Cylinder Head Replacement

[James E. Boyd]

Hi guys. I am doing a cylinder head replacement on a 1994 Explorer that I am restoring. My question is this: Before I reinstall the heads should I put some engine assembly lube in the cylinders to reduce friction on initial start-up? If not, what if anything should I use? I am not a professional technician just a guy that likes working on cars and saving himself a few bucks. Thanks in advance for any comments or suggestions.

Topic

[kevin gosselin]

For the cylinder/piston itself make sure that there is no debris from cleaning and you will be fine.

Make sure you remove any liquid or debris from the cylinder head bolt hole as it screw up your torquing overall. you need to follow dealer procedure as far as using bolt dry or applying sealant or maybe a bit of lube.

I would lube every friction point on the lifter/pushrod/rocker that are involve in your rebuilding process. you can use the assembly white grease or any superior product.

Once started let it warm up like 5 minutes to get some oil flowing but I recommend doing and oil change when the engine is warm over boiling hot. There is always risk of having a bit of coolant in he engine from when you remove the head. being said you dont want to run engine with coolant as it does more damage than throwing a hand full of sand in the crankcase.

Hope that help

[James E. Boyd]

Thanks Kgevil. I got the Ford factory service manual for the vehicle but it never did clarify whether or not to lube the cylinder walls with moly and I was just concerned about possible scuffing during those first critical seconds of initial start-up when oil pressure is low. Anyway ‘preciate the input.

[kevin gosselin]

If you really want to feel safe about the first second of start up. remove your fuel pump fuse or relay so the engine will only crank at starter speed. so that will give the chance for the oil pump to deliver some oil all across.

If you were building an engine from scratch like a muscle car for instance, you really need to prime the oil pump system…. as it will start with the oil pump discharge so the oil need to go all over the place.

Being said your system is not empty… if you feel worried than crank it with any fuel so your lifter should technically charge…. but you can feel confident you may here abit of lifter noise on start up but then the pressure will take over and it should get quite…..

I get that lifter noise from doing oil change once in a while on different vehicle,

Hope you feel better about it now

Kevin

[EricTheCarGuy]

I sometimes lubricate the inside of cylinder walls with a little axle grease. Just a light coating mind you. Don’t do it until just before assembly however as it can collect dust and debris. Also, you can remove the fuel pump fuse to prime the engine before it starts as suggested.

[James E. Boyd]

Thanks for the tip Kevin. I removed the fuel pump relay when I started this project and bled the fuel pressure off the lines to keep spilled fuel to a minimum so I will give it a few cranks when I get it all bolted together before putting the relay back in. Thanks again.

[James E. Boyd]

Thanks for the quick response Eric. I will definitely do that and will wait until I am ready to bolt the heads back on before I do it after using the old Shop-Vac. Stay safe!

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