450 cylinder heads
Discussion
What typically do 450 owners find when they look to upgrade their heads i.e. port matching & valve sizing? i have found the following info on ACT website...(please note this does not originate from ACT)
"For reference, from TVR
All non 500 engines have 38mm bore inlet manifolds, the 4.3 & 4.5 have enlarged head ports and manifolds are port matched but only at the point where they meet the cylinder heads. They also in most cases have larger valves. All of these engines use standard 38mm trumpets".
I have 44mm trumpets and matching inlet manifold to go on, 72mm plenum already on. I was looking at stage 3 or tvr500 heads to complement these but based on the info above do i already have a half decent set of heads and could save a few ££'s?
My 450 with standard act intake mods and aftermarket afm is making bang on 285bhp (main cat in, pre cats out) on 95ron fuel. Im not chasing numbers but would like some extra grunt i think better breathing is indicated to give.
thanks chaps
"For reference, from TVR
All non 500 engines have 38mm bore inlet manifolds, the 4.3 & 4.5 have enlarged head ports and manifolds are port matched but only at the point where they meet the cylinder heads. They also in most cases have larger valves. All of these engines use standard 38mm trumpets".
I have 44mm trumpets and matching inlet manifold to go on, 72mm plenum already on. I was looking at stage 3 or tvr500 heads to complement these but based on the info above do i already have a half decent set of heads and could save a few ££'s?
My 450 with standard act intake mods and aftermarket afm is making bang on 285bhp (main cat in, pre cats out) on 95ron fuel. Im not chasing numbers but would like some extra grunt i think better breathing is indicated to give.
thanks chaps
You sound like you know more than me already but I thought the 450 or Landie 4.6 engine is pretty standard Landie! Didn't think Tvr did anything to them? Can anyone come up with documentary proof of what was done to them by Tvr! I have a Chim 450 2000 so late use of V8, I have what I assume is the original cam lying around, I'll get it identified, that's a start! Are you talking Tvr 4.5 or the Landie 4.6 crossbolted crank?
I don't think any RV8 that TVR used in the Chimaera/Griffith ever came with a stock RR cam 
the later 4.0/4.6 serp RR RV8 came with bigger ex ports than the 3.9 and are in my opinion the best stock factory heads ex port wise than any previous versions (please note: Range Rover stock heads not TVR) the 450 engine as a little bit of tickling here and there but stock valves 
although some 450 cars are reported to have come from the factory BV 
someone like Spend will give you more insight into this stuff quite frankly
the later 4.0/4.6 serp RR RV8 came with bigger ex ports than the 3.9 and are in my opinion the best stock factory heads ex port wise than any previous versions (please note: Range Rover stock heads not TVR) the 450 engine as a little bit of tickling here and there but stock valves although some 450 cars are reported to have come from the factory BV someone like Spend will give you more insight into this stuff quite frankly Edited by Sardonicus on Thursday 27th December 11:01
[quote=Sardonicus]I don't think any RV8 that TVR used in the Chimaera/Griffith ever came with a stock RR cam the later 4.0/4.6 serp RR RV8 came with bigger ex ports than the 3.9 and are in my opinion the best stock factory heads ex port wise than any previous versions (please note: Range Rover stock heads not TVR) the 450 engine as a little bit of tickling here and there but stock valves although some 450 cars are reported to have come from the factory BV someone like Spend will give you more insight into this stuff quite frankly
As you say, my 450 heads are BV 43/37, so some must have been - will be putting up for sale v.shortly.
HTH,
Dom
the later 4.0/4.6 serp RR RV8 came with bigger ex ports than the 3.9 and are in my opinion the best stock factory heads ex port wise than any previous versions (please note: Range Rover stock heads not TVR) the 450 engine as a little bit of tickling here and there but stock valves although some 450 cars are reported to have come from the factory BV someone like Spend will give you more insight into this stuff quite frankly As you say, my 450 heads are BV 43/37, so some must have been - will be putting up for sale v.shortly.
HTH,
Dom
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