Do Cylinder Heads Always Need to Be Resurfaced?

Do Cylinder Heads Always Need to Be Resurfaced?

July 7, 2021

A clean, flat and smooth engine is the goal for every vehicle owner. When these conditions are met, the vehicle is much more likely to last longer and run better. Vehicle owners can clean their cylinders by themselves, but they need to hire a professional mechanic for cylinder head resurfacing to make them smooth and flat.

The smoother and flatter a cylinder head, the less likely the chance of gasket leaks and other serious issues under the hood. We typically resurface cylinder heads after an engine has overheated or after it has blown a gasket. In both of these scenarios, the head becomes distorted. Resurfacing the cylinder head restores it to its original tolerance and creates a perfect seal.

In addition to resurfacing after an engine has suffered some damage, we recommend resurfacing when you’re restoring an engine and installing OEM (original equipment manufacturer) cylinders.

How smooth do the cylinders need to be?

For many years, aftermarket cylinder head manufacturers have recommended a surface finish roughness average (RA) of anywhere from 55 to 110 microinches. But that recommendation is beginning to change. Nowadays, some manufacturers recommend an RA of 60 to 100 microinches for cast-iron heads and an RA of 50 to 60 microinches for aluminum heads.

It’s important to keep your vehicle’s make and model in mind when resurfacing your cylinder heads. For example, newer Ford engines require a very smooth finish in the RA range of 20 to 30 microinches. This is also the case for some Japanese engines.

As long as you bring your vehicle to a reputable mechanic for cylinder head resurfacing, they’ll know the perfect RA for your vehicle.

How can I tell if I need resurfacing?

The only way to tell definitively whether your cylinder heads need to be resurfaced is by measuring them. The cheapest way to measure it is with a comparator gauge. This simple tool has sample patches etched into a metal plate which indicate the different surface finish ranges.

With this tool, all you need to do is hold the gauge next to your cylinder head to see if you’re in the correct range. It’s not precise, but it gives you a ballpark idea if you need to have your heads refinished or if they’re okay for the time being.

Though it costs a bit more, the best way to measure your surface finish is with an electronic surface profilometer. This tool uses a diamond-tipped stylus across the metal to measure the surface finish. In addition to measuring the roughness, the profilometer gives you an in-depth report of the true condition of the surface.

Bring your vehicle to our team

Look no further than our pros at Auto Truck Service Inc. the next time you’re having any car trouble or need machine work performed. We offer a wide range of auto repair services that ensure your vehicle is in tip-top shape.

So whether you need cylinder head resurfacing, AC repair, an exhaust system check or something else entirely, we’ve got you covered. Give us a call, or come into our shop today to see what we can do for you.

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