Blowproof Bellhousing & Aluminum Flywheel?

[WardL]

How important is a blow proof bellhousing? I know how important it is when you have a catastrophic failure. But really, how often does that happen? Right only once... Do you need one to participate in racing events, etc? It looks to cost an extra $300.

And that aluminum flywheel! Is that worth it for a 400 HP street Cobra? Do you think it is noticeable when accelerating?

Thanks for Club Cobra! This is so much fun and I don't even have one yet!

[Ralphy]

First I would ask is, how aggressive do you drive? Do you use the upper end of your tach?

[StreetSnake]

I have a lakewood one for my 427W that I may be swamping out. If you'd be interested in it and not in a big hurry to get it let me know. If you go with a small block that is.

[WardL]

I would like to use the full range of my engine RPMs without fear of loosing my toes, yes. This would be for a small block. Why would you swap out your lakewood?

[RICK LAKE]

WardL Ward the SFI bellhousing and clutch assembly should be used in all cobras. I am not trying to hit below the belt but have you seen a soldier come back from war?? He had no choice, you do. I have seen flywheels explode at the track we where sitting half way up in the bleechers and the guy 3 feet down from me was hit in the arm and had to go to the hospital. Piec e of metal went through the car fire wall and windshield to hit us. Distance was about 15' in hieght above the track and 40'+ from the track. If nothing else, you plan on giving car rides and showing off a little. Would you want someone else hurt for a extra $300.00 dollars??? The odds of your flywheel or clutch coming apart are about 1-2%. No part is perfect but safety should not be a cost overrun ideam either. You have Fathers Day, Feb 14, Aniversary day, Birthday, and even Christmas but that's going to be a longer wait. Buy a used one with a good SFI date code. No older than 5 year if possible. Good luck. Ps I have no luck and run 2 jeeps, 1 trans am, and the cobra all with lakewood bell housings. I like walking on my own legs. Rick L.

[patrickt]

Brent Lykins (I believe it was him) posted a vid of a clutch/flywheel giving way over on the FE Forum last year. It was absolutely devastating. It would be like sticking your legs into an exploding buzz-saw. If you saw the video, you'd buy a blow-proof bellhousing without giving it another thought.

[StreetSnake]

I definetley recommend one. There's nothing there but a little fiberglass. I may be switching out to a quicktime BH, not because I dislike the Lakewood. It has a great name and I'm sure it'lll do the job. I'm more interested in swapping out my slave cylinder set up. Currently I have a push, but might go to a pull style. It'll be an expensive change but it's only mondy right.

[Ron61]

I agree with the blow proof bell housing but for a street driven car I don't think the aluminum flywheel is that big of a thing. They will wind up a little faster, but you also lose some of the deceleration when you get off the gas and have to use the brakes more. An example of this is me and a friend of mine who had identical set ups except he had the aluminum flywheel and I had a steel one. We came back from Weaverville, which is up in the mountains and on a very twisty road, it follows the old stage couch route. I hardly touched my brakes at all and he was having to use his all the time. He told me afterward that he wished he had put a steel flywheel in as when he down shifted he was all the way into the corners before he could even feel any compression start and he watched my brake lights and only saw them come on for a second a couple of times.

Ron

[patrickt]

Originally Posted by Ron61

... you also lose some of the deceleration when you get off the gas and have to use the brakes more.

Ron, are you sure about this? I would think that the stored energy in a higher weight flywheel would require additional braking to slow down. Surely there's a mechanical engineer on here that could answer the simple question: "If a Cobra is travelling, say 120mph at 5000rpm, does it take more brake force to bring it to a stand still if the flywheel weighs 18lbs or if it weighs 25lbs?" No fair pushing the clutch in during braking.

[jwd]

Originally Posted by Ron61

you also lose some of the deceleration when you get off the gas and have to use the brakes more.
Ron

Absolutely correct. You also have to rev. it a little higher when taking off from a complete stop. I've run both and personally, I would never run another aluminum one on a street driven car.

Jim

[Ron61]

Patrickt,

That has been my experience with them and that is why I went with the steel flywheel in my Cobra. I guess the heavier weight just drags down faster because I could feel the difference and as I stated, that friend of mine that followed me down from the mountains said he used his brakes on almost every corner while I barely touched mine a couple of times. He used a steel one is his next car.

Ron

[Buzz]

Originally Posted by patrickt

Ron, are you sure about this? I would think that the stored energy in a higher weight flywheel would require additional braking to slow down. Surely there's a mechanical engineer on here that could answer the simple question: "If a Cobra is travelling, say 120mph at 5000rpm, does it take more brake force to bring it to a stand still if the flywheel weighs 18lbs or if it weighs 25lbs?" No fair pushing the clutch in during braking.

I have to go with Paddy on this one. A heavier flywheel retains more inertia and resists changes in engine speed far more than a lighter one, whether accelerating or decelerating. Lift off the gas at high rpm and the heavier flywheel acts like a gyro and just wants to keep on going. The lighter one is far more responsive on deceleration as it offers less resistance to changes in engine speed (ie: "engine braking").

[Ron61]

Buzz,

I am no engineer and am not trying to BS anyone, just going on my own experience and that of my friends. I do know we drove each others cars quite often and I could tell the difference in how fast mine slowed down compared to his. Maybe it wasn't the flywheel, but except for that we had identical engines right down to the stroke and power. I know his did wind up a little faster but I didn't think it was enough to justify the extra expense for a street car. And I had no problems at all when racing in keeping up with or passing him. I could drive deeper into the corners as he started braking about a car length before I touched mine. Truthfully I had always thought that the steel would be slower to stop also. Maybe there was something else about his car that was causing this. We had the same compression, but I had to watch mine to keep from hopping the rear wheels while I could downshift his at the same RPM and it didn't do it. I am not trying to convince anyone that one or the other is better. I just answered the question from my own experience.

Ron

[Ralphy]

I think the weight difference would not be so noticeable, that one car would need to brake and the other not.

Also racers have always been trying to reduce rotating mass with smaller multidisc clutches and automatic transmissions with no torque converters. Allowing better response coming out and going into turns.

http://www.autotransdesign.com/produ...0000081_th.jpg

This would be almost the same as saying a heavier car slows faster.

[Buzz]

Quite likely it was some other reason - not the flywheel. Maybe he had to brake more because his car was running up on your tail as it accelerated faster coming out of the turns .

The heavier flywheel is generally more pleasant to drive on the street as there is less rpm drop during shifts making them smoother and less peaky. A lighter flywheel pays dividends on a high-revving car on a road course but could be more of an annoyance than an advantage behind a high torque, higher compression engine; especially in a heavy car. Was this in the lil' Cobra or the bigger, heavier one?

[Ron61]

Ralphy,

The rotating mass I understand and I can't explain why our cars acted differently. He even borrowed my engine papers to have his built to the exact same specs except for the aluminum flywheel and he is a road racer also. That is why we figured it must be something to do with the flywheel. We put the cars on his scales to balance tham and they were within 10 pounds of each other. Sorry I posted that as it was not meant to start such an argument.

Ron

[Ralphy]

Many other things can change braking. One big one is gearing in the differential. Compression ratios, cam or do your carbs close exactly the same. Do your brakes drag a little.

[Ron61]

Ralphy,

I never meant to start a big argument and now I am sorry that I posted that. All I know is, there was a noticeable difference in his car and mine, both on the track and off. He even borrowed my engine papers and had his built to the same specs except for the flywheel. We used his scales and balanced the cars and they were within 10 pounds of each other so the car weight wasn't that much. We both figured it must be the flywheel as that was the only difference except the color of the cars. Maybe white stops faster than black.

Ron

[Ralphy]

Ron,

LOL, no argument here, I see your questioning why. With equal cars, like one of Conan's skits. Things that make you go hmmm...

[Buzz]

Relax man. This is not a big argument - it's a discussion with different opinions and experiences. It's good stuff and what forums like this are all about. People don't have to agree all the time. Actually, life would be boring as hell if we did.