Clutch Frozen

[Keoke]

. You know Bob, it always amazes me how much people spend to send out their carbs for rebuilding when it is such a simple and relaxing task on the work bench.

Yeah if you get jets & Diaphragms that are compatible with Calif Ethanol fuel.

 

[Bob_Spidell]

....Yeah if you get jets & Diaphragms that are compatible with Calif fuel.

All the rebuild kits we've bought for several cars for years say 'ethanol resistant' on the packaging (they won't say 'ethanol proof,' probably for legal/liability reasons). I don't think E10 is unique to CA anymore--it's common in most of the western states, at least--and I don't know of any other ingredients that are problematic; CA fuel is seasonally blended to adjust its vapor pressure (higher in winter, lower in summer).

 

[drambuie]

That may be because working on carburetors falls into the same category as brain surgery (or rocket science) in many people's minds. Or one needs some of that magic dust to sprinkle on them to make them work right.

That said, I plan to undertake rebuilding a set of H4 carbs when the kits arrive. I hope that the kits include bushings for the shafts, as they probably need to be reamed out before fitting new shafts. Also looking for a hand reamer.

.

You can get the reamer at any local Grainger tool supply, they also can order you any custom sizes. I personally like expandable reamers as they let you adjust a little smaller, then you gradually open them up to reach your ideal bore size. If you use the standard size reamer...they do tend to ream the hole too big if you push to hard or if the reamer is dull or if you are not aligned properly... A floating head helps to correct this if you are using a Bridgeport mill use a lot of oil and low RPM. DONT PUSH TOO HARD or you will go oversize.

 

[drambuie]

. You know Bob, it always amazes me how much people spend to send out their carbs for rebuilding when it is such a simple and relaxing task on the work bench.

Yeah if you get jets & Diaphragms that are compatible with Calif fuel.

.

I wasn't aware the left coast was using any different blends of fuel then the rest of the country? I do know the fuel blends are changed for winter and summer months here in Chicago.

 

[Bob_Spidell]

.

You can get the reamer at any local Grainger tool supply, they also can order you any custom sizes. I personally like expandable reamers as they let you adjust a little smaller, then you gradually open them up to reach your ideal bore size. If you use the standard size reamer...they do tend to ream the hole too big if you push to hard or if the reamer is dull or if you are not aligned properly... A floating head helps to correct this if you are using a Bridgeport mill use a lot of oil and low RPM. DONT PUSH TOO HARD or you will go oversize.

I think the 'trick' is you need a reamer that aligns in both bushes while you ream one (sort of like the king pin reamers); does the Grainger reamer do that? FWIW, the reamer Moss sells is $270.

 

[drambuie]

I think the 'trick' is you need a reamer that aligns in both bushes while you ream one (sort of like the king pin reamers); does the Grainger reamer do that? FWIW, the reamer Moss sells is $270.

. Yes, it's called line boring.. You first must center the bores with the cutting tool, in this case a reamer. I am a machinist by trade, however I think most folks can have reasonable success with a hand reamer if they use caution. I use technics and procedures for various machiniing. Again, a floating head will help align the bores as well.

I am sure the reamer would be cheaper at
Grainger or Mc Master Carr they sell the reamers, about 20 bucks or so. They also sell the bushings 3/8 O.D and 5/16 I.D. Part # 6391k153 about 50 cents each. They are oil impergnated. Personally, I would machine Delrin bushings In place of bronze, much easier to ream and I would think the sealing properties would be better.

 

[homebeforedark]

I've had luck with almost all of the above mentioned methods for freeing a seized clutch. The most successful method lately is to let the engine run long enough to heat-soak the flywheel. This could take a couple of hours. So far this method has worked every time and doesn't put an impulsive load on the drive train.

 

[blueskies]

This thread is a bit mixed by now, everything from frozen clutches to reaming carburetors for fitting throttle shaft bushings.

I tackled the second problem today, after buying a master rebuild kit for the H4 SU carbs and a few types of reamers.

I began the reaming by trying to use the adjustable hand reamer that I had bought; what a waste of money. No control, poor quality cutting, and a disaster waiting to happen.

Then I had a look at the 5/16" Grizzly (made in India?) machine chucking reamer that I bought from Amazon for about $20. The shaft measured exactly 5/16", a perfect fit for the old throttle shaft hole in the carburetor. So I stuck the reamer through both throttle holes and connected a cordless drill to the shaft where it emerged from the carburetor. It fit very nicely and provided reasonable line boring precision to the operation. I don't think that a good lathe would have been more accurate. (My mini lathe was too small for the operation.) Since the chucking reamer is sharpened to cut from the front end only, I took a fine diamond file and sharpened the rear edges of the six blades. It then cut beautifully. I took care to stop about 1/8" short of going through the far side of the throttle shaft hole. That was deep enough for the entire new bushing to fit it while leaving enough of the 5/16" diameter original metal to guide the next hole on the other side of the carburetor. After repeating the operation for the other side, the new bushing, 3/8" OD and 5/16 ID, fit in well and tightly. The throttle shaft now moves freely and has no noticeable play. Then I repeated the same operation on the other carburetor.

Sometimes one just gets lucky and discovers an unexpected solution.