How to Install HKS Camshafts in your 4G63

How to Install HKS Camshafts in your 4G63


We are often asked what is our favorite camshaft combination for the 4G63, and it can be tough to choose especially from many of the newer manufacturers out there but HKS is still our personal favorite.

Today we’ll be installing the ever so popular 264/272 combination of bumpsticks into a 1993 Mitsubishi GSX. This GSX put down 395whp @ 17psi with a completely bone stock 1g head and just one exhaust cam gear retarded 5 degrees.



This isn’t an install for the average mechanic and should NOT be attempted without proper knowledge of the timing assembly and / or timing belt. A slight mistake can cause a slightly rough idle, or in a worse case scenario piston to valve contact. This will lead you to bending valves and ruining your head compression, so please be prepared when undertaking a project of this nature.

As with all of our writeups but especially our How to Install HKS Camshafts article, we are not legally responsible for any mods you perform on your car. This writeup is but a guide for you to use when you are doing this. If you are not comfortable doing this, then take your car to an experienced mechanic.

Note that your motor may differ in mods or placement, depending on what mods and what car.

First step of How to Install HKS Camshafts is to remove the upper timing cover.

  • In first generation Eclipse / Talon / Lasers, you must remove the upper motor moutn and remove the upper timing cover bolts so that you can remove the upper timing cover.
  • In second generation Eclipse / Talon / Lasers, you must remove the motor mount by removing the two motor mount studs sticking up in the air. After you remove the motor mount, then remove the mid timing cover by undoing the 10mil.

Get a floor jack and using a piece of wood to evenly distribute the load on your oil pan, gently jack the motor up until its high enough for you to work around.



There is a 1/2″ square drive hole in the end of it on your crank, use a ratchet to rotate the motor clockwise until you have the number 1 cylinder at Top Dead Center. Remember to always rotate clockwise to prevent abnormal slack and any jumping of teeth by your timing belt. You can insert an extension through the access hole in the plastic wheel well splash guard.



Make sure that the marks on the cam gears are both pointing up at 12:00, and that the mark on the crank pulley line up with the T mark on your timing cover. There are notches on the gears, and you will be looking at the marks where the pulleys are together in the center. Use a straight edge and make sure the marks are centered through the cam bolts themselves.

Make SURE to double check this!! DO NOT go by “eye”. If the marks will not line up, then something is wrong.. stop here and do not continue until you take apart the timing belt assembly, and redo your timing belt.IF YOUR TIMING MARKS DO NOT LINE UP DO NOT CONTINUE. Zip tie the belt to your cam gears securely.



Remove the valve cover by undoing the 10mm bolts holding the cover to your head



If applicable, remove your cam angle sensor from your intake cam and set to the side.



Next use a large adjustible wrench on the cam itself to hold it in place and undo the 17mm cam gear bolts.



The use of a breaker bar may be required to complete our How to Install HKS Camshafts guide.



It is common to hear a loud snap when undoing the cam gear bolts, sometimes so loud you may think you broke something. Dont worry, we do this install quite a bit and havent broken one yet. Break the 17mm bolts loose but do not remove them.

Pull the stock access plug from out of your rear timing cover. Its a small rubber plug with a handle on it.



Insert the cam tensioner tool Mitsubishi Part number ( MD998738 ) through the hole you just created by removing the plug. Before inserting the tool into the tensioner hole, grease the tool with a non water based oil / grease to prevent artifical wear or any possibility of seizing in place.

Screw the bolt in until you feel some resistance, this is the tool beginning to depress on the arm of the timing belt tensioner. Turn slowly and use care! If you turn the tool too quickly, the tensioner cant keep up. Tighten the screw down and wait 5-10 seconds before tightening again. When the tension is tight even after waiting for a bit, try pressing down on the timing belt inbetween the cam gears. There should be sufficient slack here.

Now its time to remove your stock cams, start with the exhaust cam. Remove the cam caps and place them in CORRECT order. Take note that they are specially stamped with arrows all pointing in the same direction. Its vital you keep the placement and order of these cam caps correct. We like to rest the cam caps directly above their locations on the head itself. Remove the bolts holding these caps on and use a rubber mallet or large phillips screwdriver to pry the caps off using the holes for the bolts.

Use extreme care and caution when removing these caps and again, KEEP THEM IN ORDER!! Now remove the bolt for the cam gear. Pull the cam gear off the end of the cam, and gently let it rest without moving. Make sure the engine does not rotate or move now. Slide the exhaust cam up and out and slide the cam seal off. Now would be a good time to replace the cam seal when you swap to your HKS cams. The part number for the cam seals is MD133317. Put a light film of Hi Temp RTV sealant on the cam seals.



Time for the fun stuff, take your HKS 4g63 cams out and install your cam seals. Install the new cam and use some assembly lube on the cam journals. Use a needle nose to GENTLY remove your lifters. Use a straightened paper clip to bleed the lifters of oil, and reinsert them. Make a mental note to lube the motor before starting it.



Now clean the deck of the head of any and all silicone that may be present. Make sure that your valve cover seal will create a clean and solid seal.

Insert your new cam and make sure the rollers are all flat and the cam rests completely flat. When you go to put your cam caps back on, make sure you are putting them back in the proper order and direction. Torque the cam caps to 16 ft / lbs. And reinstall your cam gear.



Next is the intake cam. Before removing the cam, you need to remove the cam angle sensor (except 95-96 cars).

  • Second Generation Eclipses from 1995-1996: Be careful as you are removing your intake cam. Your cam angle sensor is located directly below it and any abnormal movement from the cam gear and this will break, leaving your car non startable.
  • Second Generation Eclipses from 1997-1999 cars: The cam angle sensor is back on the end of the intake cam, you can remove the 3 bolts holding the cap on. THere is a 12mm holding the trigger in the sensor housing. Remove the 12mm bolt and the trigger before you remove the sensor housing. Note the orientation of the trigger ( long / short ) make sure when you put the trigger back that you put it back the right way.

Now torque down your cam gears, remove the one of the bolts, and put a light film of blue loctite on it, hold the cam with the adjustible wrench as before and tighten the cam bolt down. The loctite will ensure that it stays in place. Remove the tensioner tool and put your valve cover and motor mount back on the car, cut the zip ties off the cam gears.. Lower the jack and now its time for the moment of truth. Make sure to crank the motor over manually, clockwise of course, and make sure the marks on the crank and marks on the cam gears show Top Dead Center. Then its time to lube your motor. Remove the ECU plugs so that the car wont start.



  • First Generation Cars: Remove the MPI fuse at the battery positive terminal
  • Second Generation Cars: Remove the MOTOR fuse in the fuse box under the hood.

Before cranking the car, double check all of your work. Make sure the tensioner tool is no where near the car, make sure your cam gear bolts are completely on and fully tight.

Your motor can now crank over without fuel or spark.. Do this for 3 10-15 second intervals until you prime the motor with enough oil. Plug your fuse back in and begin to double double-check your work.

You have now completed our How to Install HKS Camshafts guide by installing cams into your DSM!! Enjoy!


  1. OK, about to do this exact thing but with BC 272 cams, I’m sorry if this sounds dumb but when you takenter the cams out, do they only fit in the cam gears a certain, irreversible way?? Otherwise how would you be able to just leave the gears like that and not have to worry how the new cams are oriented?

    • Hi Sean, thanks for reading. check over the guide again. You’ll be putting the cam gears at TDC and yes they will only install one way. We’ve done this install hundreds of times with great results. Let us know how your 272s turn out! sounds like a mean project!