Penguinracer

Cheb - your experience is most enlightening.

The Westwood liners - I take it that they're flanged/top-hat?

Baz at Hartech referred me to Crewe Engines who apparently do Alusil honing/etching on Mercedes engines.

I was interested to know how Alusil compared to Iron & Nikasil for hardness, durability, ring wear & seating.

Like you - I'm trying to build a tough durable motor which I can push without fear of failure.

It seems the Wossners are working well with the L1485s?

Tim

Cheburator

The Westood liners are flanged.

In terms of durability - alusil can easily last the lifetime of the engine. The Master Techinician at Porsche Zentrum Koln had a 1986 928 S2 5-spd with 700,000 odd kilometres on the clock. Apparently it had new rings and bearings at 400,000km and that was it.

However, if you are going to push big boost/bhp through the engine, the nicasil/iron is the one to go for....

Alex

blade7

Augment ?

Penguinracer

Alex, thanks for the context - your experience is invaluable.

Duncan Andrew at Westwood cylinders has very helpful & responsive.

Crewe Engines confirmed that they do Alusil honing - but I'm looking to push my little 2.5 litre as far as I can reliably do so - whatever bhp that turns out to be.

What's your motor like at start-up - not too noisy? Is your oil consumption looking ok so far?

I'd be keen to incorporate a deck plate - but I don't know who would be a good shop to approach for this.
Tim

blade7

I found a place nr Northampton that seems to know what they are doing when fitting iron dry liners in Porsche blocks. Knight Engine Services run by a guy called Dave Knight, he was interested and helpful when I rang him.

333pg333

Some years back we went through 5 motors down here between two of us. We were using the MID Darton wet sleeve system and JE pistons. Each motor failed due to the pistons nipping up in the bore. Each time we would set the clearances wider and wider. Initially, after a lot of hair pulling and research we decided that it was due to the JE's and ductile iron sleeves having very different expansion rates. We found out that there are two basic alloys used in pistons as well. One being more likely to expand more than the other. Having said that, I am also quite sure that the machinists we used back then were quite possibly responsible as they didn't employ the correct method to install the sleeves. One of many nightmares since 2006.

Personally if you have a decent block with good cylinders and are building a road or even club car, then go with stock Alusil and use the Wossners with the coatings. This combo has been proven to work on a few motors out there in 944 land.

Penguinracer

While there are a few shops here that can rebore, hone & etch Alusil - have there been problems running the Wossners in Alusil bores given that neither Mahle nor Wossner use the original ferrous coating?

I thought I'd read that there had been problems with coated Wossners in alusil - but whether that was due to the honing etching being done incorrectly or issues with the coating I can't recall.

Will an alusil bore be okay for a 400 rwhp 2.5 litre running 23 psi & being used for prolonged periods at Spa or the 'Ring on trackdays?

I'm still confused?

thingo

What fuel are you using? Running 23psi on the track with an 8valve is asking a lot.

Voith

Both Wossner and Mahle new coatings work in alusil as intended. Some say it is not as good and long lasting as original ferrostan but long lasting in this case means ~300k+ miles, I don't think track driven 400rwhp 2.5 will ever see that kind of mileage.

Penguinracer

I suppose I'm less concerned about getting to 300k miles than being able to drive to the continent at high-speed, lap the great tracks hard & then drive home again without any fear that my motor might lunch itself!

Fuel - realistically - the best pump fuel (98-99 RON) perhaps supplemented with a little race fuel if detonation/knock becomes an issue.

At ocassional summer use purely for this purpose - it will take me many years to put any real miles on the car.

I really only have time for the odd long-weekend of motorway-blasting to the great tracks, lapping & then getting back for work.

Will Alusil be reliable under these conditions?
Tim

333pg333

I'd agree with Rod's assessment. 23psi on pump for prolonged periods of boost on tracks that you've mentioned might be inviting head gasket issues at the very least. With that 'program' in mind I would definitely opt for the Cometic style multi layered metal gasket that will at least 'reseal' enough for you to turn the boost down and get home. That's a looooong tow home otherwise.

blade7

I think I'd be knocking the boost back to 16- 18lbs in far away places.

Penguinracer

I've contacted Laystall Engineering (Wolverhampton) who produce cylinder liners in Cromard steel, cast iron, ductile iron, coated aluminium alloy and forged aluminium alloy with all sorts of coatings from Microchannelled Hard Chrome, to Ceramic, Siliconised Carbide Impregnation, Nickel Ceramic & Nickel.

I'm interested in the possibility of reboring & the direct application of a Nickel Ceramic coating directly onto the liners bores.

Otherwise a high strength forged aluminium alloy liner with a Nickel Ceramic coating may be an alternative to an Alusil hone/etch.

Tim

blade7

When I contacted Laystall they didn't have anything suitable and asked for a sketch, I didn't fancy taking responsibility for the design so offered to take my block to them. Don't think I've heard back from them since.

Penguinracer

Laystall came back with two options:
(i) Ductile liner with their Laycarb - Sliconised Carbide impregnation process;

(ii) Aluminium Alloy Liner (High-strength forged aluminium) with a Nickel Ceramic coating.

I've also contacted Poeton in Gloucester who coat cylinder bores with their own variant of Nickel Ceramic (Apticote Ceramic 2000) - which they obviopusly claim is better than conventional Nickel Ceramic coatings.

They can apply directly to the bore (negating the need for a liner) - which is a plus, as Baz at Hartech confirmed that an unlined block (with the appropriate bore finish) will be stronger than a lined one.
Tim