Which Sigma do I have?

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krisfl
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Which Sigma do I have?

Hi all.

Newbie here. Advance apologies if this is a common one and I'm just being dumb! but I've had a bit of a search, and can't find the answers. So hoping to tap the collective knowledge...

Very excited as I have inbound, a new (to me) Sigma engined 7. My first. 

I'm trying to work out if its the older Fixed Cam variant, or the later Ti-VCT with the variable timing. Is there an easy way to tell? Without taking the head off of course...

I'm told my car is a late sigma Ti-VCT with 140bhp. It was first registered in 2016, but was an owner built kit, so presumably left the factory a year or two previously. Curiously it has Roadsport badging, but is being sold as a 270 - which I thought would mean 135 Bhp??

I know the sigma has been used since around 2006 in 125, 150, 140bhp states of tune. And 135 in the current 270 and of course 152 in the 310. It's not an early 150 - it doesn't have the throttle bodies (assuming I have that right)

Trying to work out what it actually has under the bonnet! I'm buying from a well regarded 7 specialist so  I'm not worried. Just independently checking the details and learning...

A few things here:
1. When did the Ti-VCT units take over from the fixed cam sigmas?
2. When did the Road sports give way to the 270 (I think this is around 2015?)
3. Was the 270 ever sold with 140bhp (was it detuned to create more room to the 310?)

Any facts gratefully received. Looking forward to years of ownership and membership!

Best
Kris

jonsymons
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Welcome Kris - I bought an old xflow so can be no help at all with your questions but whatever you have got you will enjoy it!

Golf Juliet Tango
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Kris, welcome & I hope you enjoy the car. The best approach is to check the original spec with Martin Phipps (Club treasurer but more relevantly the archivist for Caterham Cars).

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Stephen

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GulfSeven
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According to the Chris Rees book, Supersports (2011-2014) were 140bhp Sigmas. The 270 was sold from 2015, and the Ti-VCT engine gave it 10bhp more than the older engine in the Roadsport 125.

Could it be a Roadsport (2006-2015) with a Supersport upgrade?

Tim.

Gulf Racing 310R

ScottR400D
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Apparently, You can identify that it has Ti-VCT engine by the 2 camshaft control actuators situated on the front of the engine.

I believe that engine was used at least from 2010 and the 270 type naming came in early 2015. 

K7 VCT
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Yep, the Ti-vct engine is 125 in an academy car, 135 in road sport and 152 if a 310 upgrade, all 3 have the air box. Fixed cam is 125 has air filters on the throttle body, the 140 has the air box to outside, the 150 with indiviual throttle bodies and a very slim air filter over all throttle bodies. Look for the cam solenoid actuator at end of cam covers, that's a Ti-vct if it has them Post a picture of the top of the engine. Welcome btw

Orange is my new black

Ballistic orange 310s
krisfl
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Thanks all really helpful. And thanks for the welcome!

@gulf juliet tango, I'll certinaly check in with Martin - thanks for the tip.

going by the other comments here:

Its definatley not a 125 Academy car, and has no air filers on the throttle body - so thats ruled out.
It doesn't have individual throttle bodies, but the plastic manifold - so its not a 150 either.
It doesn't have the 152bhp 310 upgrade label on the rocker cover, while it could hve been left off, its not likley to have had the 310 kit... Though that would show it was a Ti-VCT if it did!

It does have a airbox to the outside, So most likely a 140 or a 135?

Here is a small (sorry couldn't seem to make it bigger) shot of the engine. There looks to be actuators and the end of the cam cover - same end as the distributor?Look right to you @K7 VCT?

Perhaps I'll need a Rolling Road to confirm the 5bhp either way!

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K7 VCT
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So it's a 135bhp Ti-vct sigma. Only way to tell would be rolling road or check on map on ECU I guess. I guess it's a 135 as the cam cover badge is part of the upgrade. Can you check with Caterham or dealers if it's been upgraded via the chassis number or number plate ? If it's a 135, o recommend the 310 conversion with a lighter flywheel....

Orange is my new black

Ballistic orange 310s
K7 VCT
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The 140 was only the fixed cam engine.

Orange is my new black

Ballistic orange 310s
K7 VCT
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Ah, I see it's still on gp sevens website. It's a 135. The advert is wrong, if it was a 152bhp as in a 310 they would be selling it for more..... The upgrade via sevens and classics is cheaper than caterham cars price. Enjoy it when you get it...

Orange is my new black

Ballistic orange 310s