Sorry guys, forgot to come back to this thread to tell you how we got on. We swapped the head for another ported/flowed head and it did the trick. There was a problem with the previous head where combustion gasses were entering the water system. The top hose was always pressurised and the cams sounded noisy. I think the second run on the rollers killed it though as we were getting a fine spray of water coming through the top of the head above cylinder 2, possibly a ruptured water jacket? Anyway, it's sorted now and it recorded a healthy 180.1 bhp with approx 150 lb/ft torque (can't remember the exact figure off the top of my head). Vince was able to map the fueling and ignition accross the rev range with the K-Star which has helped make it a very driveable car. The cams give it a slightly lumpy idle but the power band still comes in low so it's usable. We took it to Belgium for VW Mania and it was pulling like a train on those motorways. The missus is having fun with it, she's still getting used to the Quaiffe which sometimes catches her out when powering through a bend but she loves it. This was actually going to be the engine for my car before I decided on the 20vT so the idea and the bits (which she's luckily inherited) have been there for quite some time. It's good to see it finally up & running. The spec is: 2.0 9a block - rebuilt, lightened & balanced Lightened KR flywheel (balanced with the crank & clutch) KR Head, ported and gasflowed Steel Headgasket Autosprint reground cams 264/265 K-Star with 5th injector Ported throttle body Ported/matched 42mm Inlet manifold Quaiffe LSD Rebuilt 16v box Sachs sporting clutch. Magnex 4 branch stainless manifold Magnex 2" stainless system I still think there's more in there, changing to a 2.5" exhaust should help a bit and possible a bit more fine tuning with the cam timing. Vince has the plots if you want them for comparisons.
Sounds a fun engine Alex, hope you guys can make it to the next 16v day we have at Stealth - Velly's on the case.
Wouldn't a 2.25" system be better for a tuned N/A engine? or would a 2.5" be perfectly fine for the spec given
Too right get rid of that magnex ,, we had one apart on saturday and i can safely say its the worst exhaust i have ever seen for flow, especially the manifold collector and the back box,,,
We'll definitely be there, a few of the cars have changed since the last one so it'll be interesting to see the new & improved results! As for the exhaust, maybe a 2.5" is a bit big, a 2.25" should be adequate. I was going to keep the 4 branch manifold though, do the Magnex manifolds flow badly then?
I've recently changed to a 2.5" Jetex system, car feels livlier in the mid range for sure. Claire had one on her mk3 16v which gave a 5bhp improvment on Stealth's rollers and filled in that mid-range torque 'dip' in the graph that 16v's always seem to have.
Cheers for the info on the exhaust. Will have a look into the Jetex, might also look at having a custom one made, a mate of mine runs TopGear in St.Albans (powerflow dealer) and they did an excellent job on my exhaust.
Mine was just under 300 delivered from http://www.motorsportworld.co.uk Who's service is ace,order on line and receive goods within 2 days. Yep, Stainless system with twin 80mm tailpipes, sounds a bit like a petrol P100 truck on low speed, high gear,wide throttle opening though Edited by: G_V_K
