4.0 to 4.0hc

[ssc1]

once ive got the temp thing sorted i want to get the same bhp from my 4.0 that the 4.0 hc has , whats the difference internaly and externally and is it just a cam swap, as there is about 35bhp difference between the two and i cant see a cam adding that much so is it heads as well...

[2 sheds]

Probably only about 10-15 bhp difference between non HC and HC in the real world.
HC, has different cam , probably worth 5+bhp , polished heads and inlet probably worth another 5+bhp.
With ported stage 3 heads and ported inlet, you could improve enormously over the HC.
Tim

[pbrettle]

I can testify to what 2 sheds is saying. I was behind a V8S and a 4.0 Chimaera at the Duxford runway sprint... mine (a 4.0HC) is slightly faster as I did manage to gain on them... but it is in reality only a smallish difference and reasonable modifications to a 4.0 is likely to bring you into line with a 4.0HC anyway....

[Corin Denton]

What sort of cost is involved in this job and how much is the cam/who's it made by?

[2 sheds]

Corin Denton said:

What sort of cost is involved in this job and how much is the cam/who's it made by?

To do the job properly about £2K , (heads are £750).
I would use V8 Developments.
Tim

[HarryW]

When investigating this earlir this year I went through a long learning curve on cam technology/types and their respective pro and cons. The conclusion was that for a TVR the 218 profile is probably the best alround one for hydraulic lifters and the 404 for solid lifters.
I discounted the solid lifter route as tappet adjustment would become part of the servicing routine.
The 218 is a standard kent cam @ 112deg, V8 developements do a hybrid 218 at 108deg and their completely own profile, albeit still 218 based, called the MC1 with longer duration.
Speak to Shawn or Ray at V8 developements about what you want form the car and they will advise the best cam for you.
Costs, if you don't have venier timing gear and duplex chain these need to added. The cam would range from £125 for a Kent to I think £175 for V8D's profile, not sure about the vernier gear but £125 rings a bell. All in I think you'd be looking at £600-700.
Obviously all IMHO, speak to V8D or even TVR power, but they are tied to what cams they do I believe, i.e. they had never done a 218 fitting as far as I'm aware.

Harry

Editted to add the figure I have quoted above is just for a cam change, as Tim says if you do the heads as well you are into £2K country, if you have a bit more, bottom end etc then you are past the £3K mark

>> Edited by HarryW on Friday 18th July 12:27

Editted again to say don't forget if changing cam that the cam followers need replacing at the same time or the new cam may not last very long, I think there around £60 a set thenoverall price includes all gaskets as well.

>> Edited by HarryW on Friday 18th July 13:24