My spec is as follows:

1600 cvh bottom end 0.5 over bore
std compresion (mahle pistons)
stg 2 head
285t2 cam
GRS intercooler
stg3 turbo
stainless
k+n

i have completely rebuilt the engine over the winter, it has been run in properly using cheapish oil, i am now running it on mobil 1 15/50 and it has covered 3k with no leeks, knocks or bangs.
My local rolling road guy said it is one of the strongest 1600 engines he has ever set up showing well over 200 bhp, i said of course it is, i built it
But to get to the point of this post, when i rev the car past 5 thou it is loosing power allmost as tho there is a soft limiter before the harsh one at 6 thou. only started recently.
Gonna reset my plug gaps to .7mm see if this does anything for me.
I have tried turning boost right down to see if it is a boost related prob but still there, i have also tried my vernier in about 6000000000 different positions but did not have any affect.
Wonder if my dump valve is leaking under pressure? its a new venturi.

any body had a similer prob?

Cheers, Pete.

 

could be a dodgy cam mate...mine was doing this a while ago but was between 3-4k...engine would run like it was on the soft limiter...only way to rev past it was to get into a lower gear and floor it...with a few people in and my install...nething in 4th or 5th past that rev was non existant...unless i had a downhill run lol

have you also checked the timing with a proper timing gun? try setting it to +12degrees with vacuum off and take it for a drive and see how it runs

bassboy

 

I've had this problem before with my mates just after it got set up. It would be fine up too about 5500rpm then it lost power (like a misfire). I found that it was the valve springs. We fitted a set of brand new ford valve springs and it was mint after that. Hope that helps.

 

i have heard about cams wearing prematuraly, something i have to consider.
as for my timing, it has been set at 14 degrees by my rolling road guy.
i will try it at 12 and see how it performs.

cheers,pete.

 

i would like to back to original valve springs as the piper springs are softer due to less material.
But what about the springs becoming coil bound, that is what it says on the warning. what sort of cam was your mate using.

cheers,pete.

 

Could be valve float, those so called uprated springs are worse than the standard ones!

I used to use a kent cam with kent springs, engine had a real power drop between 5800 and 6200 then would pick back up again right upto 7000.

Cam could also be a prob, whip it out and have a look!

 

He's running a piper 285 T2.

When we took the old springs out they were about 2-3mm small then the fords ones. The ones he had in were supposed to be up-rated ones

 

I think that will be my next step then in the proces of elimination.
Just a little concerned about coil bound springs, but if ya mates running with standard springs then so can i

Thanks for help.

 

Problem sorted

Just tested my new puma racing double valve springs and it now revs like a chuffing ZXR

Thanks for help lads

 

was just gonna say had this problem b4 and it turned out to be my valve springs

 

So called anti coil are shite, cant even belive they sell em