Rs2 Cams!!!

[S2central.net]

@Riga - let me simplify for you...

If you have 3B engine then you need an INLET camshaft with gear for dissy. The INLET cam from RS2 will not work for you. Your only choice is the longer duration of the 7A inlet camshaft. Most people find the 7A inlet has gains at top of rev range but some losses in the mid range - I dunno if this is caused by overlap or duration.

For exhaust then both RS2 or 7A can work for you - I think I prefer 7A as it has longer duration than RS2 exhaust but the timing is very different. This changes things like dynamic compression ratio amongst other things... Its very specialised area and many engine builders will have great theories and stories, but in practice they will have adjustable camshafts to get things good.

I have a notion for funky pulleys on using the 7A camshafts on more like S2/RS2 settings for open close and to dial out the overlap.

[Jamo]

There isn't such a thing as best with this sort of thing, it's what you want out of your car. Do you want low end or high end.

Low end then stock or rs2 exhaust cam high end 7A

[rjga20]

Thanks JAMO but what is the best?I change my exaust cam and still the intake original cam 3B??or i change bought cams to 7A cams?

[Jamo]

7A is more aggresive pullls to redline but increases turbo lag in summary.

[rjga20]

7A cams

Hi
But can any one help me???I have the RS2 cams and 7A cams what I fit in my car??The 7A cams was more agressive with the RS2 cams??In case I fit the the 7A cams, I fit boght cams or only the exaust cam?I need to know this...

[S2central.net]

FOund one trustable source of RR camshaft data - http://www.isham-research.co.uk/quat...ical/00-2.html - seems to be same as 3B on 200TQ and 3B on S2 then... At least from a timing point of view - don't have lift data yet on the RR.

[Rusty]

A simple side-by-side picture might give us a good idea of how similar the cams are. It's possible that the older cams are more aggressive due to emissions laws getting increasingly stringent, this is the story of the old Golf cams, the cat equipped cars have a less aggressive profile.

[S2central.net]

That would need to be measured with a crankwheel to get it accurate, but I dare say it could be estimated reasonably well by addiing max LIFT data into that spreadsheet then applying some geometric calcs with the duration and centreline data.

[Flat on my back]

.

Good spreadsheet it is, but the real important data is a 'profile map' for each cam.

This would show lift against degrees...anyone got that?

[Jamo]

I threw this together... Uses all the data I have at my disposal... It doesn't quite align 100% with other peoples findings. I am suspicious that there 'might' be two different intake profiles on the 3B engined S2 - as it and the RR started with 'AH'.

The 3B S2 changed to 'AQ' middle of 92 - same cam as early AAN.

Does anyone have camshaft timing info for the RR engine ?


Editing the colored cells has automatic effect on the calculations - I haven't added lift info yet. Enjoy -

Sweet Jesus thats a good spreadsheet

[Bram]

I threw this together... Uses all the data I have at my disposal... It doesn't quite align 100% with other peoples findings. I am suspicious that there 'might' be two different intake profiles on the 3B engined S2 - as it and the RR started with 'AH'.

The 3B S2 changed to 'AQ' middle of 92 - same cam as early AAN.

Does anyone have camshaft timing info for the RR engine ?


Editing the colored cells has automatic effect on the calculations - I haven't added lift info yet. Enjoy -

Thanks Paul! Great overview. This should become a sticky some day.

Now we actually we need to know how to read this data, like what is the effect on duration, timing, etc.

Or will this be too difficult to explain?

[S2central.net]

I threw this together... Uses all the data I have at my disposal... It doesn't quite align 100% with other peoples findings. I am suspicious that there 'might' be two different intake profiles on the 3B engined S2 - as it and the RR started with 'AH'.

The 3B S2 changed to 'AQ' middle of 92 - same cam as early AAN.

Does anyone have camshaft timing info for the RR engine ?


Editing the colored cells has automatic effect on the calculations - I haven't added lift info yet. Enjoy -

[Rusty]

Me too

[MidnightBlueS2]

The RS2 pump can be used on an ABY with the RS2 cambelt without using the RS2 cam wheel. People such as Mark Halligan have proved this on their engines.

Proven on mine as well.

[Rusty]

Well the family album lists the ABY and RS2 inlet cams as the same part number - 034 109 021 AN, 3B is a different letter.