Most valvers using over 8k are using forged pistons. The std crank is fine for 8k but over 9k, a steel crank is advised.
What about rods? I assume this motor is full built but what about std bottom end. Also what is the limit for hydro? I've heard it is 7.5k rpm but noticed that some of you guys are going past that point. Is there any more potencial if bigger valves were fitted mr hillclimber?
I wouldn't go past 7.8K on std rods personally, which is also supposed to be the limit on hydro lifters. Although I know a few 1.8T owners who have gone to 8.5K on hydro lifters. So you takes y'choice.
I have a standard ABF and my rev limit is set at 7800rpm, as RobT has already said. On my old 1.9l engine I would take it up to 8000rpm with hydro lifters. In reality power is peaking at 7200rpm with my ABF so it is not often that I go over this threshold. Only to hold a gear to save a change etc. Lovely work Mr H it is always pleasing to see a high power valver and it is also nice to see some thought behind the achievements.
Badger Bill takes his motor to 8.5K on hydros and says he thinks that its ok so long as you are using a very high quality race/ester-based oil. Personally I think its a bit high but he has got away with it so far. However...being a turbo it uses much milder cams than on a breathed-on valver. Probably it depends on the cam you are using - hydros will only stand quite mild valve accelerations whereas with solids you can have a lot more acceleration and get the valve open sooner. You can get quite long duration hydro cams, but they will still have relatively mild ramp angles. Rule of thumb...stick to 7.8K on hydros and stock rods - as has been said, that should be enough anyhow unless you have a high spec engine.
There's a deep carbon backplate Rob which the filter clips into...you know the twist clip type...like ITG & in this case Pipercross. It "just" pushes a little when the bonnet is shut.
Thanks... It is. Big valves will give more potential for sure, we'll be looking at that on another project very soon. As Rob said, you can run long-ish duration with soft valve acceleration on hydraulics. The best solution by far is solid lifters...I've found and seen with other hydro lifters dont like regular abuse from fairly lumpy cams in the long term. These cams arnt that radical, tho much more radical than was in there...even tho there is only 7 degrees more inlet duration and 4 degrees more exhaust. Not big lifters either...0.440... so there is more to come from more cam & a big valve version.
Wow! What a result! Only just got back from holiday to read this. I had seen some info on another post too. Good work Jason as always. How much change would one need for such an engine? Ball park figure will do although I can guess it isn't pocket money... Gurds
Cheers smudge. Yr new airbox looks nice.. I have heard of the std 159mm rods taking a fair pasting! Another engine builder who's done a couple of them in the past has seen 10k+ on the telltale in the ecu from customers over-reving on the downchange without the rods breaking!...the big ends do stretch a bit at that point!...but they dont break. Tony b has been using just over 8k on std 159mm rods for a couple of years now. The thing is, you can have a decent engine with a couple hundred hp and it'll make for more than enough enjoyment for track day use. If anyone wants to go much over that for competition use then any engine should have as many best bits as budget will allow.
Cheers Gurds...good holiday?! I could'nt obviously say what this one was, plus it had some bits already that were re used, but, we can have a chat...
Yup excellent trip thanks. Was staying at Sherwood forest with my wife and daughter just to find the Robin hood festival was on too! Of course, I can appreciate that. I'll give you a call one day, lol. Gurds
Damn! Although the mrs would probably have killed and buried me in the woods for even mentioning cars while on holiday lol. Although I'll take a rain check on that cuppa. Gurds
Of course, if the car 'developed a fault' then you might have to visit a friendly local garage and meet the nice man who works there. Just pop a plug lead off in the morning
