aan engine. more revs??

[nicksonmsport]

Engine is already built. It was built by previous owner. I intend to strip it ans install rods and arp fixings then bolt I back together. Items have already been balanced. Just wondering if it were worth upgrading the valve train to allow the engine to rev higher, but tbh if 7500rpm and 500bhp are perfectly achievable without the extra costs involved in top end mods etc, then I will just stick with it as it stands.

[Quattronaut]

I thought you wanted to build up the engine new?

When you already wanted to do that, it´s not that big thing I guess. Rods, pistons, crank can be lightened when they´re out. So the only thing is change the head to mechanical valvetrain. If you build it up complete, it´s no big deal buying solid lifters instead of hydros, and headwork is headwork.

The usable powerband for cars under 500-550hp is not really increased IMHO by giving more revs. Usable powerband is in most times around 3500 rpm difference between "kick" and "choke", and those turbos which are for good 500hp kick in between 3700 and 4200 rpm in a well done and good mapped motor. No sense in higher revs, when your turbo starts to choke from 7200 rpm. To really use the higher revs, you need a bigger turbo, that for example boosts at 4500, and then you got peak power at 7500 or still bit later. But that is far more than 500 hp, there we´re spaking about 600hp+.

Lehmann, Hohenester and others say, that 540hp is the limit of a 20vt with hydros.

[nicksonmsport]

I agree I would prefer not to spend another 5k plus for an extra 500 or 1000 revs. Was just getting an idea if it was worthwhile if it meant a wider power band.

Engine needs rods installed anyway so wanted to plan engine build before it came apart. Will be doing head studs and rod bolts etc.

[Error404]

Personally I wouldn't go above 7500 on the stock oil pump.
High revs are not really what these engines are about IMHO.

[caterpillar]

use dry sump = more hp (ca 15%) and you are shure the oilfilm will not fail... if so, you need a bicykle, limp mode home

[nicksonmsport]

Cheers. Does oil pump start to cavitate at higher rpm then? Warranting need for dry sump?

[Rusty]

Head £1500+ Cat Cams + adjustable gears, £1000+, engine £5000+, dry sump £2500+... ish.

Schtick, DBillas, Cat Cams, Dahlback & various Swedish mentalists for cams.

[nicksonmsport]

What sort of costs involved in that lot? And what cams do people use?

Any dry sump kits off the shelf? If so cost?

Cheers

[Rusty]

Valve springs, retainers, tappets to solid lifters, cams and flow work up top. Usual lighten, balance & even dry sump down below.

[nicksonmsport]

Im told std aan engine will do 7500 rpm. What is required to up the revs safely so I can make use of large turbo to best effect.

Many thanks
nick