Straight engine swap

[Bi22le]

Hi all,
Im looking at buying a kit car STILL! Need to save up first. Hopefully a positive answer from the replies you give. If I go for a smaller engined BEC ie ZX9 or fireblade are the engine mounts the same for the same make of engine but larger? So could I get a 954cc fireblade and upgrade later to a modern blackbird or 1000CBR. or a ZX9 upgrade to a ZX12R. or a GSXR1000 to a Busa? If only certain ones do then could someone list them. I would like to think that when I get use to the speed of a smaller engine I can just upgrade for little more cost than just the engine and ancilleries.
Thanks in advance

[singlecoil]

Don't worry too much if the mounting points are different, which I expect they would be in many of the cases you mention, as usually the whole engine is mounted on a cradle which can be detached from the chassis.

So, worst case scenario- new cradle needed, maybe £150

[Paul1972]

I think you will find the performance difference between each engine not as large as you might think. Save some money (long term) and just go straight for the engine you ultimately want if you have a choice. To be honest, engine mounts are the least of your concern when doing an engine swap. Wiring and fuel lines will be harder to sort if swapping from say a carbed engine to an injected one later. Exhaust manifolds arent cheap etc.

Future mods can then be done to the braking / suspension / wheels and tyres / general weight saving etc areas.

[Bi22le]

Ah engine cradles, thats a clever idea! Wiring is not a problem I will be able to do that. Exhaust manifolds was another concern but again I was hoping that they would be interchangable. Paul1972 it supprises me that you say there is little difference in engines. a ZX12R will have loads more grunt than a ZX9R and as torque is what bike engines lack cc would matter. Ill take it all on board though. I think the moral of this thread is: buy once and buy big!!

[Paul1972]

A ZX12R will have more torque than a ZX9R yes - but enough to justify spending maybe £2000 - £3000 on the upgrade?? Typically the Busa / ZX12R will need the oil system looking at to prevent oil surge - dry sumps, swinging pickup wet sumps etc whereas a blade / ZX9R / Yamaha R1 etc will just need a £50 baffle plate and a 250ml overfill of oil.

If you have a look at the lap times of the 750MC RGB series for similar cars in the different classes then i think you may be surprised at just how close the Fireblade cars (Class C) are to the ZX12R / Busa cars (Class A).

http://www.750mc.co.uk/images/uploaded/Lap%20Recor...

The increased torque of the bigger engines will be less dependant on being in the perfect gear all the time so fair to say more friendly for a road car, and so in the real world of the sort of driving you are likely to do - i think the bigger engine is worthwhile going for. Arguing against my own first point really but i guess my main point is if you think you are going to want the extra power then go for it straight away and use that right foot to regulate the power till you get used to it.

[Jubal]

Having done an engine swap (919 blade to 03 R1) I would thoroughly recommend selling the car and buying one with the desired engine. Or save a bit longer and buy the one you want in the first place. As well as the engine swap which will involve new bottom cradle/engine mounts being welded in, there's the manifold, clocks, wiring, fuel pump (which may involve tank mounting and hence tank mods), fuel sender (maybe), prop, prop adapter, gear change mechanism, airbox (which may involve bonnet mods), power commander, coolant system mods and those are just the bits I remember. You may want a project so apologies if that's the case but I reckon it would've been a fair bit cheaper to sell the car I had and buy the one I wanted.

As for the end result, happily it was chalk and cheese. The R1 was faster two up than the blade was with just a driver. But I estimate I went from 125bhp to 160bhp so it was quite a leap. Later engines are closer in performance.

[Bi22le]

thanks for the advice. Im thinking i will be saving harder and buying right first. I will be driving alot on the road and two up. Im liking the idea of an r1 as they are comman and fast! When im closer to buying im going to put a post up requesting rides as i have never been in a bec! Thanks again for your responses.

[Jon Ison]

Bi22le said:

thanks for the advice. When im closer to buying im going to put a post up requesting rides as i have never been in a bec!

Once you have been in a BEC you will be very close to buying one....................

[robcollingridge]

I wouldn't recommend an engine swap either. When building my Fury R1, I did a lot of things bespoke to the engine. Exahust mainfold was custome 4-2-1 and cost £400. Oil filter plates and sensors are different. The whole engine loom and ECU are integral to the car now. Even the fuel pump was tailored to the R1 engine. The cooling system uses an R1 radiator to keep it balanced (combined oil/water coolling system). Take off adaptor, propshaft and even the diff are chosen to match the engine. You could end up spending a shed load to swap the engines over.

Buy the car you want from day one! Two years in to ownership now and not dissappointed: http://www.youtube.com/watch?v=AZj8advazpk :-)

Rob

[Bi22le]

Rob just watched your vids! Looks soOoOoO much fun. Im not going to try and swap the engine now full stop. Unless I get a bargin car with a screwed engine then it would be rude not to! I am still a little surprise that the engines from the same type and manufacture of bike are that different but hey ho sh*t happens. Not too keen on spending 1K more than the cost of the engine for not much more grunt. As you lot have said, buy once and buy right! Cheers again.

[cleggyWestfield]

might be worth trying to get a busa if you are not on too tight a budget, it is probably the engine of choice being powerful and fairly sturdy

[Bi22le]

Oh I wish Cleggy! Budget depends on two things: How long I can wait before I want one and how long it takes to find one I want! Busa, Blackbird or ZX12R are my ideal engines although I would love a V-twin. I did a post last month that asked how possible a v-twin is and the answere was its not!!

[Paul1972]

Bi22le said:

I did a post last month that asked how possible a v-twin is and the answere was its not!!

I spent Thursday lunchtime at Chester DVLA with a mate of mine....... registering his Aries Locost with an Aprilia RSV V-twin engine!!!