[Rover K-Series] Frankenstein engine

[emss]

Hello,

What about building an engine that would use :
- 11K crankshaft (63 mm stroke)
- 16k/18k engine block (EP strenghtened for example) with 82mm liners and pistons
- 18k4f head with blanking kit and adapted camshafts
The goal would be a 1330 cc that would rev to 8500 rpms in a nearly reliable manner (sounds stupidly fun to me).

I couldn't find reliable documentation related to crankshaft & block sizes so I don't even know whether a 11K crankshaft could fit in a 16k/18k block.
Should it fit, it would at least require custom pistons & conrods.

Does this just sound stupid, time consuming and expensive for a result that has no chance to run correctly or is there any hope it could run (even if requiring adapted maintenance) and outperform a 1400SS ?

Any input welcomed, thanks in advance.

Éric

[Lotobear]

the 1400ss revs to 7.5k and makes 135bhp so I can't really see the point, or the expense, of doing what you suggest even if it were possible.

ISTR that Lotus TC's have been built on a 1300 bottom end to create a screamer but that was to work with a particular racing class.

....Dave Andrews is really the man to comment on this and I think he inhabits this forum.

[Lefty]

Interesting idea.

Are you trying to stick below a 1400cc class?

[emss]

Hi,

No class regulations or anything like that.
This popped in a beer & burger friday talk with a friend, the idea of shoving a low displacement screamer based on a K-Series in the Cat seemed interesting, keeping the spirit of the 1400SS, just pushing the game further.
I'm just trying to gather information to see if this idea has any chance of success, or if it would be better not to talk mechanics after two pints

Éric

[Lefty]

Ahhh ok then.

I think a 1400 screamer sounds hilarious and awesome. Only you can judge if it’s worth the effort and/or money but I applaud you for even thinking about it. It’s a lovely engine, even in a metro or humble rover 214.

[Lotobear]

Having had a 1.4ss Caterham with the 6 speed box, to me it was the absolute sweet spot.

Dave Andrews upgraded it to 1.8 with around 155bhp and whilst he did a fantastic job and it had considerably more grunt I really missed the madness of the 1.4ss and wish I'd kept that car - quiet a rare thing now.

[DVandrews]

I have built such an engine some time ago with 1100 crank and rods and custom pistons from JE factored by Cambridge motorsport, it utilised a VVC head. Getting the compression high enough meant a raised crown piston carefully sculpted to allow decent lift at TDC for the cams. The rod angle is very low which means the engine can be revved pretty high with no serious issues. However there are no tougher bearing shells made at that journal size for the K series and this could be a problem for longevity.

The 1100 crank and rods fit as all blocks are common from 1996 onwards.

It will easily outperform a regular 1400 as it can handle much more valve area and is over square by some margin, but it wont be cheap to build.

Dave

Edited by DVandrews on Thursday 20th February 15:49

[emss]

Hi,

Lotobear said:

Having had a 1.4ss Caterham with the 6 speed box, to me it was the absolute sweet spot.

Same configuration here, SS engine, 6 speed Gearbox & LSD.
I also own an Elise S1 111S with mods similar to DVA's K06A (head porting, 270H exhaust cam, VVC retiming)
Love both of them, as the Cat is meant to be the playful toy, why not push the idea further

Éric

[emss]

Hi Dave,

DVandrews said:

I have built such an engine some time ago with 1100 crank and rods and custom pistons from JE factored by Cambridge motorsport, it utilised a VVC head. Getting the compression high enough meant a raised crown piston carefully sculpted to allow decent lift at TDC for the cams. The rod angle is very low which means the engine can be revved pretty high with no serious issues. However there are no tougher bearing shells made at that journal size for the K series and this could be a problem for longevity.

I have ongoing discussions with my friend and already accepted that there will be some maintenance burden.
I'd like to know whether this kind of setup could long 10k to 15k miles before needing partial rebuild or if I'm just dreaming.
Our only reference at the moment is his 1071 A-Series that lasts 20k miles while being hammered to 8500 rpm on a regular basis.

DVandrews said:

The 1100 crank and rods fit as all blocks are common from 1996 onwards.

Ok, so you're using standard dimensions 11K4F conrods and custom pistons to fit the engine block gasket plan and protrusion in the combustion chamber ?
My friend was wondering whether using longer conrods could help limiting the pistons size/weight.

DVandrews said:

It will easily outperform a regular 1400 as it can handle much more valve area and is over square by some margin, but it wont be cheap to build.

That's where we're coming from (beer helped), you've cleared one major hurdle stating that a 11K4 crankshaft can fit in a 16K4/18K4 block, the remaining ones are related to building and running costs.

Thanks for your help.

BR

Éric

[DVandrews]

Inherently the K series is a lot better than the ‘A’ series being 5 bearings, and componentry is light, it should do 10k without major issues.

I have 1800 and 1900 engine regularly going over 8000 for many thousands of miles without major problems and these have a relatively horrendous rod angle and much higher loadings.

A longer conrod would not work as the ring pack (which is already compact) would be too narrow and therefore the ring lands would be very fragile, you would also have the gudgeon pin bore break into the oil control ring groove which brings about further issues.

The rod angle is pretty good on the 1100 as it is comfortably oversquare.

Cambridge motorsport may still have the details of the piston…. The rest is straightforward.

Dave

[emss]

Hi Dave,

Thanks for your answers (very informative), I'll contact Cambridge Motorsport right now.
BR

Éric

[DVandrews]

emss said:

Hi Dave,

Thanks for your answers (very informative), I'll contact Cambridge Motorsport right now.
BR

Éric

As I remember I sent them a 1400 piston with raised crown to establish crown height and dimensions of intruder part of the piston and a regular Omega forged piston for position and depth of the valve pockets.

Dave

[emss]

Hi Dave,

Jon from CM wrote me the following

" We made a set of 82mm K Series pistons for another customer that were sent to Dave Andrews. This was back in 2014 and Dave Andrews designed the pistons. I believe the pistons were machined by Dave once he got them to suit the liner height. We know very little about the K series engine so we cannot say if they will be suitable for your engine.

Looking at the emails when we made the pistons, Dave was allowing for the central intruder in the centre of the piston to be machined to suit the liner height and / or to achieve the correct compression ratio? Otherwise the pistons were fully machined. Definitely check with Dave."

BR

Éric

[DVandrews]

emss said:

Hi Dave,

Jon from CM wrote me the following

" We made a set of 82mm K Series pistons for another customer that were sent to Dave Andrews. This was back in 2014 and Dave Andrews designed the pistons. I believe the pistons were machined by Dave once he got them to suit the liner height. We know very little about the K series engine so we cannot say if they will be suitable for your engine.

Looking at the emails when we made the pistons, Dave was allowing for the central intruder in the centre of the piston to be machined to suit the liner height and / or to achieve the correct compression ratio? Otherwise the pistons were fully machined. Definitely check with Dave."

BR

Éric

If they are made the same, then they will require very little modification, just a small recess to clear the plugs as the intruder is quite substantial to keep the CR up.

If they still have the details then I’d say they would be bang on WRT compression height with the 1100 crank and rods, you will need to convert the rods to run fully floating and ensure the pistons have circlips and circlip grooves.

Dave

[emss]

Hi Dave,

Thanks once again for sharing this information.
Time to count beans and decide whether I should build this engine or not.

KR

Éric

[DVandrews]

Just a quick update.. a customer of mine who was planning a 1900 build has a new set of 82mm Westwood ductile liners which he will no longer be using. He has asked if I can move them on, if you are planning an engine at 82mm bore these would be ideal.

Dave