Sunday, May 10, 2009

Installing Tomei 256 n HKS 264 Cam on SR20DE

It's always my dream to have my sr20 equipped with hi-cam and yesterday was a big day where reality came through, a combination of Tomei and HKS cam work together to support a good improvement for my sr20.


Intake Tomei Poncam 256, 11mm lift,

Exhaust HKS 264 Step 1, 10.5mm lift .

I'm still maintaining NCVS for intake as my original sr20de came with VTC which I believe doing good job for intake cam advance while before 5krpm and it was said to give good respond on low and midrange, and yes I am happy with that, it does! I'm using NS adjustable cam pulley for exhaust cam sourced locally, not only cheap but it has very good engineering work quality. I have asked my cifu whether the 2 diffrent cam can work together, his answer is yes but Tomei has it's own quality for being offset cam while HKS only a parallel cam.

Fixing cam method

1. Remove battery terminal and remove rocker cover.

2.Find TDC for piston no.1 and make sure 2nd mark on the crankshaft pulley. 1st cam lobes must be facing apart from each other.

3. Remove hydraulic fan.

4. Remove chain tensioner.

5. Remove distributor, look at the timing mark, a small dot on top.

6. Loosen cam holder using FSM method.

7. Replace cam.

8. Tighten cam holders, using FSM spec.

9. Check for timing mark, each mark on the camshaft pulley are separated by 20 chain.

10. Install chain tensioner.

11. Install distributor, dot on top.

12. Turn crankshaft clockwise as many as you can to check on timing mark.

13. Fix rocker cover and fan.

14. Install battery.

15. Ready to start.

note: FSM is a Factory Service Manual from Nissan.

Old cam ,ready to be taken out.

Tomei 256, HKS 264 and NS adjustable cam pulley.

Old cam, didn't know that exh cam is same with DET ones .

I'm selling if you are interested. rM100 each.

Now, after installing a racing cam into SR20DE, a possible question you want to ask would be "what is the outcome?"

Ok, I tell you the real thing happened, I started the car, sound like blop,blop,blop but can't hold it's idling, I tried to play with my PS Fuel Enhancer II which takes control of my stock ECU mapping but still can't. When I checked my engine bay, found that MAF connector not properly inserted. I fixed that and next was doing my tuning job, weak vacuum coz engine easily stop, the respond on 2nd gear is hard to bring the rpm from 1k to 2k, but once it in 2k and up, it will never stop and I noticed that higher rpm and above looks too much lean,no display light visible, and not only that, my PS Air Fuel Ratio indicator has never shown rich opposed to the stock cam, it's much richer. p>

Second round of tuning is to adjust it accelaration which is very hard to drive from low rpm. We use a lot of 2nd gear while coming out from 90 degrees corner or after passing by a bumper in a housing area. After getting right on the accelaration on 1-2k rpm, now I can drive it like normal stock car but if you press harder especially on higher speed, engine starting to have a knocking sound. it shows that wrong timing on the cam. At this point, engine power is really bad. This test was on a neutral exhaust cam(haven't dialled), which may need exh cam advancing?


Advancing exh Cam cause weak on low n mid rpm but powerful on higher rpm

Retarding exh cam can cause weak top end but good on mid rpm

to be continued....