Topic: The 1970 Daytona CR750s.

[Dreamer]

Hi guys, Just wondering if anyone here could post some pictures of the bottom of their CR750 gas tank? Ive searched the internet and spent a lot of time searching through this forum, but no luck.
I'm really interested in building a tank. I have a fiberglass tank that I can use as a reference for the outer part of the tank but when I flip it over and compare the bottom of the tank with some of the low res pics and videos Ive seen on the web, the two look very different.

It would be greatly appreciated if someone would take the time to post some pics.

-Ryan

I posted the best picture I could find.

[napoleonb]

As far as I know these pics are from Original kit items, hope this helps.

[Dreamer]

Hi napoleonb,

Thanks very much for the pictures!
 I went back to an old post of yours and saw some other pictures you posted of the same tank. Is the disassembled tank with the exposed baffles the one you had made in Germany or is that an original tank you disassembled? Also, is it me or is the sump offset to one side?

I found these pics last night. This tank looks a little different than the one you are showing. It looks like the tunnel is a lot larger on the red tank. Do you think the kit tanks may have had a larger tunnel to accommodate for differences in the production bikes?



 

[hondarc174]

Hi Folks
Finished one CR at last! Started the next one. Hope to finish this year... Here's a pic of the first one:

Very nice Job,
Congratulations, looks to be a sister from my kit bike.
JUlien

[napoleonb]

Hi napoleonb,

Thanks very much for the pictures!
 I went back to an old post of yours and saw some other pictures you posted of the same tank. Is the disassembled tank with the exposed baffles the one you had made in Germany or is that an original tank you disassembled? Also, is it me or is the sump offset to one side?

I found these pics last night. This tank looks a little different than the one you are showing. It looks like the tunnel is a lot larger on the red tank. Do you think the kit tanks may have had a larger tunnel to accommodate for differences in the production bikes?



 

None of the tanks are mine unfortunately, the offset is to accommodate the oil vent hose i presume.
I don't know of any other type of tunnel there were however 2 types of kit tanks, the difference being the amount of content.

[Dreamer]

Hi napoleonb,

Thanks for the insight on the offset. I didn't know there where two types of tanks, makes sense though. I was wondering why the fiber glass tank I have looks so skinny compared to all the aluminum tanks out there. The company who makes the fiberglass tank claims they are an exact replica of Dick Mann's bike. Maybe that particular tank was one of the smaller of the two.

[Honda Just]

Hi Guys, I've been following this thread for a while now, ever since I saw Kevin Bidgood's CR750 build here locally. I had gone to see him about a RC181 build, and quickly fell in love with the Dick Mann and CR750 story. Ofcourse this is all before my time, as I was born 10 years after the '70 Daytona 200! But I'm a Honda fan through and through and enjoy the classic stuff.

My question is this... is it worthwhile to use sandcast engine cases for a CR750 build? I know they weep oil etc, but I have the cases and thought it would be special to use them in my project. Also, is it going to be a mission to get the internals, or will the early K0, K1 stuff fit? I have a few bits of older K0 and sandcast CB750 - carbs, heads, etc. But not too sure how to identify. Kevin is on his CB doing a trip around the world so I cant go to him and ask.

Any advice? Would you guys go sandcast? or should I just sell the cases to someone looking to build a nice original sandcast CB?

[Retro Rocket]

Honda Just, I would sell the sandcast stuff to finance your build, if indeed they are sandcast parts, they would be worth quite a bit more to an enthusiast than to you on a race replica, What are the engine numbers on the casings ? they are relatively easy to identify..

[Honda Just]

Thanks for the reply RR.
Most definitely sandcast casings - the vin ends in 003787 or something like that, I'll post up pics of what I have a bit later today.
So you don't advise using the sandcast casings? May I ask why?
I thought it would be a nice touch on the CR750 build, and thought that it was probably what was used in the race bikes of the time?
Or am I mistaken? Being 1970 it could be a production engine that was used. Can anyone confirm?

[napoleonb]

They sure would have used much of the sandcast engine items like the cases.
The point being made was that it's a "sin" to cut into a sound sandcast crankcase for a CR750 build as it will dramatically lose its sandcast value that way.
To a real CR enthusiast these sandcast items will not mean very much I'm afraid so you'd be better of selling these (or storing it) and buy K1/K6 crankcases and modify those.

K7/F1/F2 will have a slightly different crankcase which houses a bigger bearing and an F2 head will increase power.
The internals will not differ all that much, and again K0 items are quite rare and expensive and will not increase CR value but decrease that way.

[Retro Rocket]

Thanks for the reply RR.
Most definitely sandcast casings - the vin ends in 003787 or something like that, I'll post up pics of what I have a bit later today.
So you don't advise using the sandcast casings? May I ask why?
I thought it would be a nice touch on the CR750 build, and thought that it was probably what was used in the race bikes of the time?
Or am I mistaken? Being 1970 it could be a production engine that was used. Can anyone confirm?

They sure would have used much of the sandcast engine items like the cases.
The point being made was that it's a "sin" to cut into a sound sandcast crankcase for a CR750 build as it will dramatically lose its sandcast value that way.
To a real CR enthusiast these sandcast items will not mean very much I'm afraid so you'd be better of selling these (or storing it) and buy K1/K6 crankcases and modify those.

K7/F1/F2 will have a slightly different crankcase which houses a bigger bearing and an F2 head will increase power.
The internals will not differ all that much, and again K0 items are quite rare and expensive and will not increase CR value but decrease that way.

This covered what i said well, Sandcast parts are worth a small fortune, they are highly rare and collectible, you could finance half your build by selling the sandcast stuff to the right people. In my opinion its a waste to use sandcast parts building a race replica...

[Honda Just]

Thanks guys, I appreciate the input. I still feel that if the part is period correct it should be used. I know that I will not be building a sandcast resto, there are just no parts (or very few) on this side of the world.
Can anyone verify if the CR750 had sandcast or production casings?

I'm a bit of a nut for attention to detail and have gone as far as to fit $4 a piece cable ties on my '96 Honda CR250 McGrath replica build.

Also, Kevin Bidgood TTR400 has built up a strong CB550 engine that will go into a loosely based CR750 replica, except with GSXR forks and 17" motard wheels. So this will be my rider, the CR750 I would like to keep as a collector's piece (and convince the fiancé to have it inside the house!)

Here are some pics of the casings, please, sandcast fundis, let me know what is and isn't sandcast in the images - I'm finding it difficult to see what is/isn't...

[Honda Just]

here are a few more, sorry I couldn't seem to get all loaded in one reply...

[Honda Just]

and the last few, I was hoping you guys would point out some goodies in this box (I'm a motocross nut and although a huge CR750 fan - I was born ten years after Daytona '70) 

[Retro Rocket]

Sorry dude but i don't think you are listening, it is NOT necessary to use sandcast parts in a cr, for a start, they were built for a number of years and its only you that thinks its relevant to use the sand cast engine cases, really mate, no one in their right mind would use those cases on a replica, that engine , if mostly original, could be worth a few thousand dollars to a purist, you can do what you like of course  but using that sandcast engine case won't make any CR replica any more authentic than any other CR replica, at the end of the day thats all it is, a replica.  I can't see what all the emphasis  is on the engine cases...  You going to buy the sandcast CR31's for it...? look at 2-3 grand minimum for those IF you can find them, what about the CR dash, oil tank, brake hubs {over 200 specialist parts for the CR}...?  My point is that you will either build a cheaper style replica like most people do or literally spend a fortune trying to build an "Authentic" bike {impossible anyway} that will still be a replica and still not need those bloody cases....    Sell that engine and it will finance most of your build, seriously, there's nothing to gain by using the sandcast engine, actually, more to lose.... If you are hell bent on going the "I've got to have everything authentic" route, I have a genuine set of Honda RSC rods {Racing Service Center} that you'll probably never see anywhere else, I not long ago sold my old school CR31's ....


http://www.daytona70.com/English/sales.html

Send Mark Mcgrew at M3 racing an email, he's the resident CR expert on this site, his forum name is Kos...

[Honda Just]

Ok RR, I'm starting to hear you on this one... 
I've followed these threads for a while and have seen Mark's comments and great advice, and the old drawings etc. The thing that made most sense to me is the carbs, I've seen three sets up on Ebay (been on for a while now), and I had in my mind to go with the modern CR carbs. I guess I couldn't go new carbs and be stubborn on the sandcast casings hey?
I've also read a lot on Daniel Mercier and seen his parts offerings. I guess I'll need to flog the casings for that magnesium rear hub, that has to be one of the most expensive bits for the CR project.
I was also planning on going the cheaper route to get 100Hp - 836cc, instead of dropping bombs on a legit 750cc build to make the same power. You know what its like when its early days on a project - big dreams and lots of self-justification...
Thanks again for your advice - I hear you now! 

[Retro Rocket]

Oh yes, i know exactly what its like. I've been collecting parts to build  a modern version of the old 750 for over 10 years now, started out with one old drag bike now i have enough for almost 4 bikes and I still haven't built one, whats worse is that the one i want to keep will be the 3rd one built and will end up costing around 15 grand, maybe more {Aussie dollars}...   I'm glad in a way, the sheer amount of quality parts that are around now were only dreams a few years back, the first 2 bikes will all have big improvements but its the "keeper" 3rd bike that gets all the really good stuff, the 4th one will have a Vincent influence.....
I think there are aluminium versions of that rear hub as well, still expensive, but not as bad as the magnesium hub, you'll thank yourself for not going with the old tickler type CR31's, they have no idle circuit for a start and are hard to tune, probably not as bad if you know someone familiar with them, the newer ones are much better and easily available.... I was reading an article on a guy from Melbourne that built a pretty nice CR replica, if i come across it i'll PM you the link...

[Honda Just]

Haha, if you have either an engine or a frame, you have a project! Sounds amazing, always nice to build up a stash of goodies in the knowledge that they will be splurged onto a dream machine. I like the sound of a Vincent influence!! (like the sound of a Vincent too, mind you). A chap here in South Africa has worked on most vincents in the southern part of Africa.
Have you seen these guys ... http://www.ac-sanctuary.co.jp/ they put subtle, yet gorgeous works bits to the likes of CB1100Rs etc, just take a look at those titanium headers!!
Are you talking about the Dues Ex Machina guys? They built a great CR750

[Retro Rocket]

Gday HJ, yes, I know of the sanctuary guys, been looking at their stuff for a few years now, they build gorgeous bikes but bloody expensive...   It wasn't Dues Ex Machina that built the bike i was talking about, I can't find the original page i read about it on but here's the bike anyway....

http://www.roadandtrack.com/features/web-originals/guest-feature-tank-moto-honda-cr750-classic-replica

http://www.returnofthecaferacers.com/2013/07/honda-cr750-replica.html

[Honda Just]

Too nice! But way expensive, must be for the shark-fin connoisseur @ 3,5 million YEN.
I've seen that build - phenominal! Lucky bugger got to take moulds off the kit bike for a lot of the parts... 
Did you peruse my pics and can you spot any gems in that lot?

[Retro Rocket]

Too nice! But way expensive, must be for the shark-fin connoisseur @ 3,5 million YEN.
I've seen that build - phenominal! Lucky bugger got to take moulds off the kit bike for a lot of the parts... 
Did you peruse my pics and can you spot any gems in that lot?

What size is the megacycle cam..?

[Honda Just]

The only info I can find :
Cam has a R9 stamp on it
Box has the code 12565
Make any sense?

[Retro Rocket]

Yep, its a 125/65, mines a 125/75....

If you are after info on the cam, look up member MRieck, he should be able to help you out. Its a fairly hot cam...

[Honda Just]

Yep, its a 125/65, mines a 125/75....

If you are after info on the cam, look up member MRieck, he should be able to help you out. Its a fairly hot cam...

Thanks RR!

[hotdog]

CR replica for sale (Australia)

http://www.gumtree.com.au/s-ad/parkerville/motorcycles/honda-cr750-replica/1059086065