Camshaft timing findings

[HAWAIIZR-1]

After pulling the LT5 this past weekend I finally got around to checking to see what the issue was before taking off the heads. I wanted to confirm how far off the timing was due to lower compression by 20-25 lbs on the entire bank of left side.

http://i78.photobucket.com/albums/j86/hawaiizr1/DSC01406.jpg
Set the camshaft locator

http://i78.photobucket.com/albums/j86/hawaiizr1/DSC01405.jpg

Right side no problem and pins placed.

http://i78.photobucket.com/albums/j86/hawaiizr1/DSC01404.jpg

Left side confirmed timing is off, did not check approximately how many degrees off but I'm sure the experts can tell by looking at this.

http://i78.photobucket.com/albums/j86/hawaiizr1/DSC01410.jpg

Removed pin to try to show how far off.

[HAWAIIZR-1]

:cheers:http://i78.photobucket.com/albums/j86/hawaiizr1/DSC01413.jpg

A shot of the other cam alignment for pin.

http://i78.photobucket.com/albums/j86/hawaiizr1/DSC01418.jpg

On a different note, here is the other piece of the key for the crankshaft/torsional damper that was left in. Easily taken out with tap of punch and ready for new key from Jeff. Still can't figure out how and when this happened, but not during my ownership of this Z. :dontknow:

More to follow. I'll start taking off the heads now that I am satisified I at least checked before disassembly. I was very afraid of all of this (right Jeff, Carter, Tom, Brad, Rick and others?) I feel more comfortable the more I read, watch the CPT video and work on this LT5. Thanks to this great Z brotherhood, even I can do this. :cheers:

[flyin ryan]

Can't say it's surprising...last one I had apart looked about the same, was out to lunch :dontknow:. Works good now though ;).

[HAWAIIZR-1]

Can't say it's surprising...last one I had apart looked about the same, was out to lunch :dontknow:. Works good now though ;).

flyin ryan,

Do you think being this much off was the root cause of the lower compression across this entire bank and also the smoking issue I was having? I can't imagine I have piston ring issues causing the lower compression and smoking with only 53K miles.

Thanks!

[tomtom72]

:happy1:

Subscribed!

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

[carter200]

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

[jonszr1]

craig , ryan would be the best one to run all your findings through . he has forgot more about motors than most of us will ever know .jmho

[Pete]

I can't tell from the pictures.

Looks to me like the cams retarded if i had to guess i would say at least 4 degrees basicly going from 114 to 118 +-2
When i checked my cams way back to start all the port work they were out on left field right bank was 119 109.

Looks like the same thing on yours looks like cams retarded
Intake 118 +-2 Exhaust 108 +-2

I pretty sure this is the reason for lower pressures.

I have my notes somewhere different pressures with all the different cam timings i just need to find them.

By the way 118+ intake timing is over/past the best power curve.

Good luck.

Pete

Just remembered,this is a big if, if the exhaust moved to 106 or lower you are very close to having the ex.valves hitting the piston,look at your pistons for marks if so then the low pressures could be bend valves.
Don't mean to scare you but better to check now then find out later.

[HAWAIIZR-1]

I can't tell from the pictures.

Looks to me like the cams retarded if i had to guess i would say at least 4 degrees basicly going from 114 to 118 +-2
When i checked my cams way back to start all the port work they were out on left field right bank was 119 109.

Looks like the same thing on yours looks like cams retarded
Intake 118 +-2 Exhaust 108 +-2

I pretty sure this is the reason for lower pressures.

I have my notes somewhere different pressures with all the different cam timings i just need to find them.

By the way 118+ intake timing is over/past the best power curve.

Good luck.

Pete

Just remembered,this is a big if, if the exhaust moved to 106 or lower you are very close to having the ex.valves hitting the piston,look at your pistons for marks if so then the low pressures could be bend valves.
Don't mean to scare you but better to check now then find out later.

Pete,

Thanks for all you help and advice. I am starting to actually understand what you are talking about......very scary. I have been reading and trying to be a sponge and I'm all ears. Hey, low 11s and the quickest 350 is doing many things right in my book. I'll pull the heads tomorrow and see what is going on. I am praying that I don't have bent balves or and piston damage.

What causes these to go out of timing like that?

[HAWAIIZR-1]

craig , ryan would be the best one to run all your findings through . he has forgot more about motors than most of us will ever know .jmho

Brad,

Thanks Brad. You're right and I'll definitely solicit help from flyin ryan too. Someone else already passed my invaluable infomation from Ryan. Thanks Ryan!

[HAWAIIZR-1]

:happy1:

Subscribed!

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

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.

[HAWAIIZR-1]

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

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...........:cry:

[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 :thumbsup:

[tomtom72]

Craig, thanks for letting me watch!:thumbsup:

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

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?

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

[FU]

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

http://www.zr1specialist.com/HAT%20Web/articles/timing_camshafts.htm

[HAWAIIZR-1]

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 :thumbsup:

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..........:dontknow:

[HAWAIIZR-1]

Craig, thanks for letting me watch!:thumbsup:

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

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?

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

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.

[HAWAIIZR-1]

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

http://www.zr1specialist.com/HAT%20Web/articles/timing_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. :handshak:

[HAWAIIZR-1]

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.

http://i78.photobucket.com/albums/j86/hawaiizr1/DSC01432.jpg

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.

http://i78.photobucket.com/albums/j86/hawaiizr1/DSC01433.jpg

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.

http://i78.photobucket.com/albums/j86/hawaiizr1/DSC01434.jpg

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.

http://i78.photobucket.com/albums/j86/hawaiizr1/DSC01438.jpg

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

[HAWAIIZR-1]

http://i78.photobucket.com/albums/j86/hawaiizr1/DSC01435.jpg

Getting ready to bust my nuts and the head bolts

http://i78.photobucket.com/albums/j86/hawaiizr1/DSC01436.jpg

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

http://i78.photobucket.com/albums/j86/hawaiizr1/DSC01437.jpg


http://i78.photobucket.com/albums/j86/hawaiizr1/DSC01439.jpg

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.

[HAWAIIZR-1]

http://i78.photobucket.com/albums/j86/hawaiizr1/DSC01440.jpg

Cylinder #5 and #7 all looks good except I don't know about the finish as first time with nikasil coating and trying to learn.

http://i78.photobucket.com/albums/j86/hawaiizr1/DSC01441.jpg

#1 and #3 cylinder

http://i78.photobucket.com/albums/j86/hawaiizr1/DSC01442.jpg

#5 and #7

Will get to the other head tomorrow after I eat my Wheaties for breakfast.

[tomtom72]

Craig, thanks for answering my Q's. :thumbsup:

I'll try to keep my Q's out of here as I'm sure I'm disturbing your concentration with my distractions. Sorry man. You have enough to do without holding class!

Hey Frank, thanks for the link on the cam timing! I'm gonna go study that one.

:cheers: Craig! Here's hoping that this turns out to be just a case of bad cam timing & no broken expensive parts!:pray

The combustion chamber pictures seem to show no valve hits, just carbon build up?

[HAWAIIZR-1]

Craig, thanks for answering my Q's. :thumbsup:

I'll try to keep my Q's out of here as I'm sure I'm disturbing your concentration with my distractions. Sorry man. You have enough to do without holding class!

Hey Frank, thanks for the link on the cam timing! I'm gonna go study that one.

:cheers: Craig! Here's hoping that this turns out to be just a case of bad cam timing & no broken expensive parts!:pray

The combustion chamber pictures seem to show no valve hits, just carbon build up?

Tom,

No problem and I don't mind, I am just not one you want to get advice from being a novice myself.....but I'll surely share what I do know or experienced with this tear down. Thanks for your wishes and I'll see when I get to the bottom half. Either way, I'm going to freshen it up with new bearings, pistons, rings, balance, etc. while I'm in here with all the plenum and head work too. Figured I might as we do it right so in goes the 4:10s with new ujoints and beam plate as well as the fidanza flywheel and clutch. Hopefully I'll be able to drive and change oil for awhile after that.:pray Well, let me work on the other side and get that head off.

[flyin ryan]

Hey Craig, been gone racing my Stingray on a short road trip the past couple days. Pistons & cylinder walls look good from what I can tell/see. At this point not sure what the root of your smoking is coming from? It's something, just need to dig a little deeper. What were your pumping compression numbers?

[HAWAIIZR-1]

Hey Craig, been gone racing my Stingray on a short road trip the past couple days. Pistons & cylinder walls look good from what I can tell/see. At this point not sure what the root of your smoking is coming from? It's something, just need to dig a little deeper. What were your pumping compression numbers?

Hi Ryan,

Thanks for helping out and I appreciate your input. The smoking was a wide open throttle only and I don't exact color but it appeared to be blue when I could try to look behind. Complaints from people following complained about the smell on the freeway with Corvette Club convoy.

My compression numbers were:

1 = 175
3 = 190
5 = 187
7 = 185

2 = 205
4 = 215
6 = 215
8 = 220

Second time for left bank:

1 = 190
3 = 185
5 = 185
7 = 185

Thanks again, I'll post the pics from the other head removed today.

[HAWAIIZR-1]

So I finally got the right side head off after getting some help from my neighbor that build VWs. I guess the left side yesterday stole all my energy because I could not do this side by myself and the bolt were a bugger.

http://i78.photobucket.com/albums/j86/hawaiizr1/DSC01443.jpg

Cylinders # 2 and #4

http://i78.photobucket.com/albums/j86/hawaiizr1/DSC01444.jpg

#6 and #8

http://i78.photobucket.com/albums/j86/hawaiizr1/DSC01445.jpg

Cylinder #2 and 4. What is up with the different color valves. My spark plugs had this same color and Marc H said someone else using Royal Purple had the same color too. So it this a Royal Purple thing? I will be using AMSOIL from here on out.

http://i78.photobucket.com/albums/j86/hawaiizr1/DSC01446.jpg

#6 and #8. The head gaskets were a surprise and look almost like new.

So the next step is to take off the only pan, girdle and inspect the bearings. First I have to prep the heads to ship off to Greg Van Deventer to let him work his magic. I can really see how the port work in heads and top half makes the LT5 come alive after getting this far into the motor.

[tomtom72]

http://www.4secondsflat.com/plug_chart.html


I know I'm outta my league here but I thought I post this link for you Craig....like you don't have this one already!

I am proly way wrong in using a plug chart to interpret the color of the deposits on the combustion chambers and their valves. I was comparing the plug colors on that chart and trying to match those colors to the colors on your heads.:o

I just want to apologize in advance if I should have kept quiet. It's just that it seemed kind of logical to me if the plug color matched the chamber/valve face color that maybe you could figure out what's going on in each hole?

:cheers:
Tom

[HAWAIIZR-1]

http://www.4secondsflat.com/plug_chart.html


I know I'm outta my league here but I thought I post this link for you Craig....like you don't have this one already!

I am proly way wrong in using a plug chart to interpret the color of the deposits on the combustion chambers and their valves. I was comparing the plug colors on that chart and trying to match those colors to the colors on your heads.:o

I just want to apologize in advance if I should have kept quiet. It's just that it seemed kind of logical to me if the plug color matched the chamber/valve face color that maybe you could figure out what's going on in each hole?

:cheers:
Tom

Tom,

No, I don't have this link and I'll add it to my library. I really appreciate you looking out and I do have the pics of the plugs by cylinder when I was trying to figure this out before going into the motor.

Thanks again!!!

[flyin ryan]

Up to this point everything still looks pretty decent, Craig. Unfortunatly that makes it hard to diagnose :icon_scra. Valve color is a fuel thing, not so much the fuel itself but all the junk put in the fuel by the manufactuer/refinery. Not sure what quality of fuel is available to you out there? Reality is that most stuff that comes out of the pump is very avarage, no matter what part of the country a person's in. It is getting better with Ethanol blends though. Could have a valve seal issue, maybe even a guide, how do the valve stems & back sides of valve heads look when looking down/in to the ports? Gummed up at all?

[LGAFF]

Mine smoked bad(90), switched to 15-45 Mobile 1 and no more issues.

[HAWAIIZR-1]

Up to this point everything still looks pretty decent, Craig. Unfortunatly that makes it hard to diagnose :icon_scra. Valve color is a fuel thing, not so much the fuel itself but all the junk put in the fuel by the manufactuer/refinery. Not sure what quality of fuel is available to you out there? Reality is that most stuff that comes out of the pump is very avarage, no matter what part of the country a person's in. It is getting better with Ethanol blends though. Could have a valve seal issue, maybe even a guide, how do the valve stems & back sides of valve heads look when looking down/in to the ports? Gummed up at all?

Ryan,

Thanks again for your input. Not sure about the fuel here and the only additive over the years has been Sta-bil for storage off and on. I imagine it sucks here, but we do have one station (Union 76) in the Honolulu area that sells several types of racing fuel, but have not checked it out. Looking down into the ports the intake side is really clean except for the secondaries that are a little gummed, but looks normal. The exhaust side is another story and maybe I'll be able to take some pics later as they look very gummed up. The heads are in the process of being shipped to Greg Van Deventer so we'll see what he finds when rebuilding these. Gotta head to work so thanks again.

[HAWAIIZR-1]

Mine smoked bad(90), switched to 15-45 Mobile 1 and no more issues.

Lee,

Thanks again for the TIPS. I might have to try it after I get the rebuilt motor broken in. I did not even have a chance to try the AMSOIL 10W-40 and wasted it when I found the piece of metal in the oil from the key on the crank.

[HAWAIIZR-1]

1. Did you use camshaft chain secondary pre-tensioners? If so, where do you get the J37305 chain pre-tensioner tool?
2. Where did you get the Timing pins J37326?
3. Where did you get the J38098 crankshaft locator?

Dynomite,

I got all the tools from Bill Kirchoffer in the ZR-1 Registry in the LT5 parts/tools:

http://www.zr1netregistry.com/ZR1_parts.htm

Not sure what he has in stock right now. My last order he was out of some of the items and not sure when he would get another batch.

Good luck with your project and I see you are doing some awesome stuff.

[HAWAIIZR-1]

I sent Bill an e-mail....thanks.....ya....since I had cam covers off amongst other items off :sign10: I figured I could check cam timing when I am at it :thumbsup:

You're welcome and great idea. I hope all is found well. I'm going to try to degree mine in when I reassembly if I can figure it out.

[HAWAIIZR-1]

You did some awesome stuff :thumbsup:...I just bolted things on....:sign10:
Let us know when you get er running :happy1:

Thanks, I'm sure we'll be hearing a lot from you and I'll be sure to update as I make progress.:happy1: Try to make it to the 2010 Gathering in May; I'm flying in from Hawaii. It will be a several more months for me to get er running. :cheers: