|
By DANIEL TINDER - Last Month
|
Soliciting opinions:
In my naivety, and pursuit of weight saving/heightened acceleration, I installed one on my spare motor (soon to likely be called to duty), not realizing how that might affect roadability, considering the E-4 Isky cam also. Reusing the iron OEM one (should it be resurfaced/balanced?), could complicate matters. I anticipate less driving my ‘55 as I progress into my 80s, so should I just live with it? Anyone out there with actual experience to share?
|
|
By Ted - Last Month
|
The rule of thumb is for the flywheel weight to be 1% of the vehicle weight. For a 3000 lb. car that would be a 30 lb. flywheel. Having a flywheel that’s too light makes it difficult to leave smoothly from a stop without bringing up the engine rpm higher than normal and then riding the clutch longer. For an application like a circle tracker where the clutch is not used except at the start of a race, the lighter flywheel does allow the engine to accelerate quicker out of the turns while also allowing the engine to decelerate faster (less braking) going into the turns.
Just my experience so other opinions always welcome.
|
|
By DANIEL TINDER - Last Month
|
|
Considering my OD trans. & rural location, I’m tempted to keep it. I also obtained a concentric clutch assembly, but wasn’t sure I would install it. I wonder how it would then effect operation (?).
|
|
By DANIEL TINDER - Last Month
|
|
Years ago, when I was accumulating parts, I made the unwarranted/bone-head assumption that the stock clutch fork/throw-out assembly would successfully operate a concentric clutch. I’m now having doubts, as it appears an aftermarket hydraulic rig may be required (?). I may thus just change the discs in the OEM unit (already have them).
|
|
By KULTULZ - Last Month
|
" ... stock clutch fork/throw-out assembly would successfully operate a concentric clutch. I’m now having doubts, as it appears an aftermarket hydraulic rig may be required (?). I may thus just change the discs in the OEM unit (already have them)."
They make such a kit for your BIRD? Is it a complete kit (MASTER and BEARING ASSY) or just the bearing assembly? VENDOR - KIT MAKER? DISCS?
|
|
By Litshoot - Last Month
|
Daniel what do you mean by concentric clutch. looking it up im getting hydraulic release bearing or dual disc clutch. are you referring to the pressure plate with diaphragm springs? for diaphragm pressure plate mechanical linkage is fine as long as you have flat faced bearing that contacts correctly and have proper air gap. If go hydraulic make sure you have enough travel to release fully and a pedal stop to prevent overtravel.
Seth
|
|
By DANIEL TINDER - Last Month
|
I likely won’t bother with it, and it will end up on eBay eventually. I also have two spare bell housings, in order to choose the most accurate and thus achieve the least trans. wear (though whoever inherits the car will be the only one who benefits 😁). Admittedly, I have zero experience with clutches, but assume a drop-in inexpensive/rebuilt OEM pressure plate would be simplest, and probably warranted with the alum. flywheel (100K+ miles on my current clutch). I already have a new throw-out bearing, and the discs are the right diameter/splines.
I should have remembered that when dealing with aftermarket upgrades, there are always unforeseen complications.
There must be a reason the concentric diaphragm units apparently all seem to need hydraulic operation (?)
|
|
By KULTULZ - Last Month
|
CLICK HERE - https://www.youtube.com/watch?v=vHO1Led3RZcYou bought a complete CLUTCH SET with dual clutch disc CONCENTRIC SLAVE CYLINDER actuated (CSC)?
On your kit (if kit), how is the CSC actuated? Usually, these are for FWD. Is the assembly meant for a RWD car?
And still considering using an aluminum flywheel on a street car?
|
|
By DANIEL TINDER - Last Month
|
KULTULZ (5/27/2026)
CLICK HERE - https://www.youtube.com/watch?v=vHO1Led3RZcYou bought a complete CLUTCH SET with dual clutch disc CONCENTRIC SLAVE CYLINDER actuated (CSC)?
On your kit (if kit), how is the CSC actuated? Usually, these are for FWD. Is the assembly meant for a RWD car?
And still considering using an aluminum flywheel on a street car?
Re-read previous posts.
Only have clutch & discs.
|
|
By Litshoot - Last Month
|
I had talked with ram because i needed an 18 spline clutch disc for a 10" car bolt pattern. they have a long pressure plate that can use their 10.5" clutch. the aluminum flywheel may have different options for different pressure plates as well. if you've got a diaphragm pressure plate that fits your flywheel id run that with stock clutch linkages and release bearings. for some reason i cant follow it but KISS is the best way, especially if your not planning to own it for long and helps resale.
Seth
|
|
By KULTULZ - Last Month
|
"I may thus just change the discs in the OEM unit (already have them)." You posted discs.
Modern clutch assemblies are offered with SINGLE or DOUBLE CLUTCH DISC. I am just trying to help you here. If you do not want to exchange with me, that's fine There is an IGNORE FEATURE here (I believe).
|
|
By DANIEL TINDER - Last Month
|
Sorry. I just thought my previous explanations were clear, and merely assumed you had overlooked.
Even if the OEM fork/bearing would seem to fit the concentric unit, I would hate to have to change the clutch again should the pedal effort/etc. prove to be unmanageable.
|
|
By KULTULZ - Last Month
|
You're OK ...
The CSC is the actual throw-out bearing. It is just activated (extends) by internal hydraulic pressure instead of a hydraulic slave cylinder and/or a mechanical clutch fork.
I was just curious to see if kit makers were making available kits for older applications.
|
|
By Litshoot - Last Month
|
Diaphragm springs have a lighter pedal feel than long style and multiple discs allows lower spring pressures for the same clamping force. unless the clutch is rated for way beyond your power level it should be lighter. Im doing something similar but in the stupid direction of going with smaller diameter single or double disc.
Seth
|
|
By DANIEL TINDER - Last Month
|
Online research indicates that my OEM release bearing will not successfully operate a concentric diaphragm pressure plate. Investigating now if a conversion part exists that would allow retaining the OEM fork mechanism. Otherwise, the modern unit goes on sale.
P.S. Turns out, I only have a single disc. It just looks like two stacked together (my bad 😙).
|
|
By Litshoot - Last Week
|
Daniel,
are you using a reduce diameter clutch. 38mm face for 5.5, 42-50 for 7.25 and 8.5. Tilton sells 62-063 for ford. you should double check but i believe it works with our arm. as for st 246 from Tilton instructions: RELEASE (THROW OUT) BEARING Type and Size: This clutch is designed to be used with a flat-face release bearing. The outside diameter of the bearing face should not exceed 3.250”. having reduced diameter and rounded face give you more clutch control and lighter activation. i went with quarter master tl2 hrb for mine and with a bit of back and forth got the correct release bearing. quartermaster has more options available, but you need to contact customer service or dig through catalogs to find specs. i went deep down this rabbit hole and will have a running car within a month hopefully to find out how screwed i am. i went with rally clutch for better heat dissipation. depending how it is i might try it as single disc with spacer, or sending out pressure plate to have different spring installed.
lastly if going lighter on rotating weight vehicle weight, torque, and gearing will make a big difference in drive ability. the lighter the car, the more torque it has, and higher starting line ratio make it easier to leave from a stop.
Seth
|
|
By 55blacktie - 5 days ago
|
|
What amazes me is the number of people who don't understand that what works on a track probably won't work on the street.
|
|
By Litshoot - Last Week
|
In my defense i am completely aware. i know its stupid, and its not even its full form yet. ideally id love to have this running with mechanical injection and a blower. im looking for smiles per gallon, even if its a headache.
Seth
|
|
By DANIEL TINDER - 4 days ago
|
Litshoot (6/3/2026)
Daniel, are you using a reduce diameter clutch. 38mm face for 5.5, 42-50 for 7.25 and 8.5. Tilton sells 62-063 for ford. you should double check but i believe it works with our arm. as for st 246 from Tilton instructions: RELEASE (THROW OUT) BEARING Type and Size: This clutch is designed to be used with a flat-face release bearing. The outside diameter of the bearing face should not exceed 3.250”. having reduced diameter and rounded face give you more clutch control and lighter activation. i went with quarter master tl2 hrb for mine and with a bit of back and forth got the correct release bearing. quartermaster has more options available, but you need to contact customer service or dig through catalogs to find specs. i went deep down this rabbit hole and will have a running car within a month hopefully to find out how screwed i am. i went with rally clutch for better heat dissipation. depending how it is i might try it as single disc with spacer, or sending out pressure plate to have different spring installed. lastly if going lighter on rotating weight vehicle weight, torque, and gearing will make a big difference in drive ability. the lighter the car, the more torque it has, and higher starting line ratio make it easier to leave from a stop. Seth
Clutch is correct diameter (J. Mummert supplied it). Might try to track down the manufacturer to check bearing match recs., but after 16+ yrs., not optimistic.
|
|
By Joe-JDC - 4 days ago
|
|
I am using the '55 Thunderbird clutch linkage and arm exactly as it was before I installed the T-5 and diaphram clutch. Works just fine after I was able to double nut the adjusting rod so that it does not back off adjustment. Joe-JDC
|
|
By DANIEL TINDER - 3 days ago
|
Joe-JDC (6/6/2026)
I am using the '55 Thunderbird clutch linkage and arm exactly as it was before I installed the T-5 and diaphram clutch. Works just fine after I was able to double nut the adjusting rod so that it does not back off adjustment. Joe-JDC
Thanks Joe,
I assumed some sort of linkage adjustment/alteration would be needed. Here’s hoping it will continue to work ok. My concern was eventual finger or bearing face damage. I think the flat-faced bearings designed to be used with that type pressure plate may have some type of special coating (?). The grade of steel used in an OEM unit bearing face may not hold up. But, like with the aluminum flywheel, I may be trading longevity and drivability for a few cheap thrills 😎. Satisfying curiosity seems more attractive these days, than saving the next owner grief down the road.
|
|
By miker - 2 days ago
|
|
I’m kind of late to the discussion, but I’ve been running aluminum or lightened flywheels since about 1968. Both birds, and the F code clone in my 32. All in smaller lighter cars, variety of makes. Some over 400 cid. I’m not a drag racer and starting on a hill has never been much of a problem. I use them because I like the quicker change in rpm for shifting. In the last 30 years or so all Centerforce diaphragm clutches.
|
|
By DANIEL TINDER - 2 days ago
|
miker (6/8/2026)
I’m kind of late to the discussion, but I’ve been running aluminum or lightened flywheels since about 1968. Both birds, and the F code clone in my 32. All in smaller lighter cars, variety of makes. Some over 400 cid. I’m not a drag racer and starting on a hill has never been much of a problem. I use them because I like the quicker change in rpm for shifting. In the last 30 years or so all Centerforce diaphragm clutches.
Do you remember the pressure plate-to-flywheel torque you used for the aluminum FW?
Also, I have a set of ARP bolts, and wonder if I should bother buying ARP’s special lube? Blue or red Loc-Tite? (PP under constant tension is unlikely to loosen?)
|
|
By miker - Yesterday
|
|
Been a long time. For torque I would have used either the flywheel literature (or called) or the stock spec. Never recall using loctite on those. Never had one come loose.
|