1G/2G cams different?

[cheekychimp]

This is probably a newbie question but I don't have much access to information on 2Gs over here, so cut me a little slack.

Are the cams from 1G and 2G cars interchangeable? I was told recently that 1G cams are a slightly different diameter than EVO III cams (an EVO III head being essentially the same as a 2G head ... or so I thought!) If you put 1G cams in the EVO III head, this apparently can lead to rattling (and presumably some wear issues).

Anyone able to confirm this for me? It's a bit of a shame as I had some nice cams lined up for the daily but I don't want to put them in if it is confirmed that there are fitment issues.

 

[fuel]

as far as I know all 4G63 DOHC cams are the same diameter as far as the 'bearings' go. If the 2G cams are anything like the Lancer Evo1 cams they will have a slightly lower lift but the same duration. If they are like the Evo2/3 cams they will be the same lift and duration as the VR-4 cams.

I guess you need to check the cams for the markings and check the durations and lifts with the 4G63 engine manual (I have one if you don't have a copy).

 

[EMX5636]

Two problems. First is I'm pretty sure 2G cams less aggressive than stock 1G/GVR4 cams. Second is depending on the year of the 2G DSM, the stock 1G/GVR4 Cam angle sensor won't fit in the end of the intake cam without cutting the slot in it. 95-96 cars had the CAS on the cam gear, 97-up had a threaded end. (not sure if the 2G cams have the slot or not still).

I'm looking for links for you now. But all journal sizes of the DSM/Evo1-8 are the same. People have put Evo 8 cams in DSM's. Just need adjustable cam gears, and cut the slot for the CAS in the intake cam (on the exhaust in an Evo). Evo's have more lift stock, so a slight upgrade there.

Edit for specs from DSMTuners

Theoretically 1g cams are more agressive but your not going to notice any difference

--1990-1992 turbo 5speed cams: 244 ex, 252 in
--1990-1994 turbo auto: 244 ex, 244 in
--1990-1994 n/t: 244 ex, 252 in; intake cam is advanced about 5 degrees vs. the 1990-1992 turbo 5speed, 1993-1994 turbo manual and 1995-1999
--1993-1994turbo 5pseed: 252 ex, 252 in; the intake cams have .05ish more total lift than all the other intake cams but the exhaust cam has the same lift as 1995-1999 cams
--1995-1999 all trannies: 252 ex, 252 in; same peak lift on both sides as 1990-1992 turbo 5speed, and all auto & n/t cams

 

[EMX5636]

And here's a cool read if you are trying to find the best set of factory cams (and just a lot of good camshaft info in general). Sorry, it's a little long, go make some popcorn.

click

 

[cheekychimp]

I'm sorry, I should have given a little more information in my first post. I have an EVO III head on the car with stock EVO III cams in. I picked up a set of HKS 264/272 cams that I wanted to put into that head before I was told they might not fit snuggly and start rattling around.

I take it from what has been said above that this should not be the case and there is nothing to suggest that the 'journals' should be any different? Any ideas on what might have caused the sloppiness my guy was talking about? Worn 'bearings' perhaps? This guy isn't usually one for bullshit and he was telling me this from his personal experience not third party hearsay /ubbthreads/images/graemlins/dunno.gif

Edit: Oh and thanks for the link, that was an interesting read (bookmarked for future reference).

 

[3rdstrikedsm]

same cam size and I know this 1st hand from my evo which had 1g hks 272 cams

 

[cheekychimp]

Thanks, you have no idea how much better I feel now. I thought I'd just made a real 'noob' mistake and bought something I couldn't use. Now to test my theory about using this particular set of cams in combination with the Cyclone Manifold.

 

[mitsuturbo]

Quoting EMX5636:
Two problems. First is I'm pretty sure 2G cams less aggressive than stock 1G/GVR4 cams. Second is depending on the year of the 2G DSM, the stock 1G/GVR4 Cam angle sensor won't fit in the end of the intake cam without cutting the slot in it. 95-96 cars had the CAS on the cam gear, 97-up had a threaded end. (not sure if the 2G cams have the slot or not still).




2g intake cams have the slot in them. It's not uncommon to use a six bolt block with a 2g head. Other than having to ream the holes for the head bolts, everything bolts right up, even using the stock cams.

 

[EMX5636]

Good to know mitsuturbo. I have done a lot of 2G head swaps onto 6-bolts, but it's been a while since I've re-used stock cams.

Cheeky - there aren't any bearings in the head for the cams, it's a machined surface they ride on, so if the head was worn, or someone undercut a set of cams to get rid of any scoring, it could be loose in the head.

Sorry I missed your point, I should have thought you were trying to upgrade for a deal. My uber cool HKS cam gears are dual drilled for Galant and Evo3 I think.

 

[cheekychimp]

Quoting EMX5636:
Cheeky - there aren't any bearings in the head for the cams, it's a machined surface they ride on, so if the head was worn, or someone undercut a set of cams to get rid of any scoring, it could be loose in the head.



Yeah, I think both Phil and I were struggling to find the right word to describe the surfaces the cams sit in, hence the quotation marks around "bearings" and "journals" each time. Good thoughts on the head being worn or someone machining the cams to get rid of any scoring. Both those scenarios sound feasible.

I'm probably just going to use the stock cam gears initially, but I know I should really be getting some adjustables.

 

[curtis]

Paul I measured the gross size of the lobes once on all of these and posted it here somewhere so you can search for it but I found the VR4 cams are slightly larger than the USDM 1G cams. Reason for this after I bought my first set of 272's I wanted to know what was originally in the motor since it had a talon valve cover and I had no history on the car before that. My cams spec'd out larger than the 1G ones I had in another head so I bet the JDM Evo III cams are probably the same and a 1G and a 2G from here are smaller in lift and duration.

 

[cheekychimp]

Curtis,

I can understand the lobes being different (even though most cam specs state EVO III cams and VR4 cams are identical in duration and lift) but what is being suggested here is that the diameter of the came between the lobes (the part that rests in the head) is different so that the whole cam actually moves about.

Paul.