Do I have a 4.5 or not
Discussion
ridds said:
It'll be a 4.5.
There are many 4.5's that have 4.2 on the log book and 4200 engine numbers.
Blame TVR, probably some dodgy or lack of correct paperwork when the 4.5 was first released meant they had to say they were 4.2's.
Mine is like this, 4185cc on the log book.
Well I have a 4.2 which says 4.2 on the log book, but has a 4500 engine number There are many 4.5's that have 4.2 on the log book and 4200 engine numbers.
Blame TVR, probably some dodgy or lack of correct paperwork when the 4.5 was first released meant they had to say they were 4.2's.
Mine is like this, 4185cc on the log book.
I think mine is a 4.2 it looks completley different to the 4.5's with the induction layout etc, but how would i stop any curiosity?
what can I check or post on here to confirm what engine size I have , or how would I know if it had any 4.5 parts in it like the crank(other than pulling it apart again)
I have not got any history relating to a 4.5 rebuild or replaced crank etc, I am trying to contact one of the previous owners of the car that rebuilt the engine sometime ago and changed alot of bits like later cams, bell housing mod, new clutch etc etc, to find out if he has missed anything from the history or can inform me of any unknown stuff.
what can I check or post on here to confirm what engine size I have , or how would I know if it had any 4.5 parts in it like the crank(other than pulling it apart again)
I have not got any history relating to a 4.5 rebuild or replaced crank etc, I am trying to contact one of the previous owners of the car that rebuilt the engine sometime ago and changed alot of bits like later cams, bell housing mod, new clutch etc etc, to find out if he has missed anything from the history or can inform me of any unknown stuff.
One of the best bets would be to stick it on a dyno and see what it's punting out - but it's NOT just about the top line figure of bhp...... the 4.5 should have a fatter torque curve in the mid range.
I've got an 02 4.2, put it on Joo's dyno really out of curiosity and also as a diagnostic to see if it was running OK.... was gutted with about 268 bhp, after replacing the air filter and a few runs it made just over 300bhp; then after replacing the rattling collapsing cats it made 370bhp - which would make mine a strong 4.2 (it's got new cats, and sports back box).
As you can imagine - it felt a lot stronger! (noticed this before had the final dyno run to confirm power).
Well reported that 4.2's had a decent map from standard, but 4.5's need some mapping to release full power potential - however, you should still be able to tell by the midrange - 4.5's should be stronger there.
I'd recommend getting a dyno run as a general health check anyway - helped me find an extra 100bhp!!!! Gotta be the cheapest 100 bhp gain anywhere??
I've got an 02 4.2, put it on Joo's dyno really out of curiosity and also as a diagnostic to see if it was running OK.... was gutted with about 268 bhp, after replacing the air filter and a few runs it made just over 300bhp; then after replacing the rattling collapsing cats it made 370bhp - which would make mine a strong 4.2 (it's got new cats, and sports back box).
As you can imagine - it felt a lot stronger! (noticed this before had the final dyno run to confirm power).
Well reported that 4.2's had a decent map from standard, but 4.5's need some mapping to release full power potential - however, you should still be able to tell by the midrange - 4.5's should be stronger there.
I'd recommend getting a dyno run as a general health check anyway - helped me find an extra 100bhp!!!! Gotta be the cheapest 100 bhp gain anywhere??
Hmmmmm, am I missing something here ?
You could go and book an RR session but you could, if you were pushed for time, always lift the bonnet !
The 4.2 motor has two visible fuel rails whilst the 4.5 has one, central one (hidden under the original, long, purple air intake tubes).
You could go and book an RR session but you could, if you were pushed for time, always lift the bonnet !
The 4.2 motor has two visible fuel rails whilst the 4.5 has one, central one (hidden under the original, long, purple air intake tubes).
Edited by Mr.Cerbera on Thursday 4th June 10:28
A 4.2 inlet system and fuel rails means nothing. Many later 4.2s were 4.5s as the blocks are all the same, all that was changed was the liners which were slightly bigger on a 4.5. I have it on very good authority that there are no very late 4.2s as TVR saw no point in having 2 sets of pistons and liners made when they could use one size and just badge engineer the cars.
So what it says on the block/logbook/anywhere else is meaningless. The only way to tell is head off and measure the bore. Although a figure of 388BHP is a fair clue that it's not a 4.2 engine.
I wouldn't worry about the insurance questions it raises, TVR obviously didn't. What insurance company is going to go to the trouble and expense of stripping a very expensive engine to find 300cc of extra capacity which would not have affected their premium anyway. Insurance is based on good faith anyway and you tell them what it should be and what you believe it to be in good faith.
So what it says on the block/logbook/anywhere else is meaningless. The only way to tell is head off and measure the bore. Although a figure of 388BHP is a fair clue that it's not a 4.2 engine.
I wouldn't worry about the insurance questions it raises, TVR obviously didn't. What insurance company is going to go to the trouble and expense of stripping a very expensive engine to find 300cc of extra capacity which would not have affected their premium anyway. Insurance is based on good faith anyway and you tell them what it should be and what you believe it to be in good faith.
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