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Big or small clutch for my elky?

5K views 17 replies 6 participants last post by  Crosley 
#1 ·
Hi guys, please help me decide which clutch to use, I have both a small 153 flywheel with corresponding 10 inch clutch and small bellhousing, and also have a big 168 flywheel with 11 or 12 inch clutch plus the corresponding bigger truck bellhousing.

I don't think ground clearance will be an issue with the big clutch setup, but would like to know your opinions.

I find more advantageous using the bigger units because both the obvious bigger clutch advantage plus I can use the big fat starter motor, I'm not sure if the small motor can crank my 350 well.

this is a street car, will not be raced but I love burnouts, the heavier flywheel may be more advantegous for frying the skins, the motor is hopped up and topped by a 144 B&M blower, the tranny is a 4 speed saginaw.

please comment.

Augusto.
 
#4 ·
The 153-tooth flywheel might be able to accept a 10-3/8" (10.4") pressure plate & disc. The one that came with my '69 Nova did. The reason I mention this is that the Saginaw is not a heavy-duty tranmission, and it might not last long with a heavier flywheel and a really strong clutch. Even with the smaller clutch, it might not last too long if you feed it a steady diet of burnouts.

Measure the friction surface to be sure, and check the diaphragm spring fingers on the 10" pressure plate versus the 10-3/8" one. My 10" plate had fingers that were flat, but the ones on my 10-3/8" one were bent toward the rear, so I had to use a different (shorter) throwout bearing.

The 11" clutch my sister's '69 Camaro had needed much more pedal pressure than either of the stock 10-3/8" ones I've had in a couple of Novas. I hated driving her car in traffic because of it.
 
#5 ·
DO NOT USE A FLAT FINGERED DIAPHRAM PRESSURE PLATE!!!!!!
you WILL need extra underwear if you do!
on second thought, Depends might be less messy..
wait'll that clutch pedal sticks to the floor at about 5-6K.....
myself, i like a small diameter clutch, 10.5 min.
shift a bit easier than an 11" at wfo....
as far as the sag, well,you CAN break anything;)
 
#6 ·
I think there are 2 points I must ask now

1- diaphragm or 3 finger pressure plate?

2- what about the small starter with the small flywheel setup? can the big one used here?

I used to have a 81 Blazer that had a diaphragm 11 inch clutch and was very soft and pleasant to drive, I was thinking of using the same parts.

I've never seen down here a 10 3/8 inch plate, is it a chevy item?

Augusto.
 
#10 ·
Must use a starter with straight across mounting for the 153 Flywhweel
Staggerd mounting is for the 168 tooth
(Stock type starter-------Some AT trans starters will not fit in a manual bellhousing)

I have a mini starter in my 59---seems to be working okay----however, there is usually no provision for the starter to provide power to the distributor while cranking----may need some electrical re-engineering.

If you have any value on your left knee----avoid the 3-finger Borg & Beck like the plauge.

I have an 11 inch Diaphram in the 59, with hydraulics, and it is fine with me.
I have an 11 inch Diaphram in the 79 Chev C-10, mechanical linkage, pretty easy to operate---WAY NICER than the 12" Borg & Beck it replaced.

I just put a 10.4" in my 66 Elky, but have not yet tested it out on the road, but felt okay sittin' still.

And yes---a 10.4" is a very common disc on GM products, from 4-cyl to v-8.
The 10" is a bit less common I think, but many are out there.

The pressure plate will accept either disc.
 
#12 ·
Bryan59EC The pressure plate will accept either disc.[/QUOTE said:
Not always. My '69 Nova w/230 came from GM with a 9-1/8" clutch disc, but I replaced it with a 10" disc (normally used with 307 engines) once it wore out. The inner diameter of the lining was the same on both discs, and they matched the inner diameter of the pressure plate surface. The outer diameter of the pressure plate surface was 10". The next time around, I changed to a 10-3/8" clutch as used in 327 & 350 cars, which required a different pressure plate whose outer surface diameter matched that of the disc.

The flywheel (12-3/4" diameter, 153-tooth) remained the same throughout.
 
#17 ·
Crosley,

how high did you revved it? I have used 12 inch clutches all my life in my chevy trucks and have never exploded one, I had a supercharged 350 on one that sometimes I revved up to 6.000 and didn't fail, but it was very seldom because the valves floated badly.

Augusto.
 
#18 ·
Augusto said:
Crosley,

how high did you revved it? I have used 12 inch clutches all my life in my chevy trucks and have never exploded one, I had a supercharged 350 on one that sometimes I revved up to 6.000 and didn't fail, but it was very seldom because the valves floated badly.

Augusto.
I regularly buzz'd the engine to 7k RPM.... the engine was not stock OEM specs.

:D
 
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