My 427 SOHC Build..... Finally the time has come!

[cobracammer]

Ok so the 5/8" jig borer came today. Got the small stub cam gear set up between 2 rubber blocks in the X Y slide vice and aligned the reamer.  Was able after about 20 minutes per side to make the half moon cut outs.  I was going slow and lubricating with cutting oil as I went.  Turned out perfect!
 Saturday I am going to get the 5/8 bar stock from home depot and cut 2  seperate 1/2" pieces and mig weld them to the gear. I can then use the jig reamer and X Y slide vice to mill them flush with the gear. 3 drill bits later ( one 9/16" counter sink for bolt head, 3/8" for the bolt shaft and 17/64" pilot hole for tapping the large gear ) and i am going to use red locktite on bolt threads before installation.

This is extremely frustrating, but just when I think I have the timing understood, I loose it.  I have read up on it online, I read the instructions on the degree wheel kit I got, I have watched youtube videos....  Start to under stand and then it's gone!  LOL  I think its because normally the timing instructions are for a normal engine with the center Cam.  So, I will just jot down a few things, and anyone can feel free to put in 2 cents  :0)

1.)  I should find TDC with the heads on, cams installed, chain guides installed, chains installed and the front cover temporarily installed (make sure the stub cam bearing is pressed onto the Front cover).  This way, I do not have to remove and then replace the degree wheel after the front cover is installed.

2.)  With the heads on, with cams and cam gears with long chain temporarily installed  (and using a piston stop), I turn the crank slowly until the piston stop hits the piston.  I then mark that number on the wheel.  Then, turning the crank in the opposite direction slowly until the piston hits the stop.  I mark that number down.  Then, I add these 2 numbers together and divide by 2.  I then move the pointer to reflect this new number.  Turning the wheel again clockwise until it hits the piston stop and then the other way until it hits the piston stop.  It should stop at exactly the same number (the number you came up with by adding and dividing).  If not, add these 2 new numbers together and divide by 2 and repeat until the number is exactly the same when you turn the crank clockwise and counter clockwise.  Once the Numbers in both directions are exactly the same, the TDC "0" mark on the degree wheel now marks true TDC and the pointer should not be moved until after the timing of the cams. 

3.) with timing the cams, This is where I start to get a little fuzzy.  At this point, I know exactly where TDC is and the degree wheel is still installed with the pointer.  I understand that with the dots on the cam itself and the cam gear aligned, we are at the LSA of 108 degrees on both sides. I start by installing the magnetic base dial indicator over Cylinder 1/ Intake valve .  Now if the cam car is correct (and I can check this now that I know where TDC is), the valve will start to open when I turn the crank to 21 degrees before TDC.  If this is correct, then I know the cam card is correct.  However, I still need to advance the timing to the suggested points as discussed earlier in this post.  This is where I can pull out the dowel pin and turn the gear with respect to the cam to get the next hole to align.  This advances the timing 3 degrees (to 105 degrees). Now at this point, what should I recheck for with the dial indicator?  I would assume that now the intake valve will start to open at a different value correct?

3.) once this has been completed, I repeat the same process for the other head. Then torque the cams down to ensure the timing stays fixed.  When that is complete, I need to release some of the tension on the chain tensioner so that when I remove the cover plate, I don't bend the stub cam.  This will now allow me to start sealing the gaskets for final cover plate installation.
Thanks!

[jayb]

You have #1 and #2 right.  But on degreeing the cams, I would use the intake centerline method, rather than relying on determining the timing by noting when the valve starts to open.  Comp Cams has directions on that on their web site for reference, and it will be the same idea for the SOHC, but I will try to summarize it here:

- Start with the right cam, cylinder #1.  Make sure that the only rocker arm you have that is active is intake rocker on #1, and you have the adjuster backed all the way off.  When you turn the engine go slowly and carefully.  The idea here is to avoid bending a valve against a piston by forcing the engine to turn over, in case the cams are not degreed where you think they are.  Make sure you have the chain pretty tight; a loose chain will affect your readings.

- Put your dial indicator on the #1 intake valve spring retainer, next to the rocker arm.  Now, turn the engine over in the normal rotation direction (clockwise when looking from the front) and watch the dial indicator.  As the valve starts to open it will turn in one direction, peak, and then start turning in the opposite direction as the valve begins to close.  What you need to do here is to adjust the dial indicator's dial so that at peak valve lift, it reads zero, so turn the dial indicator bezel to zero when you get to peak lift.  If you've gone past peak lift, just turn the engine backwards a little, then approach the peak valve lift again.

-  Now that you have the engine at peak valve lift and the dial indicator reads zero, turn the engine backwards so that you are about 0.150" below peak valve lift.  Now, start turning the engine in the normal direction again, slowly, watching the dial indicator.  When you are 0.50" before peak valve lift, stop and note the reading on the degree wheel.  Let's say it is 282 degrees BTDC.

- Now continue rotating the engine in the normal direction.  When the dial indicator shows you have passed peak lift and are down .050" below peak lift, stop and read the degree wheel again.  Let's say this time it reads 222 degrees BTDC.

- Now comes the math.  Split the difference between these two degree readings and you have 252 degrees.  This is the intake centerline BTDC.  What you want, though, is what is specified by the cam manufacturer, which is intake centerline AFTER top dead center.  So, subtract your intake centerline BTDC from 360.  360-252=108.  So, your intake centerline is 108 degrees.  (Depending on your degree wheel, you may be reading the timing marks in degrees ATDC from the start.  In that case splitting the difference between the two readings will give you the intake centerline reading directly, and you don't have to subtract your reading from 360).

- Finally, note that this is crank degrees, not cam degrees.  Each pin position in the cam gear will move the cams 3 crank degrees.  So, if you are off, then you can move the pin location on the right cam/gear to advance or retard the cam.  If you are WAY off, then you probably have done something wrong assembling the gear to the cam, or installing the chain.

-  Once you get the right cam degreed, move over to the left cam and do the same thing with the #6 intake valve.

Plan on spending some time on this operation, because it definitely takes some thinking on the SOHC, and it is easy to screw it up.  Just go slowly, double check things as you go, and you'll get it - Jay

[cobracammer]

Hey Jay.  Awesome, thank you.  I guess really the only question I have left is this: 

1.)Once I have gotten the above completed, I will be at cam card specs on both heads.  At what point do I advance the timing to get the 105 and 102 that we spoke about earlier? ( I think it had something to do with accounting for Chain stretch?)

2.) Did you mean 0.050 before peak lift above?  so its 0.050 before lift and 0.050 after lift.

3.) the left cam is best timed with #6 cylinder?  Just out of curiosity, does the # 6 cylinder piston mirror the movement of the #1 Cylinder piston?

Thanks again.  I think I am really starting to understand.  Going slow is perfect at this point.  I figure the slower I go, I will have time in between each task to make sure I did it correctly.  FUN ON A BUN!

[jayb]

As soon as you get a measurement on the cam you can adjust for the desired intake centerline.  Most cams aren't ground perfectly, and you may not get 108 for the intake centerline (ICL) on the first try.  Just find out where you are, and then make adjustments from there, and re-check for the ICL.  Always re-check before you finalize the cam timing.

I'm not sure what was confusing on what I wrote, but to find the ICL you are correct that you should read the degree wheel at .050" lift before peak and .050" lift after peak.

The #6 cylinder is the fifth cylinder in the firing order.  So it is exactly 360 degrees different from #1, and you can use the same procedure, and get similar degree wheel readings.

[cobracammer]

Thanks Jay.  I got it now.   I think what was throwing me was that these parts are not always as "Specified". (as you have said before).  There is a chance that the cams may come in at something other than 108.  One may come in at 106 and the other 107 and then you would have to adjust the cam timing accordingly to get to the suggested 105 and 102.

Would be great if the cam card was way off and they came in exactly at 105 and 102 "straight up"  LOL

Thanks again!!!

[cobracammer]

HAHAHA  OK.  2 days in, I got the small stub cam gear all set up with the 1/2" steel bar welded on, Milled flat, drilled and counter bored for the head of the bolt.  Got both Gears pressed onto the stub cam and drilled out the larger gear for the threads on the bolts.  I slathered the both threads with red Loctite, and inserted.  I got each bolt head about half way into the gear (meaning that I counter bored about half the height of the bolt head.  Pictures below.  From the look of it, the bolts are recessed far enough that they wont touch the bearing that goes in the front cover (end of the stub cam goes through).  Want to throw these pictures up on here before I put the crank gear and chain on and install on the front of the block....   

[cobracammer]

another picture

[jayb]

Looks good.  Before you install the stub cam, put the bearing in the front cover and then fit the stub cam in from behind, to make sure that the bolts don't hit the cover.  There's isn't a whole lot of clearance there.  If the stub cam bottoms against the bearing, and you can see the snap ring groove from the front of the cover, you should be good to go.

[cobracammer]

Hey Jay.  Thanks.  After you said that, I went back in to the garage and pulled the stub cam assembly out so the 2nd journal on the stub cam was resting on the # 1 cam bearing (So that it was sticking way out the front so that I could test fit the face plate.  I pressed the bearing into the face plate, and put it all the way onto the stub cam where I could see the snap ring groove out the front.  I spun the face plate all the way around a few times, and could hear a slight scraping.  Pulled off the face plate and saw that it was slightly touching one of the bolts.  I tightened that bolt a little and put the face plate back on.  Spun it around about 3 revolutions and no touch!  Nice!!

Once I had that all buttoned up, I pulled the heads out of storage.  I wiped the combustion chamber down (as they were a little oily from the motor oil I rubbed them down with before I sealed them for storage 3 years ago.  got the head studs and head dowels on and placed the head gaskets on.  Both heads have head studs and they were torqued in 3 increments (70-90-110) in the order specified in the 427 Cammer maintenance shop manual  (from the center out).  Once the heads were on and torqued down, I pulled the gaskets out of their box.

With this, I wanted to be sure of a solid seal, so I laid the small gaskets out that go on each head, the 2 gaskets that go where the water pump goes, and the gasket that goes around the timing chain.  After matching them up to their place for installlation (which side needs sealant), I put a bead all the way around the gaskets and used my finger to basically coat the entire gasket with a layer.  I figured this would be safer than putting a small bead all the way around.  I stuck them to the front of the block and heads, and then coated the fronts of the gaskets in the same manner.  once this was done, I sandwiched them with the backing plate.  Much like Jay said during his built, getting the bolts ready so you have all the right bolts ready to hold the backing plate tight against the gaskets was key.  once I had them all tightened up, I took my finger and cleaned all the areas where the sealant squished out.  Before I finished for the night, I remembered that the bolt next to the bottom bolt on the passenger side water pump needed to be coated with sealant and sealant under the washer and alll around it (because it goes into the water jacket).  I am going to be setting the timing and then taking the cover plate back off, so I will not be installing the second set of gaskets until after the timing is set.  See below pictures!  FINALLY starting to look like a Cammer engine@!  Not sure if you can see it on these pictures, but when I had the heads done up at Keith Craft, he did a slight port job for me.  Smoothed out the intake ports "casting texture" for better air flow. 

[cobracammer]

another picture:

[cobracammer]

Another picture:

[cobracammer]

Some more: (just learned how to use Photobucket)

[cobracammer]

OK Last night, nothing big, but got the bearing pressed onto the Fuel pump gear and then the bearing stand.  Then got the tensioner, bearing and pin all pressed into place.  I loosened the bolts only where these items will be located and went to install, but realized that the bolts I have are not long enough!!!  They are both 1/2-13 X 3", but it looks like I will need a 4" bolt (or 3.5" at the least).  I searched home depot, lowes and ACE, and no one has them, so I ordered the 4" bolts from ebay and as soon as they get here I can bolt them down.

On a side note, the backing plate has been sitting now (compressed ) for 2 days and seems solid as a rock!  I do not believe there will be any leaks nor will it ever come loose!  As soon as I get the right length bolts, I will be installing the cams, Cam gears and large chain!  This is fun.  And like everyone has been saying from the beginning, going slow is the best way to do this engine.  I forgot to mention it earlier, but I did remember to put a small piece of Gasket material on the 2 areas indicated on Jays build.  They don't seal anything, but the gaskets will ensure the backing plate stays flat against the block.  You can actually see one of these places on the above picture on the bottom right corner.

[jayb]

I was looking at your photos and it looks to me like you gave the front cam cap on the heads on backwards.  The wider flange should face to the back of the engine, not the front.  Have you installed a cam yet to check that it spins properly in the head? I doubt it would turn with the front cap installed that way...

[cobracammer]

HAHAHA  Its funny you caught that!  When I was leaving Keith Crafts shop years ago, I asked him about that as it looked backwards.  He said told me that it was the correct way, but it looked weird to me.  Last night it bothered me so much I ran in there and turned it around.  The pictures above are from the day before  LOL  Good catch as usual!