Bigger bore kit. Are these worth it?

[Asw]

Hi,
Has anyone fitted these?
https://www.coolairvw.co.uk/product/029198075b/" onclick="window.open(this.href);return false;
Are they worth it?

Do they give noticeably more power? It looks like they have flatter Pistols, do they give higher compression?

The lack of summer holidays means we have a little extra money for the van......

[sarran1955]

Hello,

Oooh, a big bore kit.....

Though perhaps not ideal for you, for the following reasons:

These cylinders achieve the larger diameter without case or head machining...by being very thin.
So if there was an overheating incident, then at least 1 cylinder can warp.

The standard spacer rings in the head will not be a very good fit, and risking blowby.

The pistons provided are slipper pistons, great for high revving engines, where the inertial mass reduction is important.

I would suggest go for standard dished pistons

AA performance, suppliers to Coolair...

Part#: VW9300T4

https://aapistons.com/collections/pisto ... orsche-914" onclick="window.open(this.href);return false;

At about £ 250,

Then you can set up for 95 ron petrol.

Spend the money saved on a decent dizzy, a full head and valves overhaul, new pushrod tubes....

and a Victor Reinz gasket set...

In case you havn't seen this video....

https://www.youtube.com/watch?v=uRXNqBHH-LE" onclick="window.open(this.href);return false;

Cordialement,

[Asw]

Thank you..
as usual wonderful advice and guidance for us enthusiastic amateurs!!!!

[ajsimmo]

Personally I like the high compression pistons, but I'd stick with the standard bore on an air-cooled. I built one with the AAPerformance Porsche style flat top pistons and it went very nicely. Best to run it on 98RON to avoid pinking, and to make the most of a little more spark advance. Set up this way has at least 10% more power than stock, with the same displacement.

Sent from my ONEPLUS A3003 using Tapatalk

[Asw]

It was the higher compression that I was thinking about when I came across these. 2mm on the bore Sounds so little on a big engine. In my innocent world I assumed they kept the cylinder wall the same and just made them bigger. Not just bore out Standard ones.