engine conversion

Discussion in '1st & 2nd Generation 1983-1989' started by ca110, Jul 5, 2008.

  1. DKC'sVFR

    DKC'sVFR New Member

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    I'll bow to your experience and look for another

    more knowledgeable expert on Honda's fix for the VF motor. Hopefully someone will translate the story of some Honda Engineer messed up in the whole gear drive cam mess from the factory. The real history of the mess may not ever be told because the Japanese are even more guarded about loosing face than americans are and I think that OLD man Honda got ill and died right around the time the mess occured or that the stress it caused made him very ill and contributed to his death. I Doubt that much of the real story behind the gear drive cam was ever revealed to the american press. If someone had a complete set of Cycle mags form that time (83-6) there might have been hints about it in there. I',m glad to find out that the 500 never got the cam treatment. I was told that by my son who bought a 500 and explained that the 86 was the preferred year for it. It probably was too expensive a modification for Honda to extend it to the 500. I'v e been kicking myself for months because I felt responsible for him failing to buy an'86 500. Now I can stop feeeling guilty.

    I go to the library all the time and I'll check out that collectors guide on Honda's again and quote you what the author said about the VF machines and get his name for you. Maybe he has a reference on the VF motor that is availabe from the inter library loan.
     
  2. GreyVF750F

    GreyVF750F Member

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    That's the thing about "collector Mags and such". Most of the writers don't really know the topic as well as they are perceived. They only do research on it before they write their story. So they end up writing something that's not correct as being "correct". The classic car hobby is notorious for that. Go to cheapcycleparts.com and you can view the micro fiche yourself. Then dispell all the:bs: that's floating around.
     
  3. DKC'sVFR

    DKC'sVFR New Member

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    Its a book of @ 170 pages with dense print and many

    personal photos of 1950's racing Hondas. I'd guess the writer was into international Honda cycle racing in the 60's. He does not brag about being a great driver, but he might have been well acquainted with the various teams that drove works cycles and privateer honda's. He might have been a journalist who covered the cycle GP circuit. I think the author owns some of the racing Honda cycles he gets into in the book. He starts with 1949-50 model Honda singles, not the famous compressor motor that Honda pressed into service as his first "motorcycle" or the excursion into 2stroke land in the late 40's that made Mr.Honda decide not to persue that path, unlike Yamaha, Kawasaki and Suzuki. And the guy does not spend any time on the early motobikes that Honda made right after WWII. He gets right into the first real production motorcycles made in 1950-2. I don't think the pictures were from a museum, I think they were privately owned collector items. I think the author owns or owned VF 750 and 500 cycles and probably a second gen (VFR 750 F). I think he might own the RC30 he pictures in the VFR chapter, he rates it as a great collector bike due to rareity and pedigree. He has chapters on the early singles and twins that look like they were filled in with private photographs as well as some commercial photographs. He has lots of early Honda race models that are obvious personal photographs. I am certain some of the early twins are his, I think he says so. He's not a lightweight about Honda's history, he has been there to take the photos and probably to collect the bikes he knew would increase in value because he was at the races when they won. He is not trying to tell the story of the VF model. The VF is only one chapter out of around 10 or so. He spends most time on the early development of the singles and twins. He is trying to point out to persons interested in Honda's as investments what is and what is not worth collecting. He thinks VF(X) models are highly collectible. So he devotes a whole chapter to highlighting the models he thinks will increase in value or remain valuable. He has a considerable investment in Honda's himself, in the 1950 and 1960 models and on into the 70 and 80 models too. But I'll get the reference and the citation for you next trip to my local library. Thanks for clearing up the misunderstanding I had over the VF 500 never getting the gear drive treatment. I did assume that Honda overhauled all VF cycles, including the 500's, by 1986. As for searching microfiche, I already do enough of that in order to keep my '86 and my sons '84 running. I haven't enough time to do that as well as I would like for the cycles we own. I'll leave that search to you. Who knows, maybe you'll write the definitive article or book on the VF models. It's too much a mystery as it is.
     
  4. GreyVF750F

    GreyVF750F Member

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    DKC that little:bs: was not meant for you. It was for all the mag writers out there. The guy you describe sounds like he's been around a long time and his book sounds like something I'd like to read. What's the name of it? I've been a Honda fan since my first ride on a 305 Dream back in the sixties and have followed most of what they did. It just goes to show even the knowledgeable people get things wrong. Also what may have happen which I have seen before. The factory is going to do XX and someone is writing an article or book and include that XX info. But during printing or after the factory decides not to do XX. One way to get bogus info in an otherwise actuate writing.
     
  5. DKC'sVFR

    DKC'sVFR New Member

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    TITLE,AUTHOR, PUBLISHER & Quote.

    The book series is by a publisher out of WI: MBI (Motorbooks International)729 Prospect Ave, PO Box 1,Osceola, WI 54020-0001 USA.

    Author: BILL SILVER
    Date published : 2000
    Series Name: Illustrated Buyer's Guide

    Title : Classic Honda Motorcycles, 160 pages


    "Chapter 9: The Sporting V-Fours (1983-2000)"
    Page 112 and following

    "VF1000F/1000R(1984-86)

    The heavy chain driven VF 1000F and gear driven VF1000R Interceptor machines have gone into the archives of motorcycle history as memorable, but not highly desirable, machines. The F is probably the better motorcycle to ride on the street, but the R's gear drive and racerboy graphics have more appeal to the collector."

    VFR 750/700 (1986-87)
    In 1986, honda made a quantum leap in upgrading teh V-4's. By redesigning teh entire engine into a gear drive system for the cams, Honda pretty much eliminated teh cam wear gremlins. The first series of these bikes, in the federally mandated 700 size and the full 750cc flavor, ran for 24 hours at a Texas track and set new average speed records of over 140 mph.

    This same series has other Honda References. I can see that I may have misinterpreted the statement on VF 1000 F and R's to mean something different. There are other references I have read and I mayhave mixed up statements. For example in the same series by Ron Burton "Classic Japanese Motorcycles". He is not so down on VF 1000R.
     
  6. mrich12000

    mrich12000 New Member

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    :thumbsup:Nice story, just a line in the drama here. My Vf has lst 2nd and 3rd gears is thid common i the Vf line? Ihnoe it; a year later still I find the read here was fasinating.
     
  7. JamieDaugherty

    JamieDaugherty New Member

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    Yes, 3rd gear failures are also common. Not so much so as 2nd gear, but I've had to repair 3rd and 4th gear gearbox failures as well. Normally those gearboxes also have a bad 2nd gear!
     
  8. deepdish

    deepdish Banned

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    i would put the 250 engine in the 1000 frame ...
     
  9. hopit88

    hopit88 New Member

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    The R was first produced in '84(VF1000RE) and was not available in the US. The US got 2 model years, 85-86(RF). The RG was available in europe in '87 only as a rothmans replica.

    Any author that reports an R as having shaft final drive is a tool and should stick to proof reading cook books.

    I have an kR motor in an kF frame, while it does fit(barely) it is not exactly plug and play. The F runs the upper rad down through the left side frame and therefore has the plumbing for the thermostat mounted on the left side. The R's thermostat is on the right side. Simply flipping the inner cooling pipes around will solve that. Once in the F's frame the R's rear cam cover cannot be removed. You also need the R's single ignition box so I would guess the R's wiring harness as well.
     
  10. matt1986vf500f

    matt1986vf500f New Member

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    man there's alot of :bs: in this thread!
     
  11. BiKenG

    BiKenG New Member

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    Another zombie thread alert for those who like to raise them. But...

    As has been stated there is a LOT of TOTALLY incorrect information posted in this thread. I won't dwell on the chain/gear/shaft drives of the various bikes as I'm sure we all know what's what there. However, there appears to still be some confusion over the V4 cam problems of the early '80s. This is what Japan informed me when at the time an instructor in the Technical Training Schools at Honda UK.

    When designing the V4 engines, the designers wanted a clean line between the head and the cam cover with a simple flat rubber seal all the way around. Normally the cam bearings are line bored along the entire width of the head, which leaves a semicircle cut out of the end of the head, in line with the camshaft(s) and which requires a rubber seal with raised semicircular 'lumps' to fill those cutouts and seal the cam cover to the head. We've all seen them. However the designers wanted a cleaner look without those unsightly rubber semicircles. The problem is how do you then cut the cam bearings in the head. The answer was to mill them in the head which is trickier, but not impossible. The result being the single flat join line between cam cover and head that the designers wanted.

    Unfortunately they then had 2 problems. The milling process was found to be inconsistent in production, so many cam bearings were not sufficiently accurately machined. There was also a problem with camshaft manufacture (outsourced to a third party I seem to recall) that resulted in incomplete hardening of the camshaft surfaces which can lead to pitting of the bearing surface of the camshaft. Put those 2 problems together and you have a lot of Honda V4s with what became known as 'chocolate camshafts'.

    I think all the VF models have this top end design feature (milled bearings that is), but any issues that might result from the above should have been sorted by now as replacement parts did cure the problem. For the VFR, they returned to line boring the head and using rubber semicircles in the cam cover seals which was less unsightly on those bikes anyway as they had more complete fairings hiding the engine.

    The reason for the gear driven cams is mixed. There's no question that gear driven cams are best for performance and hence tend to be used in racing engines (until Aprilia got told their 'kit' was not in the spirit of WSB) and if Honda had a reputation problem, it concerned cam chains and tensioners. After the VF cam problems and the CX500 debacle (unrelated, but hit them hard), it was thought they needed to quash the problems once and for all. Either that or forget the whole thing and walk away from the V4. It was not such a simple decision as might be thought and it was close to all being shelved. In the end, they were convinced to go ahead with a new V4 that would knock everyone's socks off, even if it cost them money to do so. Their reputation at that time needed a boost.

    To eliminate possible points of failure, they returned to line boring the heads and cam bearings and rubber semicircular seals and to avoid any possible cam chain and/or tensioner issues, they opted to use gear drive which had the added advantage of huge marketing appeal and techno lust.

    That was the first VFR750 that with some changes along the way, ran for 4 years, finally replaced by the new version that introduced us to the Single Sided Swing-Arm. Another racing allusion but also practical and desirable on a road bike. Anyway...

    The problem of the early VFs and the CX cannot be overstated. It was a terrible time and Honda were at pains to apologise to their staff for causing it. They then worked immensely hard, especially with the CX to rectify the problems and the disaster that was the CX slowly became the reliable long lifer we all now remember. The VF was not so problematic overall, but the V4 nearly died a death.

    Who would think nearly 40 years later we'd still be interested in these models. At the time, a 40 year old bike was just a pile of junk. We never thought the products that enthralled us then would be so highly thought of and still desirable after 40 years.

    Anyway, that's the story from inside Honda UK.
     
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  12. Captain 80s

    Captain 80s Member

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    Line bored heads, no semicircles.
    [​IMG]
     
  13. JamieDaugherty

    JamieDaugherty New Member

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    Well, you have ask yourself: what does line boring have to do with the historic top end failures. I understand the machining process, but the end result is - nothing. It has nothing to do with it. So, fixing an issue that has nothing to do with the problem does not sound like a real solution.

    As mentioned as nauseam, the problem is two fold. First is the insufficient hardening of the rocker arms. Those are the parts that wear, let's not forget. The cams lobes only get damaged after the rockers have divots. The second is the lack of good oil flow to the heads. This is also well documented, and I hope it does not need to be explained why it is important. It's really the combination of both factors that creates the perfect storm.

    Let's also not forget something: the VF1000R's had line-bored cam journals and I've personally seen many more of those with damaged rockers than any other model.
     
  14. BiKenG

    BiKenG New Member

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    Well yes and no (but not necessarily in that order.:)).

    The first VFR750s (Gen 2 - RC24) did not run the camshafts in the head, Their camshaft holders were separate parts bored independently of the head. This then maintained the flat joint and gasket between head and cam cover - no semicircles. The RC30 continued that concept, but with a more substantial cam bearing holder assembly.

    The RC36 then returned to line boring the cam bearings in the head - with semicircles and which continues to this day in the VFR800.

    I think we've flogged this topic to death now. There was a progression, a development of the engines as Honda refined their designs and techniques which were initially flawed. Thank you for helping me clarify my mind about all this and correct details of some nearly 40 year old memories. I would now indeed like to find a VF1000R to 'restore'. Have to be '85 onwards though. I prefer my V4's line bored. ;)
     
  15. BiKenG

    BiKenG New Member

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    Never ceases to amaze me that when I reveal the facts, as we were informed by Japan at the time, there's always someone who claims they know better. Than Honda. The designers of the actual engines under discussion. At that time the world's leading producer of 4 stroke engines. But hey, knock yourself out. You obviously know better than them. :rolleyes:
     
  16. jeremyr62

    jeremyr62 New Member

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    OMG. The story runs and runs. My 1986 VF500 has line bored cams btw :)
     
  17. BiKenG

    BiKenG New Member

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    Yup. First VFs had milled heads, Latest VFRs are line-bored. In between there were some with separate cam bearing holders which were bored but needed no semicircle seals and apart from that, over the years there was a progression from one method to the other as Honda found the milling process troublesome in production.

    There you have it. The whole story, on which (I hope) we all agree.
     
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