Catcam 743

[unreal106]

Hi there

Just dialing in my cams cat cam 743 and they are set to standard marks currently I have found true top dead centre goin from this I have measured max lift on the inlet cam and this is around 110 deg as book quote

Now I measure the exhaust cam and the very first moment of max lift is someway off the quoted 106 btdc by around 10 degrees so in theory I need to regard the exhaust cam by 10 degrees.......

Is this generally what people do or are there any tips?

[unreal106]

So where are all the engine people this week?

[yr51ocw]

what are you using to measure the TDC and valve lift? DTI's? If so you should be able to accuratley determine lift at TDC to within 0.1mm

[Gabbastard]

Have you determined TDC to be the middle of the dwell zone? If not, it might be enough to throw your measurements.

[unreal106]

I am using a dti and yea I am in the middle of the dwell zone what amount has everyone else moved each cam ? Generally is it exhaust that gets retarded ?

[Jimbob25]

When I fitted mine at true tdc I set mine up with what cat cams suggested the lift at tdc is. If that makes sense. Basically measured the drop of the follower at tdc. Run sweet at that and made 140 at the wheels so can't be to far out.

[Tom5190]

140 atw with 743 + standard inlet?

[unreal106]

Did you move the cam from the standard timing marks ? Also if So which way ?

[Tom5190]

Are you asking which way to move it? Retard it 10 degrees and measure again your either going to be 136 or 106?

[Gabbastard]

Hang on, have you set the cams to standard cam timing holes and youre wondering what to do with them?

If so, use your crank angle gauge to get true TDC, then set each cam using the DTI to whatever lift catcams recommend at TDC.

[Tom5190]

i think hes already done that he just wants to know if advance/retard means plus or minus??? as in if he retads it does he reduce the timing or does it increase?

[Gabbastard]

If hes got a DTI, then he should just check the lift and swing the cam, itll only be right one way!

[unreal106]

No you are all wrong

I am asking do you all generally advance the cam to get to the cam timing spot on or retard it ? I know what I will be doing I will be retarding it to give 136 I am asking is this what everyone else does? Or are you all doing different things some advance some retarding ?

My name is Tom by the way

I am using dti and angle gauge etc

[Tom5190]

I just dialed mine into the recomended marks. On the rolling road we advanced/retarded them and peak power was made spot on the recomended marks.

[Gabbastard]

Had a look on catcams website, they dont list the 743 yet so cant check the cam details.

If youre using a DTI then why are you worrying about retarding/advancing the cam from standard timing marks, use the DTI to check and then set lift at TDC as per their specs.

[unreal106]

Ok thanks for your help will do

[Tom5190]

for the record 743 details are the same as 708 matey if you need any info its the lobe design thats the main difference lift/duration is the same

[Jac000001]

ive just had the 1322705 (jp4 708 equivalents, if looking on kamracing, the one c2 trackday ones not the saxo vts with c2 head ones) fitted and dialed in but i rang up catcams because the idle and the way they were running on standard marks was appaulling it would not idle, ever, didnt even try. so i asked them what they should be set to and i spoke to the head technical guy at catcams (so he said) and he said to me that their cams are cnc machined to be used on standard timing marks so should be spot on, but is worth checking the lift at tdc, where he then said the lift for both inlet and exhaust at tdc should be 1.5mm, he was absolutely certain of this even though the official spec say 1.55mm inlet and 2.00mm exhaust (which i told him) so i had the lift checked by noble motorsport in chesterfield and they said that the inlet lift at tdc was 1.52mm which is fine and the exhaust was 2.56mm which is obviously miles out. so after having them dialed in to very near 1.5mm inlet and exhaust its just been remapped on standard 3 plug ecu by noble motorsport and made 157.6

hope some of this is of use to you or anyone else following the thread, something i thought was quite interesting anyway

[Jimbob25]

140 atw with 743 + standard inlet?

On throttle bodies and other bits.

[unreal106]

thanks for the above info I will time them up tomorrow and let you know the results.