Upgrading from 4.2 to 4.5?
Discussion
I do not think that only these are the differences... at least they sould put and different pistons on the 4.5 engine though 
Anyway , they can't be the same engines, maybe on some parts they are,for example the engine block and some othe characteristics like bore and stroke... but the 4.2 is 4200 c.c. and the 4.5 is 4500 c.c. that means that each piston on the 4.2 is 525c.c. and the 4.5 has 562.5c.c. pistons.Also the fuel trupmets (system) must be different as you said , the internal diameter sould a little larger
Also on the 4.5's the compression ratio is different , i do not want to go on some further details because i do not have the time to do that, but sure they are not same engines...
For some further details of the engines go to the official site of TVR www.tvr.co.uk
>> Edited by ByronTVR on Tuesday 22 October 18:20
Anyway , they can't be the same engines, maybe on some parts they are,for example the engine block and some othe characteristics like bore and stroke... but the 4.2 is 4200 c.c. and the 4.5 is 4500 c.c. that means that each piston on the 4.2 is 525c.c. and the 4.5 has 562.5c.c. pistons.Also the fuel trupmets (system) must be different as you said , the internal diameter sould a little larger
Also on the 4.5's the compression ratio is different , i do not want to go on some further details because i do not have the time to do that, but sure they are not same engines...
For some further details of the engines go to the official site of TVR www.tvr.co.uk
>> Edited by ByronTVR on Tuesday 22 October 18:20
Why don't you want to go in to further detail? You had enough time to write all that!
Besides, if they had the same bore & stroke, they would have the same capacity. You could use the same pistons with a different stroke to get different capacity. Who knows what capacity they both are in reality? The 4.2 could well be a 4.5 really, though I was told it still had different pistons, so maybe not.
Given that they seem to generate similar power, i.e. the variance between individual cars appears to be uncorrelated with capacity, I wouldn't bother. If you really care, you might get it dynoed to check the power. And speak to Joolz about adding another 25 with his inlet porting mods.
danny
Besides, if they had the same bore & stroke, they would have the same capacity. You could use the same pistons with a different stroke to get different capacity. Who knows what capacity they both are in reality? The 4.2 could well be a 4.5 really, though I was told it still had different pistons, so maybe not.
Given that they seem to generate similar power, i.e. the variance between individual cars appears to be uncorrelated with capacity, I wouldn't bother. If you really care, you might get it dynoed to check the power. And speak to Joolz about adding another 25 with his inlet porting mods.
danny
Well...if you see on the official site , that is not working at the moment 
they say that the 4.2 has
Engine: 4280c.c.
Bore: 86mm
Stroke: 88mm
and on the 4.5 is:
Engine: 4475c.c.
Bore: 91mm
Stroke: 86mm
As you said , that you can use the same pistons and get larger capacity with different bore and stroke but if you do that, the capacity will change to a minimum ...i mean it will not go from 4.280 to 4.475 straight away ,that's almost 200 c.c. more. ( you can not use a bore of half meter )
So i do not think they use the same pistons... propably they use larger ones and use different bore and stroke to get (different power-torque curve on the dyno) a little more power and different torque from the 4.5 engine well that differs from each 4.5 engine ..you all know that you may have the same engine but on the dyno , some of them are better, some of them are worse.
I did a mistake on my first post , when i said that these 2 engines may are common to other parts like block and bore and stroke , i didn't know how was the real bore and stroke of each engine. (i hope you will excuse me for that but i was in a rush when i wrote this msg...)
But i meant that, maybe they have common crankshaft , connecting rods , propably same crankshafts on the "pre" RR models ( i do not know if they are using different camshafts on the new models fitted with the RR from the factory...) , same cylinderheads and stuff like that.
Well that parts is not importand for the displacement though.
Better let Joolz to tell us his opinion ,he sure have seen the inside of these engines and tell us more infos about their differences.
Because i have never see or fix an AJP motor
Cheers!
>> Edited by ByronTVR on Tuesday 22 October 22:29
they say that the 4.2 has Engine: 4280c.c.
Bore: 86mm
Stroke: 88mm
and on the 4.5 is:
Engine: 4475c.c.
Bore: 91mm
Stroke: 86mm
As you said , that you can use the same pistons and get larger capacity with different bore and stroke but if you do that, the capacity will change to a minimum ...i mean it will not go from 4.280 to 4.475 straight away ,that's almost 200 c.c. more. ( you can not use a bore of half meter
) So i do not think they use the same pistons... propably they use larger ones and use different bore and stroke to get (different power-torque curve on the dyno) a little more power and different torque from the 4.5 engine
well that differs from each 4.5 engine ..you all know that you may have the same engine but on the dyno , some of them are better, some of them are worse. I did a mistake on my first post , when i said that these 2 engines may are common to other parts like block and bore and stroke , i didn't know how was the real bore and stroke of each engine. (i hope you will excuse me for that but i was in a rush when i wrote this msg...)
But i meant that, maybe they have common crankshaft , connecting rods , propably same crankshafts on the "pre" RR models ( i do not know if they are using different camshafts on the new models fitted with the RR from the factory...) , same cylinderheads and stuff like that.
Well that parts is not importand for the displacement though.
Better let Joolz to tell us his opinion ,he sure have seen the inside of these engines and tell us more infos about their differences.
Because i have never see or fix an AJP motor
Cheers!
>> Edited by ByronTVR on Tuesday 22 October 22:29
I had heard that the latest 4.2 had the same engine as the 4.5 except for minor differences.
This may or may not be true. What suprises me is that people still pay any attention to what is on the official website. We know they lied about the power of the 4.5 and probably the weight too so why believe the rest of it??
This may or may not be true. What suprises me is that people still pay any attention to what is on the official website. We know they lied about the power of the 4.5 and probably the weight too
so why believe the rest of it??I am sure that Joolz once told me that the only real difference between a 4.5 and a 4.2 on later cars was the inlets.
On early cars however, things are different. I believe that in this case the 4.2 and the 4.5 are different in capacity.
I could also be misquoting the man, and I am sure that he would confirm either way. Unfortunately I haven't seen him post on here for some time.
Steve
On early cars however, things are different. I believe that in this case the 4.2 and the 4.5 are different in capacity.
I could also be misquoting the man, and I am sure that he would confirm either way. Unfortunately I haven't seen him post on here for some time.
Steve
Unfortunately Joolz isn't able to use the internet since he installed a new burglar alarm system that pings his phone line... I think he should be back soon with a second phone line installed!
ByronTVR - I love the way you quote the TVR website or your opinions as factual
As for not being able to increase capacity significantly via increasing the stroke with a long stroke crank - how do you think TVR's Rover V8 gets from 4.5 to 5.0 litre? Yes - that's right, a long throw crank!
However, I believe the 4.5 AJP has a wider bore, just that the later 4.2's probably do as well. The engine's designer told me that the 4.2 still has a different piston (is on version 3), so am slightly more inclined to believe that.
The Red Rose 4.5 has the same crank and camshafts and unaltered capacity. The heads may be the same casting, but they're significantly ported.
Besides... original point still stands - not worth "upgrading" a 4.2 to a 4.5 imho!
danny
ByronTVR - I love the way you quote the TVR website or your opinions as factual
As for not being able to increase capacity significantly via increasing the stroke with a long stroke crank - how do you think TVR's Rover V8 gets from 4.5 to 5.0 litre? Yes - that's right, a long throw crank!
However, I believe the 4.5 AJP has a wider bore, just that the later 4.2's probably do as well. The engine's designer told me that the 4.2 still has a different piston (is on version 3), so am slightly more inclined to believe that.
The Red Rose 4.5 has the same crank and camshafts and unaltered capacity. The heads may be the same casting, but they're significantly ported.
Besides... original point still stands - not worth "upgrading" a 4.2 to a 4.5 imho!
danny
Hello!
Well, i do believe that the figures on the TVR official site are not true...but as much as refers to the performance of these cars etc etc.
I do no think they could lie also about the Engine charachteristics...why should they ???
Also..when you say crank what do you mean? crank= crankshaft ???
But let's do not rush ourselves,...let's wait for Mr. Jools to tell us his opinion and the differences.
Cheers!
>> Edited by ByronTVR on Wednesday 23 October 15:04
Well, i do believe that the figures on the TVR official site are not true...but as much as refers to the performance of these cars etc etc.
I do no think they could lie also about the Engine charachteristics...why should they ???
Also..when you say crank what do you mean? crank= crankshaft ???
But let's do not rush ourselves,...let's wait for Mr. Jools to tell us his opinion
and the differences. Cheers!
>> Edited by ByronTVR on Wednesday 23 October 15:04
It's worth upgrading to the 4.5 Red Rose if you have 4000 quid burning a hole in your pocket :-)
But given the standard car with 350 wheelspins all over the place anyway, it's probably a better idea spending around 1000 on awesome suspension instead - makes massively more difference speed wise & fun wise on road & track!
danny
But given the standard car with 350 wheelspins all over the place anyway, it's probably a better idea spending around 1000 on awesome suspension instead - makes massively more difference speed wise & fun wise on road & track!
danny
Well,,.... with a few more money , you could bold on 8 Forged pistons and a NoS kit :P just kiddin.
But the best way to have more power everywere , is the 4.5 RR as christof says When i'm say everywere , i mean on a trackday , or if you racing on the countryside roads etc etc...! NoS is only for the straights as if you use it on turns you could get yourself killed.
ByronTVR
:P just kiddin. But the best way to have more power everywere , is the 4.5 RR as christof says
When i'm say everywere , i mean on a trackday , or if you racing on the countryside roads etc etc...! NoS is only for the straights as if you use it on turns you could get yourself killed. ByronTVR
But if you have a lot of money to spend, you bold on the 4.5 , 8 good Forged Pistons and a NoS kit just in case
The NoS kits prices starts from 600 pounds i think.
If you are happy with the existing power of the 4.2 AJP or 4.5 , as danny said is better idea to put a better Suspension on the car!!!
ByronTVR
>> Edited by ByronTVR on Wednesday 23 October 20:44
The NoS kits prices starts from 600 pounds i think.
If you are happy with the existing power of the 4.2 AJP or 4.5 , as danny said is better idea to put a better Suspension on the car!!!
ByronTVR
>> Edited by ByronTVR on Wednesday 23 October 20:44
Well...if you're still intrested to have more power "Everywere" you want check out this Topic
www.pistonheads.com/gassing/topic.asp?f=13&h=0&t=4675
Little Oldy but good!
It cost's 4.5K , but sure it's gona make your car an Earth Rocket!
ByronTVR
www.pistonheads.com/gassing/topic.asp?f=13&h=0&t=4675
Little Oldy but good!
It cost's 4.5K , but sure it's gona make your car an Earth Rocket!
ByronTVR
Is it possible to fit a V10/V12 under that long bonnet and if so would that be advantageous or too heavy? with Nos of course? And another thing, is the speed 12 basically two speed 6 engines strapped together if so is it possible to do the same with two V8s. I have a Chimaera at the momment but i will be upgrading to a Cerbera soon 4.2 or 4.5. I think 4.5 but if i can sqeeze a rediculous engine in i will get a 4.2 and replace it with something better. Any suggestions? S3TAY.
>> Edited by john yates on Monday 28th October 19:07
>> Edited by john yates on Monday 28th October 19:07
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