Difference between 1g and 2g cams?

[herostar]

I'm going to have my entire engine apart for a while here, and have a set if 1g m/t cams lying around. Would it be beneficial at all to swap them into my 2g head? Is there any difference between the two sets of cams?

 

[1fast97gsx]

I believe they have a little more lift than the 2gs ... supposedly worth the swap if you have them.

 

[edmundturner]

Hey,
This topic is interesting, especially when i spent the weekend swapping my 1G cams with a 2Gs!!!
I measured 1G cam lobe height at 35.5mm and the 2G lobe height at 34.9mm.
1G cam does have higher lift but it appears that the lobe on the 2G is fatter. This led me to believe that I should the duration was longer.
I was adviced that the 2G cams would perform better on a 1G block. The tuner who adviced me didnt go into too much details, except that the increased overlap would allow the engine to breathe easier.

After i test drove the car it seems the same !!!!!(Butt-o-meter). Maybe somebody can give us some insight on the differences.

regards
edmund

 

[anoldsman]

I'm going to have my entire engine apart for a while here, and have a set if 1g m/t cams lying around. Would it be beneficial at all to swap them into my 2g head? Is there any difference between the two sets of cams?

I do not what kind of time restraint that you have but, I could measure your 2G cams and tell you how they compare to some 1G cams that I have measured. I will check them in the head and at the lobe. It would only take a couple of days plus shipping. PM me if you are interested.

Chris

 

[i1nk83]

the 1g cams are a good cheap upgrade for the 2g guys they are bigger than the 2g and dont cost too much. everyone that i know who has a 2g and doesnt have the money for aftermarket has used them with good results

 

[edmundturner]

Chris, Shipping the cams to you will cost a bomb!, ?I appriciate the offer though.

So, i think the question is: Would a higher lift or longer duration cam profile benefit a stock 1G motor. Somebody once told me that even the HKS 272 cams have lower lift that stock cams but the duration is much longer. Overlap helps engine breath better and rev better at higher rpms. Please correct me if im wrong. Im just trying to get some info here.

I honestly feel that the my mid range has improved abit (butt-o-meter) with the 2G cams.

I have in my possession :
1G cams from a 200HP GVR4.
1G cams from a 240HP GVR4
2G cams from an Mitsu EVO II

1G cams lobe are the same height. The duration look similar but its quite impossible to say when you are measuring with your naked eyes!
2G cams have a lower lobe lift, but a noticable fatter profile.

Hopefully someone can shed some light on this.

regards
edmund

 

[doug]

I've always read that the stock 1G M/T cams are "better" than the 2G stock cams-- whatever "better" means is up to interpretation, I guess. And don't forget that the 1G A/T cams are different ("milder") than the M/T ones.

 

[philipkrotch]

all 1g cams have more lift than 2g cams. in the 1g's, the 90's had the shittiest lift, the 91's had better, and the 92-94 had the best i believe. they all had the same intake cam, but the exhaust was different (i think, or its the other way around). correct me if im wrong.

 

[anoldsman]

Chris, Shipping the cams to you will cost a bomb!, ?I appriciate the offer though.

So, i think the question is: Would a higher lift or longer duration cam profile benefit a stock 1G motor. Somebody once told me that even the HKS 272 cams have lower lift that stock cams but the duration is much longer. Overlap helps engine breath better and rev better at higher rpms. Please correct me if im wrong. Im just trying to get some info here.

1G cams lobe are the same height. The duration look similar but its quite impossible to say when you are measuring with your naked eyes!
2G cams have a lower lobe lift, but a noticable fatter profile.

Hopefully someone can shed some light on this.

regards
edmund

This can get complicated but here is a basic rule. If the heads flow well at higher lift then the higher lift cam will make more power assuming the duration, separation, etc. is the same. More duration will yield more power at a higher rpm. A tighter lobe separation will yield more peak torque but will not rpm as well. It is all very application specific though. If you are looking for more top end power than the stock cams then I would add duration first, then lift, and then play with the separation. I hope that this helps. Also the HKS grinds have more lift and duration than any stock cam that I have checked.

Chris

 

[mitsugsx95]

I have swapped them into my 95, and the measurements above are correct. The cams, both intake and exhaust, are slightly higher lift than the 2g. I have a set from a 91. The only difference is the lope height, the width and slope are the same (untill you get towards the top of the lobe on the 1g). I havent got the car running yet, i have to keep fixing one thing after another, but when its up, im sure i wont be able to tell that much, but it was free for me and I had the engine sittin in the garage.

 

[2GAWD]

Information I've found reguarding this topic:

RRE states: "The 1G cams have .010" higher lift. and are an upgrade by themselves."
Location: http://www.roadraceengineering.com/1g2gheadswaptechtip.htm

 

[edmundturner]

thanks for the info guys! Appreciate the input.

Last question, just wanted to make sure I got this right.

Is the 2G motor from the eclipse identical to the Mitsubishi Lancer Evolution (1-3) ?

 

[90DSMTurboFWD]

i think the 1G is identical to the Evo motors, the Evos dont suffer from crank walk and arent 7bolts.

 

[smokey90gsx]

all 1g cams have more lift than 2g cams. in the 1g's, the 90's had the shittiest lift, the 91's had better, and the 92-94 had the best i believe. they all had the same intake cam, but the exhaust was different (i think, or its the other way around). correct me if im wrong.

Where did you get this information? I've never read that the 1g cam profile changes at all between the years....