Well I dont understand the whole timing thing before breaking in the motor.
I will install the xe268 cam in the OEM setting of the timing gear, Which comp says is actually about 4 degrees advanced since they grind that into their cams from the get go. Then turn the crank/balancer to (insert number here) according to the far left timing tooth. Prime oil pump, Then install the distributor without the cap on and seat it with the thing inside pointing toward the #1 plug. Then put on the cap and hookup the vaccuum advance on the distributor Then adjust the valves by doing this:




Then hookup the wires and fire it up to about 2000RPM for about 15 minutes.
Then what. Help appreciated, Thanks :thumbup:

Bump.
I know yes Ive searched this is easier for me to understand dontknow
about the whole timing thing.

 

you seem to get it. what is your question???


use diesel engine oil to break in the cam (rotella 30w) or use an eos additive. That cam will go flat quickly if you break it in with regular motor oil.

set ignition timing after you start it up. set it to 30 degrees at 2000 rpm. this will stop the exhaust manifolds from glowing red.

 

you seem to get it. what is your question???


use diesel engine oil to break in the cam (rotella 30w) or use an eos additive. That cam will go flat quickly if you break it in with regular motor oil.

set ignition timing after you start it up. set it to 30 degrees at 2000 rpm. this will stop the exhaust manifolds from glowing red.

Well if the way i posted above is correct, Then the only question i have
is what number do I set the balancer at according to the timing tab before I drop in the distributor facing the #1

 

just put it at zero. the distributor only drops in 8 different ways. the fine tuning of the timing needs to be set with the engine running, using a timing light.

So, before you try starting the engine, get the timing light connected to the engine. make the distributor tight but loose enough so you can still turn it by hand. have someone start the engine and hold the rpms at 2000. then you set the timing to 30 degrees with it running at 2000 rpm, I would leave the vacuum advance off for the cam break in.

 

just put it at zero. the distributor only drops in 8 different ways. the fine tuning of the timing needs to be set with the engine running, using a timing light.

So, before you try starting the engine, get the timing light connected to the engine. make the distributor tight but loose enough so you can still turn it by hand. have someone start the engine and hold the rpms at 2000. then you set the timing to 30 degrees with it running at 2000 rpm, I would leave the vacuum advance off for the cam break in.

Ill plug the vaccuum advance canister on the distributor then...

I thought I needed to get it to that before I started it to make sure
it would start right up? I dont want to chance any cam damage

 

I meant , I thought I needed to get the timing about right before I fired it to make sure it would in fact fire the first time?

 

Then turn the crank/balancer to (insert number here) according to the far left timing tooth. Prime oil pump, Then install the distributor without the cap on and seat it with the thing inside pointing toward the #1 plug. [/B]

Make sure that #1 is on the compression stroke before you try to start it up.

 

So after the timing is accurately set to 30=36 with the advanced plugged up on the distributor, Then I can just hook up the advance to the carb and not have to time it again?

 

Put it in like they describe. When you try to start it, you'll probably be close enough that it will fire, but maybe not run. If it sounds like its trying to run but can't quite get it going, advance it some. If its kicking back on the starter (sounding like its a dead battery or like its fighting the starter) retard it. It doesn't matter at this point.

You will be breaking in the cam at fast idle. Idle timing is of very little importance. You don't have to get it just right for break in. If you have it too far advanced, it might overheat. If you have it too far retarded it will overheat the exhaust, but it has to be pretty far off in either direction for that. The bottom line is, (and this is how I've done ever engine I've ever built) for break in, time it by ear. Start it up. As long as you don't have the troubles like I listed above with kickback or almost starting, just grab the cap, turn it until you have a good smooth running engine, and tighten it down. If you're worried about finding a fair break-in timing, advance it until it starts running rough, then retard it until it starts running rough, and then pick a point in the middle. If you have it running smoothly, then its neither too far ahead, nor too far behind.

I've actually used this technique many times, and then later when I went to time the engine with a timing light, I found I was very close to the proper setting.

Idle timing settings are remarkably inconsequential since there is no load placed on the engine. I've built engines that had no mechanical advance, meaning I set it at 36* BTDC and that's where it stayed. I've also had higher compression engines that didn't like more than about 10* BTDC. The point I'm trying to make is this: Manufacturers design distributors with a certain amount of total mechanical advance; lets say 24*. They also design the engine to work best with a certain total advance at peak operating load; lets say 36*. So, they determine that idle advance should be set at 36 minus 24 or 12 degrees initial. Its not important that you have 12 degrees initial timing, they just give you a benchmark so you can set it at idle instead of revving the engine with a timing light 3" from the radiator fan.

So, don't worry about getting idle timing spot on during break in. Focus on getting it running, keeping it running on fast idle for 20-30 minutes, then once you're done with that, take it down off fast idle and set the initial.

 

Put it in like they describe. When you try to start it, you'll probably be close enough that it will fire, but maybe not run. If it sounds like its trying to run but can't quite get it going, advance it some. If its kicking back on the starter (sounding like its a dead battery or like its fighting the starter) retard it. It doesn't matter at this point.

You will be breaking in the cam at fast idle. Idle timing is of very little importance. You don't have to get it just right for break in. If you have it too far advanced, it might overheat. If you have it too far retarded it will overheat the exhaust, but it has to be pretty far off in either direction for that. The bottom line is, (and this is how I've done ever engine I've ever built) for break in, time it by ear. Start it up. As long as you don't have the troubles like I listed above with kickback or almost starting, just grab the cap, turn it until you have a good smooth running engine, and tighten it down. If you're worried about finding a fair break-in timing, advance it until it starts running rough, then retard it until it starts running rough, and then pick a point in the middle. If you have it running smoothly, then its neither too far ahead, nor too far behind.

I've actually used this technique many times, and then later when I went to time the engine with a timing light, I found I was very close to the proper setting.

Idle timing settings are remarkably inconsequential since there is no load placed on the engine. I've built engines that had no mechanical advance, meaning I set it at 36* BTDC and that's where it stayed. I've also had higher compression engines that didn't like more than about 10* BTDC. The point I'm trying to make is this: Manufacturers design distributors with a certain amount of total mechanical advance; lets say 24*. They also design the engine to work best with a certain total advance at peak operating load; lets say 36*. So, they determine that idle advance should be set at 36 minus 24 or 12 degrees initial. Its not important that you have 12 degrees initial timing, they just give you a benchmark so you can set it at idle instead of revving the engine with a timing light 3" from the radiator fan.

So, don't worry about getting idle timing spot on during break in. Focus on getting it running, keeping it running on fast idle for 20-30 minutes, then once you're done with that, take it down off fast idle and set the initial.

Great post, I dont know how I missed it. Motor is finally in about to be getting to this point that this post was about.. Got everything adjusted and all will be a matte of priming oil pump, and firing. I have a holley 650 4bb and I need to know how to make the adjustment to where when the truck starts it gets to around 2200 rpm and I dont have to sit in the truck holding it!!

 

I think your getting cam timing and ignition timing mixed as one. Don't worry about if the cam is advanced or retarded. And when plugging the vacuum advance plug the vacuum line not the canister.

 

Go to this Post and scroll down to my first reply. It is #19 and explains how to install the distributor and set the timing.

Next scroll down to my second post in that above link. It is #26 and has another link as to how to adjust the hydraulic lifters.

You can also click on this LINK to go directly to adjusting the valves info.

ADDITIONAL INFO:

Because you are doing a cam break in, after the engine has started, set the timing around 32-36 degrees BTDC at 2500 RPM with no vacuum advance connected. Continue to run the engine in the 2000-2500 RPM range for around 20 minutes. Vary the RPM during this time. Do NOT have the engine idle or attempt to adjust the carb during this time. Watch the coolant temp and the oil pressure and shut down if there is a problem with either. Watch for any fuel, oil or coolant leaks and shut down and correct if found. Having a good 'Box' style fan aimed directly at the front of the radiator can be beneficial during the break in run, especially if you have a clutch style fan. If your exhaust pipes close to the headers begin to glow cherry red the timing is probably somewhat retarded OR you have a major vacuum leak OR are running extremely lean.

After the cam break in run, shut the engine down and change the oil and the filter immediately. You can now restart the engine and begin to make final timing adjustments and/or carb adjustments.

ENJOY!!!

 

main reason you want to get the base timing set, is just so your not 180 off and trying to keep cranking the engine over and over wipeing the lube off the cam lobes. you just want it to start up the first time, your not setting a exact number here, you just want it to run on the first stroke.

 

You guys are making way complicated. Try this, It's what I do.

Set the crank damper so it lines up with the amount of timing you want. Let's say that's 12 BTDC. Drop the dizzy and line up the No 1 tower with the rotor. Timing will be close enough to get you through cam break in.

After can break in...Dump that oil and discard. Change Filter too. After 500 miles, change it again, then cut open the filter and inspect for excessive bearing material.

 

Great post, I dont know how I missed it. Motor is finally in about to be getting to this point that this post was about.. Got everything adjusted and all will be a matte of priming oil pump, and firing. I have a holley 650 4bb and I need to know how to make the adjustment to where when the truck starts it gets to around 2200 rpm and I dont have to sit in the truck holding it!!

Just want to reinforce what Frisco said. Don't hold the RPM's at any one speed for a long time. Vary the RPM because the oiling pattern for the cam are different at different engine speeds.
Terry

 

I think your getting cam timing and ignition timing mixed as one. Don't worry about if the cam is advanced or retarded. And when plugging the vacuum advance plug the vacuum line not the canister.

My question wasnt about the installation procedures and timing. I already did all that a long time ago. Marked the dizzy did all the setting valves in specific orders, I turned it to 12 degrees on the damper. Made it where when you drop in dizzy #1 is facing almost righ at the #1 cylinder.

My question was about the holley as someone mentioned I should adjust the idle mixture screws I beleive so your not sittin holding the pedal when you could be running around making sure people are checking the right stuff while keeping an eye on the gauges... Just didnt want to go screwing anything up is all before I start turnin screws on the carb I know a little turn can do alot.

 

Just want to reinforce what Frisco said. Don't hold the RPM's at any one speed for a long time. Vary the RPM because the oiling pattern for the cam are different at different engine speeds.
Terry

The cam breakin procedure I was going to follow what came with my comp cam. Which is something like 2200 15 minutes, 1800 10 minutes, 1200 6 minutes.

I know those arent exactly right but thats the idea. Dont have the papers on me right now

Is that what you mean by vary RPM, or are you and frisco meaning actually vary every 5 minutes...

 

Maybe this will help you out:

Cam installation: http://www.youtube.com/watch?v=Zr_n0cL

Valve adjustment: http://www.youtube.com/watch?v=89o5rLpbCgI



Enjoy!

 

idle screws will have no effect when the engine is revving at 2000 rpms. Need to idle the engine to adjust those.

vary the rpms by moving the throttle around. For example, rev from 2000 to 2500 in 30 second cycles.

 

My question was about the holley as someone mentioned I should adjust the idle mixture screws I beleive so your not sittin holding the pedal when you could be running around making sure people are checking the right stuff while keeping an eye on the gauges... Just didnt want to go screwing anything up is all before I start turnin screws on the carb I know a little turn can do alot.

You adjust the idle speed with the throttle stop screw. You do NOT adjust the air/idle screws at this time. They will have no effect at the cam break-in RPM anyway as that RPM is well out of the idle circuit of the carb.

Carb adjusting (air/idle screws) can be adjusted after the cam break-in has been completed. Final timing adjustments are also done after the cam break in has been completed.

You vary the cam break-in RPM by changing the position of the throttle stop screw. I do this about every five minutes or so during the break-in run. Another simple method is to just 'blip' the throttle momentarily every few minutes. The exact timing for this varying of the throttle is not very important. It is done to cause a 'splash' effect of the engine oil onto the lobes of the cam. This helps to insure that the lobes are well lubricated during the break-in run.

Be sure to change the oil and the filter as soon as possible after you have completed the cam break-in. This is very important as it removes most of any particles that have become suspended in the oil during the initial start-up of the engine.

 

You adjust the idle speed with the throttle stop screw. You do NOT adjust the air/idle screws at this time. They will have no effect at the cam break-in RPM anyway as that RPM is well out of the idle circuit of the carb.

Carb adjusting (air/idle screws) can be adjusted after the cam break-in has been completed. Final timing adjustments are also done after the cam break in has been completed.

You vary the cam break-in RPM by changing the position of the throttle stop screw. I do this about every five minutes or so during the break-in run. Another simple method is to just 'blip' the throttle momentarily every few minutes. The exact timing for this varying of the throttle is not very important. It is done to cause a 'splash' effect of the engine oil onto the lobes of the cam. This helps to insure that the lobes are well lubricated during the break-in run.

Be sure to change the oil and the filter as soon as possible after you have completed the cam break-in. This is very important as it removes most of any particles that have become suspended in the oil during the initial start-up of the engine.

Okay Throttle stop screw is what I was after.... How much should I turn it out of the box?

I assume you do couple hundred rpm surges around each break in RPM range..
Example:
2200~2000 5 minute changes for 15 minutes
1800~1500 2 minute changes for 6 minutes
1200~800 2 miute changes for 6 minutes

Drain oil, replace filter, Another 5 quarts of rotella.

Also note its been almost a year since the cam was insalled with
comps red cam liquid.... Hope the add of the GM EOS stuff will
help with all the new parts that have been sittin for a while!

 

FYI, rotella isn't rotella any more. They quit making the good stuff. if the rotella oil can says "reformulated" or new formula or low emissions then you have the new rotella, which is also lacking the antiwear stuff.

do a web search for ZDDP oil additive. cost about 10.00 extra an oil change. Then you can use regular gas engine oil. I get 10 at a time and add one at each oil change.

 

Okay Throttle stop screw is what I was after.... How much should I turn it out of the box?

Rotate the screw until the desired RPM is achieved. This should be around 2000-2500 with the choke fully open.

I assume you do couple hundred rpm surges around each break in RPM range..
Example:
2200~2000 5 minute changes for 15 minutes

This is a good range for the break-in.

1800~1500 2 minute changes for 6 minutes
1200~800 2 miute changes for 6 minutes

These RPM ranges are too low for the cam break-in run.

Keep the RPM in the 2000-3000 RPM range during the break-in.

Drain oil, replace filter, Another 5 quarts of rotella.

Also note its been almost a year since the cam was insalled with
comps red cam liquid.... Hope the add of the GM EOS stuff will
help with all the new parts that have been sittin for a while!

After that period of time any of the Comp Cam red break-in lube has long since run off the lobes. Add a can of the GM EOS ( or any other additive that has zinc) before attempting to start the engine and prime the oil pump and engine well. Use either a modified distributor or the correct oil pump priming tool (the one that has the collar near the lower end of the shaft). This will enable the oil to circulate to both heads and not just the driver's side.

The newest versions of the Shell Rotella have reduced amounts of zinc. Check the labeling of the container for the zinc content.

 

Hey guy's I'kk be starting my 406 small block chevy here in the next week or so. So any info on the break-in proceedure is awesome.

thanks guys