Timing with heads on vs off

[PNWSVT]

So I have seen quite a few different kits for timing/degreeing our beasts. I am in the process of bolting it all together now but I had a few questions (yes I searched)

What is the difference with timing the motor with heads on vs off?

Is it just that when you time with the heads on you time it as a complete system vs putting the piston at TDC and then locking into place, and attaching the heads?

My heads came back from the machine shop fully assembled and off the motor. What’s the best bet for me here. I have a 18in Moroso wheel and dial indicator. I was looking at the pillar mount vs the magnetic as well.


Thanks

 

[MG0h3]

Well you cant time anything unless its in the right location--assembled. Not sure if I'm misunderstanding.

The timing you are talking about is cam vs crank so no, you cant do it with the heads off.

Sent from my SM-G950U using the svtperformance.com mobile app

 

[PNWSVT]

I just might not be explaining this correctly, no worries. I have just seen multiple kits, multiple different pieces, people saying you need two spring compressors, people saying you need one, even some people saying you don’t need any.

I don’t have stock cams, or springs.

 

[01yellercobra]

The push rod engines can have the cam degreed without the heads on. For our engines the heads have to be bolted on to the shortblock. The springs they're probably mentioning are light weight checker springs. My understanding is you don't need them degreeing the cams on our engines. But they do make checking piston to valve clearance a snap.

 

[jrgoffin]

The whole timing/degreeing process is documented with plenty of pictures in this build thread: Aluminator Gibtec Build

 

[03' White Snake]

Degreeing the cams, the heads need to be on the engine. With all the followers in place makes it harder to smoothly turn the engine over during measurements. You can remove all the followers and install the adjustable lash adjuster on cylinders 1 and 6 during the measurements. Then install the followers when done. That's how I did mine. They can be popped on with a large flat head screw driver.

 

[PNWSVT]

The whole timing/degreeing process is documented with plenty of pictures in this build thread: Aluminator Gibtec Build

sent you a message! thank you!

 

[PNWSVT]

Anyone know if I HAVE to remove my keepers during this process since my head’s are fully assembled and ready to bolt on?

 

[PNWSVT]

Degreeing the cams, the heads need to be on the engine. With all the followers in place makes it harder to smoothly turn the engine over during measurements. You can remove all the followers and install the adjustable lash adjuster on cylinders 1 and 6 during the measurements. Then install the followers when done. That's how I did mine. They can be popped on with a large flat head screw driver.

So I don’t need to buy the valve spring compressor ?

 

[01yellercobra]

You don't need to remove the keepers or buy a compressor. I removed and installed the followers with a flat blade screwdriver. I removed them before I pulled the timing stuff off and re-installed them after timing the engine.

 

[03' White Snake]

Leave the valves, springs, keepers and lash adjusters in place. Pop the followers off with a screw driver and time the motor. Then pop the followers back on.

Only need a spring compressor if you are changing out springs. I did this before installing the heads, so I didn't need to pressurize the cylinder to hold the valves in place during the swap.

 

[PNWSVT]

Heres where i am at so far

1. After not being able to get the crank socket to fit over the crank keyway correctly (the crank socket from comp cams) I was able to find a way to eventually get it to work without damaging anything, I set the keyway to the 9 oclock position so as to freely rotate the cams without having the valves touch the pistons.

2. Heres where I ran into a problem; the OTC 6498 comes with the camshaft locking tool, which I guess in theory works great with a stock cam, as it attaches to the machined center section of the cams. But I have comp cams XE274BH-116 Cams that do NOT have a machined round center section but rather a 1 1/2inch Nut on all 4 cams. So to keep my cams positioned correctly I am having to use an additional set of hands and two 1 1/2inch wrench's. So thats neat

3. I am going to pull the rockers off the drivers side head in about 20 minutes, once that is done I will go through the process outlined by @jrgoffin in his Aluminator Gibtec build.

At first I was pretty intimidated by this all, but he was right, once you actually get your hand on it and start seeing the process it gets easier. My intent is to have the engine back in the car by sunday night. This has been more than it needed to ever be, for a student, with no garage, no tools (divorce), and most of all no real paycheck lol. So far I am into my rebuild 6,000 including tools and buying a shit load of wrong AN fittings for my fuel system.

cheers!

 

[PNWSVT]

And my summit piston stop won’t work in a single cylinder. I ****ing quit

 

[03' White Snake]

I heard the SBC crank socket fits our cars. I just used the crank bolt and only went clockwise.

If you remove all the rockers then you do not need a cam holding tool. Take your measurements, adjust the timing, set the cams and crank back to timing chain Mark's and start again. I used the hex on the cams to get my cloyes keyways to line up. Pretty simple. Its trial and error.

I made my own piston stop out of an old spark plug and 3/8 bolt. Break the porcelain out, tap the body for 3/8 thread and put a bolt in there. If you have a crank socket you only need to find TDC once, the timing wheel will be set after that.

 

[PNWSVT]

Yeah I started making my piston stop tonight but just got to irritated and had to walk away. Thanks for the advice ! I appreciate t

 

[03' White Snake]

Yeah I started making my piston stop tonight but just got to irritated and had to walk away. Thanks for the advice ! I appreciate t

Yea, just take your time. I'm pretty sure I did like 22 cycles before I got my close enough to call it ok. I ended up at 114.5 going for 114 and 118.5 and 119 going for 118. I felt that was close enough.

 

[PNWSVT]

Yeah I just take one step forward three steps back every time I do anything on the car. This was the last step and then I could put it all back together. But another set bAck

 

[PNWSVT]

I ended up making a ton of piston stops, so ill be selling those lol. Thank you old plugs! As far as the wobbly crank socket, i inserted a piece of brass that fit the I.D. of the socket, and left a cut for the keyway and it worked way better, I probably took 4 degrees of play away from the wheel. But theres still 2 or so degrees of play.

I figured out what needed to happen with checking the centerline of the cams. It took multiple trials and errors and bottle of black velvet, but i got it down.

I wound up with some numbers i wasnt expecting

This is all drivers side or left bank results

Intake 120 degrees. (I did this test about 20 times, and then once I tried it again and the degree wheel spun a few degrees off, it didn't matter because I just found my max lift, .50 before and .50 after and the numbers were still the same)
Exhaust 114 degrees.

So the numbers seemed a little off from where my comp card said. As well as I was being told that Comp cams are 4 degrees advanced from the factory?

cam card
http://www.compcams.com/Company/CC/cam-specs/Details.aspx?csid=964&sb=0

using that Mark Olson cam calc with cam specs off the card

Now with my actual results

Thoughts?