re installing cylinder

OK, tore the base gasket a few days ago like a bone head. Got another today and am ready for cylinder install. I have hose clamps around the rings. Does anyone have a picture of how they supported the cylinder whilst slipping the cylinder over the rings alone? I don't want anymore mishaps and can't afford the emotional melt downs I have when I do stupid things, thanks.

I took 1/2 diameter 3' wood dowel from a hardware store, cut into four pieces and put them crossing under pistons. 2 per piston. Worked fine for me.
Bob

britbike220 said:

Does anyone have a picture of how they supported the cylinder whilst slipping the cylinder over the rings alone?

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Support the pistons.

You will be holding the cylinder barrels as you lower them. The ring clamps should be loose enough so they are pushed downwards as the cylinder barrels are lowered onto the pistons.


In the Mick Hemmings video, he uses a piston support plate with a long slot which fits over both conrods and rests on top of the base studs and not on the gasket. You could easily make a similar 'plate' from a piece of wood or plywood.

I found it a lot easier to install the pistons in the cylinder first, then support the cylinder, leaning forward against the frame tubes, with a full tube of caulk - the kind of caulk in cartridges you use in a caulk gun (and only because that's what I found around the garage at the time) while pushing through the wrist pins and installing the circlips. Was actually VERY easy this way.

Yes, if you have a circular saw, you can cut a piece of E shaped plywood to fit between the con rods and wide enough to go over all the crank case studs. What I did was use 3 pieces of flooring (3/4" thick) cut into about 1 foot long pieces. Put them under the pistons at TDC on top of the crank studs, the center one needs to be narrow enough to fit between the con rods. Push the pistons down on the wood, have your gasket in place at this time, and put the clamps on the rings tight enough to compress them, but loose enough to move over the pistons. If you have the force with you, put the cylinder over the pistons evenly and it will push the clamps down over the rings and the barrel will be over them. Take the clamps off and push the barrel on as far as you can, take the wood out and seat the barrels and put the nuts on. I have had luck with this, but then I have good first time experiences for some reason.

Sorry I didn't take pictures when I did it.

Dave
69S

I think I got it, thanks guys. I'll give it a go Thursday after work. Made more sense to me to hear E shape piece of wood for some reason.

Space the ring gaps 3 ways equally. Helps if you got an assistant to lower the jugs while easing down the ring clamps. Don't forget to put light oil down the barrels to make em slip in smoother.

Mick

ML said:

Space the ring gaps 3 ways equally. Helps if you got an assistant to lower the jugs while easing down the ring clamps. Don't forget to put light oil down the barrels to make em slip in smoother.

Mick

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Unless of course you subscribe to the modern wisdom of no lube on the rings, just a smidge on the piston skirts.


As difficult as it was for me, mentally, to do this, I did try it on my last re-ring of the Norton, and all went fine. Haven't tested compression yet (been about 1200 miles since the work) but let me assure you this motor is HEALTHY!

I have never had much luck using the clamp method of bringing the cylinder down on the pistons. The taper at the bottom of the cylinders always seemed to push the clamps down before the rings made into the bore. The other technique of inserting the pistons from the top with clamps is much easier. Install the inboard wristpin clips before hand. It takes two people to mate up the pistons to the rods, one to hold the cylinder and another to line up the pistons to the rods and install the pins and outboard clips. Quick and easy. Don't forget to install the clips with the sharp edges facing away from the pins. You mentioned that you are using a fiber base gasket. I read someplace that you should clean the mating surfaces with lacquer thinner and don't touch them or the gasket surface if you can help it.

I wasn't able to make the cylinders-over-the-pistons technique work for me either, and used the same technique as Bob. However, after watching Mick Hemmings whip through it on his DVD, I'll use his method the next time I do a rebuild. The key elements (which were missing from my abortive attempt) are SHORT ring clamps (just high enough to cover the three rings) and his resting plate.

A piece of 3/4" plywood under the pistons makes things easier and safer.

Your standart 69 cent hose clamp is just wide enough to compress all the rings if you play with it. You may need a $1.50 one to go around the piston.



I used 3 pieces of old wood flooring (3/4 thick) to put under the pistons, supports both sides of them.



Dave
69S

I use the "u" shaped piece of plywood as shown in maylars picture.

L.A.B. wrote;

In the Mick Hemmings video, he uses a piston support plate with a long slot which fits over both conrods and rests on top of the base studs and not on the gasket.

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My piston support plate rests on the gasket (yes I do fit one), but next time I have to fit a barrel, I will try this method of resting the support plate on the studs, as I do put a very very thin smear of silicone gasket on the cylinder base gasket, and am always conscious of the plate removing some of the silicone.

bpatton wrote;

I have never had much luck using the clamp method of bringing the cylinder down on the pistons. The taper at the bottom of the cylinders always seemed to push the clamps down before the rings made into the bore.

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I have found that you have to get the clamps quite tight on the rings to stop this happening, so that just as the rings are released they are well into the taper on the barrel, the barrel just sits on top of the piston ring clamps and I just tap it down with a clenched fist gently, keeping it nice and square. This last time I have fitted the pistons/rings dry with no noticable ill effects.

I don't suppose it matters how you fit the barrel as long as it works without breaking rings etc.

I never use clamps. I use a pair of inlet pushrods across ther cases to support the pistons. Set the compression rings at 180 degrees apart....top on with the gap at the front, middle one with the gap at the rear, then space the oil rings normally.

Just tilt the barrel back slightly to catch the top ring, and as you tilt it forward it will close the top ring, tilt it forward a bit more to just cover the 2nd ring, and then tilt it backwards. Both comnpression rings should now be in the bores, oil rings just slip in easily. It takes about 30 secs to do the lot!

That's how it was done in the factory!

I always but the pistons/rings in dry, and never have a problem, perfect seal still, no blowby and leak free motors

Bob, I agree with you on cylinder installation. I always cringe whenever I see someone with ring compressors or worse yet hose clamps installing barrels. It"s so easy to scatch the soft ring face or break the ring and you don't even know it.
Here is how I've been doing it for the last 30 years.

First I put a little sealant on the gasket. About as thin as I can get it. I like permatex anarobic gasket maker for base gaskets. [until I have to take it apart] Then I get three 3/8 drive deep sockets and put them over the front stud and two rear studs.



Then I install the pistons into the cylinders. No ring compressor is needed. Just your fingers and maybe a tough depressor. Then slide the pistons in to the edge of the pin hole. Make sure the two inner snap rings are in place.



Now with the rods near bottom dead center I set the barrels on the sockets. Even with the motor at an angle in the bike the sockets keep the barrels in place. There is just enough room to move the rods around and line them up with the hole in the pistons.



After you slide the pins in install the outer snap rings. A rag under the edge of the piston may keep the snap ring from ending up in the crankcase.



Now just lift the barrels enought to take the sockets off the studs and set it down. One person-no sweat. If the pins are tight in the pistons it helps to warm the barrels and pistons in the sun or the oven till they are an easy sliding fit. Jim

I've tried it both ways and prefer the pistons in cylinder slide in rod pins method. BUT, in some cases, as mine, the darn piston pins are too tight to slip in easy and heated pistons cool off once in barrel. You do not want to beat-press on rods sideways getting pins in very much. Got a new set of pistons and pins and rods for Trixie Combat, so who knows which method will do the trick next time. Good shop gem on the sockets on studs for support, cool. Better shop gem to stuff in rags for wayward items.

I had no luck with compressing the rings either and did the other method of inserting the pistons in the bores, lowering the barrels and inserting the wrist pins. I tried freezing the pins to make that easier - left them in the freezer overnight but still needed to tap them in with a brass drift. I'm a little gunshy of the force necessary to shove the barrels down over the rings - at least with the compressors I have. I have seen rings break if they don't compress properly and with force needed to shove down the barrels it seems to me that this could happen without feeling any sort of complaint from the rings. Then you could end up with broken rings in your new assembly and never realize it.

I know it is done all the time but I would personally never use a hose clamp to compress piston rings. I have one excellent ring compressor that I used for years on cars but I couldn't find another one like it in Mexico. I bought a standard ring compressor but it was too large and wouldn't allow the barrel to get past the rings before the compressor hit the plywood.

The sleeve cut-outs fore and aft allow perfect finger-squeezing space to slip the pistons in easily, regardless of the method used.

I like setting the crank near TDC and putting the engine in gear to keep the crank from rotating, working with the install at the top od the stroke for maximum working space.

Thats why you heat the barrels with the pistons in them. The barrels hold the heat for a long time and give you a lot of working time. Jim

hobot said:

I've tried it both ways and prefer the pistons in cylinder slide in rod pins method. BUT, in some cases, as mine, the darn piston pins are too tight to slip in easy and heated pistons cool off once in barrel. You do not want to beat-press on rods sideways getting pins in very much. Got a new set of pistons and pins and rods for Trixie Combat, so who knows which method will do the trick next time. Good shop gem on the sockets on studs for support, cool. Better shop gem to stuff in rags for wayward items.

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Most car engine ring compressors are not that bad. Unfortunately they don't work to well on a Norton. I have two pair of the Norton ring compressors in my drawer. They both have sharp edges and pretty poor finish. I would hate to use them.

ludwig said:

Litterally billions of car pistons have been installed with ring clamps , so they can't be thàt bad ..
But then , there are ring clamps and ring clamps ..
Comnoz , what strikes me in your picture demo is that the timing cover is allready on .
I always time the cam after the barrels are on ..

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