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

[cobracammer]

Hi Jay,

I will take a look.  I think the Rod bearings (Speed Pro- Sealed Power) that I am using have tangs on them just like the main bearings. I will check for Chamfer, but I think with the tangs I cannot reverse them if the chanfer is on the incorrect side.

Either way, I will check when I get home.

Also, I left a message with Diamond pistons, but was curious.  On the piston card, it says that I should place the "F" toward the front of the engine.  I had the Pistons ceramic coated on top and Teflon coated on the sides, so I don't know if that covered the "F".  My pistons are not symmetrical.  One side of the dome has a raised section.  Does the raised part face the front of the engine? Below is a picture from Diamonds catalog.

[cobracammer]

OK I made a call to Diamond Pistons and found out that the Raised portion of the dome goes toward the front of the engine. (Larger depression is for intake valve and the smaller is for exhaust)  While on the phone with them (and looking at their catalog) I realized that my pistons had an asterisk next to them.  Seems the pistons I selected come with Oil rail supports.  After a short tutorial on Youtube, it seems straight forward.  The only think I am not sure about is the gap they require.  They don't seal the chamber, but are more of a structural support.  So what kind of end gap should they have?  Should it mirror something like the 2nd ring at 0.028?  Or just filed so there is no overlap, and they mate up square?

[jayb]

The gap isn't critical on the oil ring rails.  The gap should not be over an open area, though, it should rest on the bottom oil ring land.  So, don't put the gap over the opening for the pin.  And make sure you install the pin before you put the support rail on, otherwise you may have to take it back off to get the pin in.  The oil ring rails will have a dimple in them; that dimple should face down, and that should be in the open area where the pin goes through.  Once you look it over carefully it will be fairly clear how the oil ring rails must be installed.

[cobracammer]

OK, Its a rainy day down here in Ft. Lauderdale, so what better way to spend it..... GARAGE.  So the correct ring alignment tool came this morning from Jegs.  I set up the ring file, laid out all of the rings, got the feeler gauge and started.  I was a bit nervous about file fit for the first few bores, and then I was able to proceed with a little more confidence.  I was able (very very slowly) to get 0.023 for the top rings and 0.028 for the bottom rings.  Only one time did I file just a TINY bit too much where the feeler gauge wouldnt stick at 0.023.  I tried that top ring on every bore to see if it would possibly fit a little more exact in another bore, but they were all identical.  I ended up using that top ring on cylinder 7.  I believe it was 0.028-0.029 range.  I hope that will be ok for 1 top ring as I dont really want to buy another whole set for just 1 ring.

I am all ready to measure each Rod Journal/bearing clearance and tap the pistons down

[cobracammer]

#1 Cylinder at 0.0025 Oil clearance at the Rod Bearing....  On to the rest!

[cobracammer]

Rod end with the upgraded ARP2000 bolts torqued to 75 ft lbs in the following increments (25-50-75)

[cobracammer]

OK Milestone!  All 8 pistons are installed.  Clearance between rods came in between 0.021-0.024 (within spec).  Of note, and I'm sure the more experienced guys will get a kick out of this....  Installed pistons 1 - 7 before I realized that the domes dont all face the same way on both banks.....  I realized that I had the exhaust valve relief was on the wrong side on drivers side of block.... so instead of almost being done, I had to go back and turn cylinder's 5,6,7 around on the Rod.  Raised portion of the dome faces the front of the block on passenger side (exhaust valve facing out) and on the drivers side the raised portion of the dome faces the rear of the block (exhaust valve facing out).  Better that I caught it now then later.
I called Diamond pistons on friday to ask, but the girl that answered the phone was just making guesses between yawning.  Said all of her techs are at the track and no ones there on Friday.... WOW, I want a job there!~

Anyway, I need to see what the next step is, but at least I am making progress.

[Joe-JDC]

You turned the pistons around on 5,6,7?  Did you take them off the rod and re-install them with the chamfer on the rod facing the correct way towards the crankshaft radius?  I hope you did from what I read.  You can't turn the cylinder.  Joe-JDC.

[cobracammer]

Yes,  I had the piston in backwards on 5,6,7.  I removed the spira locks, and made sure the Chamfer in the rod remained where it should be.  A learning experience for sure.  Anyway, the gap between the rods measured up within spec.  Turned the crank a few times just to make sure everything was smooth and it was.  So after I was done patting myself on the back for this little accomplishment, I realized I wasn't quite sure of the next step.  A little reading on Jay's 519" build and I see that the next step is to pin the gears together on the stub cam.  I managed to find the same bolts that were used in the 519" build,  I am ordering an End mill, and I already have the Tap.  Hopefully within the next few days I can get underway.

I actually have a few questions:

1.)  The heads were pre-assembled and I do not have the means to take off some of the springs to install checker springs.  Can the Cams be timed under the full load of a normal spring? (given that there are no hydraulic lifters to worry about and I have a mild cam as far as Cammers go)

2.) Since this engine does not have the cam in the center of the block, do you need to find top dead center when installing the smaller timing gears (Stub cam) and chain?  I wasn't sure (I'm guessing you still need to know top dead center when timing the cams in each head, but didn't see it mentioned on the 519" build.  I have the degree wheel and the "bridge TDC stop" that bolts over a cylinder.  I would assume you turn the crank until it hits, turn the crank the other direction until it hits, and then TDC would be the # in the middle?

[jayb]

If you don't have a checker spring installed then you don't have any way of figuring out how much clearance you have at any given point in the valve lift.  Usually around TDC at overlap you will move the crank a few degrees at a time, and then push down on the valve until it contacts the piston, and see how much deflection you get on the dial indicator at the contact point.  With regular valve springs you don't have any way of pushing the valve down until it contacts the piston.  Your alternative is to assemble the #1 cylinder with clay on the piston, rotate the engine over with the normal valvetrain installed, and then remove the head and measure the thickness of the clay where the valve has deformed it.  Since the R&R on the SOHC is such a pain, with the chain and all the gears set up, its a lot easier with checker springs. 

On the small chain and gears it is sufficient to just line up the dots on the gears.  The crank gear dot will be facing up, and the large cam gear dot will be pointing down.  Get them pointed directly at each other when you install the short chain and that will work just fine.  Also note that the gear dot on the smaller cam gear will also be pointing down, like the dot on the larger cam gear.

[cobracammer]

Thanks Jay.  I will see if I can fashion something in order to get the spring off.  I see they make a universal spring removal tool that they sell at Autozone.  Its like $20, and I don't see why it wouldn't work. 

So just so I understand, I will still use clay? (I saw you used a check spring and clay in the 519" build).  The only difference is that the check spring gives you the "worse case scenario" as far as valve depth?  And If I used a normal spring, the valve would not travel as "deep" just turning the crank by hand thus not giving you an accurate measurement?  Even when you use a check spring, the heads still need to come off to remove the clay for measurement right?

I believe out of the who build process, timing the cams has had me the most nervous (So much so that I purchased an extra set of the ferrea lightweight valves just incase)  lol  Hopefully I don't need them!

[cobracammer]

OK, slowly I am putting this timing "business" together.  I realized that I need to find top dead center with the chain tensioned.  For the chain to be tensioned, the heads have to be installed with the cams/ cam gears.  Since the chain is tensioned, the front cover needs to be installed as to not deflect or bend the stub cam.  Now I see what you are talking about Jay!

OK I just purchased a universal valve spring removal tool.  Seems pretty simple, so I am hoping it will work with the cammer heads.  I also purchased a TDC indicator (spring actuated).  The one I had ordered from Jegs originally is a TDC stop.  The indicator I just purchased screws into the spark plug hole and can be used in conjunction with the Dial indicator to find TDC.  Also, these TDC indicators only come in 14mm thread size, so I got a 18mm to 14mm spark plug thread adapter so this all can be used.  While I was on the website, I picked up 2 sets of the comp cams checker springs (intake and Exhaust for Right head and left head).

Now the question I have it this.  When I get the heads on and install the cams with the dot on the cam gears facing straight up (in relation to the head and not the floor), what is the timing at?  The LCA on my cam card says 108 (I can double check the cam measurements now that I have a dial indicator), so does that mean with the "0" on the cam shaft aligned with the dot on the cam gear (aligned) the timing on both heads is at 108 starting off?  Then I would retard the cam on each head to the proper suggested 105 degree on the 102 degrees on the right head?

This is going to sound silly, but where does finding TDC come in with relation to moving the cam/cam gears to get the correct timing.  Sorry for the silly question, but I want to make sure.

[jayb]

You don't need to have the secondary (long) chain tensioned to find TDC.  You can actually find top dead center with the heads off, using a standard piston stop method as you described previously.  But then you'd need to mark it somehow to get back to it later, after you install the heads and valvetrain.  Maybe install your harmonic balancer on the crank and make some kind of a temporary pointer to point to TDC when you find it, but that pointer will have to bolt on someplace where the front cover doesn't.  Since the harmonic balancer is keyed, you could then remove it, assemble the rest of the components, and put it back on, and if your pointer hasn't moved you should still have top dead center at that position.

I always just install the heads first and then do all the other stuff after that.  I made up a piston stop by cutting the center out of an old plug and welding in a steel rod, so I can find TDC with the heads installed.  Your dial indicator setup should work just fine too.  Also my spring compressor works with the head installed, so I can install checker springs or reinstall valve springs with the head installed.  Makes life with the SOHC a lot easier...

Once you get the chain on and tensioned, with the pins in the gears at the zero position, you should be at whatever intake centerline the cams are ground for.  You can be off a few degrees, but you should be pretty close to that number.  If your LSA is 108, and the cams were ground "straight up" (probably), then you will be at 108 for the intake centerline at that point.  From that point you would ADVANCE the cams to get to 105 and 102.  TDC gives you a reference point; you will want to check the cams based on this reference point.  If you don't have the TDC reference point, you can't know where your cams are degreed.

I think to really get all this you just have to get started on doing it.  Wouldn't be a bad idea to consider the first assembly as a trial assembly; don't use any sealer, just bolt everything together, slowly, and start checking stuff until you get the picture of what you are doing. 

[cobracammer]

OK so assuming I time the cams with the heads on (which seems the most convenient) , I would first find TDC on the crank.  Once I have TDC , I then install the large chain to that the colored links match up with the "dots" on the Cam gears.  This then ensures that if the crank moves off TDC, the cams move in sync.  Then, I advance the cams (now that TDC is locked in with the chains) to get the desired cam degree(s)?

And at an LSA of 108, an advance of 3 degrees (moving the pin to the right) will get me to 105 on the left head and moving the Pin 2 holes (and I see from the pictures that only 1 hole really lines up, so when you move the pin, you have to turn the gear counter clockwise in order to get the holes to line up to slide the pin in) to the right will get me to 102 on the right head. Sound like I have the basics?

As a side note, I understand that once I have TDC locked into the cams with the large chain, I have to double check the LSA to make sure its really what the cam card reads.

[cobracammer]

OK, so Yesterday my cam retainer bolts with the shortened 12 point heads came from Precision oil pumps.  I put a little locktite on each bolt and put on a grade 8 zinc plated washer.  On the back of each washer (just to mimic the thickness of the cam retainer plate that is not used on the Cammer), I coated lightly with the TA-31 silicone sealer.  These bolts were torqued to 21 ft lbs and any residual sealer that came out from around the washer (minimal) was wiped off.  Not a big step, but these 2 bolts sealed up the oiling system.  I have a 5/8 jig borer on its way to bore out the for the 1/2" pieces of  5/8 diameter steel rod that are to be welded on to the back of the small stub cam gear in order to pin it to the larger gear.   Have the welder, bolts, Drill bits, taps, Have an X-Y vice set up under my drill press to act as a mini mill, and just waiting on the delivery of the Jig borer.  Hopefully it will arrive before this weekend and I can get this all wrapped up by Sunday.