I have just bought a Tiger with a suspected big end failure. Its a 1.8 Silver top engine, done about 19K.

The previous owner has recent had the head professionally ported and fitted with Piper Cams, verniers and uprated springs etc.

If I fit a 2.0 bottom end, - can I re-use the entire uprated 1.8 head for a nice high comp engine??
Or do I need to use the 2.0 head as well.


'IF' I can use a bottom end only do I have have to a silver top engine, or can I use a lower mileage black top engine??

i belive the cylinder heads are basically the same for the 1.8 and 2 litre and will fit, The differences were the cams, inlet, maf, ecu on the different power 1.8's.

This should work, from reading the Turbosport website, it'll give you a Comp ratio of around 10.9-1

ATB Dan.

be careful of valves catching on the pistons. Not sure if there would be clearance for them.

Combustion chambers are a different shape between them so beware of the pistons hitting the head and the wrong flame path for combustion.

Here are some pics of the difference between the two. As you can see the combustion chambers is smaller on the 1.8. The valves are very close to the combustion chamber walls.

It looks like the heads has some steel inserts around the combustion chamber(I'm not sure of this). The 2.0 has lager bore so the steel insert would not be in contact with the head gasket and a possible head gasket failure as a result.
Rescued attachment Picture 020_20.jpg

pic2
Rescued attachment Picture 021_18.jpg

pic3
Rescued attachment Picture 022_20.jpg

PIC4
Rescued attachment Picture 023_18.jpg

Thanks Guys,

I guess Ill give it a go and see how it runs on the rolling road.

Luckily I have webers and not Injection, so it should be possible to make the adjustments.

The pics were good too Micael