod that simply won't yield much, if any, appreciable difference.

Personally, I will keep my early, heavy '28 flywheel with the multidisk clutch and will run right along side you when I am done.
 
Purdy Swoft said:
Sometimes it depends on where the model A is from. In Cal-ah-phone-ya, they say ta da ta da ta da ta da or so says the assistant guru of stuff, Bill W. I won't repeat what Vince says that they say. I think that many have a different opinion on what the model A is saying when it idles with the spark retarded.
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Slight correction, Bro Purdy: Minerva sed, TADA-TADA-TADA-TADA, except once when a plug wire fall off, then, TADA-TADA--------TADA!
Soon as Vermin's fired, I'll report whut he sez! They ALL "TALK" diffurent! (REALLY!) Bill W.
 
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This is my opinion only, and I am in the clear minority of one here. I DON'T like my lightened flywheel. First, it changes the rhythm of shifting and double-clutching, both up shifts and down shifts. I've driven stock flywheels for 40-plus years, and therefore I am not adapting well to the new rhythm. (I've been driving a lightened flywheel for about five years now.) Secondly, it is much easier, or I am much more likely, to stall the engine when I begin moving from a stop. I believe this is a definite disadvantage to the lightened flywheel; less inertia to assist in starting in motion from a stop. I'm reluctant to post my opinion, especially when I see the engine experts who I respect so much posting the opposite view; but I don't like mine. Again, my opinion only.

W. Michael
 
WOW! all this discussion jist about lightening a flywheel? Has the COLD kept many in their "cave" too long & they're out uf beer & snacks & gettin' BORED?
If I took 2 LBS off my flywheel, I'd BRAG about how fast it goes! I once milled .075" off my head & it wuz TWICE as FAST!! NOBODY ever wants to admit a mistake or a bad decision, I wunder how folks justified buyin' a YUGO??? or a "FIX IT AGAIN, TONY" car?? My old friend Tony, (R.I.P, Tony) wuz a factory trained FIAT FIXER.
Well, I gotta' go EAT, I think my BRAIN?? is outta' GAS:eek:
Bill W.
 

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Your original question, Is it worth it to use a lightened flywheel? I quess the next thing that should have been asked of you, What do you want to gain.

"Worth" is subjective. Anyway for those still interested;

The old Fordbarn had pictures on how and where to lighten a flywheel and use a v-8 clutch. If the archives are out there I would pay to have a copy or access to them.

"Bills place in the country" http://www.brauchauto.com/ used to have a picture as well but that is gone. So, I think this will be of some help, it is from Secrets of Speed magazine,
 

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WOW I just started to read on this forum and have been on allot of forum's,
and i have got to say! There are some MEAN SUM *****"S HERE!!!! DANG!
you Model A Boys cant Play in the same sand Box together:)
Allen
 
w.michael said:
This is my opinion only, and I am in the clear minority of one here. I DON'T like my lightened flywheel. First, it changes the rhythm of shifting and double-clutching, both up shifts and down shifts. I've driven stock flywheels for 40-plus years, and therefore I am not adapting well to the new rhythm. (I've been driving a lightened flywheel for about five years now.) Secondly, it is much easier, or I am much more likely, to stall the engine when I begin moving from a stop. I believe this is a definite disadvantage to the lightened flywheel; less inertia to assist in starting in motion from a stop. I'm reluctant to post my opinion, especially when I see the engine experts who I respect so much posting the opposite view; but I don't like mine. Again, my opinion only.

W. Michael
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I'm glad to read this post. I like to be able to just 'let the clutch out' and go. I like all that stored energy. I have not driven one with a lighten wheel,yet.
 
I have a 30 CCPU with a lightened flywheel and 5.5 head it will not idle like my stock 29 and going around corners have to down shift. is this a result of the lightened flywheel?
 
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