20v and aftermarket cams...

[xero]

9mm is about the limit before it fouls on the tube.
you want to be careful going with too much lift and not enough compression, you will have too much air in the chamber and possibly not enough fuel and your overlap will blow it straight out the exhaust. without compression you really wont make much more power and be very flat through the mid range making it very a peaky engine. a mild 20v engine can cope with larger duration cams better than 16v, but much more than 9mm lift and you will need to increase the compression quite a bit as well to really get the best out of the cams.

[Just1n_mc]

Sounds like you know what your talking about Xero. I've been struggling to get my head around camshafts and cam timing for ages. With 282 duration and 8.7mm lift where in the rev range do you think it will be making power??

My only other concern with the inlet cam is that it's not designed to retain VVT according to the guy who made it which may hurt low/midrange power.

[oldeskewltoy]

you want to be careful going with too much lift and not enough compression, you will have too much air in the chamber and possibly not enough fuel and your overlap will blow it straight out the exhaust. without compression you really wont make much more power and be very flat through the mid range making it very a peaky engine. a mild 20v engine can cope with larger duration cams better than 16v, but much more than 9mm lift and you will need to increase the compression quite a bit as well to really get the best out of the cams.

Do you have any idea what you are talking about????? Lift and static compression have NOTHING to do with each other... duration and compression DO.......

As to 20V coping with more duration... what proof or evidence do you have of this? Or is this just your internet opinion??????

FACTS......... do you have ANY???????

[NME308]

Do you have any idea what you are talking about????? Lift and static compression have NOTHING to do with each other... duration and compression DO.......

As to 20V coping with more duration... what proof or evidence do you have of this? Or is this just your internet opinion??????

FACTS......... do you have ANY???????

Well since this is the honesty thread...
I have NEVER found any of your information useful in any way shape or form. You are a keyboard warrior with a head full of useless information which you insist on referring to as FACTS and a dangerous little dremel tool. It is my belief that ANY head you have ever touched would have benefitted from being left totally standard as it left the Toyota factory.

There I said it...

Now Xero may have not used the duration as a reference to the cam size and its affect on performance as it is traditional to do so - but - IF you know anything about cams then you know that lift and duration are not totally independent of each other and in the course of the preceeding discussion it was actually LIFT which was being asked about... I will leave the technicalities at that and leave google to educate you on the rest - that or you can simply run your mouth off with your internet opinion again...

Cheers,
Jason

[xero]

Sounds like you know what your talking about Xero. I've been struggling to get my head around camshafts and cam timing for ages. With 282 duration and 8.7mm lift where in the rev range do you think it will be making power??

My only other concern with the inlet cam is that it's not designed to retain VVT according to the guy who made it which may hurt low/midrange power.

with that cam spec, it will mostly be above 4000rpm but there will be a good amount of power.
righto, so the 282s are no longer using VVT (i might have missed that earlier)? if that is the case i may better to swap to a cam the uses the VVT. while the VVT wont do much above say 6500rpm, low to mid range is where it will be very handy and it will make the most of what you already have.


also thanks Jase.

[trdee]

This article does not have any info specific to helping you pick a cam for your engine Justin, but it is useful background knowledge and might help you better understand what affects what when selecting a cam spec

http://www.enginebuildermag.com/2013...g-performance/

[Just1n_mc]

Holy crap this has escalated quickly!!

I didn't mean to start a war of words!!

[Just1n_mc]

with that cam spec, it will mostly be above 4000rpm but there will be a good amount of power.
righto, so the 282s are no longer using VVT (i might have missed that earlier)? if that is the case i may better to swap to a cam the uses the VVT. while the VVT wont do much above say 6500rpm, low to mid range is where it will be very handy and it will make the most of what you already have.

Well when I contacted the guy who made the cams asking about retaining VVT he was very hesitant to say that they would work. I guess I'll have to check it and see if there is clearance with VVT activated. To be honest I haven't really had a good look at the head and cams setup since I've bought it.

I'm planning on raising the rev limit to 9,000rpm so I'm hoping I've got enough cam to make power all the way to redline.

[Just1n_mc]

This article does not have any info specific to helping you pick a cam for your engine Justin, but it is useful background knowledge and might help you better understand what affects what when selecting a cam spec

http://www.enginebuildermag.com/2013...g-performance/

Thanks for the link trdee. Helps me get my head around the black magic behind choosing a cam!!

[101gze]

Well since this is the honesty thread...
I have NEVER found any of your information useful in any way shape or form. You are a keyboard warrior with a head full of useless information which you insist on referring to as FACTS and a dangerous little dremel tool. It is my belief that ANY head you have ever touched would have benefitted from being left totally standard as it left the Toyota factory.

There I said it...


Cheers,
Jason

FACT!

Justin, who supplied your cams? Those specs should easily be able to utilise VVT, but you stated you have toda gears? these negate the VVT . They will however allow the precise dialing of the cams and require dyno time to find there most beneficial range.

[Just1n_mc]

They are Clive cams. I haven't had a good look at them for ages but I'm pretty sure they aren't setup to run the VVT system.

[101gze]

What pistons are you running?

[Just1n_mc]

Stock pistons. If effectively a stock bottom end rebuilt with ACL race bearings, balanced with arp gear holding it all together.

[Just1n_mc]

I had thought of using blacktop Pistons but I wasn't sure if they were a direct drop in and how they would affect the compression ratio??

[101gze]

The BT piston is a nice design. However it has no inlet fly cutting and the duration you have may well need the flycuts. Is the engine apart? you will have to do a dummy build with a thin layer of playdoh to check what sort of piston to valve clearance you have, you may find it fouls even with the st flycuts.