Reduced clutch pressure

Oakhurst

Oakhurst

Senior Member
We are restoring a 1933 race boat that at some time was repowered with a V8 60 run in the POD class. It was run with direct drive only, no transmission, so when it was started it was moving. We want to use it recreationally so some sort of "neutral" is necessary. We found a bell housing I think originally made for midget racing as it allowed room for a clutch assembly and an in/out shift lever. We have eliminated the in/out box because we had no room for it. We are trying to activate the clutch with a lever (using a model A emergency brake lever.) However after having a stock Ford pressure plate and disc rebuilt an installed, it seems there is too much force required (legs are stronger than arms) to deactivate the clutch with the new lever. Are there any standards we could use to lessen the spring pressure required to activate the clutch. Since this is in a boat with a prop, as opposed to a rubber tire on a road, we think less pressure would be OK. If so should we just remove half the springs or are springs with less tension available?
 
Shorten the center to center measurement of the lever from the point the lever swivels on to the point that it connects to the clutch mechanism. If you can, this will give you much more leverage.
Martin.
 
The pressure plate can be modified to remove several springs. What type of pressure plate are you using the Long or the Borg? The Long has the additional weights on the exterior of the pressure plate to increase pressure with RPM. This will increase force necessary at higher RPM but at near idle, you may be fine. The Borg does not have the weights and is the original style pressure plate used in 33-34 Ford. Talk with the experts at Fort Wayne clutch.
 
I have seen flattened pipe extensions on the clutch lever
As Tyerry mentioned there are several clutches used, the early clutch ---truck clutch, and the 40 engines used the 9" with the weights---this one you could take out most of the springs

What Rpm is your boat set up for//, when I had the 60hp sedan i bought a lot of NOS parts from a boat racer, he told me that with stock valves, bottom end done to Ford specs (all weights within 1 gram) that he used 7000 rpm, that got 2 seasons from the engines between rebuilds, that at 7500 rpm less than 1/2 season ---with this knowlede I drove the 39 different than the A or big V8----found that high rpm didn't hurt fuel mileage as much as lugging it, downshifting to 2nd at 40 mph in the hills

post some pictures of your linkage---- and boat, pictures create interest and more solutions
 
Give me a lever long enough and a fulcrum on which to place it, and I shall move the world.
Archimedes

To me this is the easiest/best way. Removing springs would require the assistance of the pressure plate rebuilder. Engineering a lever with a better ratio can be done at home and will be economical too. Keep in mind that a shorter lever length on the clutch side of the pivot point will increase your mechanical advantage but also increase the throw required at the handle.
 
We are using what I think is an original pressure plate as we removed it and the flywheel from a late (1940?) V8 60. We considered a hydraulic system, but want to try to make this work first. I will remove it and look for the weights. That sounds good. Do you agree that we can get by with less spring pressure because it's a prop in the water instead of a tire on the road? Regarding the 7K rpms that seems crazy. I need to learn more about that. Still trying to figure out how to post pictures. I'm Apple and will try again. Any suggestions?
 
Why not try the increased leverage like me an fordors said? You don't have to pull the clutch, it could be as simple as drilling another hole and plopping in a clevice pin. Could be done and working in minutes. Or at least tried out.
Go simple first.
I think the prop in the water can put a good load on that clutch if you beat on it some, and why wouldn't you, it's a boat with a V8 up it. So lightening up the grabbing power of the clutch may not be a good idea.
Martin.
 
With propeller SLIP and propeller EFFICIENCY being what they are, you may just get away with the need for less pressure than being "directly hooked" like a tire on dry pavement. DD
 
Actually I slipped an 18"pipe over the clutch lever and I would say it was about a 60 lb pull.
Sure I can do it, but it is a strain. I need to pull the pressure plate out again and see if it has the weights. It was mounted to the flywheel with the larger surface area which I was told was the 1940, the last year.
 
I'd take some springs out of the pp or replace them with lighter tension ones. You don't need a clutch rebuilder to do it. All you need is a press to take a pp apart and re assemble it.
 
The 40 style would look something like this--
 

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I have been told that a Sachs BB1904 Diafram P/P for a 1983 to 2003 Chevy S-10 For all V6s & 4 cylinders will work .
 
Going to try some lever tricks first. Then either remove three of the six springs or replace them with some weaker ones. I noticed the C1 on jimvette59's message. I have a 62.
Love the C1's. hope I'm not violating the rules by mentioning this.
 
Hope not too far off first post .... (1960s) I dropped a '56 Mustang 289 into a 17 footer with a 10" x 14" 3-blade prop and clutch slipped like mad before the design 4400 rpm. Threw away clutch, substituted an adapter plate and Osco manual 1:1 marine ****** and the Prop worked great .... held 4400 rpm at top speed .... that boat really moved. At the same time Friend had a 19 foot hydroplane with modified Ford 292 and marine racing overdrive ****** that turned his 2-blade prop at about 10,000 rpm ... had no trouble exceeding 100 mph and raising a hugh roaster tail on the way .... barely got it up to top speed before reaching the end of the lake. Those were the days ....
 
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Two more good points! Unfortunately HEBE has a stepped hull, in that era called a hydroplane, and no room for a real ******. We had to machine the "box" off the midget
race car bell howling to get it to fit. The point about a boat motor always being under load is a factor I had forgotten about. Hydraulic clutch sounding better. If you click on "V8 60 marine use" on the internet there are pictures of our boat ( 0-60 HEBE) underway clocked at 85mph.
 
I have been in boats that just had a "crash box" in/out transmission without any clutch at all. Worked fine with the prop slippage.
 
Diaphram pressure plates require less pressure to operate. I don't if one is available for your application.
 
Paragon gear used to make a small in and out box for marine use called an OXKB 90 nicknamed 'the turtle'. Very short coupled affair. I was shown one in 1972 and haven't forgotten it's name because I did so much with oddball inboards and it fit everything.
 
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