Cam break-in Questions.... On an engine run stand

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Kent mosby

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I am building a 512 stroker that will ultimately have a Holley EFI, Hyperspark ignition etc.

I would like to do a break in of the cam on an engine run stand. If I did that I could run on a carb with the regular fuel pump and distributor that was in the motor originally. This way I would not have to somehow rig up the in tank electric fuel pump as well. Also, I would like to do a break-in before putting on the ceramic coated headers so that I would not burn off the coating during break-in. Either I could get a pair of $99 headers or find an exhaust manifold at the boneyard.

My question is ...Am I making a big mistake by not doing the cam break-in with the final product? If so, why? What would you do differently? Open for suggestions
 
I use a electric pump so I don't have to crank and crank to fill the carb, also set the timing manually before ever starting it.
The oil system is primed and when it starts on the first crank it at 2000 - 2500 + rpm and I turn it down to 2000 for 20 min and have never had a problem
 
brian6pac said:
I use a electric pump so I don't have to crank and crank to fill the carb, also set the timing manually before ever starting it.
The oil system is primed and when it starts on the first crank it at 2000 - 2500 + rpm and I turn it down to 2000 for 20 min and have never had a problem
Click to expand...
Can't you just pre fill the carb? I did.
 
Kent mosby said:
I am building a 512 stroker that will ultimately have a Holley EFI, Hyperspark ignition etc.

I would like to do a break in of the cam on an engine run stand. If I did that I could run on a carb with the regular fuel pump and distributor that was in the motor originally. This way I would not have to somehow rig up the in tank electric fuel pump as well. Also, I would like to do a break-in before putting on the ceramic coated headers so that I would not burn off the coating during break-in. Either I could get a pair of $99 headers or find an exhaust manifold at the boneyard.

My question is ...Am I making a big mistake by not doing the cam break-in with the final product? If so, why? What would you do differently? Open for suggestions
Click to expand...
Won't make a bit of a difference.
 
Smart move using some sacrificial manifolds or headers for the break in. You will see some high exhaust temps due to the steady rpms and possibly not being properly fine tuned. I burned all the coating off my 340 HP manifolds during break in.
 
Everyone I've done I put mufflers on, have someone to only look for leaks while you work the timing light and throttle screw, large fan blowing at the rad but keep a garden hose ready to cool side or lower rad tank, always gets hotter than I like. I now always put weak springs on flat tappet cams for first run.
 
The header thing is easy to get around. Have your timing light attached. Soon as it fires, pull the RPM up to about 3500, grab the timing light and pull the total timing up to 36*. Done. Your headers will not be hurt. People over heat headers because of retarded ignition timing at startup, causing the mixture to still be burning coming out of the exhaust port. That's what kills header finish. Get that timing up where it belongs and it'll be fine.
 
I am getting close to the break in time. I hope that I have all the boxes checked. The setup is not mopar factory stuff. The distributor is a "ready to run" that does not need a separate ignition module. The alternator is internally regulated and has a sense wire that goes to the starter relay. Coil is HEI hyperspark. The run stand has oil pressure, water temp and tachometer on the dash. Any other help, let me know

1. I have done the priming and will redo that before distributor install.
2. full battery, assembly lube, penn break in oil
3. Will set timing to 10* btdc before start up
4. Will get the fuel into carb and primed for start
5. timing light ready for 3500 set to 36* . then back down the rpm to 2000 for 20 minutes.
6. Transmission line connected together, fluid level will be monitored
7. shop fan ready to blow air on the radiator and water ready to carefully mist the radiator if need be.
8. Inner valve springs have been removed , valves adjusted.
9. The spark plug wires will be adjusted and placed in guides to keep them organized and prevent cross current
58639958061__180DABC0-0449-4E1D-908A-042A07AF3841.jpg
58639953624__8C0140CF-1C6D-4957-99D9-CE7DADB9D767.jpg
58639955639__0D5794B8-C42E-4962-A13B-B4831C0360A0.jpg

Some questions.
When using a drill to check oil, I got 80 psi on the gauge, Ok or not, I have the high volume melling pump
I have seen some vary the rpm from 2000 to 2500 or so varying slowly, yes or no?
Should I remove the carb vacuum lines to the distributor and plug them?
How much fuel will be used in 20 minutes or so? I want to have enough on hand. 91 octane premium
Thermostat is 180*, OKAY?
Any other tips and advice, Please
 
You going to put a yoke in that tail shaft?
Im sure your going to move it outdoors or at least point the exhaust out the door.
 
Put the trans in park.

We normally use a 4 speed bell on the run stand but i think in park you shouldn't have to worry about hurting the trans with no TP hooked up.
 
Kent mosby said:
I am getting close to the break in time. I hope that I have all the boxes checked. The setup is not mopar factory stuff. The distributor is a "ready to run" that does not need a separate ignition module. The alternator is internally regulated and has a sense wire that goes to the starter relay. Coil is HEI hyperspark. The run stand has oil pressure, water temp and tachometer on the dash. Any other help, let me know

1. I have done the priming and will redo that before distributor install.
2. full battery, assembly lube, penn break in oil
3. Will set timing to 10* btdc before start up
4. Will get the fuel into carb and primed for start
5. timing light ready for 3500 set to 36* . then back down the rpm to 2000 for 20 minutes.
6. Transmission line connected together, fluid level will be monitored
7. shop fan ready to blow air on the radiator and water ready to carefully mist the radiator if need be.
8. Inner valve springs have been removed , valves adjusted.
9. The spark plug wires will be adjusted and placed in guides to keep them organized and prevent cross currentView attachment 1715372444 View attachment 1715372445 View attachment 1715372446
Some questions.
When using a drill to check oil, I got 80 psi on the gauge, Ok or not, I have the high volume melling pump
I have seen some vary the rpm from 2000 to 2500 or so varying slowly, yes or no?
Should I remove the carb vacuum lines to the distributor and plug them?
How much fuel will be used in 20 minutes or so? I want to have enough on hand. 91 octane premium
Thermostat is 180*, OKAY?
Any other tips and advice, Please
Click to expand...



Don't set the crank at 10 degrees BTDC. Set the crank at 40 degrees BTDC and line up the rotor with number 1 on the cap at full advance.

There is no reason to do what you do. I'd rather see 50 total on it at start up. Slow timing will stick exhaust valves and drive exhaust temps through the roof.
 
If it's not at 36* until 3,500, what's it at the 2000-2500 you be breaking it in at? Probably nowhere near 36*. As said, crank some timing in it for break-in. No load = no problem.
 
I understand @yellow rose that you say at full advance. The best I can tell. the distributor has 15* mechanical advance and 8-9* vacuum advance maximum. So let's say 23*maximum. Can I set the #1 to 27*btdc and get the same thing ( 50* advance)? How do I tell full advance? After it starts up and running smoothly (I hope) with the carb adjusted for maximum vacuum, Should I then set it to 36*? Thanks for the help

@MoparMike1974 There is a cap in it. And we will open the shop and move it out
 
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