Author Topic: FFJMOORE CB550 BIG bore engine build. (Read 83074 times)

dave500 · « **Reply #200 on:** April 05, 2012, 11:51:29 PM »

go to a nut and bolt store or find a soft spring that will suffice,even a ball point pen spring or something similar?

bwaller · « **Reply #201 on:** April 06, 2012, 10:33:48 AM »

Even an old worn out OEM inner spring. I personally dislike the clay method.

Flying J · « **Reply #202 on:** April 06, 2012, 02:26:33 PM »

So I need to buy a valve spring compressor tool? Any suggestions on a good one, preferably cheap?

Flying J · « **Reply #203 on:** April 06, 2012, 05:07:24 PM »

Ok, getting a little ahead of my self. Not sure how to get the pistons into the cylinder. I bought the harbor freight ring compressor. Modified it a little and then threw it away. Its junk for pistons this small. Are there any tricks? I have seen this one recomended. http://pitposse.com/piriin.html

While i was at HF i bought a clamp to make a valve spring tool. I think its going to work great.

Greggo · « **Reply #204 on:** April 07, 2012, 11:44:37 AM »

Go to a hardware store, preferably one with a good plumbing section, and find yourself some good hose clamps that will work.

Flying J · « **Reply #205 on:** April 07, 2012, 10:20:51 PM »

I bought an actual copy of the Honda cb550 manual. I did not know that the con rods have to face a particular way but after read the manual i know now. So i am a little freaked out. I dont remember if i ever took all the rods off at the same time or not which would allow me to confuse the direction. So does anybody have a con rod the can look at and tell me if the little cut out is on the side of the con rod with the letter or the number?
Mine is installed with the letters to the front so i hope its on that side.

I also made some plates to bolt down the cylinder but they are to close to the middle and i can not make a full revolution. The piston contacts the bar. So i guess i will have to drill another one with a little more offset.

dave500 · « **Reply #206 on:** April 08, 2012, 02:39:07 PM »

with the rods,the side where those bearing shell tangs goes to the front.

Flying J · « **Reply #207 on:** April 08, 2012, 02:44:15 PM »

yes, i just found that out but i have already put the motor together. I can see the rods and that the letter is facing the front so im hoping I did it right and dont have to take the cases back apart. So if anybody has some spare 550 rods let me know which side the tang is.

dave500 · « **Reply #208 on:** April 08, 2012, 02:49:19 PM »

the number is also on the front,going by the bottom end i have here.

EDIT, didnt have my glasses on,,its a letter to the front.

dave500 · « **Reply #209 on:** April 08, 2012, 02:51:25 PM »

ill open it up if you want me to double check,,its an unkown spare bottom end i have.

Flying J · « **Reply #210 on:** April 08, 2012, 03:39:55 PM »

no you dont have to do that. I have a spare motor that I want to rebuild so I guess ill drain it and pull the pan when i get home tuesday and see if its the same as yours. I realy dont want to split the cases again.

Flying J · « **Reply #211 on:** April 09, 2012, 12:11:14 AM »

OK

I looked at almost every crank i could find on ebay and they all had the letter on the front and the number on the back. That is how mine is installed So i feel confident enough to leave it alone. You may want to check that one you have dave. it could be on backwards.
8695

dave500 · « **Reply #212 on:** April 09, 2012, 12:59:48 AM »

your safe then,,i have edited my post#208.

bwaller · « **Reply #213 on:** April 09, 2012, 05:22:48 AM »

ffj I just use two short pieces of steel front to back using two studs each and used aluminum spacers under them next to the top of the cylinders. This doesn't interfere with pistons at tdc plus allows you plenty of room to use a dial indicator.

Not that what you have won't work, maybe just a bit "over engineered". Respace so there is room underneath your clamps.

Flying J · « **Reply #214 on:** April 09, 2012, 04:59:23 PM »

Ok I was under the impression that I was going to torque this thing down pretty good and did not want to apply uneven pressure and warp something. But if all I have to do is get it snug the I can use the same thingI have but just put some spacers under the flat bars to give the piston room to come up. Right?

bwaller · « **Reply #215 on:** April 09, 2012, 06:38:16 PM »

Quote from: ffJMoore on April 09, 2012, 04:59:23 PM

Ok I was under the impression that I was going to torque this thing down pretty good and did not want to apply uneven pressure and warp something. But if all I have to do is get it snug the I can use the same thingI have but just put some spacers under the flat bars to give the piston room to come up. Right?

It should be fine as long as you can get your measuring tool in place.

dave500 · « **Reply #216 on:** April 10, 2012, 12:02:17 AM »

ive just gently squared them down with half a dozen sockets to space out the free stud length,ever so lightly nipped down.

Flying J · « **Reply #217 on:** April 10, 2012, 12:29:26 PM »

Well im not sure that it was the metal bars touching the piston that was stopping it as much as it was the crankshaft contacting the skirts that was stopping it.

You can see the height differance on the stock 550 skirt. you can also see where the crank is bumping.

at the top of the picture you can see where it is scuffed on the inside lip at about the 12 oclock position.

SO how about some advice. Would machining the skirts curved like the 550 skirt and give it a little extra room?
Will removing that inner lip be ok?
Anybody up to the challenge or should i take it to my local machine shop and see what they would charge me?

Flying J · « **Reply #218 on:** April 10, 2012, 12:38:16 PM »

Contact from the top angle

side view of the same.

current cutaway of the skirt.

dave500 · « **Reply #219 on:** April 10, 2012, 01:29:24 PM »

id ring the piston supplier just to check,where they sold as a big bore kit for 500/550?or are they just 750 pistons?

Flying J · « **Reply #220 on:** April 10, 2012, 01:31:39 PM »

They are cb750 pistons.

dave500 · « **Reply #221 on:** April 10, 2012, 01:36:21 PM »

oh ok,id take the engine to a machinist to take a quick look,some like to leave the skirt alone and skim the crank?im sure the skirt could be machined though.

Flying J · « **Reply #222 on:** April 10, 2012, 02:09:08 PM »

if i cut the side of the skirts any shorter im going to loose the brace that runs around the inside. Is it necessary or can i loose it?

If i skim the crank could that throw it off balance?

dave500 · « **Reply #223 on:** April 10, 2012, 02:18:03 PM »

id show your local good machinist/ engine place and pick their brains.

dave500 · « **Reply #224 on:** April 10, 2012, 02:23:07 PM »

heres some 61mm pistons in a 550 barrel,these were cb/cl 125 to 150cc big bore pistons,,they seem to have plenty of skirt clearance,they arent honda pistons though.

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Author Topic: FFJMOORE CB550 BIG bore engine build. (Read 83074 times)