building the fantasy carby 750 top-end

[carbmon]

Well this has been a hugely informative thread for me, thanks to the 'experts' for sharing their experience.

The 695 head swap sure looks tempting for the next phase of fun with my carby M750 toy.

For now I think I'll leave the engine alone and finish the frame cleanup, re-wire and repaint project I have in progress, watching forums and eBay for the necessary pieces in the mean time.

One Two Three last (yeah, sure) questions for now .... does the 695 as stock have adjustable cam pulleys and Speeddog, on your prior 695 head swap, do you recall where you ended up setting the cam timing on that project (going for the gold in trying to tap your experience here  )?  Any idea what the valve/piston clearance was with that setup?

So one version of the fantasy carby 750 top-end might be:
+ 695 heads & cams
+ 11:1 pistons
+ OEM long intake runners with my current 39 FCRs
+ adjustable cam pulleys to be able to dial-in cam timing
+ Ignitech unit to be able to dial-in ignition timing
+ Dyno time for stock baseline and to get the 695 setup tuned and see what the real gains are

[Speeddog]

So the options for a more straight forward fit are 900V cams and valves or 695 heads. What do the 695 heads go for up there? Down here I think it would be cheaper to get 900 cams and valves.
~~~SNIP~~~

The heads we used were nearly brand new, and IIRC were ~$500.
But we bought them from a bandit....
Should be able to find a set for about those $ now.

SPEEDDOG  > would hi comp pistons and big cams work with my F.I. M750 ?

Brad Black did a 750SSie with big cams:
http://www.bikeboy.org/750ss_900carb_cams.html

Likely would work well.
But, he did a lot of fueling work, so you've got to consider that in the budget as well.

~~~SNIP~~~

One Two Three last (yeah, sure) questions for now .... does the 695 as stock have adjustable cam pulleys and Speeddog, on your prior 695 head swap, do you recall where you ended up setting the cam timing on that project (going for the gold in trying to tap your experience here  )?  Any idea what the valve/piston clearance was with that setup?

~~~SNIP~~~

Yes, 695 has the adjustable pulleys.
We left 'em in the stock position.
I've got no info on what the valve/piston clearance was, I suspect we just got lucky. 
I wouldn't build it again without setting cam timing and checking clearance.

[carbmon]

.....
Yes, 695 has the adjustable pulleys.
We left 'em in the stock position.
I've got no info on what the valve/piston clearance was, I suspect we just got lucky. 
I wouldn't build it again without setting cam timing and checking clearance.

Thanks again for all the info.  Sounds like everything would fit-up pretty straightforward, it might be interesting to see what that cam profile would do to the TQ/HP curves on the longer-stroke 750.  It seems that the same profile is used in the longer stroke 800, too, so that really suggests to me it is worth a shot on the 750.  Couldn't be any worse that the stock small valve heads/cams fer sure.

Keep me in mind if you run across any of the needed bits 

[brad black]

the 696 cylinder and head swap sounds interesting.  might have to order a base gasket to see if they're the same.

[carbmon]

the 696 cylinder and head swap sounds interesting.  might have to order a base gasket to see if they're the same.

OK, I'll bite ... what about the 696 approach strikes you as more intriguing than the 695 heads?

+1/+.5 valve size?
+4deg overlap cam?

With the 696 having 4.3mm shorter stroke than the 750, would you anticipate any clearance problems (is the deck height of the 696 jug likely to work OK with the 750's longer-stroke crank)?

Just trying to tap a little deeper into that experience base you bring to the table  

[carbmon]

I've been spending more keyboard time 'running traps' on the 695 head swap idea.  Obviously since Speeddog has done 695 heads on the 750 carby, I don't have to worry about basic fitment for that specific swap and I'm using that as a 'baseline known-to-fit' for my research.

This approach is attractive to me because the head is a more modern design than the 750 carby and to fit larger valves into the 750 head requires a lot of machine work I'd have to outsource at great expense.  I can manage bolt-up swapping and tuning time, and even a bit of port-matching, but extensive machining is out of my league.  Bummer, though, that there's only one cam profile that will direct-fit in the 695 head due to the camshaft bearing arrangement apparently only shared with the 800 that uses the same cam.

I've been mainly looking to see if the 800 head with the same bore, cam and valve diameter is a candidate in addition to the 695 head, hoping that would expand the pool of source heads.  With Brad's post I've expanded to look at a few of the 696 parts fiche pages to see what I could tell about what that approach might entail.

Interesting to find that the 695 vs 800 'complete heads' are different part numbers.  Note that 'complete heads' include the guides and seats, there's no part number available for only the head casting.  The part numbers of the head pieces (valves, seats, guides, seals, rockers, cam, etc) are the same between the 695 and 800 EXCEPT the valve guides and valves (but the valve seals and seats are the same) ?!?  Wondering what the deal is there.

The throttle bodies are the same diameter though inlet runners are different part numbers.  I haven't found info on the exhaust port diameter.  All this makes me wonder if the 800 head is different from the 695 in some way other than maybe the material of the valves and guides (stem diameter must be the same if the valve seal part number is the same, right?)

No reason to expect the 696 heads to have much part commonality with those since about all that's shared in the head/cam design with the 695/800 in the bore.  So not really possible to check fitment compatibility by running part number checks against the 'proven' 695 heads.

I get comfort finding that the timing belts are the same for 750/695/800 (noting that it is different for the 696 â€" is that likely just a length issue or did they change the belt width/cog profile/cog spacing or pulley diameters on either end?)  Part of the reason I wonder about the belt is that the 696 drive roller on the layshaft end is different from the 695/800 part number.  Maybe this is a silly tangent but it seems important to me that I'm able to get belts of the correct fit for any swap and there's lots of potential dimensional variables between the layshaft and the camshaft that could affect that it seems (layshaft-to-base, base-to-deck, deck-to-camshaft, pulley diameter, etc).

It'd be nice to be in a shop with a steady stream of different bikes to explore for potential swap projects, but lacking that I'm stuck with surfing parts fiche, resources like Brad's tables and reports (sure would be neat if the “Comparison of 2V Models" were expanded to include the 695 and 696  ), and forums like this one with folks that have tried different things.

All good fun without a doubt.  

[Raux]

I have an extra 696 head that can be used for testing
i trashed the exhaust port practicing port/polish

[carbmon]

Gee, I wish I were closer to Kaiserslautern so it'd be practical for me to take you up on that offer !

Shipping to Texas would be a bear I imagine  

Though the valves are a bit bigger than the 695/800 head, pending Brad offering why he's interested in that approach, the only thing that would make that experiment attractive to me is the option of a few more cam profiles than the 695/800 (1000DS and maybe 796 according to his report info).  Could be that he says the overlap difference is a potential big bonus, and it'd have to be for me to venture into that 'unproven' swap with all the potential fitment challenges.

The 'proven' 695 swap is still really attractive, Speeddog's comment that the result was "snarly" is enough of a teaser though before and after dyno data would be nice of course.  Again, given the starting point of the 750 head/cams, it's hard to imagine the 695 swap could be anything other than better.

[Speeddog]

Kinda pressed for time right now, but I''ll be back with more thoughts on the 696 vs. 695.

[brad black]

the 2006 s2r800 has 8mm valve stems, the 2007 has 7mm stems.  2007 695 and 800 share the same heads.

will ramble more later.

[carbmon]

the 2006 s2r800 has 8mm valve stems, the 2007 has 7mm stems.  2007 695 and 800 share the same heads.

will ramble more later.

Man, your shared knowldege base is great.

I was comparing parts fiche between 2007 M695 and 2004 M800 and missed until I just re-checked that the valve guides are also different part numbers.

I now see that the '07 S2R and '07 M695 have the exact same 'complete head' part numbers so that opens the pool of parts for the 695 swap as done by Speeddog to '07-'08 695 and '07 S2R 800.  Are the earlier '04-'07 800 heads the same except for the valve stems?  Could the earlier 'large-stem' heads be 'upgraded' to the later 7mm guides/valves/valve seals (is the nominal guide OD the same for both versions)? 

Kinda pressed for time right now, but I''ll be back with more thoughts on the 696 vs. 695.

I certainly look forward to hearing your thoughts on this, Speeddog - thanks for sharing your knowledge base, too  

[Raux]

http://kaemna.de/cms_en/katalog.htm?&view=artikel&artikel=472

http://kaemna.de/cms_en/katalog.htm?&view=artikel&artikel=2572

[Speeddog]

http://kaemna.de/cms_en/katalog.htm?&view=artikel&artikel=472

http://kaemna.de/cms_en/katalog.htm?&view=artikel&artikel=2572

Nice parts, for sure, but the price is breathtaking.

[Speeddog]

Re: 696 vs 695

696 head is ~ model year 2008, vs. 2005 for the 800/695 head.
Most recent technology....

Additionally, it's the updated design like what first came out on the 1000DS, with the short exhaust port.
It's got to be ~1" shorter, and that really helps to keep heat out of the head.

And the DS ports are better than the 900 ports.

I'm not particularly sold on the 7mm valves for a 2-valver.
I've seen quite a few broken half rings on DS1000's.

[carbmon]

Re: 696 vs 695

696 head is ~ model year 2008, vs. 2005 for the 800/695 head.
Most recent technology....

Additionally, it's the updated design like what first came out on the 1000DS, with the short exhaust port.
It's got to be ~1" shorter, and that really helps to keep heat out of the head.

And the DS ports are better than the 900 ports.

I'm not particularly sold on the 7mm valves for a 2-valver.
I've seen quite a few broken half rings on DS1000's.

What about basic fitment issues … again just looking at fiche … Looks like the locating dowels are different on the 696 head compared to the 750/695/800?  The 696 head is designed for a gasket while the 695/750/800 is not? Also looks like the ports/spigots are maybe different enough to cause some real fun with fitting the 750 intakes and exhaust?

Maybe the 696 is the ultimate fantasy head from among currently available parts (well, I did invite that in the thread title) but my initial reaction is that'd be a lot bigger project than the '07-'08 695/800 approach (inviting further comment).


Re: 7 vs 8mm valve stems …
For this 750 carby swap is that concern big enough that you would look to pre '07 800 heads to get the 8mm stems?  When I started looking at prices for new valves, that alone blows the economics for a change even if it could be done.  To make this work I'll have to patiently shop for a set of complete heads and hope the valves are good enough to keep, anticipating new guides, seals & relap at the most.

If the answer is yes, do you know which pre '07 heads are a 'match'?  All the way back to the '03 Monster 800?  What about ss800's back to '03?