I'm running a 2.0 zvh engine in my rst at the moment.

As we all know zvh's don't like to revv verry well...

Wanting to raise my revvs i would like to know what's the most restricive at first and work on that..

current setup is . 2.0 zvh 8:1 cc , slightly poted/polished head with standard size valves and kent 35 cam , stage 3 t3 turbo.
Peak power at the moment is at 5550 rmp and the engine max is 5850 rmp.

What would be the best way to go?...

better inlet- exhaust manifold... workig more on the head.. bigger valves.. other cam..

Don't need the revvs to go out the roof but like 500 rpm more would be great.

Thanx

 

better inlet - Doubt it will help at all.

exhaust manifold - Also doubt it will help at all.

workig more on the head - This will help although you would need to be producing big power to benefit IMO.

bigger valves - Same as above.

other cam - Same as above.

Look at changing the turbo for something bigger. I recon that T3 will be struggling on that engine.

The other issue is the fact that the stroke is very long which won't let it rev very well.

 

[quote="DazC"]

Look at changing the turbo for something bigger. I recon that T3 will be struggling on that engine.

quote]

Don't see why the Turbo needs to be bigger..... it's a stage 3 so it's cosworth size....

As it was on the rolling road the pressure was only 10 psi ..
On the street had it at nearly 20 psi.
Both with the same max rpm so with the pressure set at 10 psi certenly it can flow enought for more rpm imo...

Thanx for the reply though.

 

put the original 1600 cvh back in

 

LOL....

that's blown away i'm afraid..

 

If you're sure the turbo is up to the job then the next issue is to look at changing the over square rod ratio due to the long stroke.

 

are you still running MFI?
you should be able to get to 6500 with this bore x stroke ratio

 

In my experiance the best mod for revs is EFI.
S.

 

Yups, stil on mfi.....

well the engine won't go any higher than 5900.... as most ZVH's struggle to go past 6000 rpm.....

Just thought the 1600 head on a 2000 block would be the cause.
Not enough air flow for the bigger block at higher revvs...

 

more revs due to efi.. please explain??

 

might be best to get it on a rolling road and have it looked at, as youre still on MFI theres a chance the system is not supplying enough fuel at higher revs.

the head is restrictive,true,but as it is on forced induction this shouldnt keep the engine from reaching 6500 at least

zetec 2L bore x stroke = 84.8 x 88
lancia delta integrale 16v = 84 x 90

 

There you have it.. it's 16v.. so much better flowing....

As for the fuel..

It was rolling roaded and the co at max rpm was 9 so there's more than enough fuel imo.....

6500 for a zvh is verry high so i've heard.....

 

integrale 8v is also 84 x 90
anyway,are you also sure the cam isnt over advanced(mixture loss) or perhaps retarded too far.
-sparkplugs set at the right gap
-ignitiontiming right

 

Well, EFI allows you to run a more sutable ignition curve for the 2.0l, this helps a lot.
Again a proper fuel map for the 2.0l helps.
You dont have to run the intake charge through and round that large flappy air flow meter.

Cam timing is also a factor, a few degrees either way can make a big difference.

Mine reved happily to 7500 in the first 4 gears at the expense of the cam which suffered oil starvation.

S.

 

Well.. it isn't on the road this winter due to a knackerd gearbox.. when that's sorted i'll have a look at it all and get it rolling roaded again as the boost is going up anyway...

When it was rolling roaded i didn't have a adjustable pulley so cam timing could be of a bit off.

When there's money, there's EFI but i'll have to cope with mfi for now...

Thanx both