Refreshing my engine found this

[JMR]

I've always wondered, when you resurface the head, do you need to do anything special on the cam timing? e.g. adjustable cam chain sprockets.
....or there is enough adjustment in the cam chain adjuster to compensate?

I highly recommend timing the cams with adjustable sprockets after milling and/or decking. It's not a bad idea for a stock engine.
Not really hard to do on an FJ as the buckets are large (plenty of space to get the dial indicator in there). Mounting the degree wheel and being able to spin it without loosening the wheel hold down bolt is not as easy.

[ribbert]

I've always wondered, when you resurface the head, do you need to do anything special on the cam timing? e.g. adjustable cam chain sprockets.
....or there is enough adjustment in the cam chain adjuster to compensate?

I highly recommend timing the cams with adjustable sprockets after milling and/or decking. It's not a bad idea for a stock engine.
Not really hard to do on an FJ as the buckets are large (plenty of space to get the dial indicator in there). Mounting the degree wheel and being able to spin it without loosening the wheel hold down bolt is not as easy.

Excuse my ignorance here but isn't that what the tensioner does, take up the slack, and whats wrong with using the timing marks on the cams?

Noel

[JMR]

I've always wondered, when you resurface the head, do you need to do anything special on the cam timing? e.g. adjustable cam chain sprockets.
....or there is enough adjustment in the cam chain adjuster to compensate?

I highly recommend timing the cams with adjustable sprockets after milling and/or decking. It's not a bad idea for a stock engine.
Not really hard to do on an FJ as the buckets are large (plenty of space to get the dial indicator in there). Mounting the degree wheel and being able to spin it without loosening the wheel hold down bolt is not as easy.

Excuse my ignorance here but isn't that what the tensioner does, take up the slack, and whats wrong with using the timing marks on the cams?

Noel

Removing material from the head or cylinder will retard cam timing. If you remove enough material the stock timing marks will not line up correctly though the stock timing marks are at best an estimate. The engine will run with the cams a bit retarded or advanced and in fact that is why adjustable sprockets are good. Different applications want different cam numbers. Land speed cams want retarded (high lobe center #'s for example).
105LC works well on the street with stock cams. The only way to know if you are at 105 is to time the cams. The adjustable cam sprockets give you the final word.
I remember Dale Walker selling his cam timing kit years ago touting the benefits of timing the cams in stock engines.

[Pat Conlon]

Removing material from the head or cylinder will retard cam timing. If you remove enough material the stock timing marks will not line up correctly....

Thanks Mike
Yep, I have heard this before and was wondering what the limit is...the limit of head shave where, when you exceed it, you will absolutely need adjustable cam chain sprockets....e.g. .025" or .010"....005"...etc...

Mike m: Sorry for the thread hijack ....but the info may be of use to you.

Pat

[Mike m]

I didn't have any luck with the machine shop at lunch today.looks like my cylinder head is going to rpm also.

[Mike m]

I been reading the comments and it occurred to me.the previous owner did the failed 1219 piston install,so I'm wondering did they resurface the head and how much did they remove.what's the number I wanna see and the number I don't wanna see.I'm sweating now

[fj1289]

I been reading the comments and it occurred to me.the previous owner did the failed 1219 piston install,so I'm wondering did they resurface the head and how much did they remove.what's the number I wanna see and the number I don't wanna see.I'm sweating now

Don't worry about the head - it's possible to cut a LOT off it.  The limit is when you start getting into the intake valve seats!

[JMR]

I been reading the comments and it occurred to me.the previous owner did the failed 1219 piston install,so I'm wondering did they resurface the head and how much did they remove.what's the number I wanna see and the number I don't wanna see.I'm sweating now

Don't worry about the head - it's possible to cut a LOT off it.  The limit is when you start getting into the intake valve seats!

I agree. I took about .025 off mine. I'd imagine you get to .050 off an FJ head you have to start paying attention. I haven't milled an FJ head to the limit but have removed more material than that on other heads.

[racerrad8]

Excuse my ignorance here but isn't that what the tensioner does, take up the slack, and whats wrong with using the timing marks on the cams?

Noel

Noel,

Yes, the tensioner is designed to take up the slack of the timing chain on the slack side of the chain. As JMR already said, when the cylinder head & cylinder block are machined they become "thinner". This drops the camshaft bore center line closer to the crankshaft center line. That effectively makes the chain longer and the cams become retarded to the initial setting.

Then there is the issue of cam chain stretch over time. That also retards the camshafts as the chain gets longer the cams fall behind.

Here are some photos I took last year from the old timing chain I removed from Mike's engine compared to a new chain: Early One Morning

So, the addition of adjustable, Slotted Camshaft Gears allows the camshaft timing to be adjusted back to proper specs.

Mike, I don't have number for you to be able to compare. But as Chris already mentioned, you can cut a bunch off before a replacement head is required. In fact we machine brand new cylinder heads before building engines to reduce the combustion chamber size.

We have machined many over the years that actually get into the outer edge of the intake seats and we still use them.

Once everything gets here, we will develop a plan to get you all back together and running properly.

One other thing you might want to send me as well is your carbs. I know you have messed with them a lot but with the overbore they need to be built differently than they are now.

Randy - RPM

[Mike m]

Thanks for all the input as I read the comments I'm feeling more confident I can let go and reach out for help as this bike is more then just a fj1200 Its the bike I dreamed of owning as a teenager.I'll trust that I can send my engine parts out and know they'll be takin care of.thanks fellas

[Mike Ramos]

Thanks for all the input as I read the comments I'm feeling more confident I can let go and reach out for help as this bike is more then just a fj1200 Its the bike I dreamed of owning as a teenager.I'll trust that I can send my engine parts out and know they'll be takin care of.thanks fellas

Howdy Mike M!

No doubt you can rest easy - with all the help available from Forum members and the RPM crew, you and your parts will be well taken care of! 

Initially some years ago, I did all the mods with the advice of, and the information provided & posted by various Forum members.      

A year ago this month my engine was rebuilt by RPM and coming up on 30K miles, the engine still runs perfect - no oil leaks or consumption... and while I do not abuse the FJ, it is at times pushed hard.  Riding with other FJ's at a Rally (take your choice) is not to be taken lightly...! 

Good luck & ride safe,

Mike R

[ribbert]

Excuse my ignorance here but isn't that what the tensioner does, take up the slack, and whats wrong with using the timing marks on the cams?

Noel

Noel,

Yes, the tensioner is designed..................
Randy - RPM

Thanks Randy, I know what happens, I was just trying to encourage a bit of discussion. I have adjustable cam sprockets (RPM of course) on my engines for both of the reasons mentioned to return the timing to spec. My current engine has 250,000km on it and is untouched except for the adjustable sprockets, without them the timing is way off.  All it's vitals are otherwise perfect, I attribute this entirely to the oil I use. 

Noel

[ZOA NOM]

I attribute this entirely to the oil I use. 

Noel

Mike m - DO NOT FALL for this... it is a PANDORA'S BOX, and it can only end in misery.   

[Mike Ramos]

I attribute this entirely to the oil I use. 

Noel

Mike m - DO NOT FALL for this... it is a PANDORA'S BOX, and it can only end in misery.   

Uh Oh... and just when things were starting to settle down...!!!

Midget

[FJ_Hooligan]

Thanks Randy, I know what happens, I was just trying to encourage a bit of discussion. I have adjustable cam sprockets (RPM of course) on my engines for both of the reasons mentioned to return the timing to spec. My current engine has 250,000km on it and is untouched except for the adjustable sprockets, without them the timing is way off.  All it's vitals are otherwise perfect, I attribute this entirely to the oil I use. 

Noel

Noel,
Did you actually degree the cams or simply set cams with the timing marks in the windows and use the slotted sprockets to remove any slack?  How far off do you estimate the timing had degraded?