HI GUYS , running into problems after fitting my 44 idf update kit and 1.4 rockers "k8"....my springs had plenty to coil bind but i did not check retainer to valve guide clearence.....they are stive timms heads that are advertised to ber safe up to.530'lift...since then i changed springs.....but ages ago....

under load around 5500rpm it seems to be missing or maybe running out of fuel?? i did not drive through this to see what happened.... i dindnt realy hear any pooping or farting...just seemed to be chocking......im racing on sunday and need to quickly rectify this.....


CHEERS............

i think the valves are floating AGAIN..... changed jets araound but still seems to be doing it at around 5500rpm.....

Did you re-jet with the update kit?
They use a larger venturi(?), which needs jetting re evaluated on a dyno.
You should be able to get it close on the road though.

dangerous, i put in the jets supplied with the kit, which was 190 airs and 165 mains... then i tried 155 mains..felt good but still hit a wall at 5500rpm....then i went and put 180 airs in...engine felt great all the way till 5500rpm...then it did the same.....it feels like it justs runs out of puff big time,hesitant etc,with a bit of a pop out the exaust.......

i have only today to rectify this, so im stressing a lil......

thanks..

I ran one of those update kits for a while, and you definitely need to rejet... you can't just go with the jets they give you in the kit.

From memory I ended up 1 size larger on idles, 2 sizes larger on mains and one size smaller on air jets. All based on what the engine was happy with before, NOT what the kit had.

Don't suppose you have an AF meter or logger, or know someone who does ???

Oh, IMHO a mix of 155main and 180 airs sounds odd.... try 160 or 165 main with the 180 air.

That'd give you more fuel in top end without affecting mid range too much, cos altho it's larger main the smaller air makes it come-on later.

sides, ill put the 165 or 160's in with the 180 airs and see how it goes...i do have some 170 airs as well..

im aliminating valve float or retainer to guide clearence because when i checked piston to valve clearence "dial gauge on retainer then adjusted valves a extra 90 thou then turned the engine over by hand slowly" i would of noticed bottoming out if that was the case... thanks, ill get back to u in 2 hours.......

Whats your timing set at for max advance...........sounds like it maybe over advanced.

Also what fuel pump and reg are you using ?

I fitted the update kit to my car about 3 months ago, and although the supplied jets weren't ideal it still pulled well past 7500 revs with no probs

craigy, reg,timing etc all good.......

heres what ive tried: oh, and i put 2mm needle & seat in....

mains: airs:
165 190 =poop....5000rpm up
155 190=poop.....5000rpm up
155 180= engine felt good up till 5500rpm ...
165 180= lil bit better....
165 175= could pull to 6000 then hesitated till 7..exaust popped a bit.....
165 170= same as above...
now ill put my old vent and jets back in...and if the probs solved in know i have jetting issues with the update kit.....

i just went for a run with my old vents and jets and it ran like shit.....spatt and hesitated at 5000 and less.....the only thing different now is the new needle and seat..2mm insteat of the 1.75mm....??????

im putting the old 1.75mm in and having a drive......

Ahh... needle and seat potentially changes the fuel level in the float bowl a fair bit, which has an impact on jetting big time...

well?

well after changing back to my old 1.75 needle n seats, readjusting floats etc....im saying im having valve float issues AGAIN.......

so i have packed up the tools & the car is back under the cover......and i will be getting a credit for the next event....which is great as it wasn't cheap.....

so what springs to try next....these are bugpack 4046's.......didnt last long.......does anyone know what ct is using with his k8 &1.4's......

cheers guys for the help,muchly appreciated....

what kind of leads and dizzy are u running ?

cb magnaspark and bosch 8mm ...u thinking dizzy meltdown...

maybe the leads

yeah could be...but to late now....race is off...ill check leads when i get back from vw nats....

Don't procrastinate on it dude... since you ain't racing, spend today sorting out for sure what's going on.

I know its frustrating as all hell to be playing mechanic when you should be playing driver, but definitely don't want to be in same mad rush the day before the next event. Been there, done that, pretty sure there was a T shirt.



I'm thinkin it's not valve float... after all, if it was why would jetting changes make any difference at all ???

sides, im flying over east to sea the family and come down to the vw nats tonight, so no time to play with it today.....when i get back ill borrow my mates leads "same dizzy" and go from there.....i just dont see how it would be the leads...cause everything was fine before i fitted 1.4 rockers ......

anyways, would you take me for a spin in your bug while im over,just a blat up and down the street outside wakefield....i have not been in a 1916cc putting out your HP only a stroker....

cheers...

Did you change the pushrod length when you fitted the 1.4 ratio rockers?

the geometry was all good with the shim removed from under the rocker block when i used the 1.25's.....

anyone with a clue.....

Who's version of the K8 cam do you have? Apparently some have harmonic issues which will kill valve springs rather quickly.

gracey, yeah i have heard dave saying this.......but i only just fit the 1.4's....and its a engle.......and the springs are only newish....

How long were your current springs in the motor?

Just sitting there installed in your motor will cause a spring or springs to fatigue due to the valve being held open by the rocker and consequently the spring is compressed for extended periods of time.

Maybe you could try these: http://www.cbperformance.com/catalog.asp?ProductID=1586 

the engine sat for maybe 2 months but the rockers off for a month of that.... the springs are less then a year old with about 1000km's driving and a handful of track days.....

im not procrastinating.im on holidays...im over here for the vw nats...

Great posts guys, thanks for the discussion

well guys im back at it again and like ct i too fell like pushing it into water to see if it floats away....

anyways i didnt finish the engine dignostics off completely "instaled new springs" then had to go away for work for a month and only just got back and had a track day today at barbagallo and didnt even complete my first warm up lap....the engines doing that same hesitation loss of power thing at 5000rpm & up.....so i packed up and left but first i checked the contact points inside the dizzy cap and cleaned them to no avail....

so what now...i need make a list to start ticking off things to check.....leads,dizzy,coil ?????????my oil pressure gauge stopped working before this problem occured....??

im running the 38mm vents,55 idles,180 airs,155 mains....2mm needle and seat.....

my hairs falling out gotta go.....