K series rebuild

[Wrightpayne]

So my 1.6 supersport K is 22 years old, still on its original head gasket and I'm looking to have it refreshed. Pistons are a known issue at 7600 redline so looking to switch to forged pistons with floating gudgeon pins.

What should I do while in bits and who to go to?

[TomB]

Lightened flywheel? Do want to keep it standard head wise and induction? Exhaust? 

[Wrightpayne]

Already has R500 flywheel.

[SLR No.77]

Firstly you need to work out what you want from the engine, no point in fitting forged pistons to rev it higher if you're, er, not going to rev it higher!

Are you thinking about cams, head porting, throttle bodies etc or just looking for a refresh? And if so why?

Stu.

[John Vine]

Is this just for the engine, or are you planning to refurb chassis and bodywork as well?

JV

[Wrightpayne]

Car / chassis is pretty good.

It does get revved to the Supersport redline and I've always wanted the stronger forged pistons as the standards are a weak point.

Planned to keep the cams though jenveys and emerald are options.

It will be for mainly road driving so dont really need more power.

Ian

[rj]

I think I'd go for Omega pistons for a 1.6.

[Paul Deslandes]

Ian

Not having any experience of the K series I don't know whether they are amenable to this thought, but my view is that a road car is more fun if it has loads of torque through the rev range rather than just top end bhp.  'Power sells engines, torque wins races', as they say. 

It may be that an engine that has to be revved to the redline is more exciting to drive but bags of torque at the bottom end can be a lot of fun, albeit at the expense of top end power.  Depending on your existing exhaust system, switching from a 4 into 1 to a 4 into 2 into 1 system can go a long way to moving the torque curve down the rev range, which is what I did with my 2 litre Vx and which pulls like a train from about 2500 rpm.

Just my bit of food for thought.

Paul

 

[Wrightpayne]

Thanks Paul. It seems an age since I dropped off those bits for you in Staines!

It has the Caterham 4-2-1 non cat exhaust system. Engine is also dry sumped.

[John Vine]

Can't comment on forged pistons as my 1.8K SS-R had standard ones.  I guess Oily would be the one to advise?

Have you fitted verniers?  That's a good way to improve torque across the range.

JV

 

[Wrightpayne]

Yes verniers fitted already.

[TomB]

If the engine has lasted 22 years, Im not sure you need the forged pistons! I thought the 1.4 and 1.6 pistons were reasonably robust?  

[Tazio]

Throttle bodies and an Emerald, pistons and cams will make it more of an occasion every time you drive it, and the intake will sound lovely, and as it's not going to be tracked, keep it noisy....

[oilyhands]

1.6 and 1.8 pistons are the same, however the mean piston speed and piston acceleration/deceleration  are lower on the 1.6 as is the rod angle so they are less vulnerable to higher rpm. 1.4 pistons are more robust, especially early ones where the rods are shorter and the ring pack wider.

Oily

[Englishmaninwales]

I'd consider getting the engine, clutch an flywheel balanced. Made a noticeable difference wrt vibration and smoothness on both my K series and Twin Cam.