Looking for the right flywheel

[Littlebeefy]

Hi y'all,

I want to mate up an internally balanced 460 to a zf 5 (s5-47). Ideally, I'd like to use the Centerforce Dual Friction clutch DF968968, which will fit the 1 1/4" input shaft, but is an 8 bolt pressure plate with a 12 1/4" disc. I called Centerforce and asked for more specifics on the dimensions and applications, and was told that this clutch kit would bolt directly onto a factory 96 F250 with a 460 and ZF5 so I would think a neutral balanced flywheel that matched the dimensions and mounting parameters of 96 OEM would work, but I take everything that Centerforce told me with a grain of salt (sadly).

When I look at that kit on Summit, it shows it as a 12" disc, but when I called Summit for assistance, they said they do not sell a flywheel that will work in this application.

I'm looking at my options for billet steel flywheels. My understanding is that a 390 flywheel will work in this application, but I still don't know about the clutch size regardless. Anyone able to point me to the right part?

Thanks

Chad

[85lebaront2]

I don't know on a 390, but a 429 should fit and will take a good sized clutch (429 SCJ possibly).

[ArdWrknTrk]

Chad,

L&L sell the flywheel and clutch you need.

https://www.landlproducts.com/460-clutch-flywheel

JBG has it too (from L&L)

Give L&L a call and ask them about a package with the Zf input spline.

A 390 flywheel can work but the ring gear diameter is not right so you'll be looking at an oddball ring gear or a custom Tilton starter to get the clocking correct.

The spacer (starter locating) plate from my engine with a T19 works fine with the Zf.

The 390 flywheel has been suggested for the shallow bell of a linkage type clutch but since your Zf-5 is hydraulic there's no need to deal with any of that nonsense.

[Littlebeefy]

Chad,

L&L sell the flywheel and clutch you need.

https://www.landlproducts.com/460-clutch-flywheel

JBG has it too (from L&L)

Give L&L a call and ask them about a package with the Zf input spline.

A 390 flywheel can work but the ring gear diameter is not right so you'll be looking at an oddball ring gear or a custom Tilton starter to get the clocking correct.

The spacer (starter locating) plate from my engine with a T19 works fine with the Zf.

The 390 flywheel has been suggested for the shallow bell of a linkage type clutch but since your Zf-5 is hydraulic there's no need to deal with any of that nonsense.

The aftermarket 460 flywheels that I’m seeing are also marketed as 429 flywheels probably because of the fact that they are identical blocks and cranks, right? Still haven’t found one that I know to be compatible with the centerforce clutch at 12.25 inch disc size. If you know of one please let me know.

@Jim - I’m familiar with the JBG package (from LandL) but I shied away from that because the clutch looked kind of puny. I’m going higher compression on my 460 so I’m worried about slippage. If anyone has real world experience with running that clutch against a high potency 460 I’d love to hear about it.

I know some people historically have use the FRPP flywheel M-6375-Z460B which is discontinued but still on a couple of shelves. Has anyone used this before and if so do you know applications for pressure plates that work?

[85lebaront2]

The aftermarket 460 flywheels that I’m seeing are also marketed as 429 flywheels probably because of the fact that they are identical blocks and cranks, right? Still haven’t found one that I know to be compatible with the centerforce clutch at 12.25 inch disc size. If you know of one please let me know.

@Jim - I’m familiar with the JBG package (from LandL) but I shied away from that because the clutch looked kind of puny. I’m going higher compression on my 460 so I’m worried about slippage. If anyone has real world experience with running that clutch against a high potency 460 I’d love to hear about it.

I know some people historically have use the FRPP flywheel M-6375-Z460B which is discontinued but still on a couple of shelves. Has anyone used this before and if so do you know applications for pressure plates that work?

There is a friend on FB that has a 1967 Mustang street rod with a built 460, if you are on there his name is Chris Austin and he frequents the Ford groups. If you aren't I can ask him what he is using,

[ArdWrknTrk]

The aftermarket 460 flywheels that I’m seeing are also marketed as 429 flywheels probably because of the fact that they are identical blocks and cranks, right? Still haven’t found one that I know to be compatible with the centerforce clutch at 12.25 inch disc size. If you know of one please let me know.

@Jim - I’m familiar with the JBG package (from LandL) but I shied away from that because the clutch looked kind of puny. I’m going higher compression on my 460 so I’m worried about slippage. If anyone has real world experience with running that clutch against a high potency 460 I’d love to hear about it.

I know some people historically have use the FRPP flywheel M-6375-Z460B which is discontinued but still on a couple of shelves. Has anyone used this before and if so do you know applications for pressure plates that work?

That four puck clutch L&L offers seems to have a good reputation among pullers.

I don't know how much juice you're putting into this Chad.

Why an internal balance crank?

Because you want shorter cylinders on both ends?

An external balance crank will fit an early (short deck) block and the throws are the same.

[Littlebeefy]

That four puck clutch L&L offers seems to have a good reputation among pullers.

I don't know how much juice you're putting into this Chad.

Why an internal balance crank?

Because you want shorter cylinders on both ends?

An external balance crank will fit an early (short deck) block and the throws are the same.

The engine that I’m using is a complete C8VE so I’m just keeping it mostly original. It already has hardened valve seats and the higher compression early heads. I was going to change out the cam and intake but keep it mostly stock otherwise. Heavy ass under hood monster...

I could switch to an external balance crank but if I ultimately want to buy an aftermarket billet steel flywheel, why not just get a neutral balance one and keep the existing crank? If I had the stock clutch and flywheel it might make sense to machine out the hatchet weight on the OEM flywheel and just install it all together, but I don’t so that’s not really an option for savings.

I don’t mind spending the money on a top-notch clutch and steel flywheel for the cleanest transfer of power. I’m under the impression that a 12+” clutch disk is the best possible option and the Centerforce Dual Friction technology is top notch for high power applications.

When I look at the OEM style LUK clutch on Rock Auto it shows it as 12.25” disk and Centerforce told me that the DF968968 will fit the factory flywheel, so I just need to find a factory-matching-dimensions billet steel wheel that is neutral balance (or has a removable weight). But when I look online no one gives useful dimensions on any of the products. Even some of the pictures are not accurate so you can’t even tell what the predrilled pressure plate pattern is.

Definitely DM me if you know someone who has put a big clutch on a 460.

[ArdWrknTrk]

The engine that I’m using is a complete C8VE so I’m just keeping it mostly original. It already has hardened valve seats and the higher compression early heads. I was going to change out the cam and intake but keep it mostly stock otherwise. Heavy ass under hood monster...

I could switch to an external balance crank but if I ultimately want to buy an aftermarket billet steel flywheel, why not just get a neutral balance one and keep the existing crank? If I had the stock clutch and flywheel it might make sense to machine out the hatchet weight on the OEM flywheel and just install it all together, but I don’t so that’s not really an option for savings.

I don’t mind spending the money on a top-notch clutch and steel flywheel for the cleanest transfer of power. I’m under the impression that a 12+” clutch disk is the best possible option and the Centerforce Dual Friction technology is top notch for high power applications.

When I look at the OEM style LUK clutch on Rock Auto it shows it as 12.25” disk and Centerforce told me that the DF968968 will fit the factory flywheel, so I just need to find a factory-matching-dimensions billet steel wheel that is neutral balance (or has a removable weight). But when I look online no one gives useful dimensions on any of the products. Even some of the pictures are not accurate so you can’t even tell what the predrilled pressure plate pattern is.

Definitely DM me if you know someone who has put a big clutch on a 460.

If you have a complete C8VE I understand.

You've found a unicorn!

Congratulations!!!!

I have the Luk HD clutch waiting for a year to go into my truck. (Same as I already have)

Not that mine is slipping, but my ring gear is toast and if I'm pulling my flywheel to change that I'm not putting a five year old clutch back in.

If you want me to measure, it's sitting in a box in the barn.

Call L&L.

Gary did not have a good time with his headers but they can give you all the specs for their flywheels.

They designed them and sent the drawings to a machine shop to be made. (And they are okayed for sub-10 second cars) so I don't think there's a problem there.....

[85lebaront2]

The engine that I’m using is a complete C8VE so I’m just keeping it mostly original. It already has hardened valve seats and the higher compression early heads. I was going to change out the cam and intake but keep it mostly stock otherwise. Heavy ass under hood monster...

I could switch to an external balance crank but if I ultimately want to buy an aftermarket billet steel flywheel, why not just get a neutral balance one and keep the existing crank? If I had the stock clutch and flywheel it might make sense to machine out the hatchet weight on the OEM flywheel and just install it all together, but I don’t so that’s not really an option for savings.

I don’t mind spending the money on a top-notch clutch and steel flywheel for the cleanest transfer of power. I’m under the impression that a 12+” clutch disk is the best possible option and the Centerforce Dual Friction technology is top notch for high power applications.

When I look at the OEM style LUK clutch on Rock Auto it shows it as 12.25” disk and Centerforce told me that the DF968968 will fit the factory flywheel, so I just need to find a factory-matching-dimensions billet steel wheel that is neutral balance (or has a removable weight). But when I look online no one gives useful dimensions on any of the products. Even some of the pictures are not accurate so you can’t even tell what the predrilled pressure plate pattern is.

Definitely DM me if you know someone who has put a big clutch on a 460.

Chad, I don't know if this will help you or not, first he is running a twin disc and second he has a scattershield since he does race the car (drag racing). Here is what he sent me:

I run a Mcleod steel flywheel and RXT twin disc, holds up to 1000 hp, damn nice clutch

Its pretty much a Hi bryd I fabricated.

Used a modern driveline pedal linkage n master cyl.

Actuates a Wilwood external puller slave, that pulls on a modified factory fork and throw out bearing. The bell is a TKO scattershield.

Lots of easier solutions, but TKO bell is unique in dimensions, didnt want to risk hyd leaks of a hyd TOB, and the external slave has better reaction times than internal hyd TOB.

Lots of trial n error in getting ratios to work.

A number of years ago I helped another friend swap a 1972 Lincoln 460 into a 1986 F350 wrecker, he had a problem burning up clutches as the factory one was a 10 1/2" (same size I had in my 1966 Shelby) we got a 12 or 12 1/2" clutch and had the flywheel drilled for the correct pattern. Only issue after that was 1 clutch fork and a clutch housing broke.

[Littlebeefy]

Chad, I don't know if this will help you or not, first he is running a twin disc and second he has a scattershield since he does race the car (drag racing). Here is what he sent me:

I run a Mcleod steel flywheel and RXT twin disc, holds up to 1000 hp, damn nice clutch

Its pretty much a Hi bryd I fabricated.

Used a modern driveline pedal linkage n master cyl.

Actuates a Wilwood external puller slave, that pulls on a modified factory fork and throw out bearing. The bell is a TKO scattershield.

Lots of easier solutions, but TKO bell is unique in dimensions, didnt want to risk hyd leaks of a hyd TOB, and the external slave has better reaction times than internal hyd TOB.

Lots of trial n error in getting ratios to work.

A number of years ago I helped another friend swap a 1972 Lincoln 460 into a 1986 F350 wrecker, he had a problem burning up clutches as the factory one was a 10 1/2" (same size I had in my 1966 Shelby) we got a 12 or 12 1/2" clutch and had the flywheel drilled for the correct pattern. Only issue after that was 1 clutch fork and a clutch housing broke.

Thanks everybody for the feedback. I’ve done a lot of research and talked to many vendors. McLeod was by far the most helpful. Did you know they manufacture some of the FRPP products?

Here’s what I found. The OEM flywheel on the 96 F350 with 460 and ZF5 would have had a flywheel that was predrilled for an eight bolt pressure plate that could accommodate the 12.25 inch clutch. The DF968968 package from Centerforce will fit that flywheel without drilling. However, every single manufacturer of billet flywheels for the 460 has them predrilled for 6 bolt pressure plates. I have yet to find a single exception.

There seems to be two options. Most of the new billet flywheels have a removable counterbalance and are available with a 15.5” outside diameter at the ring gear meaning, like Bill said, they could be drilled to accommodate the larger pressure and bish bash bosh, Bob’s you’re uncle.

Alternatively, Centerforce sells a stage 1 clutch that seems to be marginally better than stock. It’s not sold as a set but the clutch disk and pressure plate are part numbers 381968 and CF361968 respectively. This will fit the ZF5 per Centerforce and has a 12.25” disc. Ironically this will not fit the predrilled 8 bolt OEM flywheel even though it accommodates the 1.25” input shaft on the ZF5. It’s surprisingly difficult to find a really solid upgraded single disk diaphragm clutch kits that fit an input shaft that size!

I’m going to keep looking around for a bit longer but it seems like the Dual Friction CF clutch with a fresh drilled McLeod (or other aftermarket) flywheel will cost me only marginally more than the JBG combo and has to be a significantly better performer at 12.25” vs. the L & L 11”.

The OEM flywheel was ~40#. Many aftermarket billet ones target the 34# pound range but go as high as 40 and as low as 23 (and then you get to aluminum). Anybody have any recommendations for a good flywheel weight?