2.8 and 2.9 V6 differences

[Chris71]

Hi,

Can someone give me an overview of the 2.8 and 2.9 variants of the Cologne V6? Were there any significant differences in porting on anything like that, or was it just stroked?

Chris.

[plasticpig]

Apart from the longer stroke the main ones I can think of offhand is the 2.8 has siamesed exhaust ports and the 2.9 dosent. The cam drive is chain on a 2.9 and gear on a 2.8.

[Chris71]

What are the qouted outputs in their Ford applications? I have to admit the car I'm thinking of isn't actually a Ford, but a TVR. In that guise they claim 160hp for the 2.8 and 168 for the 2.9.

I'm essentially wondering if the 2.9 is worth paying a premium for. They're both quite old cars now and I don't know whether or not the 2.9 should feel noticeably stronger with only 8hp adavantage in a 940kg car.

[dern]

I assume you mean the s1/2/3 cars. More information can be found in this bit of PH which for some reason has become tricky to find... http://www.pistonheads.com/tvr/s/Default.asp?story...

I went for an s3 simply because I really didn't like the early dash and got the 2.9 for free

[plasticpig]

Chris71 said:

What are the qouted outputs in their Ford applications? I have to admit the car I'm thinking of isn't actually a Ford, but a TVR. In that guise they claim 160hp for the 2.8 and 168 for the 2.9.

I'm essentially wondering if the 2.9 is worth paying a premium for. They're both quite old cars now and I don't know whether or not the 2.9 should feel noticeably stronger with only 8hp adavantage in a 940kg car.

The increase in torque is more noticeable than the hp. Hasten to add I have no experience of TVR's but it is true of other cars.

[Chris71]

By chance I was speaking to a colleague of mine involved in the development. He said the only significant similarity was the bore spacing!

The jist of it was - the 'deeply oversquare' 2.8 is more revvy, but the 2.9 is torquier. Apparently the 2.8 was a developemnt of a V4 and had the siamese ports left over from that design. The 2.9 is de-siamesed and has considerably better flow at high engine speeds, however as standard the cam followers and camshaft profile on the 2.8, combined with a shorter stroke make it revvier. It's also said to be the stronger engine.

So, presumably what you want is a 2.8 with de-siamesed ports?

Sounds like there isn't a huge amount in it.

Hmmm - on the TVR forum (yes, it is an S!) there seem to be two favoured mods - changing the fuel pressure boost value and swapping the throttle linkage to a linear design. Most S-Series TVRs are the 2.9 though - do you get equally impressive gains doing this to the 2.8?

[Podie]

Chris - answers are here - http://www.burtonpower.com/technical_1/taunus_colo...

[dern]

Chris71 said:

Hmmm - on the TVR forum (yes, it is an S!) there seem to be two favoured mods - changing the fuel pressure boost value and swapping the throttle linkage to a linear design. Most S-Series TVRs are the 2.9 though - do you get equally impressive gains doing this to the 2.8?

No idea, it was overly eager to swap ends as standard so I left it as it was

[Chris71]

dern said:

Chris71 said:

Hmmm - on the TVR forum (yes, it is an S!) there seem to be two favoured mods - changing the fuel pressure boost value and swapping the throttle linkage to a linear design. Most S-Series TVRs are the 2.9 though - do you get equally impressive gains doing this to the 2.8?

No idea, it was overly eager to swap ends as standard so I left it as it was

I found the S1 (admittedly at 'someone elses car' speeds) very reluctant to swap ends. That particular car would have benefitted from a little more straightline propulsion though.