Is this flywheel OK to use.

[Gary B.]

Re: Is this flywheel OK to use.

More information:

... The LUK LFW 131 is a 12-3/4", 153 tooth ring gear flywheel. It weighs about 18 pounds. As far as I know, it is cast of nodular iron.

When I checked on the nature of this flywheel last year with the German company that owns LUK, I believe they said it was gray iron, not nodular.

Gary

[Gary B.]

Re: Is this flywheel OK to use.

...McCloud - one suggestion from a friend of mine. Material is noted as Steel (so I assume it is cast steel). Weight 28 lbs. 55-85 small block.
...
Don

Don,

For the McLeod flywheel that weighs 30 lbs (# 460300) and costs $335, I think it must be machined from a billet and not cast, given the price. I didn't see a 28 lbs one on the McLeod website for 327 SB applications.

Gary

[Joe L.]

Re: Is this flywheel OK to use.

When I checked on the nature of this flywheel last year with the German company that owns LUK, I believe they said it was gray iron, not nodular.

Gary

Gary------


That could very well be. I was not sure that it was of nodular iron. I was inferring that from its design. To be honest, that would give me great pause about using it. I believe that the original GM 63-68 flywheel was as heavy as it was because it was cast of gray iron and to achieve the strength required more mass/reinforcing was necessary. Nodular iron, being inherently stronger (but of nearly equal density), is used to make lighter weight flywheels.

Manual transmission 1984-85 Corvettes were equipped in PRODUCTION with the GM #14085720 lightweight 12-3/4", nodular iron flywheel. As I described above, this is the successor and basically the same flywheel as used for 1965 L-78 and 1967-69 L-88.

[Mark M.]

Re: Is this flywheel OK to use.

In the seventies when I started building engines , a method shown to me to tell a better flywheel was to hold it up with a screwdriver in one of the holes and tap it on the back with a hammer. If it had ringing type sound, it was probably nodular and strong. If it went clunk, don't use it for anything heavy duty. If you plan on spinning your engine 7K or more, a billet flywheel is the safe way to go.

[Joe L.]

Re: Is this flywheel OK to use.

In the seventies when I started building engines , a method shown to me to tell a better flywheel was to hold it up with a screwdriver in one of the holes and tap it on the back with a hammer. If it had ringing type sound, it was probably nodular and strong. If it went clunk, don't use it for anything heavy duty. If you plan on spinning your engine 7K or more, a billet flywheel is the safe way to go.

Mark------


A billet steel flywheel is the best, no question about it.

[Donald H.]

Re: Is this flywheel OK to use.

Here's what I'm thinking of using. Jegs and Summit both sell these. This one is closer to OEM weight for the C2, is billet steel, and not unreasonable price for what I plan. I good running street L79 engine.

RAM 1511 - Billet Steel - $239 (seems a decent price with free shipping)

1963-1985 Chevy
Balance: Internal
Ring Gear: 153
Approx. Weight: 26 lbs.
Bolt Circle: 10.5" B&B/Diaphragm

[Gary B.]

Re: Is this flywheel OK to use.

Don,

I noticed these two comments about the RAM 1511 flywheel on the Summit website:

1) "Performance and SFI-approved flywheels must be used with performance clutch discs only. Use of a stock-style clutch disk with a performance flywheel will often result in insufficient operating clearance between the disc hub and flywheel bolts."

2) From a reviewer: "This flywheel is about .200 in. thinner than stock cast fw. App is 64 Impala w/327. Coupled to new Ram clutch kit."

Will that flywheel significantly restrict your choice of a clutch?

Gary

[Donald H.]

Re: Is this flywheel OK to use.

Don,

I noticed these two comments about the RAM 1511 flywheel on the Summit website:

1) "Performance and SFI-approved flywheels must be used with performance clutch discs only. Use of a stock-style clutch disk with a performance flywheel will often result in insufficient operating clearance between the disc hub and flywheel bolts."

2) From a reviewer: "This flywheel is about .200 in. thinner than stock cast fw. App is 64 Impala w/327. Coupled to new Ram clutch kit."

Will that flywheel significantly restrict your choice of a clutch?

Gary

Good question!

I think I will contact RAM directly and discuss my situation. This shouldn't be that hard.

Don

[Joe L.]

Re: Is this flywheel OK to use.

Don,

I noticed these two comments about the RAM 1511 flywheel on the Summit website:

1) "Performance and SFI-approved flywheels must be used with performance clutch discs only. Use of a stock-style clutch disk with a performance flywheel will often result in insufficient operating clearance between the disc hub and flywheel bolts."

2) From a reviewer: "This flywheel is about .200 in. thinner than stock cast fw. App is 64 Impala w/327. Coupled to new Ram clutch kit."

Will that flywheel significantly restrict your choice of a clutch?

Gary

Gary------


This is exactly the kind of problem that often occurs with aftermarket "hi performance" parts, especially clutches and flywheels. Even if this flywheel works with a stock clutch, there may ensue other problems.

[Donald H.]

Re: Is this flywheel OK to use.

Here is my email exchange with the RAM technical folks -

I am having a 1967 chevy small block 327 engine built. It will be built as a stock 327/350HP L79 engine. So I need a 153 tooth flywheel and using a 10.4/10.5 inch clutch setup. I am in need of a flywheel for this car. I am looking for something close to OE, in particular weight wise. From my research, the OE flywheel weight was 28-30 lbs and the RAM 1511 is listed as 26 lbs. This will be for normal street use, not any racing.

In reading on Summit Racing's website the following is a comment included for the RAM 1511 flywheel "Performance and SFI-approved flywheels must be used with performance clutch discs only. Use of a stock-style clutch disk with a performance flywheel will often result in insufficient operating clearance between the disc hub and flywheel bolts".

Does this statement mean that I will not be able to use a stock type single disk clutch setup? I have a LUK 04021 raised diaphragm clutch kit that I am intending to use. Is this clutch setup not compatible with the RAM 1511?

Here's the reply from the RAM tech guy -

That is an old notation from when the center recess was not as deep and would not accommodate stock discs. I would put the weight of that flywheel closer to 28 lbs.

[Gary B.]

Re: Is this flywheel OK to use.

Don,

That's good news. Thanks for finding out the answer.

Gary

[Joe L.]

Re: Is this flywheel OK to use.

Here is my email exchange with the RAM technical folks -

I am having a 1967 chevy small block 327 engine built. It will be built as a stock 327/350HP L79 engine. So I need a 153 tooth flywheel and using a 10.4/10.5 inch clutch setup. I am in need of a flywheel for this car. I am looking for something close to OE, in particular weight wise. From my research, the OE flywheel weight was 28-30 lbs and the RAM 1511 is listed as 26 lbs. This will be for normal street use, not any racing.

In reading on Summit Racing's website the following is a comment included for the RAM 1511 flywheel "Performance and SFI-approved flywheels must be used with performance clutch discs only. Use of a stock-style clutch disk with a performance flywheel will often result in insufficient operating clearance between the disc hub and flywheel bolts".

Does this statement mean that I will not be able to use a stock type single disk clutch setup? I have a LUK 04021 raised diaphragm clutch kit that I am intending to use. Is this clutch setup not compatible with the RAM 1511?

Here's the reply from the RAM tech guy -

Don – the 1511 will work fine with your stock style clutch.That is an old notation from when the center recess was not as deep and would not accommodate stock discs. I would put the weight of that flywheel closer to 28 lbs.

Donald------


The potential problem mentioned on the web-site looks like it should not be a problem based on the response you got from RAM tech. However, that does not mean that there will not be other problems. The critical dimension is the "thickness" of the flywheel as measured from the face of the crankshaft flange surface to the friction surface. This needs to be the same as the stock flywheel. If it is, the flywheel should work OK. If it's different, there could be ensuing problems. Personally, in the latter case, I would not use the flywheel.

[Donald H.]

[Joe L.]

Re: Is this flywheel OK to use.

Thanks Joe,

Do you happen to know the dimension you refer to fir and OE flywheel? I don’t have one to measure.
I am going to email the Ram tech back and see if he can give the dimension for their flywheel

Donald------


For the 14" GM flywheel the dimension is 1.00". I believe it is the same for the 12-3/4" but I am not absolutely sure.

Perhaps, someone else here who has a 12-3/4" flywheel handy could check and confirm.

[Donald H.]

Re: Is this flywheel OK to use.

Thanks again Joe.

I sent an email to RAM to provide the specs, especially this dimension for their flywheel.

Don