Engine build... advice needed on 1900cc and strengthening!

[Craig!]

Right due to unforseen circumstances I'm now bench building an engine for my Cupra, will let everyone know what's happened fully in due time when I've got the motivation to strip it down further and see what is actually dead... but it's looking like it dropped an exhaust valve on cylinder 3 and possibly took the VF34 with it.

Any how, just got myself a spare engine, an AGU 150bhp engine out of a Golf and fortunatly for me they run a largeport head an 20mm pins as standard, so the rought plans plans are;

- One Piece Valves
- Forged Rods
- Forged Pistons
- 1900cc Conversion
- ARP Bolts
- General Rebuild
- Baffled Sump
- Oil Cooler

The question are, for a 1900cc conversion whats the best route, a eurospec crank and standard sized pistons, or a bore out using JE pistons? Which pistons do I go for 82.5mm or 83.0mm? Don't want to leave the bore wall's too thin! I know aftermarket pistons don't have any skirts on them so they'll rattle when cold but what they like when warm, and whats life span like on them?

Valves, rods and pistons... what options do I have available and at what prices? Seen quiet a lot of talk about SCAT rods and Supertech valves. Is it worthwhile fitting some titanium tapered guides?

And finally, what other bits would you replace whilst the engines in bits, it's "aparently" done 40k and the clocks with it say 40k but I'd rather not take any risks and replace anything that's viable to do. So should I replace the valve stem oil seals, all gaskets, valve guids... what about bottom end bearings and shells??

Any help is much apreciated, please feel free to post up what your running, and also let me know what you replaced whilst you had then engine in bits...!

Ta!

 

[ibizacupra]

forged pistons do have skirts on them.. who told you that? rattles are down to forged pistons generally needing more bore clearance as they expand more.

supertech valves a must have for BT build imho. installed professionally however else one WILL drop again rapidly.
scat rods best value around

Ti guides?

 

[PhilW]

What sort of power would you reccomend going to supertech valves on bill?

My engine is having, scat rods, with all new guides, seals, oil pick up, bearings, shells, gaskets, head cleaned and the bores honed to take new rings on standard pistons. I think thats about it.

 

[cupra_matt]

Bill are you refering to the valve spring seating when saying to professionally install valves?

 

[Yumann]

Most people with clamp style valve spring compressors will install the valve assembly with the head on the side hence not seating the spring properly.

I find putting the head between two tables so the head is in its natural position works best.

Proper maching shops will have a vertical valve spring compressor.

 

[ibizacupra]

What sort of power would you reccomend going to supertech valves on bill?

My engine is having, scat rods, with all new guides, seals, oil pick up, bearings, shells, gaskets, head cleaned and the bores honed to take new rings on standard pistons. I think thats about it.

If its apart, its insurance for a known weakness, exaggerated by BT performance thru 1.8T

Having suffered the same on golfy a few years back, which resulted in total loss of the engine, and a £4K+ rebuild, £375 of valves seems like an investment worth making. Thats why I went out and found some way back when, and its been adopted by ALL the engine builders since. Go figure

its your money of course

 

[ibizacupra]

Bill are you refering to the valve spring seating when saying to professionally install valves?

yep.
I certainly am.

For those who have'nt read it, please do>> http://badger-5.com/bin/5v-installation-note-supertech.pdf

 

[PhilW]

****. My engine is being put back together as i type so i guess i wont have time to order valves. I would order it but i've taken the piss a bit by the length of time they've had the car (waiting on rods etc...)

I take it its head off again to replace valves at a later date then?

 

[Mark@VAGWORX]

Craig.

I've got a brand new JE Piston set, 8:5:1 - 82mm - 20mm Pins - Ceramic Coated, and a brand new set of SCAT 20mm Rods i'm selling if you're interested.

PM me

Mark.

 

[ibizacupra]

I take it its head off again to replace valves at a later date then?

yes it is

 

[Craig!]

Hi Bill.

Presumed they'd be like forged bike pistons where the skirts are shorter and you get a slight bit or bore knock or piston slap when cold. Once warmed up the engines are still pretty quiet then?

Will be going supertech valves for sure, and when it comes to installation if theres any doubt I will have them professionally installed. I know what Bill went through with his total loss, and it's typical it happened on my last rn out before taking the car back off the road to do internals, but **** happens!

I do also remember Bill been one of the first people to start doing the valve, and every other tuner saying it wasn't needed, etc... ohh how things change a few years down the line.

So you wouldn't bother with tapered valve guides either? Also what is the standard bore size, and what CR should I be looking at acheiving for a BT engine?

 

[ibizacupra]

Ti guides? not come across these, tapered tho, only small to start with, and you will port the head also?
there is usually more cold start noise yes... consider option of rifle drilled rods also, pauter offer this $$ option. pressure fed small end lube vs splash lube on some other rods which can have some annoying small end rattle (like mine has from new) but keeps running ok.

 

[Craig!]

Sorry got disrupted when writing the first post, it was meant to be titanium retainers and tapered valve guides. Was considering having the head ported, hence the need for valve guides. Think I'll just stick to the standard head design and just fit a set of one piece valves and be done with it as costs were mounting for not too much gain, or the need for gain.

You running SCAT rod's in your engine Bill? Not bothered about noise as long as it's not actually doing any damage.

Also another one, BAM oil injectors, aren't they different to the ones in the AQX, AYP, AUG engine? Is it worth investing in some?