I would disagree with that personally. Tell an insurance company that you have an upgraded head, manifold, cam and fitted LPG and I reckon they are a lot more likely to ask more questions than a simple engine swap. Thats from my experience anyway.
IF you 'tweek' the motor, yes....sort of; but suggestion was to simply do a propper overhaul by the book.
Most insurers IF they know what you are talking about usually accept a Turner 2 head without grumble, as a legitimate change to be able to use 'unleaded petrol'.
Electronic ignition, doesn't normally raise too many eyebrows either; its a reliability and ecconomy mod, and again, to some degree can be justified as part of 'unleaded fuel conversion'
Cam?..... well, we're not talking about building a wild sprint or rally car here... just giving a very lazy old engine design a bit more enthusiasm! I'd probably 'forget' to tell them abouit it, unless I did go down the route of fitting tube manifolds and an SU......
But then that would give me the ACR 'Power+' spec engine, and I'd just tell them that it was an ACR P+, as again, it's a pretty well known quantity.
Just the head, and possibly the ignition, most insurers would class those changes as 'upgrades' rather than modifications or conversion, and be happy to accept it as a 'standard' car.
LPG I agree with you; many insurers wont even look at you, particularly the big 'stack it high sell it cheap' names, but then they often wont accept ANY modifications, even a change of wheels, and a lot of them wont insure cars that aren't in thier database; Ie anything over about 12 years old! They have to reffer you to thier 'underwriter'!
The 'specialists' or even just the more accomodating Ins co's, though are usually quite content, as they dont deem it a 'performance inhancing modification'.
But fitting an engine with a Turbo attached, even though its an oil burner will be deemed a performance mod, and specs on TDi rate it 110bhp which is a pretty significant increase from a 2.25's miserly 70odd!
(co-incidentally; 110bhp is about what you get from an ACR P+ spec 2.25)
