The Top DSM Community on the Web

For 1990-1999 Mitsubishi Eclipse, Eagle Talon, Plymouth Laser, and Galant VR-4 Owners. Log in to remove most ads.

Please Support STM Tuned
Please Support Fuel Injector Clinic

ACL vs CNS oil pump comparison

This site may earn a commission from merchant
affiliate links, including eBay, Amazon, and others.

This site may earn a commission from merchant affiliate links, including eBay, Amazon, and others.

Since I had a cheap 4g63 oil pump and a regular replacement (ACL) pump, I decided to spec each one and see what, if any, difference there is.

Follow along in the pictures, it is heavy.

The one thing I noticed is the casting on the ACL pump looks like it has been glass beaded compared to the CNS pump which has a rougher casting.

The CNS gears hadn't been cleaned as well as the ACL model.

The ACL cavity had some porosity to it, but I don't believe it will effect pressure or volume.

The CNS driven gear was slightly lighter in weight than the ACL model but the drive gears were almost the same weight.

The ACL drive gear looks different as far as the diameter of the shaft BEFORE the oil pump pulley threads and its the only thing that I forgot to measure, was the diameter. My bad but you can see the difference in the pictures.

The CNS pump was $40
The ACL pump was $120

The orifice diameters were the most different with the ACL pump having larger openings at the pump output but the CNS pump had larger diameter holes that feed the front housing castings on the block, check out the different hole sizes.

I made my own Castle Nut tool out of a Pawn Shop 1 1/8" junk socket, go get a .50 cent socket and take your hand grinder and grind your junk socket to match the castle nut, you never know, you might need it again some day!

I put the pump housing back on at 160 INCH POUNDS. 13 ft lbs just seemed to act like it would pull the threads on the pump body even though they are the same spec, the inch pound wrench worked much better at feeling the tightness of the bolts.

I reassembled the stubby shaft and used Red Locktite at 29 Ft/Lbs.
I assembled the pulley with Blue Locktite at 29 Ft/Lbs also by wrapping an old timing belt around the pulley and gripping it with a huge set of Channel Lock pliers, gripping the old belt very tight while my helper torqued the pulley nut down. I reassembled everything with Assembly Lube not grease.
I did this just to see what, if any, difference there is between the 2 pumps.

If I had a stock, no hi perf parts motor, I probably would use the cheap pump.....if I had too.
The specs are here for all to take notes on and if there is anything else I can add, let me know.

Marty

You must be logged in to view this image or video.
You must be logged in to view this image or video.
You must be logged in to view this image or video.
You must be logged in to view this image or video.
You must be logged in to view this image or video.
You must be logged in to view this image or video.
You must be logged in to view this image or video.
You must be logged in to view this image or video.
You must be logged in to view this image or video.
You must be logged in to view this image or video.
You must be logged in to view this image or video.
You must be logged in to view this image or video.
You must be logged in to view this image or video.
You must be logged in to view this image or video.
You must be logged in to view this image or video.
You must be logged in to view this image or video.
You must be logged in to view this image or video.
You must be logged in to view this image or video.
You must be logged in to view this image or video.
You must be logged in to view this image or video.
You must be logged in to view this image or video.
You must be logged in to view this image or video.
You must be logged in to view this image or video.
You must be logged in to view this image or video.
 
Last edited:
Support Vendors who Support the DSM Community
Boosted Fabrication ECM Tuning ExtremePSI Fuel Injector Clinic Innovation Products Jacks Transmissions JNZ Tuning Kiggly Racing Morrison Fabrications MyMitsubishiStore.com RixRacing RockAuto RTM Racing STM Tuned

Latest posts

Build Thread Updates

Vendor Updates

Latest Classifieds

Back
Top