Lotus Twin Cam - Capacity reduction to 1400 ccm possible? Short stroke crankshaft?

As I wrote in my last post, I have a Lotus Europa S2 which is waiting to be transformed in a track car. Originally the car is equipped with a Renault R16 TS Engine with about 1600 ccm. Class regulations require to keep at least the block of the cars original engine, or to change to any other engine the car manufacturer has ever build or used. So I'm thinking about using the Lotus Twin Cam 1600 engine instead of the Renault engine. My experience, here in Germany, is that the 1600 ccm class is "threatened with extinction". Actually in the 1400 ccm class we have more than 15 competitors in one race and just 3 competitors in the "up to 1600 ccm" class. So, my question is: Is there a possibility to reduce the capacity of the 1600 ccm Lotus twin cam to 1400 ccm? My first thought was to change the Lotus crankshaft for a short stroke crankshaft from the ford pre crossflow engine, but I realized that there are no forged competition crankshafts available which have a shorter stroke than the original 72.75mm of the Lotus crankshaft. Are there any other options?

Thank a lot in advance.

Best regards

Alex

not knowing how tight the valves are to the bore, you might be able to sleeve the block, and then get a custom made shorter stroke crank made.....

I know this isn't what you asked, but what's competition like in the 2L class?

A magazine in the UK is currently building a 1800cc? twin cam using a Fiesta Diesel crank, IIRC.

Wasn't there a 1300 cc version of the 1600cc kent (which the the lotos twin cam was based on??) that with oversized pistons might get you close??

IK Engineering would be a good place to start. BDA's have been run in smaller displacement classes for years, don't see why a Lotus Twincam would be any different. There's so many good sources for this stuff in the UK. Saw an article in Classic Ford years ago about a BDA in a Ford Fiesta hillclimb car...the BDA was 1380cc, 10K+ rpm and 186hp!

Custom cranks are possible (takes time). I know a guy who destroked a 1275CC BMC engine to 970cc for a Bonneville class. Used a crank shop in Michigan. Same shop also made a 180 degree crank for a LS engine (customer wanted his corvette to sound like a Ferrari)

Anyway, link for the destroked midget. 9k A-series screamer

Wiki says the 711 was the 1300 cc version of the crossflow and the 711M was the 1600 cc engine. Looks like they were available in at least the Mk II/III Cortina.

Thank a lot for the fast response. I followed the link, Pushrod gave me to IK Engineering. They seem to have a crankshaft with a 63 mm stroke for the Ford Crossflow. They write that the Shaft will also fit into Pre Crossflow engines, the Lotus Twin Cam and the Cosworth BDH. By now, I haven’t known that this type of crankshaft is interchangeable to so many different engines. Anyway, the 63 mm stroke and the standard pistons will result in a displacement of about 1350 ccm. That would leave enough metal to overbore the engine and fit slightly larger pistons if that would be necessary anytime. The 9,75 mm shorter stroke could be nearly compensated with 125,120 mm long con rods. These would allow me to machine the top of the cylinder block only 1,677 mm instead of 4,875 mm. Due to the smaller capacity of each single cylinder, the compression ratio will drop from 10,35:1 of the original Lotus TC engine to 8,96:1.

@BoxheadTim: Competition in the up to 2 Litre class is really hard: VW, Opel and BMW with up to 290 HP, sequential gearboxes, perfect chassis,… Not the right place for a unexperienced builder and driver like me.

"Welded stroker crank" might be an option, just done the opposite of normal, reduce stroke rather than increase it.

Moldex is the crank shop here in Detroit:

http://www.moldexcrankshaft.com/

They did the custom cranks for the T/A Challengers and AAR Cudas that were used in Trans-Am. I believe they did the cranks for the AMC Javelins as well. Really old-school place, been around forever. Probably best to call, their website isn't much to look at.

From postings I've seen, order now if you want it sometime next year.
They are not slow, just have that much of a work backlog.