Jump to content

4L to 4.6L what bits to use?


Recommended Posts


So I have taken the plunge and bought a 4.6HSE range rover to use the engine to upgrade my tvr 400HC. I am planning to rebuild the engine, get top hat liners fitted, megasquirt it and use arp bolts where podsible. I would like (but not necessarily get) about 300Hp. I would love to supercharge but am thinking normally aspirated will be easier to insure.

I am planning on head porting and larger valves. Does anyone know if there are benefits to using either the tvr or lr heads? I believe the tvr heads will have double springs etc but obviously these can be moved to either head.

Is it worth increasing the compression ratio? I believe the 4L pistons in the 4.6L will increase it but by how much? Would this increase be negated by composite head gaskets? It's only ever be run on 98 Ron.

Increasing the rev range would be nice to do as well. Are there any well known ways of doing this? I have googled but there doesn't seem to be any normal mods for this... yella Terra roller rockers maybe? Solid lifters? I don't want it to be a pig to drive but don't mind reducing low end power/torque a little to get it to sing.

Will obviously be getting a new cam etc any recommendations for a lighter car?

On a full rebuild is there any other mods/suggestions to improve oiling or anything else?



Link to comment
Share on other sites

I have 4.0 LC pistons in my rebuilt 4.6 - by my calculations you will get somewhere around 9.2:1 comp ratio but I have never found any confirmation of that number.

If you do go the 4.0 piston route just be aware that the gudgeon pins have a thinner wall than the 4.6 gudgeons (same outside diameter just a thicker wall so stronger). So get your 4.6 piston gudgeons pressed out and pressed into your 4.0 pistons.


Link to comment
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.
Note: Your post will require moderator approval before it will be visible.

Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.


  • Create New...

Important Information

We use cookies to ensure you get the best experience. By using our website you agree to our Cookie Policy