I thought it would be interesting to weigh out all the aftermarket camshafts. As you all know Mitsubishi elected to go with the hollow core camshafts because of the improved response of the engine. Thought I'd get it started with the HKS, OEM, and Helix camshafts.


OEM EVO VIII (non-mivec) - Hollow Cored, Chilled Cast
2lbs 15.8oz

HKS 264's - Chilled Cast
4lbs 2.9oz - you can probably take off like 0.5oz for the plastic wrap, but even at 4lbs 2.4oz it's kind of chubs

HELIX 272s - Billet
2lbs 15.8oz

It would be interesting to see how the EVO IX cams as well as other camshafts weight out!

 

Nice. I just put in a set of Tomei 280s and those things are porkers!

 

I dont know what my comps weigh, but the intake cam looked hollow and the exaust cam wasnt

 

I wonder if there's any negative long term effect on the recieving end of the cam lobes due to the excess weight of heavy cams and is also why OEM ones are hollow. Like the inertia durring high RPM - heavy cams will push and plow through the rockers while light ones will drive the valvetrain

How much, do they require upgraded springs or anything?

 

Yeah, I'm not a big fan of anything heavy rotating inside my engine, be it piston, crankshaft, or camshaft.

The Helix V2 camshafts don't require valvetrain. Basically they are very simialr to the HKS / Buddy club 272s, but just MUCH lighter. They were able to achieve the weight reduction by using a billet camshaft (which is stronger than chilled cast) and hollowing it out. This is important with the larger lobe performance camshafts.

Cheers,

Gary
Gruppe-S

 

bump for the weight of IX cams

 

the weight of the cams due to the location of the extra mass in the aftermarket cams wont make any noticable difference in any engine performance. we are talking 4 pounds between the two cams. when the mass is rotating, but because it it rotating around the center of the cam, that mass has a very very small inertia. additionally, the cams spin at half the rpm of the crank. saving 4 pounds in the clutch will be a much much bigger difference then in the cams.

 

can you weigh comp and gsc cams? Anyone using these helix cams?

 

Shouldnt be a problem..dsm cams are not hollow and John Shep seems to do just fine.

 

Actually from a physics standpoint becuase the mass is rotating you will actually see a greater effect from the reduction of mass. This is similar to the positive benefits of reducing wheel weight and their effect on performance. Simply shaving 2lbs off a rotating wheel is worth far more than shaving 20lbs off the weight of the vehicle. Although it is true that the inertial mass is close to the center of spin, you always have to keep in mind you have camshafts (and gears!) spinning at 7000+RPM.

Here's Mitsubishi's own comments regarding the hollow camshafts - "Under the magnesium valve covers, hollow camshafts save rotational weight, and less inertia means that engine RPMs build faster and acceleration times go down. " - Mitsubishi Motors USA

Although it is difficult to measure the true benefits of the weight of camshafts, I think it's reasonable to say Mitsubishi invested some time and energy in making hollow camshafts - it is very difficult for any camshaft manufacture to make a chilled-cast hollow camshaft that can withstand the high revs found in modern high performanc engines. This is primarily why none of the chilled-cast camshafts have hollow cores, and why Helix was only able to do it with a billet core. And for Mitsubishi to invest this time and energy, there must be substantial performance gains, as God knows they didn't invest much time and energy on the interior of our cars!

Cheers,

Gary
Gruppe-S

 

True but you also forget that the 4g63 was a great motor before it had hollow camshafts. And I am sure they didnt spend much time on the motor its pretty much the same as the old one lol they just went in the library and blew the dust off the cover. Lancer Evolution made a name for itself way before the ones we have in America came out and so did the 4g63. Except the small crankwalk issue in 1996 lol

 

It sounds ok in theory, but the camshafts are only spinning at half the speed of the motor, as mentioned earlier by KevinD. Also, the extra mass is at the very center of the camshaft, the area that has the least effect on inertia. Given these two facts, the reduction in rotational inertia by removing those two pounds would be about the same as removing less than 4 oz's from the flywheel. The biggest positive effect may be reduced wear on the camshaft journals, although most of the load on the journals probably comes from the rocker arms. If I were going to put effort into reducing weight on my car, I probably wouldn't start with the camshafts.

-Paul

 

i think we need to start looking at the "reciprocating mass" instead of the "rotational mass".

okay we all agree that the weights of the cams are different, however, when the cams are stationary, it provides its mass stationary. when it is in motion, where is the weight centered?? is it in the center of the cam or on the outside lobes of the cam?? see the difference?? take a piece of string with a small 2oz weight on it on one end and 4oz on the other. now holding the 4ozweight itself, swing the string around. not much there right?? that is because the weight is in your hand and not at the rotating end. now take the same string with the weight, holding the 2oz this time and swing it around. there is where it makes a difference. even though the TOTAL combined weight is 6oz, it is where it is placed.

i hope i explained that right...

interesting facts none the less on Gruppe S's part.

 

Thanks for the interesting discussions guys

I definitely agree, porky camshafts or not it's not going to be a HUGE difference in peformance, probably just a small one. Maybe a bit more friendly on the valvetrain, a bit better response, but no one should expect to see big gains from going lighter versus heavier. Probably not worth paying more for either (Helix cams are less expensive )

For me personally I think the biggest difference going from the old HKS (3 leg gears) to the new Helix light weight ones, the engine does definitely feel more responsive. This is probably because of the larger diameter of the gear and where the weight was saved (on the outter gear itself).

Cheers,

Gary
Gruppe-S

Edit: Oh, I also wanted to mention, the billet material itself is actually lighter than the chilled cast material. If you check out the stock camshaft, it actually has a much bigger hollow portion. Furthermore, the Helix camshaft actually displaces more volume because it has larger lobes. Something to think about!

 

Just weighed in the BC's at 4lbs 4oz!

Cheers,

Gary
Gruppe-S