Hayabusa Cam Timing on standard cams

[geefin]

Hi Guys,

Hoping someone can help me with some info. I'm running a Gen 1 busa on TD05 turbo with Wossner pistons and a 10tho baseplate. The engine was fully worked (bottom end/ported head/cams/valves) but after an issue on the dyno we reverted (for now) back to a standard head (standard cams/valves/no porting). The engine is currently cam timed to completely standard (to the marks, as per the manual).

I have been recommended to time the cams to 105/105.

The engine is in a kit car (Westfield), so it's a fair amount of work to get it in and out. To time to anything but standard we'd need to remove the engine to get the degree wheel on.

Can anyone advise if you can accurately time standard (non vernier/non adjustable) cams to 105/105? Or do I need adjustable sprockets for that?

Cheers,
Graeme.

 

[POWERHOUSE]

Hi Guys,

Hoping someone can help me with some info. I'm running a Gen 1 busa on TD05 turbo with Wossner pistons and a 10tho baseplate. The engine was fully worked (bottom end/ported head/cams/valves) but after an issue on the dyno we reverted (for now) back to a standard head (standard cams/valves/no porting). The engine is currently cam timed to completely standard (to the marks, as per the manual).

I have been recommended to time the cams to 105/105.

The engine is in a kit car (Westfield), so it's a fair amount of work to get it in and out. To time to anything but standard we'd need to remove the engine to get the degree wheel on.

Can anyone advise if you can accurately time standard (non vernier/non adjustable) cams to 105/105? Or do I need adjustable sprockets for that?

Cheers,
Graeme.

You cannot "accurately" adjust cam timing without adjustable cam sprockets. It sounds like you have a lot of time and money into your build . . . get some adjustable cam sprockets and do it right . . .

 

[GIXERHP]

No you need adjustable sprockets!

 

[geefin]

Thanks for the info, is the standard cam timing on 100/105?

Will try to get some adjustables, just not sure we can land them here in time. But if it can't be set to 105/105 on standard cam sprockets then it saves the effort of engine out today!

 

[GIXERHP]

Thanks for the info, is the standard cam timing on 100/105?

Will try to get some adjustables, just not sure we can land them here in time. But if it can't be set to 105/105 on standard cam sprockets then it saves the effort of engine out today!

No possible way without sprockets!

 

[geefin]

Understood, thanks!

What are the expected gains/benefits of changing to the 105/105 over standard?

 

[OZBooster]

Your not going to notice much difference with .010 spacer, your timing will be close enough to standard to leave well enough alone

if you had a .080 spacer like most use the cams do need retiming and adjustable sprockets are the best way , and while your doing it optimise the timing for your use, street or needing more mid range pull around the 105/105 but serious race using mostly top end power will go further like closer to 110 deg

 

[icemansid]

Mine are timed close to 110/112 for big end power. going the other way will make lower end power if I remember correctly.

 

[geefin]

Thanks, so I guess my final question is, is it going to be worth the effort of changing to adjustable cam gears/sprockets to get the 105/105 or is the gain negligible over the standard timing?

I don't plan to change cams/head at the moment, I would like to keep it as standard as possible.

 

[POWERHOUSE]

Thanks, so I guess my final question is, is it going to be worth the effort of changing to adjustable cam gears/sprockets to get the 105/105 or is the gain negligible over the standard timing?

I don't plan to change cams/head at the moment, I would like to keep it as standard as possible.

OZ is correct when he said that an .010" spacer plate won't throw things off enough to bother. Anything thicker would mandate checking and/or adjusting the cam timing. Stock cam timing, BTW, is not 105/105. Spreading cam lobes out decreases overlap and takes advantage of something called the "fifth cycle" . . . turbos especially like that . . .

 

[geefin]

Yup, I'm just wondering if on stock head, changing *to* 105/105 with adjustable gears is worth the effort for the gains over standard timing?

 

[POWERHOUSE]

Yup, I'm just wondering if on stock head, changing *to* 105/105 with adjustable gears is worth the effort for the gains over standard timing?

How much boost are you running on top?

 

[geefin]

It's just a TD05 16g, so 10psi on pump gas, 16psi on VP109/race gas.