exhaust cams instead of inlet cams

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vtrnewboy
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exhaust cams instead of inlet cams

Post by vtrnewboy »

can anyone tell me what sort of increase this mod gives , ie bhp , torque :crazy:
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lloydie
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Re: exhaust cams instead of inlet cams

Post by lloydie »

Both :-) I'm having it done to both my engines :-) tony.mon will do it at a good price . And if he's ran out of cams pm me and I will sell you a set :-)
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VTRDark
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Re: exhaust cams instead of inlet cams

Post by VTRDark »

You will get a little boost. Nothing compared to aftermarket cams like stage 1 Yoshi's or Moriwaki but then you are talking about serious ££££ and would want to port the heads to get the full benefit from them. IIRC you get a little bit more lift than the intake on the exhaust cams but don't get any more duration. So it's a good cheap option for a little boost. It all adds up, a little here and a little there. I did have the figures wrote down somewhere. I will have to see if I can find them. As for bhp and torque I have no idea as every bike will be slightly different anyhow and depending what else you have had done/installed. Having a bit more lift is all well and good allowing more in but you need a longer duration to go with it for any real gains. You would benefit from degreeing the timing rather than using the bikes timing marks and experimenting with this but you need some slotted cam wheels for this.

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ebenviljoen
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Re: exhaust cams instead of inlet cams

Post by ebenviljoen »

I have heard bout this mod. Where can i buy a set of exhaust cams? Want to do this mod too.
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lloydie
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Re: exhaust cams instead of inlet cams

Post by lloydie »

ebenviljoen wrote:I have heard bout this mod. Where can i buy a set of exhaust cams? Want to do this mod too.
here - http://www.vtr1000.org/phpBB3/viewtopic ... 38&t=29586
ebenviljoen
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Re: exhaust cams instead of inlet cams

Post by ebenviljoen »

lloydie wrote:
ebenviljoen wrote:I have heard bout this mod. Where can i buy a set of exhaust cams? Want to do this mod too.
here - http://www.vtr1000.org/phpBB3/viewtopic ... 38&t=29586
:thumbup:
Thanks mate, ill see if he has a set left
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lloydie
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Re: exhaust cams instead of inlet cams

Post by lloydie »

if he dont pm me if you can
ebenviljoen
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Re: exhaust cams instead of inlet cams

Post by ebenviljoen »

lloydie wrote:if he dont pm me if you can
Cant post on that link mate or send pm's yet. :thumbdown: think i need to post 50 posts b4 i can
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lloydie
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Re: exhaust cams instead of inlet cams

Post by lloydie »

ten more posts and you be there :thumbup: wont take long
adyf
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Re: exhaust cams instead of inlet cams

Post by adyf »

Did my cams at same time as doing manual ccts ,mainly cos no tension on camchain and reshim and reset timing ,so if you need ccts doing or valve clearances doing then its a good time to swap em ,not big improvement but cheap to do ,should help a little with airfilter and race cans ignition upgrades etc ,thought they had slightly longer duration Carl , but maybe wrong.cheerz ady f.
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VTRDark
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Re: exhaust cams instead of inlet cams

Post by VTRDark »

The manual only gives the lobe height :(

LOBE HEIGHT
Inlet 40.080 to 40.240mm
Exhaust 40.230 to 40.390mm

I'm not sure what the two different measurements are for unless the second set (higher numbers) is as new and the first set (Lower numbers) is the service limit. Anyhow basically there is less than 1mm difference in lift.

Maybe there is a tad more duration but from what I have read on the Superhawk site there is not. But then that is just hear say. Mikstr has done a lot of research into things like this, so maybe he can shed some light on it.

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lloydie
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Re: exhaust cams instead of inlet cams

Post by lloydie »

Open BTDC /Close ABDC /Lift (mm)/Lobe Center

MORIWAKI:
IN:: 22/ 53/10.3/105.5
Ex:: 53/16/10.1/108.5

YOSH:
IN::17/53/10.7/108
EX::55/15/10.7/110

Stock
IN::20/45/?/102.5
EX::50/15/?/107.5

As posted in Tony's engine build thread . What they mean I don't know
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VTRDark
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Re: exhaust cams instead of inlet cams

Post by VTRDark »

What I have given you is the actual physical specs in mm and what you have posted is the degrees of opening and closing times and the lift in mm like myself. But Tony's lift in mm differs from what is in the Honda workshop manual unless the measurements are taken from somewhere different literally... on the cam. I still don't under stand why there is two sets of numbers for the lift. Tony's got two sets as well, though he has a ? on the lower numbers for the standard cams.

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vtrnewboy
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Re: exhaust cams instead of inlet cams

Post by vtrnewboy »

hum interesting , :think: I was going to have the cam sprockets slotted and timed up and some porting done , so might be a idea to do this mod at the same time , :D
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VTRDark
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Re: exhaust cams instead of inlet cams

Post by VTRDark »

I was going to have the
..... That's exactly what I'm going to do but I may go down the route of purchasing adjustable sprockets. But I wouldn't port the heads unless using aftermarket race cams. You may end up loosing power/velocity, especially if not done without the aid of a flow bench. Just a very light porting, well....just a good clean up really.
http://www.faliconcranks.com/sprocket_price.html

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