Cheapest Reliable Way To 230-240Bhp Xu10J4Rs

[blandy 29]

Ah it could of been your for sale thread I saw then for your mates car on gti6oc. I'll do some more research before buying but it does seem it'll end up having to just bite the bullet and get forged pistons and rods in the first place. Was just trying to work out if the compression ratio is something that is dictated by the cams or pistons etc I.e for instance a pt82 requires a different compression ratio to pt81's etc.

 

I think ill strip down my spare engine and head and start with measuring what I have to begin with and work on from there

[petert 586]

Yes, camshaft choice and CR are related. To eliminate guess work you need to download a dynamic compression ratio calculator. It will ask you for inlet closing angle, stroke and rod length, in addition to all the other static CR variables.

[cheesegrater 43 1 Cars]

I was led to believe the THP engines weren't all that great? Something to do with cam chain/belt?

[Gman 29]

I was led to believe the THP engines weren't all that great? Something to do with cam chain/belt?

 

They can suffer from tensioner rattles which can have engine killing effects, but the cambelt on a 6 engine is hardly robust and we still all praise the engine!

[kyepan 291]

How to people work out the compression ratio needed when building a n/a engine. I'm still reading up on pretty much every thread on here and gti6oc regarding bigger n/a builds but noticed a couple had engines with 2 higher compression ratio's

don't take this the wrong way, it's not meant to sound how it does...

 

Have you built an engine before?

 

If not get a couple of books on building engines, there are many ok, and a few good ones on amazon. Once you've read these you'll have a much better idea of what you're undertaking.

Simply rebuilding a spec engine to manufacturer tolerances so it holds together is one thing, getting it to run reliably and make good power is another, it not expiring due to a small mistake after a few thousand miles is yet another..

 

Building an increased capacity, increased bore / stroke engine.. that's going to be revving it's tits off most of the time is not a trivial task... getting it to run reliably and make expected power is another, it not expiring due to a small mistake after a few thousand miles is what professional engine builders charge 10k for, and even they make mistakes.

 

Anyone can throw an engine together, only for itself to throw itself right apart again!

 

Sarty's engine irrc lasted for perhaps 6 months, and no slant on him for doing a very interesting project, he did choose a slightly suspect head gasket material, and it was never really discussed publicly what actually killed it..

 

now.. i'm not in any way trying to discourage you, if you're game, go for it, but do your homework, find your answers from good quality engineering books, not the internet. (unless it's pug specific info, in which case this place is about as good as you'll get on the net)

 

Adopt a fastidious nature and attention to detail bordering on OCD. I've built exactly one, it took me months, several trips to the engineers to get things right, it wouldn't start because of a mess up on my part being too fastidious.. go look at my thread. It now runs, makes good power, and hasn't died (yet) and is a great thing to do. Highly recommend it as a personal project, just try not to bite off more than you can chew!

 

Here's a question, who owns the engine on here that's been rebuilt to higher spec and done the most miles?

Edited September 2, 2014 by kyepan

[blandy 29]

Yes in a way.

 

I'm a technician by trade so have worked on plenty of all aspects of plant and agricultural machinery and rebuilt a good few engines but all of it diesel and repaired to a manufactures standard.

 

So for me the basics of the actual build is fine Allthough I have never built a overhead cam engine and never to this kinda spec which is the bit I was hoping to get from this thread as if I can get the parts I can build it but its the deciding on the correct parts that is the difficult bit.

 

I must admit though the supercharger option is a hard one to steer away from

[kyepan 291]

it is bolt on, and reasonably simple, linear power delivery... but i still completely identify with a rorty normally aspirated engine screaming it's tits off as opposed to super charger whine...Tom's (Cheesegrater on here) car is mental quick, i won't say how quick because it would steal his thunder, but it makes my 200ish hp Mi look slow.

 

For a high spec xu10j4rs

 

You'd be looking at a diesel crank, ask Sandy what make pistons and rods he recommends, go with them.

You'd also need to have a good idea of what piston bore clearances to run / type of rings.

Depending on how hard you want to rev it, you may be looking at double valve springs and some 270-80 ish duration cams - possibly solid lifters for a fast opening solid

with enough compression you may get there on standard revs, 6 engines have a habit of dropping valves if you rev them too hard.

I'm not completely up on the piston to valve clearances on the 6 engines but understand they are very tight, decent cutouts are a must

I'm also not sure if you can deck the block to reduce the squish height and get some free compression.

Dry sumping would be very sensible to reduce windage and crank case pressure again free horsepower

A decent long primary exhaust manifold will keep the power tractable

and a dual bank phased 8 injector setup is worth 7-8 ftlbs across the rev range

colin satchell makes manifolds from standard xu10j4rs ones to fit the dual TH, this will give you both decent inlet tract length, tractable power through the rev range and lots of torque.

 

that's my ten cents.

 

The critical points would be, lots of compression, enough valve clearance, not too much cam, not too many revs to need all the expensive valve train addtions.

IIRC sarty ran standard revs to get his 240bhp.

[unariciflocos 49 1 Cars]

What kyepan said about engine building, everything needs to be measured 10 times and everything needs to be perfect.

Just go with a compressor, I've heard no rational arguments against it yet and it will be cheaper and possibly more reliable.

[dcc 855]

depending on how to take the figures with Sarty's engine, it wasn't just 240bhp - but it was 196 ftlb ish... something which is not easy to achieve. iirc, his engine was very much similar to the v6 when we were side by side down the french motorway, the v6 maybe having a slight advantage (we're talking like 1 car length over a mile or so).

[Roon 29 1 Cars]

I personally don't think you need bags of power for a track car. I had probably 185-190 at a push around the ring and I was passing all sorts and putting in solid 8.45-8.58's all this with road tyres no cage a passenger and my first track time in the car after a rebuild.

 

Just get a well sorted chassis right amount of usable reliable power and decent box set up and your away and laughing.

 

You'll get people asking you are you running 230-250 bhp and you can be smug lol.

[dcc 855]

being smug is when people ask you "Is that an Mi16 mate?" - and you can look back at them and their empty emotionless stare, knowing they'll never understand why men never have 16v's.

 

8VTID.

[kyepan 291]

being smug is when people ask you "Is that an Mi16 mate?" - and you can look back at them and their empty emotionless stare, knowing they'll never understand why men never have 16v's.

 

8VTID.

yes yes, 8v vs 16v.. the old argument, would it upset you to know i've never owned an 8v 205...and i probably never will. *empty emotionless stare.

That argument is like saying - would you like more economy, efficiency and power... no sir i'll have a cup for warm piss and a mouldy biscuit

 

it's worth considering the weight distribution penalty for the boat anchor iron block, vs an all aluminium variant... 25kgs over the front axle.

 

1.1s handle so well for a reason!

 

The 1.8 xsi engine's rod to piston ratio, gti-6 head, bodies, cams, rev happy rocket of a motor.

Edited September 3, 2014 by kyepan

[Roon 29 1 Cars]

Haha can't say I ever noticed really turn in was porn.

[kyepan 291]

Haha can't say I ever noticed really turn in was porn.

fair enough... gonna use a wanky word now...

 

Holistic.. it's the whole package, not just the engine.. if you look at the satchel hill climb car, they've thought about everything from weight distribution to suspension geometry, even a little aero. you could do a lot of simple things that all go in the right direction, or a few that go in the wrong one.

 

TBH, i know i'll get shot down for saying this but i think 205's are a bit long in the tooth for track cars, there are plenty of 172's out there just crying out to be stripped, caged, bodied and off you go. Less rust, less problems.. and really nowt between them.

[Roon 29 1 Cars]

Haha nice word, yeah very true you want a reliable car that's for sure.

 

I've been blessed with a minter of a shell and reasonably reliable for what it's done but your always waiting for something unusual to go wrong and ruin your day evening weekend week life marriage etc lol

[welshpug 1,657]

You cant really compare ring laps, Baz has done similar times to you with a 1.6

[stu8v 68 1 Cars]

fair enough... gonna use a wanky word now...

 

Holistic.. it's the whole package, not just the engine.. if you look at the satchel hill climb car, they've thought about everything from weight distribution to suspension geometry, even a little aero. you could do a lot of simple things that all go in the right direction, or a few that go in the wrong one.

 

TBH, i know i'll get shot down for saying this but i think 205's are a bit long in the tooth for track cars, there are plenty of 172's out there just crying out to be stripped, caged, bodied and off you go. Less rust, less problems.. and really nowt between them.

Kind of agree, but they s*it gearboxes like there going out of fashion.

 

One went bang in front of me, it took the Clio's gearbox, radiator and engine block with it.......

 

Oh and dinted my bonnet!

[petert 586]

A guy I race with dropped a Magane engine & box into his Clio. It solved the gearbox issue and lots of other problems! My goodness it's fast.

[johniban 59 1 Cars]

Shame the THP engines are a lot of work to get in and arent as well regarded

 

 

Please don't even mention that rubbish on this forum!

An engine made from chocolate would be more reliable than that rubbish!!

All i can say is im glad i no longer work for a french manufacturer as i spend nearly every week messing about with them crappy horrible engines.

[welshpug 1,657]

Shame its part german then isnt it

[cheesegrater 43 1 Cars]

I was literally just talking to someone who's sister bought a brand new rcz when they came out which I believe use the THP engine. It's just had a complete new engine fitted after a mere 9k under warranty.

[johniban 59 1 Cars]

yep, we were replacing loads of engines for piston slap, knocking, under powered, flat spots, smoking ect, all under 10k miles!

they bought out a software update witch basically stopped bringing the engine light on when the engine has a fault, witch was annoying when you plug it in and find nothing in there,

 

The main problem with them was the rocker cover breather was directed staight into the inlet mani and would coat the back of the valves in soot, if you have seen how small the valves are on them engines you will realize the problem.

Stupid thing was peugeot rectified the problem by fitting blanking caps to some of their models to delete this pipe but citroen never issued it.

 

citroens idea was to supply some injection cleaner to clean out the back of the valves witch was stupid considering they are direct injection.

[johniban 59 1 Cars]

the problem with the timing is a big issue as you were to fit new chains but the fault would come back as the chains would stretch ever so slightly and bring back the fault.