Advance or Retard the cam?
Discussion
confusionhunter said:
Yea... Bottom line you probably need to try it and see. For us with single cam V8s, Inlet theory cannot be implemented in isolation, ie its always a balance between inlet and exhaust. The disadvantage of a single cam is you cant alter inlet to exhaust timing. Overlap is set and there is sod all you can do about it short of a regrind or new cam.
This article shows a single cam V8 making more power with 4 degrees advance over 0 degrees straight up.
http://www.hotrod.com/articles/mopp-1211-degreeing...
you need to look at the pictures for the results. 'By Advancing The Camshaft Four Degrees, We Ended Up With 329 Hp And 320 Lb Ft Of Torque. That's An Increase Of 8 Hp And 16 Lb Ft Of Torque'
However I agree with the theory of retarding the inlet higher up. For example Audi advances the inlet only at more than 80% throttle and between 1k and 4k revs on their VVC twin cam cars, meaning on a pull at 100% throttle it retards the inlets again above 4k revs.
Oh and also Comp cams do actually generalisethe other way.... retard means more HP up top.... so forget what I said
http://www.compcams.com/Pages/413/cam-timing-lobe-...
So its all clear as mud
Confusion: yhanks but i I can not seem to open it:http://www.hotrod.com/articles/mopp-1211-degreeing...This article shows a single cam V8 making more power with 4 degrees advance over 0 degrees straight up.
http://www.hotrod.com/articles/mopp-1211-degreeing...
you need to look at the pictures for the results. 'By Advancing The Camshaft Four Degrees, We Ended Up With 329 Hp And 320 Lb Ft Of Torque. That's An Increase Of 8 Hp And 16 Lb Ft Of Torque'
However I agree with the theory of retarding the inlet higher up. For example Audi advances the inlet only at more than 80% throttle and between 1k and 4k revs on their VVC twin cam cars, meaning on a pull at 100% throttle it retards the inlets again above 4k revs.
Oh and also Comp cams do actually generalisethe other way.... retard means more HP up top.... so forget what I said
http://www.compcams.com/Pages/413/cam-timing-lobe-...
So its all clear as mud
Edited by confusionhunter on Wednesday 22 March 13:49
I realized that maybe I can gain a few HP (about about ten?)....
or i change with more agressive cam...
now my gtr with semislick, have problem with traction in 1 and 2 gear....
845ste said:
ciao Dom.
thanks for photos: a good job!
There are two type of Edlbrock Pro-Flow: 1 SBC and 1 LS.
I have the type for LS,
Edelbrock advertises increased by ten hp ....
With that yours "X" ,how much increase + hp?
tried you , on dyno?
ive not measured it but it revs easier and at 6k sounds like its doing 10k.thanks for photos: a good job!
There are two type of Edlbrock Pro-Flow: 1 SBC and 1 LS.
I have the type for LS,
Edelbrock advertises increased by ten hp ....
With that yours "X" ,how much increase + hp?
tried you , on dyno?
the main reason for change was exhaust note... its sounds like a dfv F1 engine now and is megga to hear
vey interesting.
Dom I'm curious to hear sound that F1 has your gtr ..
I seem to see that you have the mufflers (one each cylinder bank) towards the exhaust end?
please post some video of acceleration.
I seem to remember wich also the the yellow Lee's GTR sounded like a F1, with exaust system similar yours
Dom I'm curious to hear sound that F1 has your gtr ..
I seem to see that you have the mufflers (one each cylinder bank) towards the exhaust end?
please post some video of acceleration.
I seem to remember wich also the the yellow Lee's GTR sounded like a F1, with exaust system similar yours
http://www.hotrod.com/articles/mopp-1211-degreeing...
Try again!.... I now want to retard my cam after all that. as it makes plenty torque and can spin the wheels fine.... Might do that ... hmmm
Hopw you don't mind Dom, Ive previously noise perved on this:
https://www.youtube.com/watch?v=JDsl2duk1CY
you can really hear it after 1min 35.
Try again!.... I now want to retard my cam after all that. as it makes plenty torque and can spin the wheels fine.... Might do that ... hmmm
Hopw you don't mind Dom, Ive previously noise perved on this:
https://www.youtube.com/watch?v=JDsl2duk1CY
you can really hear it after 1min 35.
Dom yours GTR have a right sound! 
mine: https://www.youtube.com/watch?v=upIRQ_oBIys
but please, your system exaust have 2 muffler (each for 1 part) or is direct?
mine: https://www.youtube.com/watch?v=upIRQ_oBIys
but please, your system exaust have 2 muffler (each for 1 part) or is direct?
Just a word of caution when advancing or retarding a cam on any engine. Check you valve to piston clearance. If you have a "HOT " cam you may run into a clearance issue.
If your going through the pains of replacing the chain, replace the cam with one more suited to your needs.
The cam I have currently in an LS7 pulls from 2200 rpm to 7800 rpm over .650 lift and can still be driven on the street.
If your going through the pains of replacing the chain, replace the cam with one more suited to your needs.
The cam I have currently in an LS7 pulls from 2200 rpm to 7800 rpm over .650 lift and can still be driven on the street.
I love the exhaust on Lee's car, having heard it it in and out of the car in person, but my neighbors would line up to stab me if I fired that up early in the morning. Not too mention there's no way I'd be able to run that exhaust at any track here in CA, which I find ridiculous.
Also, good point on cam to piston clearance. It won't be much of a worry for mild cams, but anything with .650" lift or high duration should be double or triple checked.
Will
Also, good point on cam to piston clearance. It won't be much of a worry for mild cams, but anything with .650" lift or high duration should be double or triple checked.
Will
845ste said:
Dom yours GTR have a right sound!
mine: https://www.youtube.com/watch?v=upIRQ_oBIys
but please, your system exaust have 2 muffler (each for 1 part) or is direct?
1 small straight through silencer for each exitmine: https://www.youtube.com/watch?v=upIRQ_oBIys
but please, your system exaust have 2 muffler (each for 1 part) or is direct?
update for noise of mine compared to others... try playing on a pc and crank up the volume as its megga
https://www.youtube.com/watch?v=PSFcAUiRuAc
4.30 come passed twice
https://www.youtube.com/watch?v=PSFcAUiRuAc
4.30 come passed twice
always raining in the UK ..... I ask myself how do aad have shiny and clean cars forever. 
Dom seems a good sound but you should make a nice video acceleration from standstill to hear better.
For cam question, thank you all.
I want to try to retard as soon as I have some time.,
If we are interested ,I will update or if someone will do it before, I hope you tell us here, please.
Dom seems a good sound but you should make a nice video acceleration from standstill to hear better.
For cam question, thank you all.
I want to try to retard as soon as I have some time.,
If we are interested ,I will update or if someone will do it before, I hope you tell us here, please.
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