Superlight R Caterham with Honda 2.0VTec K20 complete re bui

[sundance002]

dsl2 said:

Are you using the Caterham 6 speed box still?

Yes still use the 6sp Caterham box, but had to have the bell housing made so it fitted the box,also have fitted a twin plate clutch that we had made, the gearbox was also strengthened, and a AP master cylinder with bigger brakes were added.

[Dave J]

sounds and looks like a great car, but I fear for the gearbox with 9000rpm and 280bhp

[DJWuk]

Having had an Ariel Atom with the Honda Civic type R engine at 245bhp, I can imagine your car must be ballistic !!!

Always found it to be a reliable engine with tons of grunt, so perfect for the Caterham.

[sundance002]

Dave J said:

sounds and looks like a great car, but I fear for the gearbox with 9000rpm and 280bhp

Hi Dave, the box has been shot and peened by the gearbox man, so should be fine, and have added an oil cooler.

[sundance002]

DJWuk said:

Having had an Ariel Atom with the Honda Civic type R engine at 245bhp, I can imagine your car must be ballistic !!!

Always found it to be a reliable engine with tons of grunt, so perfect for the Caterham.

Hi, Yes thats why its such a good engine to use, its pretty bullit proof.

[dsl2]

Very good engine even as standard, massively reliable as per the V de V speed series use. Only downsides are the weight & height for a 7.

I've chosen a Duratec for the Juno I'm having over the standard fitment Honda for those reasons despite the extra work involved in designing & machining a new super low profile drysump plate, required as it actually bolts the engine into the chassis.

Hope I've made the right choice!

[dsl2]

Very good engine even as standard, massively reliable as per the V de V speed series use. Only downsides are the weight & height for a 7.

I've chosen a Duratec for the Juno I'm having over the standard fitment Honda for those reasons despite the extra work involved in designing & machining a new super low profile drysump plate, required as it actually bolts the engine into the chassis.

Hope I've made the right choice!

[sundance002]

dsl2 said:

Very good engine even as standard, massively reliable as per the V de V speed series use. Only downsides are the weight & height for a 7.

I've chosen a Duratec for the Juno I'm having over the standard fitment Honda for those reasons despite the extra work involved in designing & machining a new super low profile drysump plate, required as it actually bolts the engine into the chassis.

Hope I've made the right choice!

What is the weight of the Duratec with the gearbox? as other than the height I believe there is not much diff in the weight maybe 10kg at the most ,but wouldnt the extra power make up for that? and the cost to run is minimal, 2 seasons before each re build
It fits very well, after a quick measure its under 3inches difference to the Duratec. so for me in the Seven is a perfect marriage.
The only thing that is more prominent in the way they drive is the Honda vibrates more at high revs than the Duratec, so makes yore eye balls wobble,.

Good luck with the build, Will be an awesome machine..

[dsl2]

Totally different gearbox set up as the Juno is using a Hewland FTRS. Its not fully built yet so hard to say but the expectation is a weigh saving over the Honda engined V de V car of 50kg overall, mine is going to be used for sprint racing only so lots of changed parts & more carbon that usual!

The engine change is expected to provide 20/25kg of that alone with careful matching of ancillaries / machining off surplus mounts & lugs etc. We are doing away with a front anti vibe engine mount as it shouldn't be required, it was only added to try to stop the vibes from the Honda as they were making the drivers feel sick.

There will be no power deficit over the Honda, it should be a bit stronger to the tune of 10-15bhp if all goes to plan!

[Dave J]

the k20a is circa 38-45kg heavier them a duratec - on a like for like stock setup.

[dsl2]

In the Juno install they remove the Honda water pump & cast housing as it weighs a ton apparently, replacing it with a BMW 5 series electric pump hence my weight saving won't be quite as high as you may expect from looking at Dave J's figure.

[sfaulds]

Dave J said:

the k20a is circa 38-45kg heavier them a duratec - on a like for like stock setup.

WTF? Last time I weighed them next to each other, they were within a couple of kilos.

[sundance002]

sfaulds said:

WTF? Last time I weighed them next to each other, they were within a couple of kilos.

+1 when we weighed them side by side inc the changes we made to the Honda engine it was around 10kilos. not sure how they got 40 unless someone's foot was on the scale too.

[sam919]

Dave J said:

the k20a is circa 38-45kg heavier them a duratec - on a like for like stock setup.

Where's the weight comign from? i picked up a K20 block, now being used in a sc elise, and compared to the duratec block in my garage it was much lighter!

[TelfonTurd]

I ran 280bhp through a Caterham 6 speed with no issues.

[terrybourne]

Hi Caterham Owners, With many years developing the Honda k20a and FD2 engine and mapping software for vdev and the speed euro series, this was a really exciting project for bourne to be involved in. The final spec of this car was adapted to produce a outstandingly fast track car which can also be driven to and from the track with 100% reliability and peace of mind. We will be producing many more of these conversions also with the option of upgrading to a sequential box with paddle shift and an added option of traction control.

Bourne Honda
F88 ECU and loom with 8 switchable engine maps
AT power throttle bodies
450 cc high flow injectors
Mugen fd2 vdev pistons
Mugen fd2 vdev cams
ARP upgraded rod bolts
Mugen upgraded big end bearings and main bearings
Bourne vdev flywheel and spigot bearing
Dry sump kit with pace oil pump
option of electric water pump
Bourne tuned exhaust system with cam coat


Chassis upgrades
Bespoke CNC machined bell housing
AP Racing clutch
Bespoke engine mounts
Gear box rebuild to hold 310hp and 210nm of torque
AP Racing master cylinder
Aim data logging system with can bus link to engine management system

Below are the power output sheets
We have four consisting of Track, fast road, wet and fuel save.

[terrybourne]

[terrybourne]

[terrybourne]

[terrybourne]

Hi all would just like to add that a complete running Bourne Honda weighs in at 97 kilos complete with ecu, loom flywheel etc. From a harmonics point of view any straight four engine that you use will have a lot of vibration due to the secondary pulse you get which a characteristic of all straight four engines. With many years of developing vdev and speed euro series cars there are ways around vibration issues.