S2 Two litre - extra power

[Rolls]

Hi

I'm new to the Lotus esprit world.

For those in the know - what the best way to maximise the power output for a 2 litre? Keeping costs at a reasonable level.

Even some correct post links would be appreciate.

Many thanks

Roland

[Rolls]

What sort of HP would a standard versus a warm 2ltr produce?

[DaveyT]

Didn't realise the weather in Oz made em more powerful:-))

Think the (claimed) standard output for both 2 and 2.2 was 160, but the torque curve made the alter engine more drive-able.

Not sure how wear would affect it, assuming you meant "worn".

[Rolls]

Warm as in mildly modified.

Just curious if many folks out there tweaked these engines to increase HP - what's the best bank for buck.

I've never driven a Lotus before but I was thinking that 160 would be a little dull at one tonne.

[Bibs]

Wait until you go around a corner at speed

[DaveyT]

OK, ( feeling suitable dumb )

Can't help you there, but on our roads, I never felt the need for more power in my 2.2 n/a.

It's an old car now, and won't keep up with modern metal on most straights, but it still makes them look like they're reversing towards you when you get to the twisty bits.

I remember once, when an NS-X ( pretty new car at the time) pulled out ahead of me............

Either way, enjoy the journey.

[peteyg]

It's a car of it's time, enjoy it for what it is and ditto what Bibs says about going round corners.

 

If you want a faster Esprit, buy a Turbo. Read up on lotusbits.com. They can uprate a 2.0 to get about 210bhp but it will cost you. 

 

Pete

[Rolls]

Sure. I'm certainly into being in the era. I was worried it would be a little underpowered. From what I'm reading is that it's not sluggish and handles well which is good to hear.

What would you all identify as the key minor upgrades to improve performance? Without going too crazy with the cash. Port and polish? Exhaust? Balance? Valves? Etc... Any comments would be appreciated.

[Daniel]

I find my 2L a beautiful engine to play with higher up the rev range. Perfectly suited to the car, but I can understand why the 2.2 was introduced to give that extra torque.

 

In terms of modifications, you're primarily dealing with head work to get the engine flowing better. It's something I'll be looking at in the winter.

[slewthy]

OK, here is the Lotusbits 'menu' to give you an idea of costs vs increase in bhp if thats what you desire.

Engine Upgrades

Initially use the Lotus parts bin to upgrade to the Lotus 912 HC spec (180bhp).

After this:

Step 1

2.2 litre (Developed in Lotusbits Lotus Micra)

• 200 to 220 bhp
• Engine - £4500 to rebuild and upgrade your standard HC engine - £5500 if donor engine supplied
• HC spec plus cnc ported head and inlet manifold, +1mm inlet valves, L14 cams, oil restrictor to head, balanced bottom end
• Actual power developed by the engine will be determined by the carburettor / fuel injection setup and the Exhaust manifold and system
• Peak power will be between 6700 and 7300 rpm
• Rev limit 7700rpm

This is aimed at road use or clubman competition cars

For competition cars there are further modifications required to the sump and oil system

 

Step 2

2.2 litre (Developed in Lotusbits Lotus Micra and Lotusbits Lotus Sunbeam

• 220 to 250 bhp
• Engine - £7000 to rebuild and upgrade your standard HC engine - £8000 if donor engine supplied
• As per Step 1 plus ultra light 13:1 compression pistons, lightweight steel rods, uprated valve springs, ultra high lift cams, steel followers baffled sump
• Actual power developed by the engine will be determined by the fuel injection setup / intake length and the Exhaust manifold and system
• Peak power will be around 8000 rpm
• Rev limit 8500rpm

This is aimed at competition cars

 

Step 3

2.5 Litre Road use (Detuned version of the current Lotus Sunbeam competition engine)

• 250 to 270 bhp
• Engine - £9000 to rebuild and upgrade your standard HC engine - £10,000 if donor engine supplied
• Custom 2.5 Litre steel crank and rods.
• Custom pistons to match
• Peak power between 7000 and 7500 rpm

Contact Lotusbits for further technical details

 

Step 4

2.5 Litre Competition use (Currently used in both Lotusbits Lotus Sunbeams, 2014 season)

• 280+ bhp
• Engine - please contact Lotusbits to discuss price
• Custom 2.5 Litre steel crank and rods
• Custom pistons to match
• Peak power between 7500 and 8000 rpm
• Rev limit 8200 rpm

.pdf download for further information regarding "Improving your Lotus" (3.7mb)

[peteyg]

When my engine was rebuilt 15 years ago it was ported & polished, lightened flywheel and higher lift camshafts and electronic ignition put in. Since then I have added a tubular manifold and K&N air filter. 

 

I now sound like a bit of a hypocrite after my previous comment but the engine was knackered when I bought the car so being young and naive those sounded like worthwhile improvements and were recommended by the garage, whilst the engine was in pieces, rather than something I felt the need to have done. The stainless manifold was put on due to unavailability of the cast iron manifold at the time (which blew itself apart) and for it's weight saving and the hope that stainless would mean it wouldn't need replacing again. The K&N air filter is cleanable with a kit and has already paid for itself by not having to order replacement filters for each service.

 

Have I noticed any performance improvements? Not really. It's a bit louder but that's about it. Am I bothered? No. I get a huge grin every time I drive the Esprit and revving the nuts off it without going silly fast is the best bit. You can still just about get away with 'driving' it properly before your driving license gets taken away.

 

At the end of the day, as everyone on here will agree it's your car, enjoy it whichever way puts the biggest smile on your face!

 

Pete

[Freemason]

I asked Gary Kemp the same question a while back and received this response:

I would suggest you convert the 907 to a 2.2 litre. They drive much nicer than the 2.0l engine and the crank will fit in your 907 block, so it will look original. You can get 210hp and keep nice road manners, in fact it will drive a lot better than your existing 907. For that you would need, the usual stuff like bearings and gaskets, but also:

2.2 crank

Forged 2.2 pistons

A pair of cams

Cam followers

A good exhaust manifold

Some gas flow work to the cylinder head and oversize valves.

I would also recommend a lightweight steel flywheel, it will really sharpen the throttle response.

[Rolls]

Thanks Antonio.

I've sent him a message to try to get an indication of cost.

One question - I'm a little miffed.

Factory docs States my car was a 2L when it left the factory in 1979. My current engine number matches these docs.Yet when I review rego notes, import papers everything States it's a 2.2L. Apart from opening up the block to check out the crank is there any other way to confirm what sized engine it is?

Cheers

[ramjet]

I would suggest that the import docs are incorrect. I have seen errors on current VicRoads documents so would not pay much trust in the officialdom that oversaw your car coming in. They would look up Esprit on their system and just copy the info.

 

You could also try Steve Taylor of Lotus Marques (right here in Victoria) as he has a very good knowledge of these cars. Well worth the call.

[DaveyT]

^^^. What he said.

Also, I think the 2.2n/a was still at least 18 months off when yours left the factory...

[Rolls]

Okay - thanks for the feedback. I guess my curiosity is what's the likelihood that someone has uprated the engine to 2.2 specs. Seems unlikely. I'll try Steve.

Cheers

[Chillidoggy]

My take on it is you'd be better off making sure your suspension is all good and brakes are spot on before anything else.

[Daniel]

BINGO BONGO!!!

[Rolls]

All of the suspension components will be as good as new. Just keen to work out what's the best "bang for buck".

I recently completed a resto on another marque and the lack of power was disappointing.

[Rolls]

I'm slowly getting ready for the rebuild. Who are the main vendors to talk to for an engine rebuild?

Lotusbits

Lotus Marques (Australia)

Any other recommended vendors?

[giorgio67]

Garry KEMP is the man..

[Freemason]

Contact details on his website:

http://lotusengineparts.com

[ramjet]

I don't know Gary Kemp so will pass no judgement as I have not required his services. He has a very good reputation on here.

Steve's website, I think, shows some of his rebuilds and I know of no returns Steve has had on his work. That's my bit for keeping money in Australia. Lord only knows we need it here.

[Rolls]

Gary Kemp isn't taking on new work at the moment just so you all know. I've heard nothing but good things about his work.

[910Esprit]

I had the pleasure of a guided tour of his workshop many years ago and the quality of work and the extreme HP mods he was doing for himself, I've still not seen anywhere else.