I got the new Cometic .027" thick head gaskets. They are just 3 layers of very thin coated stainless gaskets riveted together. Hopefully they work well. They've gotten good reviews, so we'll see.

Cool thread Bob!


I have a 440 that's .030" over in my Jensen with the same deck height pistons- I cut my 902 heads .030" and have a 270H Comp cam, I love the way it runs!!

Keep the progress pics coming!

Thanks! More to come...

I was disassembling and checking the lifters and I found that some are different. The short one measures 1.850" and the tall one measures 1.90". As you can see, they are completely different looking from the side. I looked at the ones on Summit and they don't give a height spec, only diameter (.904"). I measured the plunger height and they are exactly the same measurement from the base of the lifter to where the push rod sits. The oil hole height is .050" different, but since it goes up and down in the bore, it shouldn't matter. The tall one is stamped "Johnson HT 2011" which I found on Summit and application is for this (and many other) motors and are sold separately. Maybe he was missing a few and just got replacements.

In any case, I think I'll order new ones to be safe. I really don't like the looks of the Johnson ones. They look very crude overall...

After all the bad stuff I am finding with this motor, I decided to check all the main & rod bearing clearances with plastigage. It isn't as accurate as a micrometer/bore gauge, but it's supposedly within .0005", so that's close enough to get an idea of how it was put together.

This is what I came up with:

Mains
.0020
.0019
.0017
.0019
.0018

Rods
.0017
.0018
.0020
.0020
.0018
.0021
.0020

It's a little difficult to get an exact (to the ten-thousandths) reading because the lines on the paper aren't broken down that far, so it's really a best guess. I did it with the red and green and the red tended to read the same or a little higher than the green. For instance, I did one with the green and it read .0016. I double checked it with the red and it read .0020. So, who knows which is accurate.

These are a little tight compared to what I have read is optimal (.0025-.0027) but I understand that the plastigage tends to read a little on the low side compared to a micrometer/bore gauge. I called Clevite tech and he said it's well within the spec window. For the 440, he showed a huge acceptable range, for example, one I remember is for the mains which was .0008-.0030!

So, this is good news and I can move on to the valve train.

I sandblasted then painted the headers. Hopefully they will hold up.





...and installed the new rear main seal...

I bought a new Std volume oil pump from Autozone. I went to install it today and there was no gasket or o-ring. And, of course there wasn't one in the gasket kit!! It turns out that no-one includes this in the gasket kits. Why??? Makes no sense!

I scored a nice 402 oil pan from ebay. Really nice shape with a perfect original pickup tube and windage tray.




I installed the pickup in the motor and adjusted it so it just touches the bottom of the pan as the FSM calls for.

I installed the new rear main seal using this set up from the FelPro gasket kit for the side seals. It consists of two pipe cleaners that you are supposed to dip in water. First, you fill the side cavities of the retainer with silicone, then push the wet pipe cleaners into the slot. It's supposed to cure the silicone since it requires moisture (never knew this). The first time I installed this, I just filled the cavities with silicone and nothing else. A week later, it was still as wet as the day I did it. So, maybe they know what they're talking about? I hope so, I don't want to pull it apart again...especially when it's in the car...

That oil pan Looks too Clean like it might have been glass beaded.
Look in the seams of the baffles and MAKE SURE all the sand in out.
That is a Good way to shorten the life of a new motor. We tape the seams off REALLY GOOD before we bead them but we have seen A LOT of pans people don't and that sand will eventually come out and it doesn't break down. It Looks Nice though. Just an FYI for you to look at before it's on the motor and too late. David

Well, I spent most of the day today trying to figure out what length push rods I need. What a tedious and time consuming job.

With the rocker shafts all torqued down, I ended up with .113" preload on the lifters with the stock 9.31" pushrods, which is way too much. It should be between .020-.060". I don't know why it's so far off. The Stealth heads are supposed to be stock dimensions and the deck has not been cut. I measured two different ways to double check myself but it always comes out the same. I am using thinner than normal (.027") head gaskets, but that only accounts for .013" or so.

I'll be on the phone with Smith Bros. tomorrow to order up some custom length rods. 9.23" long should get me around .033" preload. The next build will have adjustable rocker arms. Much less hassle.

After speaking to Comp tech, it was decided that .045 preload would be better. Should have the pushrods in a week or so.

Well, I got the custom pushrods from Smith Bros and they look nice. I put it all together and the preload was still a little too much but not bad. It ranged from .053-.075". Comp calls for .040-.060". They said I can use some shims under the rocker shafts, so I ordered some .015" ones from Mancini to get me right in the ballpark. They came in today, so I decided to put it together tonight. I was just going to slap it together without going through the measurement process, but I figured I'd better just in case. Good thing I did. Now it has zero preload! I don't get it. I carefully measured for the pushrod length and it was still too much, and now the .015 shims somehow negates over .050" preload? So I took them out and measured again and now they are in spec...all the ones I measured were around .053" so screw it, I put it together. Done. I used exactly the same procedure to measure, but somehow it's inconsistent.

The Mopar rocker shaft setup is generally a good design, but with non-adjustable rocker arms, it's a major pita! The stock Chevy design is much better IMO. Turn the nut to zero lash, crank 3/4 turn down and go on with your life.




I learned this trick from my buddy. Put a piece of coat hanger across the head to hold the pushrods in place until you get the rocker arms installed.

I was warned that there may be a pushrod clearance issue around the intake ports with the Stealth heads, but mine were a-ok.

Its getting there Bob.

BTW, all the work on the stock 906 heads cost about $650 plus the cost of springs and special spring shims I had to find, so almost $800 total.
They were a mess for sure.

--Chad

How did the 906 heads come out? Did you do any more port or chamber work to them?

Ok, time for a little update. I have the car up in the air and the motor ready to pull out. I just have to unbolt the engine and trans mounts and she's outta there.



Since there was no safe place to store the hood in the garage, the wife let me use the pool table as a temporary prop. lol.


I drilled some holes in the windage tray to help the oil drain back better and installed the oil pan.



Also installed the timing cover, oil pump & water pump. It's just about ready to paint now. I just have to prime the aluminum heads with self etching primer. I'm going to be a little different and use Chrysler red. You can see the shade on the water pump, which I painted before I installed it.

What do you think of my new valve covers? Just the right amount of tackiness with that GOT-EM-FOR-A-BUCK-AT-A-YARD-SALE look, don't you think?


LOL! KIDDING! I got those with the car. I'm going to use them to cover the valve train while painting.
Nasty!

I was going to say you just ruined the the whole motor.

The amazing thing is that at one time, someone actually paid money for those and thought they were cool