115 replies to this topic

[Dave E]

Just make sure you don't use the company I did for a refurb.

[siztenboots]

markings on top of pistons 85.96-00 73/6 . Sorry but I can't get access to read whats underneath them.

[siztenboots]

Just make sure you don't use the company I did for a refurb.

who were they?

[Dave E]

AET

[siztenboots]

Was planning on this going back to Turbo Dynamics who did the K06 build on it originally. Sadly if it had been as described by the .org that sold it , the refurb would not have been necessary.

[Dave E]

I finally bought a new vxr unit from courtenay's with uprated internals and I believe the work was carried out by Turbo Dynamics. Imagine my delight as it lasted longer than 300 miles, unlike............well you get the gist.

[siztenboots]

All talk about VXR pistons really is pointless, I've tried to pick up a set, and noone is selling. We will pop these pistons out, inspect the piston material between the rings and decide from there.

[The Batman]

Why don't you buy a VXR engine? Least then you have the piston oil jets

[cnrandall]

All talk about VXR pistons really is pointless, I've tried to pick up a set, and noone is selling. We will pop these pistons out, inspect the piston material between the rings and decide from there.

The Cosworth pistons look really nice :-)

I use Turbo Dynamics, always been very impressed with them and very easy to deal with.

[siztenboots]

Why don't you buy a VXR engine?

Least then you have the piston oil jets

I've tried, asked Duncan, but was told it wasn't for sale. It then got offered on the forums a few days later and sold before I saw it. For me it would have been a fairly easy drop in install.

[The Batman]

I posted a few links in your thread

[siztenboots]

hoping I can get one from Sevenoaks, that got missed on ebay over Xmas, just engine, no turbo or gearbox, £800

[siztenboots]

nope, reply from ebay'er , sold outside of auction.

[steveboyslim]

Hmmm, it's hard to know if that is justified. Maybe.

The main reason the Z20LEH had piston jets installed was for emissions reasons (particularily at idle) apparently, not specifically for cooling at high revs.

That is not correct, they were/are installed for under piston cooling.
I would also wedge the waterway.

Steve

As I understand it the stock VXR had to run very lean (and hot) to hit emissions targets, so the under piston squirters were used to keep temps in check. I ran my car for 3 years without them with no detrimental effects although I am now using them. We have found these engines are quite knock limited so anything you can do to keep the combustions temps down is a good thing. Its one thing making the numbers on the dyno, quite another to keep hold of them when the car is heat soaked on the race track. Remember though, if you do use the oil squirters the cool the pistons you then need enough oil cooling capacity to shed that heat into the atmosphere...

Just about all engine manufactures use oil jet cooling for reliability on turbo engines, diesel or petrol.
Oil cooling does not apear to be a problem using the watercooled set up although with a thicker core water radiator with road use.
I have seen the water cooling replace with an air cooled cooler.
I have used a supplementary air cooled cooler, fitted in the supply feed to a lamova type water cooled cooler, replacing the standard water to oil cooler.

Steve

[steveboyslim]

Steve,

We are only aiming to make 330 BHP and 370 ft/lb. The question we are wondering is if the existing OEM pistons will be happy with running just 10% more power than many 'stage 4' cars are...

This is a 'budget' engine so we are not keen on splashing out on new pistons + rebore/hone if they are not requried for this 'humble' spec.

You cannot quantify everything Nev.
I would suggest, if standard bore, secondhand C20LET pistons machining the bowl to a larger size (re-machined exhaust valve cut outs if using more than fast road cams) as they use the same forging as the LEH pistons.
The standard ZLET pistons just fail without warning, with or without inspection.
I have new Omega pistons 86.5mm and 87mm.

Steve

Steve

[cnrandall]

Hmmm, it's hard to know if that is justified. Maybe.

The main reason the Z20LEH had piston jets installed was for emissions reasons (particularily at idle) apparently, not specifically for cooling at high revs.

That is not correct, they were/are installed for under piston cooling.
I would also wedge the waterway.

Steve

As I understand it the stock VXR had to run very lean (and hot) to hit emissions targets, so the under piston squirters were used to keep temps in check. I ran my car for 3 years without them with no detrimental effects although I am now using them. We have found these engines are quite knock limited so anything you can do to keep the combustions temps down is a good thing. Its one thing making the numbers on the dyno, quite another to keep hold of them when the car is heat soaked on the race track. Remember though, if you do use the oil squirters the cool the pistons you then need enough oil cooling capacity to shed that heat into the atmosphere...

Just about all engine manufactures use oil jet cooling for reliability on turbo engines, diesel or petrol.
Oil cooling does not apear to be a problem using the watercooled set up although with a thicker core water radiator with road use.
I have seen the water cooling replace with an air cooled cooler.
I have used a supplementary air cooled cooler, fitted in the supply feed to a lamova type water cooled cooler, replacing the standard water to oil cooler.

Steve

For the road the little laminova is fine... For track worth it can't even start to keep things in check on high powered cars. I tend to use the oil laminova for the gearbox and a big air/oil cooler up front although on my car there isn't the room up front so I have twin massive Setrabs at the back with a 13" high capacity puller fan which just about gets the coolers into a sensible efficiency range. Keeping things cool in high powered little plastic mid engined cars ain't easy...

[Duncan VXR]

Why don't you buy a VXR engine?

Least then you have the piston oil jets

I've tried, asked Duncan, but was told it wasn't for sale. It then got offered on the forums a few days later and sold before I saw it. For me it would have been a fairly easy drop in install.

Steve really sorry I forgot all about you wanting it when posting it for sale was a last min change of plans and brain never caught up with my actions

DG

[luke.]

Surely you can pick up a vxr engine for fairly cheap anyways. Those cars are surely crashed a fair bit. Wrote off and or broke for spares

[siztenboots]

Why don't you buy a VXR engine?

Least then you have the piston oil jets

I've tried, asked Duncan, but was told it wasn't for sale. It then got offered on the forums a few days later and sold before I saw it. For me it would have been a fairly easy drop in install.

Steve really sorry I forgot all about you wanting it when posting it for sale was a last min change of plans and brain never caught up with my actions

DG

don't worry, putting in a complete Z20LEH was a plan B lazy option , but now thinking about it probably makes the most sense. If anyone wants to split some bits off a VXR , I might buy one and sell off the turbo, clutch+fly if there is a market. There is one on ebay that I could split, if we can get it back to Bristol.

would still have to change the rods , but that would be a strong engine.

[siztenboots]

jsut seen another come on ebay overnight , its in Luton if anyone has a van?

he's being a bit keen on price , I wonder if he would take £1500 cash in person, rather than auction.

http://www.ebay.co.u...=item1c22eea36d