Just had my Chim 430 Rolling Roaded...

[Mark_S_24]

As it says I've just had my Chimaera 430 on the rolling road. (it's a '93 with 56k miles)

Figures should be 280 bhp & 305 lb·ft @ 4000rpm
Mine came out as 225 bhp & 245 lb·ft @ 4030rpm

Now, I realise that they probably didn't come out the factory with exactly the stated figures...
but even so it seems a bit low.

Having read up a little, I'm assuming that it's probably the cam, am I correct?
If it is the cam, does anyone know what the correct cam is?
Can I get a sharper cam, if I do, will it need a different chip & it setup?

I've got my Bible at home so I'll check it later.
But how easy is a cam & lifters change?
(With the help of a friend I installed a turbo in my MX5, I've also removed the head from a Mk1 MR2 myself, )

Is there anything else I should do while it's apart?

And my bonus question... why do men have nipples? they don't need to feed babies :-)

Thanks in advance
Mark

[deadmau5]

Not sure about your engine work, but it's because a foetus' sex isn't determined until it's a few months old, so all foetus' grow the same way in the first few months.

[Mark_S_24]

Damn! you knew my bonus question :-)
Well done

Mark

[pwd95]

I'll be putting mine on the rollers at the 'Roar' tomorrow so it'll be interesting to compare. Mine has had a new cam & has been mapped by MA. I take it your quoting flywheel bhp there. What was the 'at wheels' figure?

[Zippee]

If thats a fly figure then it does seem rather low. My old 400 (97 model with 54k on the clock at the time of the RR) put out 228 at the fly and I'd have expected a 4.3 to comfortably be higher than this.

[Mark_S_24]

The @ the Wheels was 166 bhp which was at 5410 rpm

Mark

[pete]

My old Griff 500 had 275bhp and 300lb.ft at the fly (and that was a good one, apparently), so I would be pretty happy with around 230bhp from a 4.3. A lumpier cam, better breathing (trumpets, plenum etc) and Mark Adams remap seemed to be the way to bigger power for the Rover V8, from what I can remember.

Either that or a supercharger...

[rev-erend]

Don't think you are too far out .. best do a compression test to start followed by checking each exhaust pipe at the head with a lazer temp gun ..

If any of the individual cylinder compression or temp readings stands out from the others you know you have an issue.

[Chris71]

Isn't the correlation between capacity and output supposed to be a little random this far down the road? I got the impression that these days a particularly healthy 4.0 could be producing close to an average 5.0 through a combination of age and the fact that TVR lied even more blatantly about the power output of the later engines?

[spend]

I think he's assumed he has a BV... its not greatly down on power for a std 430, maybe cam or even as simple as a quick tune up will sort it out. Std 430 will be good if it is anywhere above 240 IMHO (ignore much of the pub talk )

[Mark_S_24]

Cheers Chaps,

I'll start with HT leads, plugs etc etc
and see about getting it tuned up,

Mark

[pwd95]

The shape of the graph will tell you if the cam is worn, or it there's something restricting it at the top end. Can you post a pic of it at all?
I'll post mine tomorrow night when I get home from the 'Roar'

[900T-R]

Chris71 said:

Isn't the correlation between capacity and output supposed to be a little random this far down the road? I got the impression that these days a particularly healthy 4.0 could be producing close to an average 5.0 through a combination of age and the fact that TVR lied even more blatantly about the power output of the later engines?

Indeed. The bigger the RV8, the bigger the gap between TVR quoted power and reality...

[grahamw48]

Just for comparison, I had my 400SE (with Chim 400 engine and 218 cam) R/Roaded at a reliable place in April, and the figures were given as 195 at the wheels and 230bhp flywheel (5,400rpm), with 251 ft/lbs torque at 4,000rpm and 200lbs at 2,000rpm.

Edited by grahamw48 on Friday 4th September 21:45

[Mark_S_24]

I was going to scan the graph at work (as my scanner doesn't work on Vista)
But They made me Work!!! can you believe that :-)

The graph starts rising at about 45 degrees from 1500 to about 2000 when it leaps near vertically upwards and starts curving as I would expect. There is a slight blip at about 2750 ish, it is easier to spot in the torque curve.

I'll see if I can get it scanned soon

Mark

[sunwharf]

Mine's a 1992 Griff 430 and recently had a RR done, see graph below. For reference, I have an Emerald ecu (no AFM) and piper 285 cam. I gather they were expecting a 430 to come out at 225 - 250 bhp at the flywheel based on others thay had run.

[combine]

Last time I went to Northants motorsport rolling road I was told the Audi/Porsche/BMW 's are usually more bhp than the stated figure due to the regs over there , maybe they should have built Tvr's in Germany !

[pwd95]

Ok, here's my graphs from the 'Roar' today. I thought it might be a tad more, certainly feels it, but I have a very healthy looking graph so I'm more than pleased. I also learned that 6k rpm on my tacho is in fact 4500rpm!!!!! 6K rpm is in fact over 8k rpm on my tacho!!!

So you can imagine the fun I had on the way home.

At the flywheel...275 ft/lbs of torque.




At the wheels...220 ft/lbs of torque.



P.S. This is with a recent new cam & a MA RR set up. Standard intake etc.

Edited by pwd95 on Saturday 5th September 19:17

Edited by pwd95 on Saturday 5th September 19:19

[900T-R]

Yes, that's about where a healthy and well set up std 4.3 should be...