Member Contributer rctwentyfour Posted January 20, 2008 Member Contributer Share Posted January 20, 2008 Here is parts-fiche link to a VFR750R (RC30) exhaust system, U.S. street model (so, that means 1990). http://www.cmsnl.com/honda-vfr750r-rc30-us...list/F++18.html The astronomical cost of this aside, has anybody "out there" ever done this successfully? By "done this," I mean install the system on an RC24 (in any of its iterations)? The RC30 was "derived" from the RC24 (a.k.a. 750F) and I know that at one point HRC offered a Race Kit for the 750F, which included a titanium exhaust. So, it simply had to be very, very much like this. Why do I ask? Well, what drives me nuts about the exhaust systems on the "tariff beaters" (700F and F2), the '86 750F Interceptor, the '87 FH, and (albeit a bit different) the '88 FJ & the '89 FK is the 180 degree "U-Turn" that the headers take on the rear two cylinders. Just curious. Link to comment Share on other sites More sharing options...
The Phantom Posted January 20, 2008 Share Posted January 20, 2008 The 1st/2nd Gen VFR750 definitely runs a different exhaust system to the 3rd/4th Gen VFR750 - dimensions are different. Which one is closest to the RC30 motor design? Link to comment Share on other sites More sharing options...
Member Contributer JZH Posted January 20, 2008 Member Contributer Share Posted January 20, 2008 RC24. I understand you can "make" an RC30 crankcase out of an RC24, essentially. Don't know about the heads, but I'd venture a guess that it might work! Search on the Yahoo RC30 Group for messages discussing this. Ciao, Link to comment Share on other sites More sharing options...
Member Contributer rctwentyfour Posted January 20, 2008 Author Member Contributer Share Posted January 20, 2008 The 1st/2nd Gen VFR750 definitely runs a different exhaust system to the 3rd/4th Gen VFR750 - dimensions are different. Which one is closest to the RC30 motor design? Well, that is just it. The RC30 is/was "derived" from the RC24. So, I have to imagine things are pretty close. That is, maybe close enough to "bludgeon" on an RC30 exhaust system. Hmmmm, I'll keep poking around, and see what I can find. When I am Ruler of The Universe, I'm gonna insist that ALL on-line parts-fiche systems show measurements and specifications. Hey, CAD files too! What the heck. Thanks. Link to comment Share on other sites More sharing options...
Member Contributer rctwentyfour Posted January 20, 2008 Author Member Contributer Share Posted January 20, 2008 RC24. I understand you can "make" an RC30 crankcase out of an RC24, essentially. Don't know about the heads, but I'd venture a guess that it might work! Search on the Yahoo RC30 Group for messages discussing this.Ciao, This is what I know: The part number for the '88 VFR750FJ (RC24) and the '89 "FK" (my bike) Crankcase Set is 11000-ML7-920. The part number for the '90 VFR750R (RC30) US, the '88 VFR750RJ, the '89 VFR750RK, and the '90 VFR750RL Crankcase Set is 11000-MR7-000. So, this is enticingly close, but all this doesn't really tell me what I am trying to figure out. What I was really hoping to find out here on the Forum is whether or not someone had ACTUALLY DONE THIS. If so, what problems/challenges arose. The RC30s, of course, have the single-sided swing arm, and the exhaust runs down/off-of the left-hand side of the bike. So, all that pipe may not clear the “conventional” swing arm on the RC24. There is a fellow “around,” Chuck Crites, who used to race the 750F. I’ve seen pics of him racing, and there is definitely this RC30 “style” exhaust on that bike (can’t seem to locate the pic just now). However, he may have been running the HRC race kit available for the 750F at the time, whch included a titanium exhaust. I know he sells stuff on eBay. I’ll ask him, and see what happens. Thanks. Link to comment Share on other sites More sharing options...
Member Contributer evl_twn Posted January 21, 2008 Member Contributer Share Posted January 21, 2008 The RC30 crankcase is more like the 90-97 RC36 cases than the RC24. The exhaust will not swap between the RC30 and VFR unless you get custom rear pipes made. There was some talk of this on the RC30 yahoo list a while back, the heads are different and the rear cylinder exhaust pipes are at different angles. Link to comment Share on other sites More sharing options...
Member Contributer rctwentyfour Posted January 22, 2008 Author Member Contributer Share Posted January 22, 2008 The RC30 crankcase is more like the 90-97 RC36 cases than the RC24. The exhaust will not swap between the RC30 and VFR unless you get custom rear pipes made. There was some talk of this on the RC30 yahoo list a while back, the heads are different and the rear cylinder exhaust pipes are at different angles. Aha, evl twn, that is the kind of information I am seeking. I guess I'll check out the Yahoo! discussion group. (Yikes! ANOTHER discussion group? Oy!) So, in short, is this to say, "Forget it buddy, you're gonna beat your brains out trying to do this"? Link to comment Share on other sites More sharing options...
Member Contributer JZH Posted January 24, 2008 Member Contributer Share Posted January 24, 2008 This is what I know:The part number for the '88 VFR750FJ (RC24) and the '89 "FK" (my bike) Crankcase Set is 11000-ML7-920. The part number for the '90 VFR750R (RC30) US, the '88 VFR750RJ, the '89 VFR750RK, and the '90 VFR750RL Crankcase Set is 11000-MR7-000. So, this is enticingly close, but all this doesn't really tell me what I am trying to figure out. What I was really hoping to find out here on the Forum is whether or not someone had ACTUALLY DONE THIS. If so, what problems/challenges arose. Sorry, that doesn't mean anything. Most Honda crankcases begin "11000" and the MR7 and ML7 refer to the different bikes involved, and the last three digits refer to revisions and sources for the parts. If ONLY the last three digits are different, then you have a good chance of having something interchangeable. Ciao, Link to comment Share on other sites More sharing options...
Member Contributer rctwentyfour Posted January 25, 2008 Author Member Contributer Share Posted January 25, 2008 This is what I know:The part number for the '88 VFR750FJ (RC24) and the '89 "FK" (my bike) Crankcase Set is 11000-ML7-920. The part number for the '90 VFR750R (RC30) US, the '88 VFR750RJ, the '89 VFR750RK, and the '90 VFR750RL Crankcase Set is 11000-MR7-000. So, this is enticingly close, but all this doesn't really tell me what I am trying to figure out. What I was really hoping to find out here on the Forum is whether or not someone had ACTUALLY DONE THIS. If so, what problems/challenges arose. Sorry, that doesn't mean anything. Most Honda crankcases begin "11000" and the MR7 and ML7 refer to the different bikes involved, and the last three digits refer to revisions and sources for the parts. If ONLY the last three digits are different, then you have a good chance of having something interchangeable. Ciao, I finally found an image of the exhaust I've been talking about / thinking about. This is an image of an '86 (or '87) VFR750F. Obviously, the exhaust is not "stock." Having read the replies herein, and now knowing the RC30 exhaust won't fit, I, therefore, have to assume this is the HRC exhaust available for the 750F at the time. http://pages.cs.wisc.edu/~john/vfr/specs/86-87-vfr750f2.html So, I'd have to imagine my chances of getting my hands on such a system are deep into the "Forget it, Fella" department. Link to comment Share on other sites More sharing options...
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