New Honda V-4s? - Page 2 - SV650.org

SoulKiss · 23-03-07, 11:37 AM

Hey Bluesteel - never noticed you were so close to me

Anyways on topic....

I must admit that I am looking fowards to finding out more about the new Honda V4's.

A VF750F yahoo group I am on (I considered restoring an 83 VF) was buzzing about this a bit - the VF being the "prototype" of the VFR and a V4 (it had SERIOUS engineering problems with the cams being too soft/oil starved so much so they killed the name)

David

23-03-07, 11:50 AM

Quite right David, a magna owner friend of mine told me about this problem.
Magna is a detuned VFR engined custom type of motorcycle.

Here's some information from an old magazine...

More Cam Problem Perspectives, from Performance Bikes magazine

The April 1996 issue of Performance Bikes, a British magazine, contains a retrospective of the development of the V4, from the founding V45 Sabre in 1982 through to the current VFR750F and RC45. Naturally some discussion of the cam problems of the first generation VF motors is included. The authors provides the details on a problem I had previously known only vaguely as "manufacturing variations". They also make explicit reference to problems which I've heard about only anecdotally and have never before seen in print. Without permission, I reproduce this section of the article. Footnotes refer to comments of my own afterwards.

"The big blow came when MCN's (Motor Cycle News) long term VF750S developed abnormal wear on a rear camshaft. At first it was put down to poor metal hardening, but when they printed the tale other VF owners came forward with their own horror stories. A major row blew up with Honda UK at first refusing to acknowledge the problem before coming clean, claiming they were waiting until they'd located and solved the problem before doing anything about it.
"And the trouble was this: poor oil feed to the cams caused by kinked oil pipes, restricted banjo bolts, and oil bleed holes in the camshafts. All three were cured by changing the oil pipes so they wouldn't kink [note1], using banjo bolts with larger holes and restrictors removed [note2], and drilling extra holes at the base of the cam lobes (and plugging the bleed ends on the camshafts). [note3] Honda also halved the oil change intervals to 4000 miles.

"But there was more. Instead of line boring the cam journals with the caps attached to the head (so the caps were accurately matched), Honda milled them in two separate operations (for neatness, they said). This led to play in the cam bearing, which meant that when setting valve clearances, valve spring and camchain tension tilted the camshaft. This artificially reduced clearance between cam lobes and rocker arms so that what looked right during a service could double when the motor was running. Result: the lobes hammered the rockers, knackering both.[note4]

"To solve the problem Honda produced a special tool to hold the camshaft in place during adjustment [note5], but not before the VF earned a reputation for being unreliable -- the last thing Honda needed with the motor which was supposed to be their super-techno-flagship of the future.

[...]

"For 1985 the 750 [Interceptor] carried on unchanged although Honda returned to line-boring the head and cam cap as a matched pair." [note6]

The following are my comments on what Performance Bikes said.

[1] I have never heard of kinked oil pipes until this article.

[2] If you have read my other cam articles you know that Phil Rastocny noticed the upgraded banjo bolts after some detective work with the Honda parts microfiche. His oil modification scheme calls for replacement of these bolts and/or drilling them out for greater flow. I have never seen anything "official" on this subject until now.

[3] You may also recall that my own V4 mechanic told me about the changes to the later camshafts, and that when I swapped engines he welded the ends of the camshafts closed as he had seen on the later model camshafts. Again, I've never seen anything official about this before.

[4] This seems like a key downfall in the VF valvetrain. Mention has often been made of tilting camshafts and the need for the special tool, but this is the first time I have ever seen this explanation for what caused it. Shortly after this article in Performance Bikes appeared, I received email from a fellow in the U.K. who is a former Honda development tester. He describes the same thing. In my original article on the cam problem, I list the item "Variation in cam-to-bearing clearance because of manufacturing method." Now at last we know exactly what this was referring to.

[5] When I adjust my valves, I not only use the special tool, but I position the cams differently from what the manual recommends. My V4 mechanic taught me this. Don't bother with searching for TDC and lining up the timing marks. When you do this, the cam lobes are not pressing on the valves anywhere. Instead, rotate the crank so that the cam is at full lift on the opposite end of the camshaft you're working on. Now install the special tool at the end you are working on. This results in both ends of the camshaft being forced up against the cap, so there is no tilt. Please note that this is not an official procedure recommended by Honda. It is merely the method that my mechanic taught me, and it seems to work well for both of us.

[6] I've never heard of this change to the 1985 Interceptor. Any owners of this model are welcome to send me mail with your observations. You should be able to spot two half-circle rubber gaskets on the cylinder head where the valve cover meets the cylinder head.

Looking at photos of the 1987-8 V45 Magna (the one with the four upswept pipes and solid disc rear wheel) it seems to me that it has gaskets like this, implying line-bored cam journals and thus safety from the cam problem.

Keith Marshall on the Cam Problem

Shortly after the article in Performance Bikes magazine came out, I received email from Keith A. Marshall of Heschimura Racing. Keith is a former pre-production tester with American Honda. Here's what he has to say about the cam problem.
I have been road racing Hondas for over two decades. Our team, Heschimura Racing, has won three 24 hour races and one 30 hour race. We won the 24 Hours of Nelson's in 1983 on a VF750. Beating all the 1 liter machines in the race on a stock VF. I was sold!
During my career in the motorcycle industry I worked for Honda Research of America, in Torrance CA. We were responsible for testing pre-production units to make sure they would last the life of the warranty and we did emission testing. We rode all models of Hondas for tens of thousands of miles without ever changing any fluids. The only maintenance we were allowed to do related to safety, tires, brakes etc. We tested many V4s that had the poorly designed heads. We NEVER had a cam failure during all the testing we did. We would put over 30,000 miles on the bike without ever changing the oil! This had to be done to check for compliance with the Federal laws concerning warranties.

A typical day of testing started with a thorough check-over of the machines and topping off any fluids, airing the tires, etc. The machines would then be started and HEATED up to OPERATING temperature before riding. We then proceeded to flog the machines for approximately 350 miles per day.

Of all the items I have read about the cam problem I cannot think of one that addresses the cause of the problem. So here is my take, from my experiences in the industry. First and foremost Honda decided to save money on the construction of the head assembly by not align-boring the cam journal-head assemblies. This procedure is performed on all of plain bearing crank Hondas prior to this with some exceptions. Instead they generically milled the heads for the cam bearings then made generic, open journal, cam holders. This saved costly machining operations and allowed individual replacement of the cam holders. This also allowed the cams to move around quite a bit in the head, especially since the cams were short and not rigidly supported. More so than a cam in an align-bored head. This movement caused the edges of the lobes to take the bulk of the load on the rockers instead of the flat surface of the lobe. [Certainly on the cams I've seen, it is the edges that fell to pieces first, although I've also seen signs of slight scoring on the flats. -- RBL] This along with the standard hardening process started to destroy the coating of the rockers and the lobes of the cams. The gear driven versions are align-bored to keep the cams from moving around and keep the gears in mesh. The later year, chain driven, Magnas are align-bored to CURE the problem.

There is another problem with ALL Honda model cams, and probably other make cams, that is not related to the above problem but is mistakenly associated with the design problem. Cams may develop pits that look something like blue cheese pits (the only example I can think of). This is caused by defects in the manufacture of the cam. This problem as been around, I think, since day one. I've seen the defect on all models from 50's to 1500's. [Agreed -- I've heard of cam problems on mid-80s GSXRs, among others. --RBL]

All the fixes that are out there are just Band-Aids on the wound. The V4 can and has lasted for many miles without cam failure, and without expensive oiling modifications. The key to keeping them alive is to take extreme care of them. The most damaging time of an internal engine's life is when it is first started. The ideal situation is that the engine is not put under load until it up to OPERATING temp. Not merely WARMED up! I mean engine HOT not people WARM.

All the fixes you have on your page will and have helped to keep the V4 alive. Since we cannot redesign the heads, at least not on the money I make, the fixes are the way to go. I also know that the brand and type of oil will affect the life of the cams. Since the design puts undue stress on the cam lobes and rockers you need excellent oil.

About the cam adjustment tool that holds the cam up against the cam holder. What is happening here is the tool overcomes the pull of the cam chain to place the cam against the load surface to make the adjustment. This helps to keep the cam from moving around (rocking around(?)) in the head as much. This can cause lots of other problems. If the machine was in good tune before using the tool then after adjusting the valves the idle will be lower. You will have to increase the idle with the idle screw. If all the carbs are in sync and the carbs are in good shape then you will probably be OK. On the other hand you may experience fluctuating idle speeds and stalling. There are lots of frustrating problems associated with adjusting the cams and I do not have the time to go over them all now.

Thanks for reading my opinions. V4's forever!!!!
Keith A. Marshall

SoulKiss · 23-03-07, 11:55 AM

Yeah - I still have an option on the VF750F Interceptor that was abandoned where I live, but too many people have said to stay away, so stay away I shall.

Its everything I dont like in a bike - single headlight, 80's styling, but there is something about it - maybe its just that it was the first bike I imagined owning.

Oh Well

David

23-03-07, 12:16 PM

VFR's with decent cans rock, big time. Closest thing to sounding like a GP bike on the road. Deep throaty "raw" note. Blooming wonderfuel !

.

23-03-07, 12:35 PM

Quote:

Originally Posted by SoulKiss

Hey Bluesteel - never noticed you were so close to me

Anyways on topic....

I must admit that I am looking fowards to finding out more about the new Honda V4's.

A VF750F yahoo group I am on (I considered restoring an 83 VF) was buzzing about this a bit - the VF being the "prototype" of the VFR and a V4 (it had SERIOUS engineering problems with the cams being too soft/oil starved so much so they killed the name)

David

Hey neighbour!

I love old Hondas. They went a bit nutty in the 80s. I used to have a CX500EC Eurosport in white. I loved that bike, but it was such a badly designed engine. I replaced the alternator 3 times. Mind you, it had covered nearly 200,000 miles (how?!?).

I think a new V-4 superbike would do really well, and help to bring a little variation to the configuration of the topline supersports bikes, in line with the variety people now enjoyed in the 600cc class (or there abouts).

SoulKiss · 23-03-07, 12:51 PM

Well heres a treat for you Bluesteel

currently sitting rotting away....

David

23-03-07, 01:23 PM

Its actually the VF750F that I had (mine was blue and white) … its heavy, breaks are not that great (verses the weight), its not powerful or torquey (bearing in mind CC and that it is a V4 – to be fair this is probably exacerbated by its podge) the anti-dive air-filled forks give little to no feedback … the tyres are odd sizes and finally and most importantly - the cams are made of cheese … cam rot is what killed mine off … with only 20k on the clock …

If it was free I’d have it, but I’d not spend £100s buying new heads and harder cams to get a rogered one working again … I’d rather get a different bike …

If you like classic Honda, go for something else … one of my fave classics/retros I had was a CB400/4 … I wouldn’t mind a CB750 or CB1000!

… I was a little disappointed with my GS1000 thought … I must buy a Z1000 at some point too

23-03-07, 01:42 PM

Oh as you can tell I am quite a classic connoisseur ... I've had all manner of 4-stroke classic/retro bikes

As for classic 2-stoke, the most famous/well know I've had are:- YR5, RD250B (did my first trackday on this

), RD250LC (I actually raced this -front end was shockingly bad/scary!

) GT185 ... and probably a couple more .... wouldn't mind a 'Kettle' at some point

Ridden an RG500 too

23-03-07, 11:37 AM	#11
SoulKiss Member Mega Poster Join Date: Jul 2006 Location: Sunny Croydonia Posts: 6,124	Re: New Honda V-4s? Hey Bluesteel - never noticed you were so close to me Anyways on topic.... I must admit that I am looking fowards to finding out more about the new Honda V4's. A VF750F yahoo group I am on (I considered restoring an 83 VF) was buzzing about this a bit - the VF being the "prototype" of the VFR and a V4 (it had SERIOUS engineering problems with the cams being too soft/oil starved so much so they killed the name) David

23-03-07, 11:50 AM	#12
zunkus Guest Posts: n/a	Re: New Honda V-4s? Quite right David, a magna owner friend of mine told me about this problem. Magna is a detuned VFR engined custom type of motorcycle. Here's some information from an old magazine... More Cam Problem Perspectives, from Performance Bikes magazine The April 1996 issue of Performance Bikes, a British magazine, contains a retrospective of the development of the V4, from the founding V45 Sabre in 1982 through to the current VFR750F and RC45. Naturally some discussion of the cam problems of the first generation VF motors is included. The authors provides the details on a problem I had previously known only vaguely as "manufacturing variations". They also make explicit reference to problems which I've heard about only anecdotally and have never before seen in print. Without permission, I reproduce this section of the article. Footnotes refer to comments of my own afterwards. "The big blow came when MCN's (Motor Cycle News) long term VF750S developed abnormal wear on a rear camshaft. At first it was put down to poor metal hardening, but when they printed the tale other VF owners came forward with their own horror stories. A major row blew up with Honda UK at first refusing to acknowledge the problem before coming clean, claiming they were waiting until they'd located and solved the problem before doing anything about it. "And the trouble was this: poor oil feed to the cams caused by kinked oil pipes, restricted banjo bolts, and oil bleed holes in the camshafts. All three were cured by changing the oil pipes so they wouldn't kink [note1], using banjo bolts with larger holes and restrictors removed [note2], and drilling extra holes at the base of the cam lobes (and plugging the bleed ends on the camshafts). [note3] Honda also halved the oil change intervals to 4000 miles. "But there was more. Instead of line boring the cam journals with the caps attached to the head (so the caps were accurately matched), Honda milled them in two separate operations (for neatness, they said). This led to play in the cam bearing, which meant that when setting valve clearances, valve spring and camchain tension tilted the camshaft. This artificially reduced clearance between cam lobes and rocker arms so that what looked right during a service could double when the motor was running. Result: the lobes hammered the rockers, knackering both.[note4] "To solve the problem Honda produced a special tool to hold the camshaft in place during adjustment [note5], but not before the VF earned a reputation for being unreliable -- the last thing Honda needed with the motor which was supposed to be their super-techno-flagship of the future. [...] "For 1985 the 750 [Interceptor] carried on unchanged although Honda returned to line-boring the head and cam cap as a matched pair." [note6] The following are my comments on what Performance Bikes said. [1] I have never heard of kinked oil pipes until this article. [2] If you have read my other cam articles you know that Phil Rastocny noticed the upgraded banjo bolts after some detective work with the Honda parts microfiche. His oil modification scheme calls for replacement of these bolts and/or drilling them out for greater flow. I have never seen anything "official" on this subject until now. [3] You may also recall that my own V4 mechanic told me about the changes to the later camshafts, and that when I swapped engines he welded the ends of the camshafts closed as he had seen on the later model camshafts. Again, I've never seen anything official about this before. [4] This seems like a key downfall in the VF valvetrain. Mention has often been made of tilting camshafts and the need for the special tool, but this is the first time I have ever seen this explanation for what caused it. Shortly after this article in Performance Bikes appeared, I received email from a fellow in the U.K. who is a former Honda development tester. He describes the same thing. In my original article on the cam problem, I list the item "Variation in cam-to-bearing clearance because of manufacturing method." Now at last we know exactly what this was referring to. [5] When I adjust my valves, I not only use the special tool, but I position the cams differently from what the manual recommends. My V4 mechanic taught me this. Don't bother with searching for TDC and lining up the timing marks. When you do this, the cam lobes are not pressing on the valves anywhere. Instead, rotate the crank so that the cam is at full lift on the opposite end of the camshaft you're working on. Now install the special tool at the end you are working on. This results in both ends of the camshaft being forced up against the cap, so there is no tilt. Please note that this is not an official procedure recommended by Honda. It is merely the method that my mechanic taught me, and it seems to work well for both of us. [6] I've never heard of this change to the 1985 Interceptor. Any owners of this model are welcome to send me mail with your observations. You should be able to spot two half-circle rubber gaskets on the cylinder head where the valve cover meets the cylinder head. Looking at photos of the 1987-8 V45 Magna (the one with the four upswept pipes and solid disc rear wheel) it seems to me that it has gaskets like this, implying line-bored cam journals and thus safety from the cam problem. Keith Marshall on the Cam Problem Shortly after the article in Performance Bikes magazine came out, I received email from Keith A. Marshall of Heschimura Racing. Keith is a former pre-production tester with American Honda. Here's what he has to say about the cam problem. I have been road racing Hondas for over two decades. Our team, Heschimura Racing, has won three 24 hour races and one 30 hour race. We won the 24 Hours of Nelson's in 1983 on a VF750. Beating all the 1 liter machines in the race on a stock VF. I was sold! During my career in the motorcycle industry I worked for Honda Research of America, in Torrance CA. We were responsible for testing pre-production units to make sure they would last the life of the warranty and we did emission testing. We rode all models of Hondas for tens of thousands of miles without ever changing any fluids. The only maintenance we were allowed to do related to safety, tires, brakes etc. We tested many V4s that had the poorly designed heads. We NEVER had a cam failure during all the testing we did. We would put over 30,000 miles on the bike without ever changing the oil! This had to be done to check for compliance with the Federal laws concerning warranties. A typical day of testing started with a thorough check-over of the machines and topping off any fluids, airing the tires, etc. The machines would then be started and HEATED up to OPERATING temperature before riding. We then proceeded to flog the machines for approximately 350 miles per day. Of all the items I have read about the cam problem I cannot think of one that addresses the cause of the problem. So here is my take, from my experiences in the industry. First and foremost Honda decided to save money on the construction of the head assembly by not align-boring the cam journal-head assemblies. This procedure is performed on all of plain bearing crank Hondas prior to this with some exceptions. Instead they generically milled the heads for the cam bearings then made generic, open journal, cam holders. This saved costly machining operations and allowed individual replacement of the cam holders. This also allowed the cams to move around quite a bit in the head, especially since the cams were short and not rigidly supported. More so than a cam in an align-bored head. This movement caused the edges of the lobes to take the bulk of the load on the rockers instead of the flat surface of the lobe. [Certainly on the cams I've seen, it is the edges that fell to pieces first, although I've also seen signs of slight scoring on the flats. -- RBL] This along with the standard hardening process started to destroy the coating of the rockers and the lobes of the cams. The gear driven versions are align-bored to keep the cams from moving around and keep the gears in mesh. The later year, chain driven, Magnas are align-bored to CURE the problem. There is another problem with ALL Honda model cams, and probably other make cams, that is not related to the above problem but is mistakenly associated with the design problem. Cams may develop pits that look something like blue cheese pits (the only example I can think of). This is caused by defects in the manufacture of the cam. This problem as been around, I think, since day one. I've seen the defect on all models from 50's to 1500's. [Agreed -- I've heard of cam problems on mid-80s GSXRs, among others. --RBL] All the fixes that are out there are just Band-Aids on the wound. The V4 can and has lasted for many miles without cam failure, and without expensive oiling modifications. The key to keeping them alive is to take extreme care of them. The most damaging time of an internal engine's life is when it is first started. The ideal situation is that the engine is not put under load until it up to OPERATING temp. Not merely WARMED up! I mean engine HOT not people WARM. All the fixes you have on your page will and have helped to keep the V4 alive. Since we cannot redesign the heads, at least not on the money I make, the fixes are the way to go. I also know that the brand and type of oil will affect the life of the cams. Since the design puts undue stress on the cam lobes and rockers you need excellent oil. About the cam adjustment tool that holds the cam up against the cam holder. What is happening here is the tool overcomes the pull of the cam chain to place the cam against the load surface to make the adjustment. This helps to keep the cam from moving around (rocking around(?)) in the head as much. This can cause lots of other problems. If the machine was in good tune before using the tool then after adjusting the valves the idle will be lower. You will have to increase the idle with the idle screw. If all the carbs are in sync and the carbs are in good shape then you will probably be OK. On the other hand you may experience fluctuating idle speeds and stalling. There are lots of frustrating problems associated with adjusting the cams and I do not have the time to go over them all now. Thanks for reading my opinions. V4's forever!!!! Keith A. Marshall

23-03-07, 11:55 AM	#13
SoulKiss Member Mega Poster Join Date: Jul 2006 Location: Sunny Croydonia Posts: 6,124	Re: New Honda V-4s? Yeah - I still have an option on the VF750F Interceptor that was abandoned where I live, but too many people have said to stay away, so stay away I shall. Its everything I dont like in a bike - single headlight, 80's styling, but there is something about it - maybe its just that it was the first bike I imagined owning. Oh Well David

23-03-07, 12:16 PM	#14
Jelster Guest Posts: n/a	Re: New Honda V-4s? VFR's with decent cans rock, big time. Closest thing to sounding like a GP bike on the road. Deep throaty "raw" note. Blooming wonderfuel ! .

23-03-07, 12:51 PM	#16
SoulKiss Member Mega Poster Join Date: Jul 2006 Location: Sunny Croydonia Posts: 6,124	Re: New Honda V-4s? Well heres a treat for you Bluesteel currently sitting rotting away.... David

23-03-07, 01:23 PM	#17
Blue_SV650S Guest Posts: n/a	Re: New Honda V-4s? Its actually the VF750F that I had (mine was blue and white) … its heavy, breaks are not that great (verses the weight), its not powerful or torquey (bearing in mind CC and that it is a V4 – to be fair this is probably exacerbated by its podge) the anti-dive air-filled forks give little to no feedback … the tyres are odd sizes and finally and most importantly - the cams are made of cheese … cam rot is what killed mine off … with only 20k on the clock … If it was free I’d have it, but I’d not spend £100s buying new heads and harder cams to get a rogered one working again … I’d rather get a different bike … If you like classic Honda, go for something else … one of my fave classics/retros I had was a CB400/4 … I wouldn’t mind a CB750 or CB1000! … I was a little disappointed with my GS1000 thought … I must buy a Z1000 at some point too

23-03-07, 01:42 PM	#18
Blue_SV650S Guest Posts: n/a	Re: New Honda V-4s? Oh as you can tell I am quite a classic connoisseur ... I've had all manner of 4-stroke classic/retro bikes As for classic 2-stoke, the most famous/well know I've had are:- YR5, RD250B (did my first trackday on this ), RD250LC (I actually raced this -front end was shockingly bad/scary! ) GT185 ... and probably a couple more .... wouldn't mind a 'Kettle' at some point Ridden an RG500 too

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