Need some help. Been away for the last few weeks and have been deciding in what to do with my VVC k series with the DVA K06A kit on. Currently it made 175bhp and 190Nm a couple of months back down at Emerald. A Cadwell Park outing saw the coolant system get pressurised so it means me taking the head off to see the damage. Anyhow, wanting more power I have emailed Dave Andrews and he has given me some options. However, I’m really tempted with the 1.9 k conversion at the moment and have spoken to Scholar…not a bad price TBH for block work and pistons. However, would retaining the VVC mechs prove a complete waste of time in trying to crack the 200bhp mark? I mean, with a balanced bottom end, decent conrods and light pitons would this prove a better route than just junking the VVC mechs and spending more money on head work for stiffer springs and to make room for the cam lobes?
As I undersatnd it the VVC mechanisim is a limiting factor for revs and if you want that kind of BHP then you need to junk it as you needs revs to get there.
That could be complete bollocks of course so people who really know will be along to put me right …
There are physical limitations on the VVC mechs as mentioned, the lift and valve acceleration of the VVC cams are also limited. The exhaust cam is also constrained to 10mm lift and 264 degrees duration due to the lobe size and non availability of blanks. Add these factors together and this will seriously limit top end power. Solid cams have no such limitations. Ideally the inlet and exhaust cam should have around 278 degrees and 11.5mm lift and a much more rapid valve acceleration giving a larger area under the lift curve.
I have spoken to Piper today to find out more about the 1227 and the 1444 grinds. Although the power outputs are very impressive with these cams it worries me that the car is very flat before 3500rpm even with a decent map and DTH bodies (according to Gary at Piper) Wanting to use the car around town and out on the road I would like something as flexable as the VVC unit. Now im wondering the following and please correct me if im talking crap (i usually do!)
Retain the vvc head
1.9 K block
Forged rods
pistons(supplied by scholar)
balanced standard crank
DTH throttle bodies
Now, if i remember correctly Dave, an email you sent me some time ago, you mentioned that if the internals were uprated then the absoloute maximum the VVC mechs should see is 8000rpm. Im guesstamating that with my spec above it should be a reliable engine? I can then perhaps go for further headwork at a later date if I change my plans for the car (wanting to get into the odd track day you see)
I appreciate the nature of the VVC unit is limited as you mentioned previously, but possibly, would this work?
I have 1227’s with a DVA ported head, and Emerald…
NOT flat at all! Nice smooth power and torque from 1500 to 6000, then a nice bump up in the power to 8000!
I can potter about town at 30 in 4th with no probs. The cams are great… I believe 1444 are even better. But the correct ign and fuelling courtesy of Emerald makes things super!
I’ve had a Scholar 1.9 with a DVA head with 1444 cams and Jenvey throttle bodies.
Like Pete mentioned in his post it had no dead spots and the torque curve was excellent. At low revs it was extremely tractable and easy to drive but on a wide open throttle it was pretty much a straight line from 2500rpm to around 6000rpm where it peaked at 170lbft before eventually redlining around 8250rpm.
Fair enough I had it in my racer at the time but I came from using Piper BP320 cams which made a real bucking bronco of the engine -it was either full on or full off! the 1444s transformed it into one of the most user friendly k series I’ve ever driven regardless of whether it was on a road or track.
Hi Steven, what spec you running at mo in your race car. I intend to fit my K out of TF cup car into my exige build rady for next year. Current spec is good, Janspeed built all steel bottom end, dry sump etc. Intend fitting new piper cams with Emerald and new TB’s, currently running old rover items. The only area I am struggling with is whether to upgrade to Scholar 1.9 or leave as is as 1.8 Does the conversion give meaningful increase in torque / bhp? Cheers Tony
Tony,
A standard 1.8 VHPD is about 130lbft and the tuned versions can get around 140-150lbft so the 1.9s are worth it for the extra torque which subsequently doesn’t harm the power curve either…
Not really, without knowing what the best result I can achieve from 1.8 I can’t compare against 1.9 i.e. is it worth upgrading or am I better spending money on other areas of engine / car.
Thanks so much for your replies, the solid cam conversion is now starting to make sense with the 1444 cams.
As stated previously, the engine needs to be revved to reach peak power and I have been looking for conrods today and have come across THS. They claim that these rods can certainly handle BHP and they certainly look very fast(!) but has anyone got experience of this manufacturer? Anyone used such a rod?
TBH Ben the stock rods are up to the job provided you have them bushed at the small end and you use the early single tang type or remachine the bearing location slots.