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RDMG
D R

(43 posts)

Registered:
04/07/2016 08:29PM

Main British Car:
MGB Still Stock (temporarily)

Flywheel options for a late 4.6
Posted by: RDMG
Date: December 15, 2016 09:50PM

Hi all,

I have a lead on a leftover aftermarket flywheel for a Buick 215, but I don't know if it willl fit my 2004 Rover 4.6 that originally had an auto trans.

Anything I should look for, or is it a direct swap?

I'll be using a ford-pattern T5, so I'll need a bellhousing spacer anyway.

Dave


minorv8
Jukka Harkola

(115 posts)

Registered:
04/08/2009 06:50AM

Main British Car:
Morris Minor Rover V8

Re: Flywheel options for a late 4.6
Posted by: minorv8
Date: December 16, 2016 02:37AM

I have a McLeod flywheel in my 4.6 engine. You need to remove a guide pin from the crank flange, otherwise no issues.


40indianss
don foote

(27 posts)

Registered:
08/01/2013 04:35PM

Main British Car:


Re: Flywheel options for a late 4.6
Posted by: 40indianss
Date: December 16, 2016 11:20PM

D&d has new aluminum flywheels about ten pounds in weight. I am using it with a ford t5 in 77 mgb


RDMG
D R

(43 posts)

Registered:
04/07/2016 08:29PM

Main British Car:
MGB Still Stock (temporarily)

Re: Flywheel options for a late 4.6
Posted by: RDMG
Date: December 18, 2016 02:41PM

Many thanks!

I just bought a pile of good Buick stuff for what I think was a good price:

4-spd bellhousing with dust cover
Aluminum 300 heads
4-bbl intake
Many gaskets
NOS motor mounts

And the flywheel. Turns out it's new, came front d&d long ago, but it weighs 35 lbs!

I got it as part of the overall deal, so I don't have any regrets.

That said, what are my options with it?

Will the machining costs exceed the cost of a custom lightweight flywheel?

Does anyone in the old car universe want the heavy ones?

Dave


RDMG
D R

(43 posts)

Registered:
04/07/2016 08:29PM

Main British Car:
MGB Still Stock (temporarily)

Re: Flywheel options for a late 4.6
Posted by: RDMG
Date: December 19, 2016 09:53PM

To clarify my last post, does it make sense to mill the $h1t out of my 35lb Craigslist special, or to sell it on eBay and buy a custom lightweight?

I've read that a stock Buick flywheel can drop to about 17lbs with heavy machining, but I'm not sure if that was in reference to the lighter stock flywheel, and Ican't guess at the machining cost. My local machine shop quoted me at "$100, maybe a lot more." Very helpful...

There's a McLeod flywheel on eBay and a custom job from tsimported, each about $300 all in. Haven't seen any stock Buick flywheels sell on eBay, don't know what my fat pig is worth.

There's quite a lot of firm and conflicting opinions about flywheel weights on this board and others, adding to my confusion. I'm pretty certain I won't like a 35 pounder in my car, but it if I can get it milled to 20-ish pounds and be happy with that for less than the cost of a custom flywheel, I might. The conflicting threads on 12-lb flywheels make me nervous. Some suggest that it's not a streetable option, others seem to say it's the best decision they ever made.

Tentative plan is for a mild 4.6L build in a late MGB, with ford T5 with Hoyle and Fastcars suspension kits. 3.35:1 first gear, 3.34:1 rear differential. I'm drawn to the tsimported option because it's already drilled for a ford clutch.

Dave


BlownMGB-V8
Jim Blackwood
9406 Gunpowder Rd., Florence, KY 41042
(5153 posts)

Registered:
10/23/2007 12:59PM

Main British Car:
1971 MGB Blown,Injected,Intercooled Buick 340/AA80E/JagIRS

authors avatar
Re: Flywheel options for a late 4.6
Posted by: BlownMGB-V8
Date: December 20, 2016 01:21AM

I had that flywheel and had it machined down to 20 lbs. At that weight it is still plenty strong as it is billet steel. You could go lighter without hurting anything. I had it on a supercharged 215 and would have been happy with a little less weight. But you can also go with a lighter pressure plate if you want to shed weight. It did make a big difference. I had as much weight removed from the outside as I could for less rotational inertia.

Jim


tr8todd
Todd Kishbach

(314 posts)

Registered:
12/04/2009 07:42AM

Main British Car:


Re: Flywheel options for a late 4.6
Posted by: tr8todd
Date: December 20, 2016 06:32AM

Call Ted at TS imports in Ohio. His website lists lightened flywheels for $260 and aluminum ones for $400. Probably have to look thru the TR8 parts section to find the V8 goodies. You could probably get yours turned down for $100 or so, but I don't think you can get them down to the 20 pounds ted lists his at. Then there's the whole drilled for multiple clutch covers thing.



BlownMGB-V8
Jim Blackwood
9406 Gunpowder Rd., Florence, KY 41042
(5153 posts)

Registered:
10/23/2007 12:59PM

Main British Car:
1971 MGB Blown,Injected,Intercooled Buick 340/AA80E/JagIRS

authors avatar
Re: Flywheel options for a late 4.6
Posted by: BlownMGB-V8
Date: December 20, 2016 10:09AM

You can Todd. Cut the back down to the ring gear and enlarge the center hole a little and that will do it. Plus inside the PP bolt holes you could cut a recess in the back side for more weight removal if you wanted to.

Jim


MGBV8
Carl Floyd
Kingsport, TN
(3042 posts)

Registered:
10/23/2007 11:32PM

Main British Car:
79 MGB, Buick 215

authors avatar
Re: Flywheel options for a late 4.6
Posted by: MGBV8
Date: December 20, 2016 12:38PM

Mine was a new McCleod from D&D. Not as light as Ted's, so a friend chucked it up on his Bridgeport & cut it down to the low 20s. Metal was removed from the outside back (engine side). That & a lighter 9" pressure plate, it is noticeably lighter when driving.


roverman
Art Gertz
Winchester, CA.
(2846 posts)

Registered:
04/24/2009 11:02AM

Main British Car:
74' Jensen Healy, 79 Huff. GT 1, 74 MGB Lotus 907,2L

Re: Flywheel options for a late 4.6
Posted by: roverman
Date: December 22, 2016 11:28AM

Dave, are slaloms/etc. in the future ? Lightweight flywheels/clutches are worthless for drags, but for other "sporty" driving, they are an advantage. $400. seems absurd to me,(machinist). You might ask the machine shop, how much to machine the aluminum blank ? Fidanza steel insert,( jeg's/etc.) with bolts/nuts and ring gear, about $80. ? Aluminum $20-30. ? Once the "blank" is machined, YOU can put in all the holes, with just a drill press. Use a RV8 flex plate reinforcing ring,(crank drill pattern) and the Fidanza steel insert as drill jigs, to transfer holes into the aluminum blank. Good Luck and Merry Christmas-all. art.


BlownMGB-V8
Jim Blackwood
9406 Gunpowder Rd., Florence, KY 41042
(5153 posts)

Registered:
10/23/2007 12:59PM

Main British Car:
1971 MGB Blown,Injected,Intercooled Buick 340/AA80E/JagIRS

authors avatar
Re: Flywheel options for a late 4.6
Posted by: BlownMGB-V8
Date: December 22, 2016 11:53AM

How long has it been since you checked prices Art?


roverman
Art Gertz
Winchester, CA.
(2846 posts)

Registered:
04/24/2009 11:02AM

Main British Car:
74' Jensen Healy, 79 Huff. GT 1, 74 MGB Lotus 907,2L

Re: Flywheel options for a late 4.6
Posted by: roverman
Date: December 30, 2016 11:42AM

Jim B., you're right, they have went down ! Inserts with bolts start at $56.,(Jeg's). Remnant alum., in SoCal, starts at $1.50/lb. Nuff said. Happy New Year-all, Art.


tr8todd
Todd Kishbach

(314 posts)

Registered:
12/04/2009 07:42AM

Main British Car:


Re: Flywheel options for a late 4.6
Posted by: tr8todd
Date: December 30, 2016 02:27PM

I had an aluminum one in a daily driver TR8 coupe 20 years ago. Other than exhilarating acceleration from a built 3.5, you never would have known there was an aluminum flywheel in there. I'm planning on using one of Ted's on the 4.6 thats going in another TR8 coupe.


BlownMGB-V8
Jim Blackwood
9406 Gunpowder Rd., Florence, KY 41042
(5153 posts)

Registered:
10/23/2007 12:59PM

Main British Car:
1971 MGB Blown,Injected,Intercooled Buick 340/AA80E/JagIRS

authors avatar
Re: Flywheel options for a late 4.6
Posted by: BlownMGB-V8
Date: December 30, 2016 03:28PM

Art, I'm happy for you, having a scrap dealer who has usable aluminum blanks the size of a flywheel close by and so cheap. A little jealous too I'll admit. My machines are big enough to do that job but the cost for a 12" x 12" x 1" blank of 6061-T6 is about $120 plus shipping. Or you could buy a foot of 12" round for $1000 and saw off an inch. By the time you do that or make a square round and then machine it, well it makes more sense to just buy one really, especially if you can find a second hand one like maybe a Schaeffer on ebay. Might even find one with a steel insert which would be a definite bonus.

What you lose with an aluminum flywheel is ease of starting on the street. That is the only thing. Everything else gets better. So if you are comparing it to your original MGB 1800, I can't see where anyone could say it made the car worse. Compared to a new car, sure. I could see it. The bottom line is that it is a personal preference and if you know what you like you should be able to make this decision. I got down to 20 lbs with the steel flywheel and would have liked to cut it in half yet again and maybe more besides, but then again, I like to use a little gas coming off the line. If you like to just ease out the clutch and then use the gas, well then undoubtedly your mileage will vary.

Jim


RDMG
D R

(43 posts)

Registered:
04/07/2016 08:29PM

Main British Car:
MGB Still Stock (temporarily)

Re: Flywheel options for a late 4.6
Posted by: RDMG
Date: January 05, 2017 01:36PM

Local (DC area) machine shop prices for me are sky high-- $100 per hour. Really cool old place, but they seem to be catering to dealership service departments.

It appears I'm looking to sell a NOS Buick flywheel, and buy a custom one from Ted or D&D.

Anyone care to speculate on what my NOS Buick flywheel might sell for? USPS shipping estimates are $50!

I'm thinking aluminum is the way to go. Time to check for spare change in the couch...



Edited 1 time(s). Last edit at 01/05/2017 04:54PM by RDMG.



BlownMGB-V8
Jim Blackwood
9406 Gunpowder Rd., Florence, KY 41042
(5153 posts)

Registered:
10/23/2007 12:59PM

Main British Car:
1971 MGB Blown,Injected,Intercooled Buick 340/AA80E/JagIRS

authors avatar
Re: Flywheel options for a late 4.6
Posted by: BlownMGB-V8
Date: January 05, 2017 08:30PM

If that's a new D&D steel billet flywheel it should be worth just about what a new one costs now from D&D.

Jim


RDMG
D R

(43 posts)

Registered:
04/07/2016 08:29PM

Main British Car:
MGB Still Stock (temporarily)

Re: Flywheel options for a late 4.6
Posted by: RDMG
Date: January 06, 2017 08:45AM

Art,

I'm coming around to your idea:

The ring gear on my flex plate looks good, and I bet I can remove it with an oven and some pre-molded ice.

You can't beat the price for the jegs steel insert. I might buy two!

I drill the holes for the pressure plate, then have a shop balance the entire assembly.

What alloy plate should I use? 7075?

Other than the offset to ensure the ring gear is in the right location, is there any other critical depth measurement?

Dave


roverman
Art Gertz
Winchester, CA.
(2846 posts)

Registered:
04/24/2009 11:02AM

Main British Car:
74' Jensen Healy, 79 Huff. GT 1, 74 MGB Lotus 907,2L

Re: Flywheel options for a late 4.6
Posted by: roverman
Date: January 06, 2017 12:31PM

New starter ring gear from "Pioneer/other", is easiest and best. I like 7075 T6 as likely strongest, commercially available. Don't make it too thin ! For extra strength, put crank bolts in individual counterbores. No need to fret about a few extra ounces, in this area, but make SURE everything clears the disk hub, allowing for disk wear ! Use a "flush mount" clutch assembly, as a step mounted will only weaken the flywheel. Don't use any larger diameter clutch , than adequate for your application. Just counterbore for steel insert to flush with aluminum and use this to locate insert,(aka. drill jig plate), to drill the insert attachment holes. You can use a RV8 automatic flywheel stiffener plate/ring, as a drill jig for crank pattern holes. Same deal, counterbore it just enough to locate concentric. Good Luck, art.


BlownMGB-V8
Jim Blackwood
9406 Gunpowder Rd., Florence, KY 41042
(5153 posts)

Registered:
10/23/2007 12:59PM

Main British Car:
1971 MGB Blown,Injected,Intercooled Buick 340/AA80E/JagIRS

authors avatar
Re: Flywheel options for a late 4.6
Posted by: BlownMGB-V8
Date: January 06, 2017 05:56PM

Just about any billet alloy is going to be strong enough. 6061 will be the most common, therefore cheapest and easiest to find. Many aftermarket ones were cast aluminum. Cast aluminum plate such as "Mic-6" is available and might hold up ok, but I'd stick to billet, it is stronger and will handle the rpm's better.

Jim


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