Author Topic: FFJMOORE CB550 BIG bore engine build. (Read 82986 times)

goldarrow · « **Reply #300 on:** June 12, 2012, 10:36:56 PM »

yes, i was right behind you and pick up your left over....just kidding.

i got the rest. since you mention the Gent's Express. that's the direction i'm going with my bike also, but not gonna do 750 pistons mod as this will drain my pocket real quick.

crazypj · « **Reply #301 on:** June 13, 2012, 09:45:38 AM »

Quote from: ffJMoore on June 12, 2012, 09:34:35 PM

I just used a harbor freight dial gauge on the mounting arm. Stuffed it in a drill chuck. It was about 4.5 long, so 9" from side to side and was off by .003. This was a rough measurement.

0.003" in 9" isn't too bad and should be easy enough to get to a lower number.
It works out about 0.004" per foot.
Was it front to back or side/side?
Side/side isn't a problem, start cutting fron the 'high' side and trailing edge will give a finer finish.
Front/back will need fixing though as you'll get angle and steps across surface (unless you make a heavy duty fly cutter to do entire surface in one hit)

sinister902 · « **Reply #302 on:** June 13, 2012, 01:24:34 PM »

It is rough seeing all the unneccessary hurdles you've had to overcome, but I thank you for your documentation and experiences because I plan to start on my 650 w/836 kit hybrid motor soon and I'm certain this will be an invaluable resource for me...

Keep at it!

Flying J · « **Reply #303 on:** June 22, 2012, 04:02:41 PM »

Started to do a little milling for the oil sleeve. the o ring depth is not enough. Its a 2mm thick o ring so Im shooting for 1.5mm. Getting the right depth is not going to be easy. I dont have a way to check the depth while its in line with the bit. I have to move it to the side so i can check with my caliper. ANyway, back to the garage and do the other side.

crazypj · « **Reply #304 on:** June 22, 2012, 05:08:33 PM »

Do you have a DTI and magnetic base?
You should be able to index off depth stop
Looking good

You may already be too deep, what thickness is head gasket?

Flying J · « **Reply #305 on:** June 22, 2012, 05:15:53 PM »

~~Well I think this will work but~~ i have been doing some reading and it looks like the 8mmx2mm o ring needs closer to a 13mm hole for it to expand.
http://www.oringsusa.com/html/gland_design.html
I dont really have much more room to go bigger with out cutting into the sleeve. So i think when i do my cylinders ( this set are my old cylinders) Im going to try and get some 7mm dowel tubing. So far all I have found is aluminum. I guess that will work. What do you think?
http://www.hobbylinc.com/htm/k+s/k+s9806.htm

Flying J · « **Reply #306 on:** June 22, 2012, 05:21:12 PM »

Quote from: crazypj on June 22, 2012, 05:08:33 PM

Do you have a DTI and magnetic base?
You should be able to index off depth stop
Looking good
You may already be too deep, what thickness is head gasket?

Yeah I was just thinking about that. I think I am to deep. Good thing Im practicing but i did just F up a set of cylinders. So if i need to go 1.5mm deep and the head gasket is 1.09mm thick I only need to go a half mm.

crazypj · « **Reply #307 on:** June 22, 2012, 06:27:22 PM »

Not really a big deal, you can find a washer to fit under 'O' ring and put a dab of silicon under it
Isn't there an inch size that will match up with what you have? (5/16"ID)
Alloy dowels will be fine, if you want to 'rescue' those cylinders I'll make some specials with a flange on them
Are the alternator cove dowels 7mm? (I think that's what I used but, it was over 30 yrs ago

)
BTW, was it as easy as I said?

Flying J · « **Reply #308 on:** June 22, 2012, 06:48:23 PM »

Yeah. Its easy but the engineering part is what is difficult. I'll do some more research tonight to find the best dowel size and o ring. I'll just deck those cylinders to bring it back down. They have to be decked any way.

crazypj · « **Reply #309 on:** June 23, 2012, 09:39:27 AM »

Cool, bump compression and re-shape combustion chambers to get better burn

I think I AM having more fun machining than building or riding

Flying J · « **Reply #310 on:** June 25, 2012, 04:09:23 PM »

I think Im going to build this motor w/o the modification. I have another 550 i need to rebuild so ill practice on that one and then if this one ever starts to leak ill fix it.

Here is the shaved down and tapped tachometer plug. Im going to get a button head for the top bolt also.

11884

Flying J · « **Reply #311 on:** July 10, 2012, 06:06:33 PM »

been a bit since i messed with the motor. Its hot in the garage but my little swamp coller is helping. I also have been building a gate for the side of the house along with other honey do projects. But I think im in good enough graces with the wife to spend some time in the garage. Got the top put together and I just need to make a mounting plate for the dial indicator. Then I will degree the cam and check clearances on the pistons/ valve.

I have also been a little distracted by my 175 build.

12227

Tintop · « **Reply #312 on:** July 10, 2012, 06:10:38 PM »

The 175 looks like fun, but glad to hear there has been more progress on the 550.

Was thinking I should pack up the sidecar, and make another trip to Pomona in January. Would probably win my class, of course I'd also likely be the only one.

Flying J · « **Reply #313 on:** August 09, 2012, 03:09:22 PM »

Go figure that degreeing a cam would be a pain in the ass just like everything else on this motor.

~~So at 0 lash im getting contact with the valves and cant make a full 360~~. Now for the timing card. The 750 cards have much more info then the 550 cam. Here is the one I have.

So am I looking for .050 for lift when the degree wheel hits 248? 0 being TDC.
My degree wheel only has 90 so would i be shooting for the 68 after BDC? ~~Is it normal that i have piston contact before the cam is dialed in or am i looking at trouble?~~ No its not normal. HELP!

Flying J · « **Reply #314 on:** August 09, 2012, 04:36:25 PM »

Ok so i figured part of the problem out. The idiot who installed the cam was wrong on how to install it. It was off by almost 180 degrees. So i fixed it and now there is no contact. but i still need to know what degree it opens and closes. I feel like there is a lot of info missing from this card.

Flying J · « **Reply #315 on:** August 09, 2012, 09:05:02 PM »

Just need some help dialing in the cam. I am totaly lost on what numbers im shooting for. Where i have it set right now im at:
Intake OPEN 5* BTDC, CLOSE 51* ABDC
Exhaust OPEN 20* BBDC CLOSE 37* ATDC

Why does my cam card not have any of this info?

that is only 236-237* duration @.050

bwaller · « **Reply #316 on:** August 10, 2012, 05:39:47 AM »

WebCam has been providing timing cards with numbers that never seemed to be achieveable. I was told those #'s should be read at the lobe or some such... Not providing any numbers is not the answer.

I have the 58a cam and it should be "squared" so that intake opening & exhaust closing numbers were identical 24/51 & 51/24, again this for the 58a cam. Maybe someone will provide the 58b info.

You should aim to match lobe centers.

Flying J · « **Reply #317 on:** August 10, 2012, 08:06:10 AM »

Im going to send out some emails to the suppliers of this product and see what they have to say. As for matching the lobe centers. With the numbers i have my lobe center is 118° ~~so i ll try and set the lobe center 118° Atdc for intake and 118° Abdc for exhaust. Am i understanding that right?~~ edit: after thinking about it that is not possible. I will continue searching for the answer.

Flying J · « **Reply #318 on:** August 10, 2012, 11:25:00 AM »

Slowly movng the cam around I am very close. Here is the response i got from Buzz at Dynoman.

Quote

Hello Jason,

As your motor is a rocker are design the specs are going to be different on every motor depending on the rocker arm ratio. Using the lobe center method set the cam strait up or 1 or 2 degrees retarded if you are wanting more high RPM power. When the lobe center numbers are as close to the same as possible your cam is strait up.

Sounds like the specs they gave on the 750s were so un-achievable that they just left them off completely for the 550. Hard to be disappointed in the specs if there are none.

Flying J · « **Reply #319 on:** August 10, 2012, 12:17:49 PM »

Ok. I have the cam "squared" in now. Final result is Intake 11 and 44, exhaust 44 and 11. I will double check it again to make sure im dead on. Now i need to check the piston/valve clearance. The numbers i found for that on the forum are 0.080" exhaust and 0.050" intake.

Flying J · « **Reply #320 on:** August 10, 2012, 02:32:39 PM »

Cam is dialed, 13 45 and 13 43. Good enough. Checked the piston to valve and had plenty of room. Not even close to the min clearance. SO whats next? I guess tear it down, make sure i didnt hurt any valves when i bumped them and then put on fresh gaskets?

Its been hard to stay motivated on this stuff as it is supposed to be 111° today and the garage is not air conditioned.

those are not tears its sweat.

bwaller · « **Reply #321 on:** August 10, 2012, 03:15:52 PM »

Something I just thought of when you have it apart place the cam in the valve cover upside down with the rockers in place. Spin the cam & make sure the lobes don't contact the underside of the rocker shaft "beam". The other issue with some cams is lobe/cylinder head clearance of the cam tunnel walls.

Hopefully this isn't the case or it's already too late. I don't think these cams are close anyway.

Good job, when you final assemble it, it will go easier and you can likely match LC's even closer.

RAFster122s · « **Reply #322 on:** August 10, 2012, 03:19:49 PM »

Well for a couple hundred you could buy a small window unit to help take it down some but you really need to spend the money for enough capacity. Is the garage insulated enough even if you were to add AC? The big portable swamp coolers you can roll around work pretty good if you can deal with the air movement and work pretty close to them, 6-8 feet. Or the portable AC units do an OK job.

Flying J · « **Reply #323 on:** August 10, 2012, 05:06:10 PM »

Thanks bwaller, i will double check all that.
RAFster122S I have a window unit swamp cooler that i put on wheels. It keeps it ok temp up to about 95 but above that it has to be right on me and i move around to much in the garage and have no space to roll it. garage is not insulated or finished so that is the biggest issue. I just work in shifts, 20min here 20 min there with time inside to cool off. I really would like a 3 car garage or a shop Then i could fit all my stuff and the stuff i want but cant fit like upholstery sewing machine, english wheel, planishing hammer, lathe, tube bender ect.

RAFster122s · « **Reply #324 on:** August 10, 2012, 05:32:05 PM »

Now you just crossed over to fantasyland with all the cool toys...if you magically become rich/billionaire or several millions, then maybe...

News:

Author Topic: FFJMOORE CB550 BIG bore engine build. (Read 82986 times)