Land Rover 4.3 V8 - revision and tuning
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Land Rover 4.3 V8 - revision and tuning
Hi all
First of all, I'd like to introduce myself.
My name is Christoph, I'm 35 years of age, German, based in Basel, Switzerland and having had a spleen for Range Rover Classics since I was a little boy.
Currently, I own 5 of them in varying states of rot and shine
back to topic:
I recently bought a 4.3 engine out of a RRC LSE, which I'm going to rebuild and - hopefully power/torque tune to suite one of my RR.
CR question
As the 4.3 engine has a standard CR of 8.95 : 1, I'd like to go for 10:1 or 10.5:1.
What will be the best way to go for? Head skimming? Block skimming?
Different pistons?
Camshaft question:
Does anyone know Kent cams H180 (symmetrical) and H200 (assymmetrical)?
Which one would you go for in a Range Rover with auto transmission?
Thanks and kind regards
Christoph
First of all, I'd like to introduce myself.
My name is Christoph, I'm 35 years of age, German, based in Basel, Switzerland and having had a spleen for Range Rover Classics since I was a little boy.
Currently, I own 5 of them in varying states of rot and shine
back to topic:
I recently bought a 4.3 engine out of a RRC LSE, which I'm going to rebuild and - hopefully power/torque tune to suite one of my RR.
CR question
As the 4.3 engine has a standard CR of 8.95 : 1, I'd like to go for 10:1 or 10.5:1.
What will be the best way to go for? Head skimming? Block skimming?
Different pistons?
Camshaft question:
Does anyone know Kent cams H180 (symmetrical) and H200 (assymmetrical)?
Which one would you go for in a Range Rover with auto transmission?
Thanks and kind regards
Christoph
Last edited by Chris on Tue Jul 25, 2017 1:15 pm, edited 1 time in total.
Re: Land Rover 4.3 V8 - revision and tuning
Just a minor clarification - if the engine is out of a RRC LSE it will be the 4.2 engine (4,275 cc) rather than the 4.3 (4,280 cc) which is out of a TVR. Other than the little 5cc difference I am not sure what other differences may be in the block etc but I believe the major differences are in the heads where the TVR breathes a lot better.Chris wrote:I recently bought a 4.3 engine out of a RRC LSE,
Thanks and kind regards
Christoph
Not sure if this impacts on what you are planning.
Oh - and welcome to the forum - some great information to be had here.
Cheers
garry
Hi
It's from a RRC.
Head gaskets are tin already, so no easy improvement to be found here.
Is there a thumb rule to estimate CR inrease after skimming? e.g. 0.1mm less means 0.1 more CR?
It's from a RRC.
Head gaskets are tin already, so no easy improvement to be found here.
Is there a thumb rule to estimate CR inrease after skimming? e.g. 0.1mm less means 0.1 more CR?
Rossco wrote:If it's on composite head gaskets you could swap over to tin head gaskets. You'll pick up a full point of compression just by doing that.
- Rossco
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That would give you at least a full point if you stayed with tin gaskets
http://www.not2fast.com/turbo/compressi ... sion.shtml
http://www.not2fast.com/turbo/compressi ... sion.shtml
The 4.2 and 4.3 engines have the same bore as the 3.9, 4.0, 4.6 and 5.0 engines (94mm).
The 4.0 and 4.6 engines have both LC and HC pistons and indeed if you put 4.0 LC pistons in a 4.6 you get a compression ratio between the 4.6 LC and HC compression ratios. If 4.0 HC pistons went in the comp ratio would probably higher than a 4.6 HC.
My point is that by putting in other 4.0/4.6 pistons you may be able to achieve a higher compression ratio. However it will require a bit of research and a lot of calculations.
I recently built a 4.6 and only had 4.0LC and 4.6LC pistons - I put in the 4.0 LC pistons which in the 4.6 give it a comp ratio of about 9.2:1 up from the standard 8.15:1
It will need a bit of research.
Garry
The 4.0 and 4.6 engines have both LC and HC pistons and indeed if you put 4.0 LC pistons in a 4.6 you get a compression ratio between the 4.6 LC and HC compression ratios. If 4.0 HC pistons went in the comp ratio would probably higher than a 4.6 HC.
My point is that by putting in other 4.0/4.6 pistons you may be able to achieve a higher compression ratio. However it will require a bit of research and a lot of calculations.
I recently built a 4.6 and only had 4.0LC and 4.6LC pistons - I put in the 4.0 LC pistons which in the 4.6 give it a comp ratio of about 9.2:1 up from the standard 8.15:1
It will need a bit of research.
Garry
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It's possible to fit 3.9 pistons into a 4.2 but you need to machine their tops to put them just below the deck. This then gives you a piston with a reduced dish and the compression ratio will be higher. I don't know the number though.
The top ring will however be closer to the crown but unless you are going forced induction or nitrous it should not be a problem.
The top ring will however be closer to the crown but unless you are going forced induction or nitrous it should not be a problem.
DEVONMAN wrote:It's possible to fit 3.9 pistons into a 4.2 but you need to machine their tops to put them just below the deck. This then gives you a piston with a reduced dish and the compression ratio will be higher. I don't know the number though.
The top ring will however be closer to the crown but unless you are going forced induction or nitrous it should not be a problem.
This is what tvr did with their 4.3 motor. I imagine on tin gaskets you would be about there. For your wanted cr. Or use high comp 3.9's machined down with composite gaskets.