Nuts, bolts, washers, gaskets - what must be replaced with engine apart?

[LeeH]

I put up a "want to buy" post for the Z block and gauge a few days ago. I'll bump it up.

The engine is out of an '82 and still has the CIS. It's basically stock except for the cams. Records show it was reringed and heads done about 5K miles ago - so it wasn't a total rebuild. It really ran great and made a lot of power. I'm not sure why they went into the engine in the first place. The receipt claims it only had 50K miles when bought for the conversion.

After the over-rev at the DE, I finished the session. I didn't think there was any problem as it still seemed to make good power in the upper rpm range. It stalled after the session and was hard to restart. Once started, the power was down a bit and it ran rough under 2000 rpm. A cold compression test showed zero compression on three cylinders, 5 pounds, 80 pounds, and 145 pounds on the others.

[Gunter]

If you don't find the right gauge, get one from a tool supplier and improvise a long extension. These dial gauges are pretty cheap now.

Engine out of an '82 is vague; who knows what happened in the past?
To be sure, post the engine type 930/..???

[LeeH]

The case is 930 16.

I'm still waiting on the Pelican order for the camshaft tool. About all I can do right now is clean up the old gaskets... and from the looks of it that's going to take a while.

[tech 1]

Ok rod bolts are always a good idea to replace after an over-rev,especially one that happened on deacceleration! Remember the rev limiter only works electronically,it DOES NOT work on a mechanical over-rev ie; aggressive downshifting.That being said....My previous thread was NOT about checking deck height...it was about checking valve to piston clearance.This is VERY important! Especially if you have bent valves! Like I said before, I have seen an 8.5:1 c.i.s. 3.0 bend exhaust valves on aggresive downshifting with 964 cams.It's not a good idea to fudge on the cam timing to improve on this clearence. Perform the valve to piston check & increase the eyebrow depth on the piston if necessary. Tim

[Gunter]

Sounds good, Lee.
930/16 has 1.4 - 1.7 mm overlap with SC-cams but, you may want to find what setting would be recommended with your 20/21 cams.

For the camshaft, did you order the P9191 tool?

[Gunter]

Originally posted by Gunter
Tim, Re the higher lift of 964-cams on your stock 3.0:
What type? 930/07 or 930/16?
What CR?
CIS-piston-domes?
What overlap did you adjust for the cam timing?
I have 98mm P/C's for CIS, 9.8:1 CR, 964 cams and I set the overlap at 1.4mm without any issues re deck height.

Tim: Can you give more details on your set-up?

[tech 1]

Hi, This is an engine we are doing right now in my shop,so it's all fresh in my mind.And by the way it is still apart. The cams are Elgin 964 clones. Cam timing will be 1.4, comp. ratio will be 10.5:1 with JE pistons,and the engine will be C.I.S. This,again is not an issue about deck height! It is about V.O.T.C. (valve over top center) or as we call it,valve to piston clearence,an entirely different measurement. You should have,to be on the safe side,.080 on the intake and .0100 on the exhaust.When this engine came apart it was 8.5:1 and the exhaust valves hit.Not because of a deckheight issue but because of valve to piston clearence.964 cams have a higher lift than stock C.I.S. cams do,and someone did not allow enough room last time,for insurance.Remember nobody plans to over rev their engine,***** just happens when your on the track or driving aggresively.Tim

[LeeH]

I really appreciate all the help on this. It's the one thing that makes me want to borrow a truck and take it to a shop. That and the fact that I'll spend as much on the Z-block and dial gauge than it would cost to have it done. But, I'd really like to learn how to do this.

As far as the rod bolts go - what would I be looking for? I assume to inspect them the pistons and cylinders have to come off.

Here's the cam timing info that came from Web Cam:

[MBEngineering]

HI Lee your cam timing from the note you posted is 1.9-2.2mm of lift with the clearance set at .1mm , as for the rod bolts you will not see anything to say that you have to change them unless you have the length/size of the bolts when thay where fitted to now check if the length is the same, the rod bolts are a lot cheaper than a set of cases/rods/crank/oil pump/oil pump drive/intergear/pistons/cylinders, and the hassle of taking it all to bits again to make a coffee table out of what is left, or if you are really lucky a wine rack for 4 or may be 5 bottles.

regards mike

[Gunter]

Originally posted by tech 1
The cams are Elgin 964 clones. Cam timing will be 1.4, comp. ratio will be 10.5:1 with JE pistons,and the engine will be C.I.S.

WITH 10.5 : 1 CR, I ASSUME IT'LL BE TWIN-PLUG UNLESS 94+ OCTANE IS USED?

This,again is not an issue about deck height! It is about V.O.T.C. (valve over top center) or as we call it,valve to piston clearence,an entirely different measurement. You should have,to be on the safe side,.080 on the intake and .0100 on the exhaust.

THE NUMBERS DON'T LOOK RIGHT. GOING BY WAYNE'S BOOK PAGE 173 RE: CLEARANCE CHECK, THE EXHAUST VALVES SHOULD HAVE MORE CLEARANCE THAN THE INTAKE VALVES.
WHEN USING THE 1.0 MM PITCH ON THE ADJUSTMENT SCREW, AND TDC FOR #1, WHAT MEASUREMENTS (HOW MANY TURNS) DO YOU GET WITH YOUR 964-CAM FOR IN AND EX?

When this engine came apart it was 8.5:1 and the exhaust valves hit. Tim

SOMEBODY DIDN'T SET THE CLEARANCE FOR A 964-CAM.
GOING BY THE CR YOU MENTION, WAS THIS A '78-'79 ENGINE?

[tech 1]

Gunter, This was a '78 3.0 I didn't check it when it came apart,obviously when the valves are bent the valve to piston clearence changes and the measurement is irrealevent.If this engine had stock cams this may not have been an issue. When you go into a corner too hot, lets say 4th gear at 7000 rpms and your not slow enough and decide to select 3rd gear to slow down alot of ugly things can happen.I don't know how much clearence we will have yet going back together because I'm using JE pistons,and bumping up to 10.5:1,but I will be looking for .080" intake and .100" exhaust.I'll let you know when I get that far what I had out of the box and if I have to increase the valve relief in the pistons.However as a rule of thumb you should always make that check for valve to piston clearence especially if you are changing cams.TIM

[LeeH]

My camshaft tool arrived today. I read the section in Wayne's book concerning removing the nut. One thing I don't understand is how to release the tension on the chain so I can get everything apart. Should the tensioners compress?

[Walt Fricke]

With the chain box cover off, you see that there is only one 13mm nut holding the tensioner on. Take off the nut and washer, and just pull the tensioner off. It will spring into the fully extended position, but this won't damage anything.

Walt Fricke

[LeeH]

More questions... are there any alternatives to the tensioner tool Wayne shows for setting up the cam timing on the right side?

I really appreciate the support on this project. I'm beginning to feel like I'm in over my head. I keep telling myself, one step at a time...

[Gunter]

Originally posted by LeeH
My camshaft tool arrived today. I read the section in Wayne's book concerning removing the nut. One thing I don't understand is how to release the tension on the chain so I can get everything apart. Should the tensioners compress?

What do you mean by "Camshaft tool"?? P9191?
Rotate the engine to the Z1 position.
Slack off ALL valve adjusters.
Compress the tensioner with large channel-lock pliers and insert a 1/8" nail to lock the tensioner in the compressed position as shown on page 152-5 of the Bentley.
Read that section.
You do not need the P204 or P 214.
Compression should be slow and resistant, leave the nail in.
Now the chain has enough slack for you to pull out the tensioner.

When dismantling an engine, there will be lots of parts, nuts, bolts, etc.
Keep the parts together in cans and label them, take notes, take pictures.
Before you remove the cam sprockets, read that section in Wayne's book page 157-58, note the number of shims on each side of the sprocket and keep the shims tied together with the sprocket exactly as they come out!

One step at a time; refer to the books, it's all in there.
Read first before you take the next step meaning: Use both books, they explain things slightly differently but, between the two, it should become clearer.
And yes, it is a complicated job to rebuild an engine.

If you feel uncertain, maybe someone nearby can help you?
Put out some feelers.

[Gunter]

Originally posted by tech 1
I'm using JE pistons,and bumping up to 10.5:1,but I will be looking for .080" intake and .100" exhaust. I'll let you know when I get that far what I had out of the box and if I have to increase the valve relief in the pistons. TIM

Tim:
10.5 : 1 CR with Single Plug?

Re Clearance:
To be clear: You would be setting the piston to TDC, then using the valve adjusters to check for 0.080" intake and 0.100" exhaust meaning: With 0.004" exhaust valve clearance, the distance from piston to exhaust valve would be 0.100" (2.54mm)
Is that correct?
In other words, at Z1, the exhaust-adjuster screw with 1mm pitch would have to turn about 2.5 times before the valve hits the top of the piston?

[LeeH]

Yes, the tool I mention is the 9191. I've seen it described as a camshaft tool and cam bar.

The tool I was asking about from Wayne's book looks like (or possible is) a mechanical tensioner and is used on the right side to tension the chain during valve timing. He says to use vice grips on the case for the left side. Is there a reason why the tensioners aren't used? Chance they might compress a little?

I've read and reread the section on valve timing in Wayne's book a dozen times or more. It's actually starting to make sense. I'm going to see if I can find a dial gauge today so I can try the valve timing before pulling everything apart.

[Gunter]

Originally posted by LeeH
Yes, the tool I mention is the 9191. I've seen it described as a camshaft tool and cam bar.

The tool I was asking about from Wayne's book looks like (or possible is) a mechanical tensioner and is used on the right side to tension the chain during valve timing. He says to use vice grips on the case for the left side. Is there a reason why the tensioners aren't used? Chance they might compress a little?

The hydraulic tensioners have some tension need pressure to fully extent/work.
Full pressure is only there when the engine runs.
Before teardown, you can check the cam timing with the tensioners as is because they have an inherit spring tension to keep some tension on the chain.
Go ahead, check the timing without adding extra tension.
After rebuild is complete, when it comes to final timing:
Vice-grips on left is good.
For the right side, mechanical tensioners, or any support to keep the tension on the chain.

My improvised set-up for the right (Socket and bolt/nut):



Stay organized, take pictures, step by step by the book, don't jump ahead.

[tech 1]

Gunther, That is correct! But you Must turn the engine over through one full cycle like this! Remember the valves open faster that the pistons retreat to the bottom of the bore.In other words the Valve chases the piston down the bore.The trick here,obviously is that the valve must never cath up with the piston.If this test passes,then you are safe! On our race motors we ALWAYS continue this test by increasing the turns on the valve screw (1/4 turn at a time) untill we make contact,then we know exactly how much margin we have.Tim

[LeeH]

Gunter - super solution! I guess the trick is to get the temporary support out and get the real tensioner in place without moving anything.