Camshaft timing findings

Originally Posted by tomtom72

Subscribed!

It's okay if I just sit here in the corner & watch? I promise I won't make any noise... I wanna learn.

Tom,

I hope there is value to my drama. I just figured I would share what happened to me. You sure have a lot to share too so don't be shy.

Originally Posted by carter200

Tom,
Pull up a seat and watch the show. It promises to be a good one

Carter,

Thanks for all your research and trying to help out. You always have my back; I need you in combat. Come to think of it, the Air Force always has the Army's back. I'm dating myself but I'll never forget when those A10s came flying in for air support and I knew my arse was covered on the ground. Okay, gotta quit now...........

[jonszr1]

craig ,pete also is awsome on these motors he has done more research on porting and cam timing in persuit of power than just about anyone . he is also very willing to help us out when we get in over our head

[tomtom72]

Craig, thanks for letting me watch!

This is waaaay over my head. Number of motors that I ever assembled: 4, and they were all 350 sbc's

So, I guess that with our motors you can't be very far off in cam timing and have the valves survive, and/or have good compression even if the valves don't hit?

How come the cam looks like it has spots all over it? Is that just the metal, or is that something else?

How did they assemble & time the cams at MerCruiser? Did they have to do what you you are doing using those "pins"? What's with the "gear set" at the chain end of the cam, is that how the timing is determined?

sorry, I'll try not to ask too many Q's.

[FU]

Thanks for the posting Craig Cam timing by Marc H. as posted on the ZR1.net by dave B. :

http://www.zr1specialist.com/HAT%20W..._camshafts.htm

Originally Posted by jonszr1

craig ,pete also is awsome on these motors he has done more research on porting and cam timing in persuit of power than just about anyone . he is also very willing to help us out when we get in over our head

Brad,

Thanks, I'll definitely ask him for help and I also read he is a master with the heads too. I'm in over my head..........

Originally Posted by tomtom72

Craig, thanks for letting me watch!

This is waaaay over my head. Number of motors that I ever assembled: 4, and they were all 350 sbc's

So, I guess that with our motors you can't be very far off in cam timing and have the valves survive, and/or have good compression even if the valves don't hit?

How come the cam looks like it has spots all over it? Is that just the metal, or is that something else?

How did they assemble & time the cams at MerCruiser? Did they have to do what you you are doing using those "pins"? What's with the "gear set" at the chain end of the cam, is that how the timing is determined?

sorry, I'll try not to ask too many Q's.

Hi Tom,

I don't have much to share as a novice but I figured there might be someone more novice than I; especially since our cars are changing hands lately more than ever with the economy and great prices.

Hey, you have more than me. I have only really worked on 2 SBCs and 1 BBC....about 30 years ago (my age is showing now).

I went into the garage just now to look at the pics versus reality and yes, there is like shading on the lobes but not as bad as it looks on the pics. I have a neighbor coming over in the next hour to help me break the bolts loose on the camshafts as I was afraid when trying this by myself. The color appears to be the metal and does not coincide with wear area on the lobes. I don't know what new or correct looks like, but I'm sure the folks with a lot of experience will comment about the spot appearance. I'll try to take better pics of my progress and what it looks like under the heads. A few have asked to see the bearings for mains and con rods too.

I'm pretty sure that mine did not hit valve/piston and if it did still amazingly strong motor with all considered before teardown. The left side that was off had compression about 25-30 lbs less that the correctly timed side. I am hoping anyway.

Yes, everything I have read and seen the cams are timed this way with the pins from the factory; so every ZR-1 has power to be gained with more accurate timing if untouched from the factory. The factory settting is not very accurate so I will degree them and use Marc H and Jim Milstead's instructions on the registry and Marc's site. I can see why the factory did not take the time and I'm sure Ferrari, Lambo, etc. don't use the good enough approach. I can also see why it cost a lot to degree in these cams as it does take time and I probably won't get it right the first time. I'm going to buy extra bolts just in case since you can only use them once when torqued. I think you are talking about the vernier plates near the gears and yes, those are the actual timing adjustments, again using pins. The factory will line up the cams with the retainer pins and the vernier plates with pins but I consider it just a baseline and good enough. If you degree the cams then you will find these settings are off. I'll get offline with you more on this.

Glad if I can help, but again.....I just a novice trying to learn.

Originally Posted by FU2

Thanks for the posting Craig Cam timing by Marc H. as posted on the ZR1.net by dave B. :

http://www.zr1specialist.com/HAT%20W..._camshafts.htm

Thanks for thinking of me. I did stumble across it when doing all my searching and searching for info. Printed and in my binder with document protectors. I'm so glad that people like Marc H is willing to share all this info.

I had a chance to start taking off the heads and what a challenge it posed to try it alone. My neighbor came by to help me break the camshaft bolts loose, but I let him go before trying the head bolts. Man these are tough buggers to do alone and I even went out to buy a 24" breaker bar. Just hard on the engine stand and trying to hold the motor from moving and use enough force to hear the loud crack to break it loose.



I had a little trouble initially wth the tension on the chain and had to all Jeff at ALMS Road Atlanta while he was trying to watch the race. Thanks Jeff, it worked like a champ and got the chain loose to get camshaft off. There sure is a lot of oil in all the drain areas on the heads.



My Mickey Mouse egg tray modified to keep the lifters in order for storage. Thanks USPS for the box to slide this tray in and store for assembly later. No issues with the lifters and very precision fit into the heads.



Then I have a little concern with the brown stuff that looks like cooper or something after sopping up all the oil in these areas.



I have no idea what the heck this stuff is after wiping it out and a little thick in areas.

Getting ready to bust my nuts and the head bolts



Trying to clean up and do an inspection of all the wear surfaces and looking for anything obvious.






After fighting with the head bolts a little at a time in reverse torque sequence, finally I get off the left side (the low compression side). Cylinder #1 and #3. Please tell me it this looks normal for a 53K mile motor. It is very smooth like glass and can't really see cross hatch pattern. I'll try better, close up pics later. I was burnt out by then and ready for dinner.