Engine number query

[Alba]

Having removed my engine as part of a re-furb project I have noticed that my 4.2 is possibly not a 4.2 !!!! I seem to remember a tale of woe with the engine and a previous owner and I would suspect I have had a transplant, presuming the engine number is at the front near the Hyd pump drive (doesn't match reg doc) can anyone throw some light if they saw the engine number or any other features on the engine, or do records exist that could be cross referenced.
It does state 4.5 on the head and the build date is 2002 (car is 1998) according to the engraving. Every other marking on the car and its components refers to the correct chassis Number that I am happy with.

Thanks

Edited by Alba on Monday 20th January 19:17

[Supateg]

http://www.pistonheads.com/gassing/topic.asp?h=0&a...

[Alba]

Supateg said:

http://www.pistonheads.com/gassing/topic.asp?h=0&a...

Thanks but I don't seem to have enough digits !!! According to the reg docs mine is supposed to be 4200875

[fatjon]

I have now rebuilt 3 known factory original 4.2 engines that were in fact 4.5 litres. It looks like TVR at various times stuck 4.5 engines in the cars with 4.2 inlets and then were economical with the truth on the registration documents. I could be wrong but I rather suspect that from some point the later cars all got 4.5 engines and the only thing that was different between the 4.2 and 4.5 models was the ECU map and inlets. Like I say, I'm 3 for 3 on 4.2's that are secretly 4.5s (91mm bore). The engine numbers all indicated 4.2 as did the log books. This might well explain why the performance figures are so similar in many cases too.

I suppose it was cheaper to just have one size of piston and liner made and also be able to line up engines ready built and just fir the right inlet manifold for the spec sold to the customer.

[scotty_d]

What year where the 4.2's you rebuilt? Maybe after crank issues the just started using 4.5 guts instead of risking further issues.

[fatjon]

Two were 99 cars and one was a 2000. I think, from speaking to a few people who have noticed this, that it's mainly later cars which are secretly 4.5L whatever the badge says.

[scotty_d]

fatjon said:

Two were 99 cars and one was a 2000. I think, from speaking to a few people who have noticed this, that it's mainly later cars which are secretly 4.5L whatever the badge says.

I could be lucky mines a 99 won't know till I pull the heads next year,

[cshaw4200]

Sounds very Interesting mine is a 4.2 registered DEC 99

[Alba]

Interesting .... But do records exist to double check my engine number?

It's clearly stamped 4.5 but are there any external features to check for? Talk of restricted manifolds and induction chambers but how do us "halfbreds" check without an internal examination?
Thanks

Edited by Alba on Tuesday 21st January 22:18

[ridds]

The number in the first picture is just a Head ID number.

4200 in the engine code means nothing as TVR labelled a lot of 4.5s 4200.

Only way to really check is take head off and measure bore diameter I would guess.

[Quentin1]

On the original engine, the number would have been something like XXXXP4200875

XXXX stands für YYWW (week of the year the engine was created, yours might have been from 1998 something)
P Petrol
42 4.2 ltr
00875 serial number

Your actual engine was done in week 24 of 2002.

[Alba]

Quentin1 said:

On the original engine, the number would have been something like XXXXP4200875

XXXX stands für YYWW (week of the year the engine was created, yours might have been from 1998 something)
P Petrol
42 4.2 ltr
00875 serial number

Your actual engine was done in week 24 of 2002.

Thanks Quentin, seems to fit the history timeline and could explain all the other 4.5 engine markings.

Do records exist to track down the history of the engine from the engine number as in was it new for the car or was it originally in another car?

Thanks

[m60ddy]

Sorry cannot help with referencing but just a quick question. What's the issue with the oil dip stick. I remember reading that the 4.2 engines had the dip on top in the middle of the engine, like mine,and the 4.5 had it to the front. How true is this and can it be applied to determine which size of engines??

[scotty_d]

My 99 4.2 has a dip stick at the front, no idea about the bottom end as I have yet to pull the heads.