Valve timing

Kate

Kate

Kate

Associate
Joined
24 Apr 2006
Posts
29
Hi,

We have put some adjustable vernier pullies on the DIY 2.0 Turbo motor.

It is a 2.0 Zetec (silver top) with the "130" spec n/a cams.

Now it has a turbo the cam timing and overlap will not be optimum, any ideas on exactly what to adjust to make a bit more power / torque.

I was thinking we should advance the exhaust cam, so the valve closes sooner and does not let gas back into the chamber. Exahuset manifold pressure is higher than inlet so overlap is not as usefull with a turbo...

Any ideas?

Cheers.
 
Yes, the only way you are ever going to optimaly set the verniers is by spending some time on a rolling road. Just guessing is almost certain to make things worse.
 
any reason the cams haven't been replaced?
it's unlikely that the lobe profiles for the n/a version will be equally as suitable for forced induction.
 
As a rule you want high lift and low overlap (duration) on blower motors. For some reason the lobe timing of 110 to 112 degrees pops into my head.

I'd say the 130 is a fast road normally aspirated grind which is longer duration than a stock cam. Normally you'll find blower grinds look very short and pointy on the lobes.
 
hello there it's my car we are playing with

its a 2.0 mondeo engine

8:1c/r
accralite pistons
farndon H section con rods
ballanced crank
standard head (silver top)
2.0 cams from 137PS blact top focus
T34 turbo

after reading thease posts maybe i would benafit from a regrind of my existing cams? and any idea on price?

i can get dedicated zrtec turbo cams ground from blanks for £400 inc vat from Cylinder Head Developments in Bromsgrove near birmingham

i have the option of fitting focus RS cams in if i can get hold of some from ford but they probably will want to charge be more than the ones ground from blanks
 
MrViper said:
hello there it's my car we are playing with

its a 2.0 mondeo engine

8:1c/r
accralite pistons
farndon H section con rods
ballanced crank
standard head (silver top)
2.0 cams from 137PS blact top focus
T34 turbo

after reading thease posts maybe i would benafit from a regrind of my existing cams? and any idea on price?

i can get dedicated zrtec turbo cams ground from blanks for £400 inc vat from Cylinder Head Developments in Bromsgrove near birmingham

i have the option of fitting focus RS cams in if i can get hold of some from ford but they probably will want to charge be more than the ones ground from blanks
Click to expand...
if you've gone to the trouble of using Farndon and Accralite components you'd be crazy not to get the right cams my friend.
 
i have run out of cash now and have to make doo with what i have

and i forgot to add omex 600 to the list and rover 220 turbo injectors
 
MrViper said:
i have run out of cash now and have to make doo with what i have

and i forgot to add omex 600 to the list and rover 220 turbo injectors
Click to expand...

They should be Ok tbh, Vtec boys do fine with 'nasp cams' even with loads of overlap.

How much power are you aiming to make on this engine?
 
What A/R is on the T3 Turbine?

Most 'turbo' cams ive seen on T3 setups perform worse than the stock NA units, both in terms of midrange and peak hp. Crane seem to a good choice for cams though.

Anyway why spend money on pistons over cams? Easy, its turbo if you dont have enough power just wind the boost up, no need to mess with cams :p Forged pistons actually make it robust enough to do so.

220Turbo injectors are more of a worry than the cams IMO anyway.
 
Kent Cams quoted me £125 for a custom ground Crossflow cam, but getting that price was like trying to milk blood out of a stone. They really are difficult to deal with. My guess is double that for the Zetec cams as there's two of them :D
 
Hi,

We have been playing with the cam timings and to be honest it seems best left at the stock setting. We have access to a RR (occasionally) so will see if some tweaks can be made.

I think the engine is at a point now where it just needs to be turned up all the way (21 - 22psi on this turbo) and mapped on the RR.

Oh and don't worry about the 220 injectors, we have AFR and EGT gauges to monitor it so it will be clear when they are over worked. Might need some uprated cossie injectors but they are not as accurate as low flow rates. :(

Not really got a power figure we are aiming for but I suspect about 300 would be reliable as long as we can keep det. at bay and keep the egt's down. More than enough in an Escort RST!

Will let you know how it goes...
 
Pants said:
Hi,


Oh and don't worry about the 220 injectors, we have AFR and EGT gauges to monitor it so it will be clear when they are over worked. Might need some uprated cossie injectors but they are not as accurate as low flow rates. :(
Click to expand...

220 injectors are maxxed out at about 285-290 hp, and when I say maxed out I mean 100% duty. (380cc)

Seimens 660cc injectors are a direct replacement for the 220 ones, and are what I have ready to go on mine. Cost about £200 for the set
 
You must log in or register to reply here.
Back
Top Bottom