Topic: 1972 CB750K2 (start from scratch) project. Cases back together

[Davez134]

I think they should be fine, but I ride a lot and want peace of mind so I'm torn.

[Davez134]

Well, if you're feeling sporty, you could always upgrade to a set of Carillos and dispense with the worries over the stock/possibly worn rod bolts. Or, get some ARP bolts if there's an application for your stock rods.

I was looking at arp, but would be a custom order and pricy for 8 bolts/nuts. Really leaning toward cycle x rods/bolts now, getting my stock crank balanced as well.

[edwardmorris]

Dave,

     Found this when searching around for my own 836 build. If you haven't already, give this a read

     http://forums.sohc4.net/index.php?topic=135886.msg1529730#msg1529730

     Covers a lot of ground, should answer your stock rods question, among others

[Davez134]

Dave,

     Found this when searching around for my own 836 build. If you haven't already, give this a read

     http://forums.sohc4.net/index.php?topic=135886.msg1529730#msg1529730

     Covers a lot of ground, should answer your stock rods question, among others

Awesome thanks!

[Davez134]

Got my cylinder head back from Mike Rieck today. Wow! Very happy!

[Davez134]

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[SOHC4 Cafe Racer Fan]

Another satisfied MR customer.  Gotta love the personalized engraving on the head, too!   

[edwardmorris]

Post up some pix of those nice Stage 2 ports please, would love to get an idea how extensive Stage 2 is.

[Davez134]

Post up some pix of those nice Stage 2 ports please, would love to get an idea how extensive Stage 2 is.

Here ya go...




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[Davez134]

Stock replacement springs, Dave? And stock size valves? Did you have Mike do a Serdi cut on the head?

Yes, yes, and yes 

[edwardmorris]

Ports look great! Any word on what cam you're going with yet?

[Davez134]

Ports look great! Any word on what cam you're going with yet?

I wish I knew. Definitely not my area of expertise. I'm going to use the wiseco 836 10.25/1 pistons. I want to take advantage of the extra displacement and flow through the head, but I still want a very street-able bike.  I ride pretty much daily so I want something that has a pretty broad range, nothing extreme. Very open to suggestions/experiences!!

[Davez134]

So, I'm at a little standstill with my project due to some car problems that I had to fix first. (responsibility ugh!) I want to get going with it again soon, but I would like some advice/opinions before I do. My questions are concerning the crankshaft and connecting rods. My plans for the engine are ported /polished head, wiseco 836 kit, HD studs and primary chains. I checked the crankshaft bearings which were all well within spec. As I was about to check the rod bearings I stopped because I'm not sure what I should do. I don't know if I should remove rod bolts, check bearings and reuse (can't tell if they've ever been taken apart) Get new rod bolts (seem hard to find and expensive, plus read factory rods could be weak link here ) or with everything else I am doing just go with lightened and balanced crank/forged rods from cyclex. (not sure if this would be overkill) I'm not afraid to spend the money for the right parts to do this right, I just don't want to waste $$. I'm split down the middle on this one so any advice and past experience from you all wold be greatly appreciated! Thanks!

I've decided to use factory rods and crank, with new F2 rod bolts and nuts (supposedly stronger?). Crank and alternator are getting balanced right now. Ordered rod bolts 1 week ago and they already showed up yesterday. They look the same as what I have already, did I get the right ones? part number is 13213-kv0-000



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[Davez134]

Making slow progress, mostly trying to locate parts. Some showed up today...



Got a deal on swingarm, complete triple tree from Dennis (Old Scrambler) so I can get frame mocked up, then powder coated.


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[edwardmorris]

I just saw Wiseco and Forged in one of the pix, here is some reading you might wanna glance over, been doing some research myself, thought I'd save you some time

http://forums.sohc4.net/index.php?topic=132990.msg1489322#msg1489322

http://forums.sohc4.net/index.php?topic=75828.msg847562#msg847562

http://forums.sohc4.net/index.php?topic=85642.msg971049#msg971049

[Davez134]

I just saw Wiseco and Forged in one of the pix, here is some reading you might wanna glance over, been doing some research myself, thought I'd save you some time

http://forums.sohc4.net/index.php?topic=132990.msg1489322#msg1489322

http://forums.sohc4.net/index.php?topic=75828.msg847562#msg847562

http://forums.sohc4.net/index.php?topic=85642.msg971049#msg971049

Thanks! Have seen the first link, just read through the other two. Same Pistons I have in my other bike, have a little over 8000 miles on em since my top end rebuild, and who knows how many before that as I just switched out the rings. Going to read a little more on the subject before taking to machine shop for peace of mind though.

[Davez134]

These are what the pistons look like. Same "height" as Honda pistons, but with more pronounced "u" shape cutaway on skirts as I saw mentioned in the linked posts. Also noticed no oiling holes under piston pins like stockers I have to compare to...



 Packaging states .0020 piston to bore clearance

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[Davez134]

One down, one to go...



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[Davez134]

Been trying to get the nasty paint off cases, and finally got my cylinders bored for 836cc pistons. Almost done with cases...


Here are cylinders. Bored, surface trued, media blasted old paint off.

Must have blasted after surfacing as I noticed this rough spot in next picture. It's in front of number 4 cylinder around the hole dowell goes into. Surface is still true there using my strait edge, just feels a little rough. Is this anything I should worry about?



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[Davez134]

Welded/repaired chipped fin. Going to do final shaping tomorrow, then clean/paint.



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[rickmoore24]

Just had to say, your finished K2 is pretty sick. Well done!

[Davez134]

Just had to say, your finished K2 is pretty sick. Well done!

Thank you! This one is gonna be more resto than mod but hopefully just as nice!

[Davez134]

Early Christmas today. Got my balanced crank back and a box from CycleX with:
HD studs
HD primary and cam chains
Gasket kit with MLS head gasket
All new main and rod bearings
Primary and cam chain tensioner wheels
Clutch plates
Progressive fork springs
New fork tubes
Think I can have motor and forks completely done by end of month. Hopefully.

[Davez134]

Well, wife is gone for a few hours. Engine cases in dishwasher, curing carburetor paint in oven. If she comes home early, I may not live through this. I'll post up some pics when done


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[timbo750]

I did similar recently,  turn on exhaust fans and when you are finished but a pot with water and lemon juice in the oven on a high temp for 20-30min. Have done it three times now and still living under the same roof.