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Cylinder Head Oiling Modification


mr2racer

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Hey All,

I have an '84 VF750F that has the usual cam/rocker wear problems. And I've found modifications to increase oil flow to the upper end. But they involve expensive kits or drilling a hole in the lower case, neither of which I'm partial to. In looking at the problem there seems an easier solution. Why not just tap into the oil gallery at the oil pressure switch? The hole is already threaded and is only a few inches above the point where the hole is drilled in the DIY modification. Plus, it is only inches from the existing oil pipe?

Kevin

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I'm surprised that no one has responded to this thread especially as this problem seems common to so many V-4's. I did find what I'm proposing on a website, sort of, and included some pictures. Notice under description the website says there may be as much as 80 PSI of pressure at this point. Also notice the price difference. The advantege is no drilling. Stock filter. A shorter run for the oil lines. Why hasn't someone thought of this sooner?

post-32890-0-94132800-1431304725.jpeg

post-32890-0-66295600-1431304736.jpg

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Why do you need to put an analog pressure gauge there? There wasn't a gauge before, why does the kit come with one (or require one)?

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No, hole shot, as per your link, is the same as the others. I guess I could have been more clear. My proposed repair is to attach the line to the heads in place of the pressure gauage.

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I'm surprised that no one has responded to this thread especially as this problem seems common to so many V-4's.

Euh.......... you join on the 9th, do not introduce yourself in the welcome section and expect people to jump to your aid within 24 hours from posting???

And then "you already found it yourself on the internet"

I -obviously- donot know you, but this is some Interesting human behavior..... :unsure:

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Well, first let me say I apologize. I wasn't even aware of the 'welcome section' and when I find it will take advatage of it. gll429, in my research all I found were the numerous articles and oiling schemes. I was unaware of the cam/follower problem as outlined in the article. I read the article through, twice. Thanks for the link! I have a set of race cams from this bike's original engine. On the end of one cam is scribed Pop-Y. I'm assuming this is 'Pop' Yoshimura. One front intake lobe is damaged and most of the others have some chips out of the tips of the lobes.

I have a plan. I'm sending the cams and followers to Delta camshaft in Portland. Scott will fix the damaged lobe then ginrd all of the cams to get a smooth surface. Even ground to clean them up they will still have more lift and duration than the stock cams. The cams will then be hardened. The hard chrome will be removed from the rockers and then the rockers will be 'hard faced'. This, I'm hoping will take care of the problem. I think this is comparable to the Mega Cycle process. And Scott tells me this can be done for about $250 complete.

But having read the descriptions of the unfiltered low pressure oil used to lubricate the valve train it seems logical to do something about it? Regardless of the reason for this modification, poor oiling or cracking oil pipes, it seems the easiest place to draw the oil from is the port beneath the oil pressure switch. That is the question I really wanted answered.

My comment was from amazement that 70 people had viewed the original post but no one had commented. And I was thinking this problem was one that most on this forum would be aware of. Especially with the proliferation of 'oiling kits.'

Kevin

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My comment was from amazement that 70 people had viewed the original post but no one had commented. And I was thinking this problem was one that most on this forum would be aware of. Especially with the proliferation of 'oiling kits.'

Well, it's a big forum... and 1984 is a very long time ago... we have many members, tens of thousands perhaps, who could have owned multiple VFRs during the 30 years since - and who whould have no reason to be aware of the issues the earliest V4 Hondas (may or may not have) experienced.

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There was/is a reason they were called chocolate cam shafts as per the earlier link not oil to head issues !

Additional oil pressure will not help & is not needed, if you think about it, Honda would have built & run a test engine or a few for some very long hard cycling before releasing it as production ready, adt cam bearing wear would have been noted. The reason it wasn't was because the test engines would have been built individually & properly, so no cam issues were apparent in testing. The cockup came during the mass production, where incorrectly hardened parts & incorrect tolerance parts were combined accidentally for the perfect storm of mechanical bad news :(

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My 83 was no myth !

read the link , all of it . :beer::fing02:

STOP SPREADING THIS MYTH!!!

for gods sake!!

http://www.motorcycleproject.com/text/v4_cams_what.html

I did and my 83 had the myth .

And it also had the unbreakable fiber fuel the tubes that BROKE !!!

Still loved'er anyway !

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My 83 was no myth !

read the link , all of it . :beer::fing02:

STOP SPREADING THIS MYTH!!!

for gods sake!!

http://www.motorcycleproject.com/text/v4_cams_what.html

I did and my 83 had the myth .

And it also had the unbreakable fiber fuel the tubes that BROKE !!!

Still loved'er anyway !

yeah. neither of which were NOT FROM OILING PROBLEMS!!!!!!

thats the myth.. oil problems ..

the true cause has been known since 1985!!! 30 damned years and people are still saying oil problems!!

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My 83 was no myth !

read the link , all of it . :beer::fing02:

STOP SPREADING THIS MYTH!!!

for gods sake!!

http://www.motorcycleproject.com/text/v4_cams_what.html

I did and my 83 had the myth .

And it also had the unbreakable fiber fuel the tubes that BROKE !!!

Still loved'er anyway !

yeah. neither of which were NOT FROM OILING PROBLEMS!!!!!!

thats the myth.. oil problems ..

the true cause has been known since 1985!!! 30 damned years and people are still saying oil problems!!

I prefer this story .

Now, the history of the problem. Most of these engines, especially those driven hard, wore out cam lobes, rocker faces, and cam bearing surfaces prematurely. This was especially common in Europe where the bikes are driven harder and faster. Honda came up with many explanations:

  1. Incorrect valve adjustment because of forked rocker arms.

    To avoid this, use identical feeler gauges under each fork of the rocker arm at the same time, so the rocker arm doesn't tilt. When tightening down the adjusting nuts, tighten moderately at first, then recheck the clearance, then torque it down hard.

    This problem is worsened by the fact that the cam caps don't extend very far around the tops of the cams. On the 500cc engines, and the later generation Interceptors, the cam caps extend much farther over the camshaft to hold it snugly in place. This may explain why the problem occurs less frequently in these bikes.

  2. Variation in cam-to-bearing clearance because of manufacturing method.

    To combat this, Honda developed a special tool to hold the cam in place. Any bike shop tuning a V4 had better have this tool. It doesn't cost much ($15) and isn't hard to use. Get one; even though it doesn't completely solve the problem, it is a requirement. Part number is 07979-MK30000, name is "V4 tappet adjust". The service bulletin issued with this tool recommends valve clearance of .006 inches instead of .005 that the Sabre/Magna originally specified, as well as use of premium motorcycle oil, changed frequently, and avoidance of prolonged idling.

    (To aid in valve adjustment, you probably also want to buy the special 10mm wrench for the locknuts. It's ideal for the job: very long handle so you can get adequate torque by hand, large offset between the handle and the box end so you can reach down to the locknut and keep the handle clear of the cylinder head, and very thin-walled box end to slip over the nut where there's not much clearance. Part number 07908-MB00100, "valve adjust wrench", about $15. I'm sure glad I bought one.)

  3. Improper cam chain tension.

    Various redesigned cam chain tensioners have been developed. My mechanic says none of them really work much better; other mechanics say they do work better. It's basically a screen-door arm-stop design. If your engine rattles a lot at idle but gets much smoother and quieter at 3000 to 3500 rpm, one or both cam chain tensioners are not working. Sometimes you can poke the adjuster to make it take up the slack, but this doesn't always work. The shop manual describes this procedure and includes a diagram showing how to do it.

  4. Soft cam lobe material.

    Later replacement cams use different camshaft material and hardening procedure, so they should last longer than the original cams. As most of us are aware, Honda offered an extended warranty which essentially meant free cams and rockers whenever needed. This warranty was discontinued in 1989 or so, and it costs about $1000 or so for parts (camshafts and rockers).

    Aftermarket shops such as MegaCycle can resurface and regrind your cams, which should be lots cheaper than new parts.

  5. Heat. (according to mechanics, not official Honda pronouncements)

    Despite liquid cooling, these engines do get hot. Usually the rear cams are the first to go because they get hottest. There was no official remedy for this to my knowledge, but there are a couple things you can do.

    • Rejet the main jets up one size to run richer and thus cooler. This may result in slightly higher fuel consumption and EPA violation, and you don't run on main jets all the time, but it may help. (Incidentally, Honda upped the main jet size on the '83 Sabre from '82, but we're not sure why.)
    • Install a manual over-ride on the radiator fan so you can turn the fan on before the engine gets too hot (when you know it is about to, such as when you're coming into stop'n'go traffic), instead of after it gets too hot, the way the system normally works.
    • Upgrade the thermal switch that controls the radiator fan. Here's some info from Eric Sterbenz, ers@cbnmva.att.com:

      "I have a V65 Sabre. I was going through some old VF Sport Touring Association newletters the other day and came across a tech article talking about a lower temp fan switch for the VFs, part no. 37760-MB4-770. It is supposed to lower the fan threshold about 50 degrees. I checked at the dealer and this is now the standard part in the database."

  6. Inadequate lubrication.

    According to Honda Racing, all the previous items contribute to the problem, and if you adjust the valves properly with the special tool and have new cam chain tensioners and the harder cams, you may escape the problem. But one final factor remains: inadequate quantity and quality of oil to the top end. (Apparently, Honda has upgraded the oil supply lines to allow greater flow to the head, but this isn't enough. Refer to articles by Phil Rastocny (philip@okstatealumni.org) on do-it-yourself oil system modifications, including research of these oil supply line upgrades. Both Part One and Part Two are available on my web site.

V4 Oil System

The oil system picks up oil from the sump through a strainer and routes it two ways. One goes to the filter and from there to the crankshaft. The other goes to a T joint where one branch goes to the transmission and the other splits again to feed each cylinder head. Therefore the oil is not as clean as it could be. The oil lines are of small diameter. On '83 Interceptors there was a restrictive banjo bolt in the pipes up to the heads. This was fixed for '84, but any '83 owners should make sure theirs has been retrofitted. I'm told by Honda Canada that this bolt was not a problem in the Sabre/Magna engine and no oil system parts upgrades were ever released for the Sabre/Magna engine. (Phil has found otherwise; perhaps US models only?)

On the whole, adequate oil pressure is not developed below about 3000 to 3500 rpm. Therefore, there is often not enough oil getting to the heads. Honda Racing figured this out and modified the race bikes to pick up oil from the main gallery and take it externally to the head. This solved (not just lessened) the problem for them.

The company which designed this modification is Amol Motorcycles, Dumont, New Jersey, phone (201) 384 1103. The mod costs $175 for parts, $300 for labour including removal of engine from frame, or $110 if you remove the engine.

From about '88 to '91, Tierney-Hollen in Westlake Village, California offered a kit for $250 which is much nicer. You can install it yourself with no special tools. A collar is inserted between the oil filter and the engine case. Two braided steel hoses take fresh clean filtered oil in larger quantities to the heads. The existing oil feeds to the heads are blocked off. This looks like a winner if you want to spend the money and solve the problem once and forever. I have installed this kit on my bike and it works great. A separate write-up on this kit is available from me.

But there are less complicated ways you can help slow the onset of chewed cams (while of course using the updated valve adjustment procedure and special tool and so on as described above).

  1. Use premium quality oil, such as BelRay or Golden Spectro. Don't use 20W50. You need the pumpability of 10W40 on start-up.
  2. Change it a lot. Temperature and gearbox thrashing break down oil. Every 1500 to 2000 miles would be nice, although if you're using a synthetic, perhaps you can extend this.
  3. Avoid extended idling. Long idles mean heat buildup and low oilflow because of relatively low pressure feed to the heads.
  4. Don't cruise around in top gear at 3000 rpm. Again, oil flow.
  5. Use premium gasoline. Prevents detonation; burns cooler.
  6. Install the upgraded oil supply lines if available for your model. Consult Phil's articles for description and part numbers, as well

6. Was my myth on 83 Magna.

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"On the whole, adequate oil pressure is not developed below about 3000 to 3500 rpm"

run it like ya stole it. :)

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Ok, I've sent the cams off to be lightly ground and a good used set of rockers to be hard faced. While I do believe the cams were the source of the problem the oiling issue also concerns me. The idea that unfiltered engine oil would be directed to the heads seems at odds with my expirienece of Honda engineering. (I was a Honda motorcycle tech for three years and a Honda car tech for four.)

I'm in Toledo Ohio, home of Aeorquip, and have access to just about any kind of fittinges available. For this reason I reiterate, If I were to do an oil modification to draw cyclinder head oil from the filtered system wouldn't it make more sense to draw the oil from the main bearing galley via the port for the oil pressure switch? Rather than the expensive kit or the iffy drill the block method?

Can anyone give me a reason this isn't a better alternative?

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  • 2 weeks later...

I've done some more research and thought a lot about this. I believe the cams were soft in some cases and overloaded in all cases. But one of my sets of cams were Yoshimura machined from billet and then heat treated by YOSHIMURA, not Honda. For that reason I think the oiling problem needs to be addressed. I just haven't decided what to do yet.

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I've done some more research and thought a lot about this. I believe the cams were soft in some cases and overloaded in all cases. But one of my sets of cams were Yoshimura machined from billet and then heat treated by YOSHIMURA, not Honda. For that reason I think the oiling problem needs to be addressed. I just haven't decided what to do yet.

You know if your going to put money onto the bike go ahead and upgrade the oiling system .

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For anyone following this thread I've just returned from Autozone, (They're two blocks away) and bought a 2010 Honda Civic oil filter. I did this because Honda only has one car oil filter and that 20 x 1.5 mm dimension sounded really familar. Anyway, the Fram PH7317 oil filter for the Civic fits my 84VF750F engine perfectly!

Why you ask is this important? Because any Civic oil filter sandwich plate will fit the engine just as perfectly. They are only about twenty five bucks on eBay. And with that my friends running an 1/8" brake line up into the vee and connecting it to the existing oil lines is easy and cheap!

Edited by mr2racer
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I never had this problem on my 83 VF750F, but the cam chain and tensioners were rubbish! I didn't keep it long enough (30000km) to develop any cam issues that I knew about, but I did have to get new chains and tensioners in that time.

It is good to be able to see that Honda learned their lesson with later engines, the cams and buckets in both my 99 VFR800 and 97 VTR1000 look like new after 90 and 70,000km respectively.

However, the camchain tensioners in the VTR are STILL RUBBISH!!! Installing manual tensioners was my first upgrade, more like an insurance down-payment.

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As an original owner of an 83 VF750, I was intrigued by Greg Pullen's account in "Honda V4 - The Complete Four-Stroke Story":

"With the early V4s, the problem was camshaft wear - in an ironic twist- was blamed on the decision to use the 'less troublesome' threaded tapped adjustment rather than shims. In essence, the problem was that the camshafts could rock in their bearings if the tappet adjustment was incorrect, or if the top and bottom castings that had the camshaft bearings machined into them were not a good match. Honda did not match components to get the best fit from the inevitable variations in mass production, instead trusting to the precision of their new machinery to avoid such variations. In addition, rough castings could lead a mechanic to 'feel' he had the tappet correctly adjusted and secured by a locknut, when in fact further tightening was needed.

As a result, camshafts and cylinder heads continued to wear catastrophically. ———

At first, Honda believed the solution lay in improved oil ways, and they pressed ahead with V4 road bikes in an even higher state of tune, with disastrous results. ——— Because the V4s woes stemmed from unmatched components, some engines were affected far more than others, and some not at all; it depended on how poorly the components matched one another when they came together on the production line."

So there you have the real problem, with no logical fix.

Edited by Allyance
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