Another Engine Rebuild Thread - 80 3.0L

[Gunter]

[QUOTE=mca;4058556]This weekend I managed to install the pistons and cylinders with the help of Kevin (fellow Pelican). The wrist pin clips could not have been more difficult. Initially we installed the piston in the cylinder and then tried to install it as a unit. This made it virtually impossible to work the clip into the groove on the piston - the cylinder seemed to get in the way.

That sounds familiar

We then went out and bought a different ring compressor which allowed us to install the pistons on the rods first and then slip the cylinder over the piston. Much easier but the clip is still unacceptably difficult. Ended up cutting a notch in a screwdriver which provided some leverage on the clip. Still the most difficult task thus far.

Yep, that worked for me

Today I installed the cylinder tin, heads, and head stud nuts (not torqued - just tight enough to keep heads on). I am still cleaning up the cam housings and waiting on a new bottle of loctite to arrive before I can move further.

Very important:
Leave the heads loose enough so they float when the cam tower is installed!
The cam tower will align the heads! Follow page 154.
Use lube on the oil return seals so they slide easily into the holes.
When torquing the heads, go with the pre-torque for the 4 studs per cylinder cross-wise 10 o'clock- then 4, then 2, then 8.
Then do the final torque, again cross-wise on each cylinder.

[mca]

Originally Posted by sabeo.m

Looking good mca! Sorry for not providing you the sealant information sooner, but at least now you know where to get the stuff if you need it I am at a complete halt with my rebuild. I'm waiting for my replacement connecting rod bolts to arrive. Luckily I went over each step one last time and discovered I was sent the wrong size RaceWare rod bolts. The Rod's were not turning as freely as they should so I started to go over the assembly again. The packaging listed all the right information (miss print or something) but after measuring the diameter of the bolt I realized I had the wrong ones. I sent them back to the supplier and I was right. So, more waiting.. BTW, I don't sleep much at night either.

Nice catch on the rod bolts. I wish I knew how "freely" refurbed rods are supposed to turn. Mine moved consistently around but seemed sluggish - I assume that it is due to the assembly lube and everything being back in spec. For example, with the crank in the case I could set a rod vertically and it would stay for a few seconds before falling one way or the other.

Glad you got it sorted out. Do you have to replace the rod bearings too? Many people would say you do - I think it is one of those 50-50 things.

[mca]

This week I received my new bottle of Loctite 574 so I went ahead and installed the cam housings.

Mating the housings to the heads was a little more tricky than Wayne's rebuild book suggests. It wasn't hard by any means, but I had to break out the soft mallet to get the oil return tubes to seat inside the cam housings. Not big deal, just unexpected.

Here are some pics:

[mca]

Today I installed the chain housings, chain ramps, cam shafts, and sprockets for each side. Next step is to check the sprocket alignment.

I am clear on how to take the measurements. I don't understand where to place the 3ft rule - says in the book to place on the case flanges? The pics in the book don't help much either. If anyone has insight please share with me.

I thought that I would mention that I am using new chains. I only changed ONE of the intermediate shaft sprockets - the first one towards the rear of the engine (pulley side). The sprocket on the intermediate shaft towards the front of the engine (flywheel side) looked brand new. I am guessing that the PO had the sprockets misaligned which resulted in unusual wear on that sprocket ??

[Gunter]

If I remember correctly, the straight edge is placed on the chain case face. (Correction: It's placed on the I-shaft cover flange)
Try that and see if you get the measurements mentioned in the book.
It'll take several tries and many repeat calculations.
If you installed the shims the same way as they came out, you should be close.
Chain case and sprocket assembly has to be tight for these measurements.
Hope you maintained the correct float (Page 157) of the large O-ring?
If you need to change the shims for chain alignment, take a picture showing the space for the O-ring-float.
As for the I-shaft chain sprockets, it's unusual to change just one.
They may look o.k. but to really check any sprocket correctly is to wrap the new chain around on the old sprocket and make sure the chain rollers sit on the bottom of the valleys.
When you use a new chain on an old sprocket, the new chain will ride higher and will stress the tips of the sprocket-teeth; not good!

New chains without new sprockets? Read this!

Because the I-shaft chain sprockets are the drivers, they wear more than the cam sprockets or idlers.
Unfortunately, a lot of folks still feed new chains (the ones with the lock) onto old chain sprockets, not recommended!
Hope it works out for you.

[N11Porsche]

Not an engine rebuild expert but anytime you change the chain on a bike you need to check the chainrings VERY carefully. Putting a new chain on worn rings will cause the chain to skip (or slip a tooth) or cause the new chain to prematurely wear out. As Gunter said, I would check the old sprocket very carefully to make sure the new chain is riding in the bottom of the sprocket......

[ChrisBennet]

To measure the sprocket parallelism you place a straight edge across the face case where the intermediate shaft cover goes. In the picture, it would go between the 3 studs. In my experience, it's a very tricky operation. I couldn't get consistent results until I got the Stomski Racing tool that holds the straight edge. The Stomski tool uses the intermediate shaft cover studs to hold the straight edge against the face of the case.

Note that a (machinist's) straight edge is a precision ground piece of metal stock not a "3 ft rule".

If your measurement show something besides 3 shims on the left and 4 on the right, I would seriously question you measurements (on a pre-3.6L motor).

I mention this not as an expert but as someone who has made the same mistakes that I think you might be about to make.
-Chris

[mca]

Chains / Sprokets:
I read Gunter's thread regarding the chains / sprockets a while back. Very good info and an interesting read. Hopefully I won't find teeth in my sump down the road. If I do, I will absolutely share the info with the forum.

Sprocket Alignment:
I looked at the Bentley manual and it has a nice diagram. The only straight edge I have is a long level. During the tear down I found that the left side had 4 shims and the right side had 3. This seems contrary to Chris' statement. Which is correct?

[ChrisBennet]

Originally Posted by mca

Chains / Sprokets:
I read Gunter's thread regarding the chains / sprockets a while back. Very good info and an interesting read. Hopefully I won't find teeth in my sump down the road. If I do, I will absolutely share the info with the forum.

Sprocket Alignment:
I looked at the Bentley manual and it has a nice diagram. The only straight edge I have is a long level. During the tear down I found that the left side had 4 shims and the right side had 3. This seems contrary to Chris' statement. Which is correct?

I confirmed the 3left/4right shims in the factory manual just to be sure.

If you can't borrow a proper straight edge, I'd put the shims in 3 left/4 right. Your "straight" level is nowhere near straight enough. Remember the sprockets must be even within +/-.25mm.
Except for 964 motors, I've never seen a 911 motor that came with something different thant 3L/4R shims. Hopefully someone who has counted the shims on more than a dozen motors can chime in.
-Chris

[mca]

Originally Posted by ChrisBennet

I confirmed the 3left/4right shims in the factory manual just to be sure.

If you can't borrow a proper straight edge, I'd put the shims in 3 left/4 right. Your "straight" level is nowhere near straight enough. Remember the sprockets must be even within +/-.25mm.
Except for 964 motors, I've never seen a 911 motor that came with something different thant 3L/4R shims. Hopefully someone who has counted the shims on more than a dozen motors can chime in.
-Chris

Thanks Chris. I will hold off until I can get a good measurement.

[mca]

I measured my sprocket alignment over and over with the best tools I had.

Measurements confirmed that I needed 4 shims on the left and 3 on the right (as it was when I took it apart).

However I changed to 3 shims on the left and 4 on the right as stated by the Bentley manual. After pulling a shim out and studied its 0.5mm thickness, I realized that there was no possible way for me to make an accurate measurement of alignment withing +- 0.25mm ... that would be half of the width of a shim.

I think that old gasket juice on the case flange (where the straight edge is placed for measurement) would be enough to botch my measurements anyhow.

So, I am going to stick with the book in this case and hope for the best. Also, due to the fact that I replaced a sprocket on the IS shaft (had lots of wear) I am guessing that it was caused by the PO using the wrong number of shims - maybe they accidentally had the shims reversed.

[mca]

I managed to finish the engine this week. After installing the flywheel, flywheel seal, and intake rockers 1 and 4 Kevin came over after work on Thursday night and showed me how to set the cam timing.

We had some strange readings initially which was the result of not having enough tension on the chain (left side with the vice grips holding it - totally my fault). It is absolutely essential to have the chain tight on both sides.

After the timing was set I installed the chain tensioners and re-checked the timing. The cam timing actually advanced from 1.23mm to about 1.4mm. Since both sides advanced equally and since 1.4 is within the acceptable range I just rolled with it. Actually, I was pleased that his happened. I suppose the chain tensioners could apply more tension than what I could apply without them.

Kevin came over again on Saturday and helped me button up the chain housings (see pic below - he is doing a fine job). We then installed the exhaust rockers on 1 and 4 and checked the valve to piston clearance. All checked out fine.

I then installed the rest of the rockers, performed the valve adjustment and checked it three times - used the backside method and the regular method. This was the first valve adjustment I have done and it was quite nice to get a feel for both methods.

After that was complete I installed the valve covers and oil cooler. Phew ... finally done. Next weekend we will drop the engine out of my 82, pull the CIS off and put it on this engine, and the put this one in the following weekend. Just two weeks away before I find out if she runs.

Here are some pics.

Chain tensioners installed.


Kevin lending much needed help and guidance:


Rockers installed.


Valve covers installed.

[Gunter]

Looking good but........................some observstions:
Cam timing for a 1980 US 3.0 liter is 1.4 - 1.7 overlap meaning that 1.4 mm is the bottom of the range.
It should work although the overlap will decrease as the parts wear in.
Search for tips on how to do the run-in of the engine.
Wayne recommends 20W50 oil but I used 10W30, it's thinner and flushes better IMHO.
Some people recommend an additive like GM-EOS.
Leave the airbox cover/filter off.
I recommend building up oil pressure by disconnecting the 6-pin CDI module (Not the coil) and cranking the engine until the oil pressure light goes out. (After about 5-10 revolutions)
Stop, reconnect the 6-pin, ignition ON, bleed the CIS briefly by lifting the Air Sensor Plate inside the airbox; the injectors should screech. Stop lifting. Ignition OFF, you're ready.
Page 194 tells you how to start up and rev the engine so the rings will seat.
Watch for potential gas and oil leaks.
Set the mixture and idle by ear as you keep revving.

[Superman]

Conventional wisdom is to use single-weight (30w) non-detergent oil for initial startup and early break-in. I'm no expert, though. Just saying'........

[Targa4now]

awesome - subscribed!

[mca]

Originally Posted by Gunter

Looking good but........................some observstions:
Cam timing for a 1980 US 3.0 liter is 1.4 - 1.7 overlap meaning that 1.4 mm is the bottom of the range.

The cam timing for 3.0 with 964 cam grind is 1.26 mm. This was the number given to me by EBS.

Kevin spoke with John at Dougherty Racing Camshafts. He said "the setting is 1.26mm. If you want to advance the cams a little set them at 1.4 - 1.5 mm."

I guess that puts me at the bottom of the advanced end.

[SP2]

I set my 964's in an 81SC at 1.26 at jd's rec and it works fine.

[mca]

Do I need to be worried about oil temps when I first crank it up?

Just thought about that this morning ... 15-20 mins at 2000 - 4000 rpms ... hot garage ... hot summer ... hot south.

[Gunter]

Fantastic, mca.
Didn't realize that you went with 964-cams.
Absolutely agree with 1.4 mm overlap for 964-profile as recommended by a few experts including JW.
I set my 964-cams at 1.4 and like it.

[Elombard]

I think with no load on the motor you will be OK. Perhaps others will chime in. I was trying to think if there was a strategic place you could put a fan that could help but I dont think so. Do you have a radiator cooler in the front or the loop?