Help!! 4.0HC Chim' 202BHP!!
Discussion
monkeypilot said:
had mine measured at the hubs and it's around the 200BHP mark - 230ish at the flywheel I guess. This seems to be typical for a 4.0HC. If your power keeps dropping check your cats haven't melted (this happened to me and it got down to 140ish before I got it fixed!)
hub losses are less ( you don't have the tyre loss), 200 at the hubs is about 220bhp at the fly, bit low for an HC, but not unusual
Dont want to open a can of worms here but all hc's had pocketed pistons, hc stands for high lift cam, tvr 435, the same cam as the 500's had they also had vernier timing gears, none hc's had the tvr 51 fitted and a standard timing chain, funily enough we had two chims in last week for the stealth cam, one guy thought his was a hc and it wasnt and the other guy thought his was a non hc and it was an hc!
Even when it's measured on a rolling road, the figures that are reported are normally corrected back to equivalent figures at the flywheel. Taking a 200 bhp rolling road measurement and totting it up to 230 at the flywheel is probably misleading unless you *know* that the figures you're starting from are the raw figures not the flywheel corrected ones.
200 bhp at the flywheel is about typical for a standard 4.0 (not HC) on a 'typical'
rolling road, slightly more for pre-cat, slightly less for catted. You might expect to get 5-10% more from the HC so 210-220 is credible.
200 bhp at the flywheel is about typical for a standard 4.0 (not HC) on a 'typical'
rolling road, slightly more for pre-cat, slightly less for catted. You might expect to get 5-10% more from the HC so 210-220 is credible.jellison said:
Agree partly - a 4.0 is really a lightly modded range rover lump and 205 at the "fly" is about right (remember that is what the first Sierra Cossie made).
But 500's make (from all mates and other that I have seen that are std) 245 - 280 - you would be suprised that som many are under 260 (ask VIXPY to confirm this)!
A slightly modded range rover lump?
Daft question but what about all the quotes on PH that state "...its only the sump plug and block that are rover...all the rest are TVR bits".
Does anyone know how much of the engine is original rover and what parts are TVR specific?
Jellison - YHM
To add to the debate I had my standard 4.0l re chipped by Mark Adams. Prior to the mods it was pulling about 20-30 bhp less then the final figure of 228 bhp (at 5655 rpm) /235 lb ft (at 4000 rpm). In part this was because my 'rev limiter' (for want of a better word) kicked in too early and moving this up past 6,000 let the engine fly. I've had a 4.0l before this one and the old one didn't feel as strong at the top end nor as flexible through the rev range.
So if there are any fueling/electrical/other probs a session with Mark would be money well spent.
andy-w said:
ok...i have looked and cant find cam info for the hc...is it the same as a 4ltr or 5ltr?
Can anyone recommend a decent cam for the HC or what the spec for the original one is?
Have seen on this thread there is mention of a typhoon 218/220 combo???
The Hc cam is the same as the tiv 500 cams tvr 435
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