K Series VTC

[LiL FiLo]

BY how much + / - does VTC advance and retard in degrees's the intake on k series motors. can this be changed to greater amounts with after market modifications?

reason: planning on running a big cam with high comp, and will need to retard timing for down the bottom.

[DR HONDA]

Your builder should be able to explain all the ins and outs of vtc vs comp on a k

[LiL FiLo]

my engine builder normally dus big v8's and dusnt normally deal with things like VTC and VTEC, i said ill do some research for him so it can give us an idea of what cranking comp we can try to achieve and the profile of the cam that were going to get made up. Just thought id ask some people on here that would have some knowledge thats all. It is a forum isnt it? Thanks anyway Dr Honda

[Mr_will]

in all honesty dude, your builder might be good, but why not find someone more experienced with the sort of engine youre dealing with

[LiL FiLo]

tru, he's a mate aswell and wants to crack into the 4cyl category, since i was building mine, he sed he'd do the project for me and change me nothing for labour so he cood use it as "his project", im speaking to other people on here aswell like yonas from JDM Yard and Adrian from TODA that are helping me out. the fundamentals of engines are pritty much all the same (although i may be wrong), but i never see the wrong in asking people information

[TODA AU]

BY how much + / - does VTC advance and retard in degrees's the intake on k series motors. can this be changed to greater amounts with after market modifications?

reason: planning on running a big cam with high comp, and will need to retard timing for down the bottom.

The maximum change in cam angle in crank degrees is 55deg though listed as 50deg VTC pulley.
The Hondata K-Pro tables allow you to advance up to 60 deg however deg deg fails back to 0 deg.
55deg advance is the max usable.
In most cases with larger cams the VTC is less effectual & the max advance used on the high cam is rarly more than 30 to 35deg.
Less in most cases.
Same can be said for the low cam on larger profiles.
So, to put it in perspective, the cam centre line is @ approx 25deg advance with + 30deg & -25deg available.
Care should be taken when using larger cams, particularly on an engine combination that is unknown to you & or your builder.
The VTC pulley can be disasembled & manualy locked in max advance (or less) allowing the piston to valve clearance to be checked & also the valve to valve clearance.
This is a time consuming & bothersome process but should not be overlooked.
Same as claying an older V8 with big cams etc.
NB: Exhaust cam should be set precisly with adjustable cam sprocket so your measurements are valid.
& If your cam supplier can provide you with the information you require, then seek another supplier.
Hope that helps

[LiL FiLo]

thanks for the information - much appreciated!