300hp N/A Engine Options?

[DSL]

Defo not the same engine, it's still installed in the Chiron car out in Oz giving and I quote "amazing acceleration"

 

The origional Cosworth engine gave less than 250bhp with an undrivable torque curve but they are chuffed to bits with the SBD motor.

 

What spec was yours and what was promised and what did it deliver then Pen?

[Pendennis]

High port CNC stage 2 head, oversize valves with CNC seats, double titanium springs, 13.5/12.7 lift cams (300bhp), intruder type slipper pistons with 1:12.5 ratio, 690cc injectors (over the top), ported 50mm DTHTB's (also over the top) Power 274 @ 8600, but suspect making a bit more now it's run in. It was still climbing the higher we went, so suppose with double injectors would provide a bigger smile

 

Edited by - Pendennis on 17 Nov 2012 11:10:36

[Mr Locust]

Lotus engine for sale

 

Curved cam cover sealing face which leaks

[Roger King]

Told ya (about the cam carrier faces)!

 

The only reason I can think of for this design is that it makes it easier to measure the valve clearances with feeler gauges; but seeing as cranked feeler gauges have been easily available for literally decades I still don't understand.

[Nifty]

As Roger says the Lotus 900 series originated from the Vauxhall block.

I believe ACBC saw the engine on a stand at a show and at the time he was considering moving on from the Twink.

At that time the engine was installed in the Vauxhall Victor.

They produced a Lotus head to fit the block and used this engine in a Europa race car as a test mule.

 

I understand ACBC decided to switch to making his own ali block, partly to reduce weight and partly because of the modifications to install the engine on a slanted angle to reduce the height / lower the centre of gravity.

 

The original production 900, the 907, was fitted in the Jenson Healey and the earlier Elie / Eclat / Esprit cars. This was a 2 litre engine.

 

The 2.2 litre came in three guises, 910, 911 and 912.

 

The 910 is the turbocharged engine used in the Turbo Esprit, it had lower compression (though an HC version was produced from about '86).

Horsepower did get up to 300 in it's final incarnations ... but obviously this is not N/A.

 

911 - this was the engine used in the Lotus Sunbeam.

Standard hp was 150 IIRC but the last team rally cars were doing over 250bhp.

 

912 - this was the N/A 2.2 used in Esprit 2.2 and later and the Excel.

Standard 160 hp, HC (after '86 ?) 180 hp.

 

I cannot recall what the differences were between 911 and 912 but they were minimal ... however, as 911 was fitted exclusively to Sunbeam's you will pay a serious amount for one I'd have thought.

912 is the most common and therefore cheapest.

These engines have been tuned to much higher horsepower.

 

There is a chap in North Norfolk who has put a 912 into his Lotus Sunbeam and it is a reputed 300 bhp N/A. It certainly goes like sh*t off a shovel as both myself and OBNS can testify (he easily out dragged my R400 at Snet) .. he has some footage on YouTube I think.

 

However .... 300 bhp will cost you some serious money, I expect more than 300bhp from a Duratec. The plus side is there is a sort of heritage link

 

Personally I would choose either to uprate the existing engine .. as would have been the case in the period, or drop in a Lotus engine .. as might again have been the case in the period .. but this will reduce the historic value of the car.

Putting a modern engine in will reduce value further IMO.

[Nifty]

Leaking cam carriers .... tell me about it ❗

 

I cannot remember when they changed the profile but certainly my early 80's S3s still had the round carriers.

[Roger King]

One tiny correction to that comprehensive history (sorry) - it wasn't a Lotus move to make it a slant four; the Vauxhall engine was already a slant four, for the simple reason that it was really one half of a V8 that was killed off by the early seventies fuel crisis.

[Mr Locust]

Lots of stuff about 91X engines.

[Nifty]

I stand corrected there Roger