Hello,

What is the max rev you would drive with on a stroked XU10j4RS engine, build like this:

98mm custom steel crank
87mm piston
High comp.
Jenvey trottlebodies
4-2-1 manifold

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/Henrik C

wherever it makes peak bhp cams will have a big bearing on where it makes the power as well as its basic geometry.

that is an epic crank, custom steel?

Tbh if you want an engine with dimensions similar to that I would use an EW12, they are 86x96 as standard! might give you some idea of how they'll behave, the EW12 on its standard inlet+exhaust makes 160 BHP @ 5500, and 160 lbft at 3800 IIRC, not sure of the curves but given the rpm and CC they are likely to be quite broad.

EW is bit lighter and stiffer bottom end than the XU


9k is way too much for a pug hydraulic tappet for repeated use.

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need a part number? get on here - http://public.servicebox.peugeot.com

Bring on the Trumpets.

Currently my engine contains a crank from the EW12!
And the top got valves from the same engine (can't find the messurures from the valves!)

________________________________________

/Henrik C

As I said, I will base my posts only on my experience, not rumours from other people.

What experience do you have that forms the basis of your comment?

I have run some high-revving engines with hydraulic lifters, I know of a race car running 9,500 RPM on hydraulics, reliably. Remember, cam speed is half crank speed, so cam speed is 4,750 RPM.

People just assume that they can't do it, without actually testing anything.

Look at my old engine for example - that has been revved to 8,500 with the best part of 2 BAR of boost pushing the valves open - and there is still no valve float or hydraulic lifter pump-up. This is due to the low mass / intertia of the valve train components, and the fact these engines have extremely good double valve sprin gs as standard.

It's really frustrating - years ago people were trying to tell me the cast crankshaft is only good for 300 BHP, the exhuast manifold is restrictive, blah blah blah.

For the last few years i've been building 450-500 BHP engines, which are high revving, use the standard cast crankshaft, hydraulic cam followers, and standard exhaust manifold.

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Contact Details:

rich@lynxpowerengineering.co.uk
07732 822546

What changes need to build mechanical valve lifters? Any pics how the proces is...

________________________________________

/Henrik C

This company http://www.a-e.dk/ sells custom steel crank in sizes:
98mm
100mm
102mm

________________________________________

/Henrik C

What about the normal standard crank, lightended flywheel and pully, 86.5 pistons, standard head, standard size saanz rods, arp bolts ?

You think 8.5k would be safe ? or should i push it to 9k with my turbo setup?

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Dimma + Gt35 turbo =
Solid rear beam mounts £130
07889376885
Dan

Maybe he's sweet talking you coz he fancies you? Just saying!






or is it big bad BOB????

What point is Erving the sh1t out of the engine if peak power on the cam is say 8k ?

Or is that only for n/a ?

My old engine had a limit set to 8.2k as peak power was around that ? Any more was just wasting revs ?

So in that context, what has Rich done with long stroke N-a engines??

I was passing direct info from an engine builder, not "rumours".

next we'll be hearing how Rich was right and Sodemo was wrong all along, they didn't need to put steel cranks in all those maxi and WRC engines, nor did they have to stick very long very expensive manifolds on them or solid tappets to get to 9k.

after all standard stuff will do the job just fine?

he's starting to sound like that B11BOB fella

________________________________________

need a part number? get on here - http://public.servicebox.peugeot.com

Bring on the Trumpets.

Maxi engine revved to 11k

Welshy longmans knew exactly what they were doing

The main reasons for using a solid instead of hydraulic lifter are:

1 - High rev reliability. At high engine speeds hydraulic lifters interfere with valve operation and account for the sudden and dramatic drop in power build up at a little over 6000 rpm. Look at any power graph for a CVH and see how strongly the curve climbs before drop-off occurs, then imagine projecting the power line at the same rate of climb for another 1000 rpm! A thousand extra revs may not sound like a lot, but even with a fairly standard road car the extra power generated can be quite significant.

2 - Positive Valve Opening. Even at lower revs a hydraulically operated valve suffers  from a “soft and soggy” opening operation. By replacing this with a positive mechanical lift, a more precise motion is achieved. This leads to a faster change in manifold vacuum, greater gas speed and ……...more power!

3 - Predictable Operation. Hydraulic lifters are subjected to large and frequent variations in oil pressure and temperature. Solid lifters are a known quantity that simplify valve operation and remove such variables.

4 - Weight and friction reduction. A solid lifter is 10% lighter than it's hydraulic counterpart, and given the overall weight of CVH valve train, this is an important bonus. Any loss of weight in this area will help with engine efficiency and life expectancy. Also, a hydraulic lifter exerts a constant pressure to the total circumference of each lobe base circle resulting in a certain amount of drag. A solid lifter does not contact the camshaft base circle, so internal friction is reduced.

Enough said now shut up and feck off