Help! Camshaft problems

[Rwheezy]

I just replaced the rear cylinder head and camshafts on my 1983 Interceptor V45. I'm now trying to get the camshafts properly phased to each other. I've reviewed both the Honda factory manual and the Clymer manual and have found conflicting information between them.

Does anyone have a known good setup that they can check to verify for me?

At TDC compression on cylinder 1 my intake cam is at 1o'clock position in relation to the head surface, my exhaust cam is at 11o'clock. On cylinder 2, at that time my intake is at 10o'clock and the exhaust is at 4o'clock. Is this right?

Based on the fact that it rotates nicely by hand and builds compression in the firing order 1,4,3,2 I assume I have it right. I'm just very unnerved by the fact that the Honda manual that I have is so vague about the whole procedure.

Thanks in advance for any help - this has been driving me crazy for a couple days now and I need to get this thing back together.

[Jakobi]

I just got done putting the heads back on my '84 VF500 and the orientations you have described were the same when viewed from the left side. Did you also use the timing marks on the cam gears?

The best advice I ever got for setting cams was to set and check them, take a 5-10 coffee break and then come back and check them again.

-Jake

[Rwheezy]

Yes, That is as viewed from the left side. Yes I did use the index marks on the cam gears.

When I line up the rotor at the T1-3 mark I have alignment of all the index marks on the cam sprockets with the head top surface.

At the T2-4 mark, the markings on the end of the cam sprocket holders showing IF and EF are both facing up and forward at approximately a 45 degree angle.

I've taken many many coffee breaks, just concerned by apparent differences between the 2 manuals and implications of incorrect cam phasing.

[Jakobi]

I compared my Clymer manual to my Honda one and the Clymer procedure switches to the right side for the front head which would caused me some confusion until I read the picture titles. Unless someone else chimes in I'd say you've got everything in correctly.

-Jake

[Rwheezy]

Ok…here’s the main concern that I have. The whole time looking from the left of the bike. When I have cylinder 1 at TDC (rotor lined up at T1-3), the lobes are pointing at intake = 1, exhaust = 11, the valves are completely closed for combustion to occur. When I then rotate the engine counterclockwise to the T2-4 position which should be TDC for cylinder 4, the lobes do not point straight up as they do for cylinder 1.

Another example…when I have TDC at cylinder 1 (intake = 1, exhaust = 11) cylinder 4 is at intake = 4, exhaust = 10. As I rotate the engine counterclockwise, the lobes on cylinder 1 follow each other (I = 12, E = 10; I = 11, E = 9; etc) whereas the lobes on cylinder 4 would start at I=4, E = 10 and would go through the sequence (I=3,E=9; I=2, E=8, etc). At no point do the lobes on cylinder 4 ever reach an 11/1 position which I have associated with the valves being completely closed during the compression stroke. Even though I set it up per the Clymer instructions it seems as if the banks of cylinders are out of sequence to each other as far as camshaft position is concerned.

[DKC'sVFR]

You have stumbled onto a conundrum that similarly baffled me. But step back and look at the two cylinder banks together and I think you will see where the confusion comes from. There is only one crank shaft with two rows of teeth. Think of one point on the rear cylinders timing chain passing over the cams on the rear cylinder bank (I hope I've got this right). Lets say you painted one link on the rear timing chain white. That mark would have to pass over the intake cam and then the exhaust cam in sequence before it returned to the origin on its respective crank. The crank would have to turn a full 720 degrees to have the mark return to its original starting place. Now from your removed vantage point consider the front cylinder banks timing chain. It has to rotate in the same direction as the rear timing chain when viewed from the same side. So if you are viewing a paint marked front timing chain from the same side as you did the rear, then the front timing chain passes over the exhaust cam first and the intake cam second before returning to the place it began after the crankshaft has made two complete revolutions. This is going to cause the positioning of the cams on the respective timing chains to be different for the two cylinder blocks. Don't expect the front cams to have the same 1 and 11 oclock positions as the rear (no 1 cylinder) cams do . Trying to make it happen will drive you crazy. You need to consider that the crank position vis that of the cam shafts is different for the front and back cylinder banks. This is complicated by the 90 degree V of the motor as well. You could figure it all out if you had an elaborate clock mechanism that you could manipulate through the complete compression cycle of the motor. It would be a gas to see it illustrated as a computer animation.

As for the scribed lines on the various cam drive sprockets, what a mess all that is. I have to concure with your observations regarding the various interpretations of the alignment of those scribed lines. It's even more difficult when the various marks on the flywheel are different for different models of V four engines. I'd like a tutorial on the various ways that Honda marked the time marks over the years. Hope you can sort it out for the rest of us. The worst part is that my son got seriously burnt by a timing problem caused by this sort of confusion. DKC

[GreyVF750F]

remember the 83-85 engines have a 360 degree crank, while 86 and up have a 180 crank. That will change how the cams are installed and how they line up. I never really liked Clymers or Haynes books. They seem to never have the technical info for in depth work or the info is not correct.