Bonneville America Forums Forums Technical Forums Performance Mods Weisco Big-Bore Cometh

Okay, I know all those that are interested in such things have viewed Pat's website (Dinqua). But, by way of reiteration, I will start this thread so as to have all of you journey with me on this Big-Bore installation. You see, I am not a mechanic, - but I am mechanically inclined (I was a backyard VW freak in the early 80's).

Anyway, I figure, if I can do this, many of you can too. So I hope to inspire. I'll post pictures as I go.

Here goes.


First, I stripped all the obvious stuff off my Speedy, - and cleared a nice area to work on the thing.


Here's a picture of the kit itself (bought on sale at bellacorse.com for $399.99)

Stay tuned...

-BT

goodluck withe the work. pictures are good and a final dyno is even better

Frank

Yes, good luck BT. You may give additional hope to us 'junior wrenchers'.

Hey I have the same oil drain pan!!!

Good luck, have fun and go slow.
Then you get to go fast.

Thanks for posting this. So are you going to ship your jugs off to Wiseco to get them bored out, or are you having it done locally?

Pat,

Second night, I'm at this page in your "Big-Bore Saga." I can see I will need to get a better set of feeler-gauges tommorrow.

Here's a picture for where I'm at now.


Note the yellow arrow. This was the only valve that seemed really tight. My 152mm feeler-gauge wouldn't slip in. I'll check more accurately tommorrow.

-BT

Pat,

Here's a question. The "backlash retainer pins" that BA.com member "BUDWEISER" sent to you (see pic below), - are they a do-it-yourself replacement for what the manual calls "Service tool T3880330"?

If so, what are the diameter of those pins?



-BT

Keep the photos coming BT,

I enjoyed observing your Barnett clutch project. Beats most TV offerings.

john

BT,
I don't know the exact size, look like about 1/4" bolts. He cut the head off them and put them in a drill and just filed them down till they fit. There is a slight taper to them as the holes are different sizes. This is not a big deal, you can use a couple allen wrenches crammed in the hole justa s well. As long as they dont pop loose you're all set. Even if they do, a quick trip to a dealer can get them retensioned and shove a tool in the hole. As soon as you remove them, the tension from the big spring clip between the two gears will hold the tool in place as well.
Are ya done yet?
How bout now?
Now?

Pat,

So if I could make sure that I make something that would not allow those backlash springs to lose their tension (become unsprung), I won't be needing that "Service Tool" (pictured below)?



-BT

Exactly! The tool pictured is used to retension the cams should they loose the pressure. All you need is a version of the locking pin to hold them before removing them.
The part that you cannot really see in the picture here is that the gear in the middle of the cam is really 3 pieces.
The cam has one half of the gear as part of the casting. The other side (the sides are the big facing parts with teeth for the outer edges) then there is the other side/face of the gear and a big "C" type spring clip inside between teh two gear faces. The clip is applying tension on the gears in oposite directions, making it want to spin itself in half. {This design keeps the cam chain from slapping around or skipping across the cams themselves.}
Each face gear (for lack of the actual terms) has a hole in them where the locking pin slips into and keeps this big spring clip from flinging the cams apart when you take the cam drive gear tension off of them.
get your face down in there and you'll see that these gear face holes are lined up when everything is in place. If you slip a wedge in there (the locking pin) then you cam remove them and the little tool thingy keeps them from comping apart. Then you can manhandle them pretty much any way you desire. Just be sure to note which ones are intake and exhaust. The manual shows this clearly.

Thanks for the explanation!! I was wondering what was goin on in there...

After spending some time carefully checking all the valve clearances I finally got a pretty good reading (see pic below).



Looks like I'll be in need of some shims.

-BT

Pat,

I thought of a clip I can make of aluminum on my milling machine that would hold that backlash spring in place, so that I wouldn't have to worry about it. But I thought I'd run the design by you to see what you think. Anyway, look at the pic below, and let me know if you think it would work.



Perhaps it's me taking the "chain-saw to butter" approach yet again.

But, they could be passed around after I'm done with them.

-BT

Looks cool. Did you chrome them too?

edit: way way too much work there BT. Just shove some allen wrenches in the suckers and be done with it.
The locking pin MUST be long enough to go completely through both sides and stick out the back of the other side. If not, It will slip off and sproing!

Also, use the shim program I attached to the one page and see if you can re-use/swap any of the old shims to get a correct fit on the ones that are out.

I get really fussy with valve clearances, I like them all to be as close to the same as possible, not just within the tolerances, closer to each other and in the range.

BT go slow. I love reading about this even though it's already been done; as I am planning to add my BB kit to a 360 degree bonnieville motor(865 not 790)

Report from Wednesday.

Well the good news is that I'm shipping the new barrels and my old jugs to Weisco today. The bad new is that I think one of my "locater dowels" fell in my crank case. I'm bummed.

Anyway, the motor has stayed put at TDC, and I will fish around with a flexible magnetic retrievel tool.

If I can't find it, I'm not sure what to do (yet).

-BT

That's a bummer if one did fall in. Don't turn the motor over until it is retreived, else it may become hopelessly lodged in a bad spot. You have a good chance of fishing it out with the magnetic tool though if you're carefull. You can also drop the entire oil pan and see if you got real lucky and it went all the way down.
If not, you can actually lift and flip the bike over and shake it if you have access to a good motor hoist and some good cloth straps. You've already got about 100 pounds off of her, both wheels are also heavy. It would probably be about 300lbs by the time you get everything stripped anway. Not to heavy to be askert to flip her over. Just don't try it by hand, you do need a secure lift.
That may sound extreme, definetly a last ditch effort, but it beats the heck out of splitting the cases apart.

Pat,

Yeah, I would not like having to split the case. I do have an engine hoist (a "Cherry-Picker"). I also could fire up my compressor an shot some air around down in there (to maybe dislodge the thing.

Nevertheless, I'm committed to whatever it takes

I'll keep you posted.

-BT

BTW, Pat, - Weisco is now charging $155 per cylinder for resleeving.

-BT

$155 EACH? Yow, that's highway robbery.
I will be using my local guy then, when I do the ones for Matt and Jaymo.

What happened to the $80-some dollars when Pat did his?

Pat, when I get ready to do mine I know I'll be emailing you plenty of questions. Any progress with Tinman on the cheaper Freak? I want to do that at the same time along with the Barnett clutch. Have Matt and Jaymo removed their airboxes? I don't know if I'll tackle it this winter, maybe after the GA rally.

Greg, keep me posted on the cheap freak too. I have the real thing, but I was thinking of replacing some of the brackets with better, perhaps lighter ones. Maybe stainless or Aluminum. Seems like a bench vise, some bending and a drill press could accomplish it.

Benny,
I was thinking that maybe you could enter the freak brackets or something similar into that parts program you posted the link to about a week or so ago and see what they come up with cost-wise. I just don't have the equipment to fabricate anything or the measurements for the bracket placement. In order to get them I'd have to remove my airbox. That would mean I'd have to stop riding but since you guys in the northern climes are getting close to slowing down for the season...

I'll see what I can do. (this should really be another topic...) But I was thinking that since some folks complained about the mudflap/tood box holder breaking, I would link it to the front bracket (you'd know what I mean if u do it) and then re-fab that bracket to hold just my cheese graters not the underlying side cover) and better align for the side cover. That and eliminate the carb brace part since I have a separate carb brace. We'll see... Need to take my seat off again and see what I'm getting into! All that wiring in there... yikes...

Fridays report:

Since Weisco almost doubled their resleeving fee, I decided to utilized a local machinist that specializes in this type of thing. The proprietor is Mike Auderer (pronouced odd-er-er). His company website can be viewed here. He also going to polish my intake ports. He also urges me to allow him to break it in at his shop on his dyno-machine.

I've removed the oil-sump cover probing around for the locater-dowel I think might have dropped in the crank case, but I haven't found anything. I'm going to look a bit longer, and if nothing sticks to my magnet, I'm going to take the motor off and put it on my work bench and turn it upside down.

Anyway, the pic below shows the point I'm at tonight.



You know, the more I look at this thing, the more I realize how it's just a real basic motor.

-BT

Quote:

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You know, the more I look at this thing, the more I realize how it's just a real basic motor.

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Exactly! It is a very easy motor to work on and very simple in design. High quality, but simple.

Simple is good. Engineer's manta, K.I.S.S.

Oh man, just looking at that makes my stomach queasy!!
You and Pat got the golden nads for jumping in there. Good luck on finding the pin..
Keep the story unfolding it's kinda like a manly man soap opera.
ModelMaker

ModelMaker,

I've delivered the cylinders & pistons for resleeving & matching. I've also delivered the head to have the ports polished. As for the bottom-end, I haven't located the locater pin yet, but I didn't try that hard over the weekend as we had company. However, at this point, the more I look at that bottom end, the more I think I'd like to remove it anyway because it's really filthy up close.

This reminds me of the good ol' days as a backyard VW motorhead with align-bores, over-sized bearings, dual DeLortto carbs, etc.

Stay tuned,

-BT

I like it!! Smart guy...

I can feel for you. I broke the banjo nut and the head and copper washer fell into the return tube. It wasn't fun but after 4 hours I fished out the head. 5000 miles later the washer is still there. I took the risk and so far so good. I'm with you on removing the motor and flipping it upside down. The only problem you may have is the residual oil having that pin stick. You may need to wash it out. No fun either way but I do hope you get it out.

Well, the plot thickens. I had plans the pull the bottom-end of the motor out this coming weekend. But, so as to give it one more try, I decided to probe around with my Craftsman magnetic retrieval tool. Well, I probed around a bit, and all of a sudden I noticed the magnet was off the end of the tool. Now, it seems, I have a 1-1/2 lb. magnet in there also!

It's that friggin "Murphy's Law!"

Well, I went and discussed this issue with AMI Racing engines, and they offered a "wimp clause" for me. They said, "bring the bottom-end to us and we'll split the case and get the pin & the magnet out and put it back together for around $350."

Ouch! I feel neutered!

More to come...

-BT

So it won't be a total loss, see if they can put in a stroker kit while it's open. You may end up with the first 1100!

Quote:

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So it won't be a total loss, see if they can put in a stroker kit while it's open.

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oooooh good idea!

What does a stroker kit do?

Longer stroke = more cubic inches to play with because you gain more on the bottom of the heads. But you also lose a little compression if you make them too long. Gotta balance the needs.
They can be done two ways, a completely different crank (big big $$$$$) or just different length connecting rods. Rods just unbolt and are easier. You might even be able to swap them out by just removing the oil pan on the bottom if you already have the head off. (Hmmmmmm? I wonder....)
I hear that there are also many easily bolt on Cabrillo (sp?)rods available for our bikes too. Jojje (the turbo Swede) has a lot of great information on this stuff. He da man. I know the ones he uses can take over 120hp (so far) without blinking. not too shabby.

It increses the displacement of the engine by lengthening the stroke of the piston...usually with a different crank and longer connecting rods.

edit: Pat must have beat me by seconds with his reply.