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Finally ZR vs RS cams lobes measured and compared together
http://mivec.co.nz/forums/viewtopic.php?f=29&t=8488
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Author:  brccrx [ 30 May 2012 13:34 ]
Post subject:  Finally ZR vs RS cams lobes measured and compared together

Finally got round to do it and here are the results:

ZR Cams ---------RS Cams

Exhaust
34.17 mm---------35.42 mm small lobe

35.82 mm---------36.52 mm valve lift lobe


Intake
34.47 mm---------35.48 mm small lobe

36.25 mm---------36.25 mm valve lift lobe

Can this be made sticky pls, or there's no point ?

Author:  brccrx [ 30 May 2012 13:36 ]
Post subject:  Re: Finally ZR vs RS cams lobes measured and compared togeth

After knowing the lobe measurements thinking of fitting ZR intake cam along with RS exhaust one and ZR ecu to RS engine,

Any thoughts on this idea?

Author:  Spetz [ 31 May 2012 03:20 ]
Post subject:  Re: Finally ZR vs RS cams lobes measured and compared togeth

Are you sure that the cams did not have wear on them?
As the high lift lobes should be the same, just the primaries are different

Author:  brccrx [ 31 May 2012 13:27 ]
Post subject:  Re: Finally ZR vs RS cams lobes measured and compared togeth

Well no, i went trough all of the lobes to be exact and that what come up, of course there was variations between them but would you not say difference about 1mm wouldn't be noticeable the way the lobes look he he

i can go trough this again just to be sure its all measured proper

any thoughts on the idea?

Author:  Spetz [ 31 May 2012 23:40 ]
Post subject:  Re: Finally ZR vs RS cams lobes measured and compared togeth

To be honest I don't know what gains would be had but I doubt mixing the 2 cams would be a good idea. Either go RS cams or normal cams.
Maybe talk to a tuner see what he has to say?

Alternatively get some custom cams made up, depending on your budget

Author:  brccrx [ 02 Jun 2012 11:43 ]
Post subject:  Re: Finally ZR vs RS cams lobes measured and compared togeth

After giving it a thought there's what im thinking of:

I want the ZR ECU and ZR intake camshaft because ECU its tuned to the ZR cams and need to have predicted amount of air to mix with fuel as well as proper spark time, but as well is tune up to turn mivec on at 5500 rpm's, so i could safely lower the mivec activation point from 6800 to 5500 and that's a lot.
Meaning is that i would have mivec kick in 1300 rpm's lower than now and could have exhaust gases escaping better

Having RS exhaust camshaft ZR ECU doesn't see the difference as still getting same amount of air only exhaust gasses will escape quicker due to higher lift on smaller lobe and valve lift, there's only one if:

If the timing on the RS ones is same as on the ZR lobes.
It is quite possible, and it would mean RS camshafts are more aggressive, with we know they are.
I will measure the lobe durations but first need to figure out how to do it, any suggestion's?

Author:  Sack of Spuds [ 02 Jun 2012 21:17 ]
Post subject:  Re: Finally ZR vs RS cams lobes measured and compared togeth

Exhaust cam WILL effect the air intake as well as the exhaust side. The cams will overlap, depending how the interact you will get more or less scavenging effect (the exiting exhaust gases pulling the fresh inlet charge in as they exit).

Mitsubishi spent an awful lot of money getting the cams right and matched to each other, sure you can fit more aggresive cams to gain more power higher up the rev range but mixing stock parts that are not optimised to work with each other is sure to see losses not gains.

Author:  Spetz [ 03 Jun 2012 01:24 ]
Post subject:  Re: Finally ZR vs RS cams lobes measured and compared togeth

I agree with sack of spuds. I doubt you will get better performance from mixing and matching parts.
I've only heard of this being good on some Honda motors by using B16B cams and also on SR20DET motors, apparently using one NA cam (can't remember which one) yields good results.
But with the MIVEC it just doesn't seem like you will be able to attain better results than a stock RS motor by mixing cams

Author:  brccrx [ 03 Jun 2012 10:22 ]
Post subject:  Re: Finally ZR vs RS cams lobes measured and compared togeth

Your input means a lot to me lads, thanks.

Still tempt to measure the lobes timing on them if i can find out the way :)
Reason im doing it is just to gaiter more info and ideas together, more we know about them, more better for aftercomers lol

Author:  Spetz [ 03 Jun 2012 11:05 ]
Post subject:  Re: Finally ZR vs RS cams lobes measured and compared togeth

The only way you'd be able to accurately measure the profile is by taking it to a cam specialist. Keep in mind though that it seems there are many ways of "measuring" or rather representing data, specifically the minimum lift for the duration timing (some measure @1mm, others at different lift etc).

Author:  brccrx [ 04 Jun 2012 00:08 ]
Post subject:  Re: Finally ZR vs RS cams lobes measured and compared togeth

I would rater give him two exhaust cams ZR and RS to compare timing at the same degree range.
Barely see people doing that here around my place, so need to compare it by myself, thats why i need to figure out some way of doing that.

Author:  Spetz [ 04 Jun 2012 03:11 ]
Post subject:  Re: Finally ZR vs RS cams lobes measured and compared togeth

Maybe use a digital micrometer?
It may be tough to accurately measure duration etc though

Image

Author:  Sack of Spuds [ 04 Jun 2012 03:53 ]
Post subject:  Re: Finally ZR vs RS cams lobes measured and compared togeth

Mount it in a lathe and then use a DTI guage to measure it

Author:  magn1t [ 06 Jun 2012 14:34 ]
Post subject:  Re: Finally ZR vs RS cams lobes measured and compared togeth

To make it worthwhile you really need to measure the base circle, then the lift, then the opening and closing angles.
Lift on it's own doesn't really mean much.

Steve

Author:  mickeybo [ 09 Jun 2012 08:16 ]
Post subject:  Re: Finally ZR vs RS cams lobes measured and compared togeth

dti gauge probly the best option, but youd would you want to watch the degree of turn then to get an accurate measurement on both :? ??

Any good engineering place would have a lathe and tools to measure, or if you got a professional engine builder they should have ways and means of doing it

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