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engine swap legalities
Posted: Tue Jan 13, 2015 8:37 am
by stew72
I've got a feb 1993 registered 318 cab with a catalyst, I may have the chance of buying a 1989 325 as a donor for the running gear, the plan would be to completely refurbish and fit as factory.
Is it possible to do this legally given my cars post 93 and needs catalyst testing for the mot?
I'd prefer to do it properly and change the log book, will this cause further complications?
Thanks
Re: engine swap legalities
Posted: Tue Jan 13, 2015 8:51 am
by DanThe
Im sure the tester has to test for whichever is the oldest, therefore they would test with the earlier rules/pre cat as your engine is older. If your buying the car just keep the reg doc and take it with you for MOT to prove the age of the engine.
There is no requirement to change your reg document, and just because you have doesnt mean the conversion is 'done properly'
Re: engine swap legalities
Posted: Tue Jan 13, 2015 8:59 am
by Gert_8
And don't forget to inform your insurer...!

Re: engine swap legalities
Posted: Tue Jan 13, 2015 9:50 am
by stew72
Insurance is a given.
I've got a feeling that at some point engine swaps not declared on v5 may become an issue, hence wanting to changethe v5 if practical.
Re: engine swap legalities
Posted: Tue Jan 13, 2015 9:54 am
by Gert_8
I was only pulling your leg, but it's surprising how many would make a change and not advise the insurer.

Re: engine swap legalities
Posted: Tue Jan 13, 2015 11:11 am
by jmc330i
As Dan says, the emissions test will be carried out to whichever is oldest so as the engine is pre-cat test, a pre-cat test is what you should get. But, the testers around my way are now getting hot on wanting proof of engine age (if you say its older than the car) and it's down to whoever is presenting the car for mot to prove, so keep a copy of the donor V5 and take it with you (as long as the engine number matches).
As for informing the dvla, I personally wouldn't bother as it can bring more hassle than is needed. The dvla will only be interested if the change of engine cc moves the car into a different tax bracket, which it won't with an E30.
Re: engine swap legalities
Posted: Tue Jan 13, 2015 11:13 am
by Kos
One for Jamie I think
Re: engine swap legalities
Posted: Tue Jan 13, 2015 11:49 am
by jmc330i
Just to add, before I fitted the M44 engine to my '93 touring I MOTd it with an '89 engine fitted. It had a pre cat test without issues.
Re: engine swap legalities
Posted: Tue Jan 13, 2015 1:39 pm
by DanThe
stew72 wrote:
I've got a feeling that at some point engine swaps not declared on v5 may become an issue, hence wanting to changethe v5 if practical.
Not exactly the best reasoning for causing yourself a potential load of hassle, if the DVLA want to inspect your car you wont be getting the V5 back anytime soon
It is not the law to inform the DVLA of an engine change unless for reasons that James has stated
Re: engine swap legalities
Posted: Tue Jan 13, 2015 1:59 pm
by polsta
Gert_8 wrote:I was only pulling your leg, but it's surprising how many would make a change and not advise the insurer.

Seems every time you click an ebay add for a "325" for it then to go on saying it started life as a 316 , and it's still registered as a 316 and up to you ...
Re: engine swap legalities
Posted: Tue Jan 13, 2015 2:10 pm
by Brianmoooore
If it was born a 316i, it is still a 316i and will always be a 316i. This is the model name, that happened also to be closely related to the engine size of BMWs at the time, but is still a model name, such as Corsa, Panda, etc.
It may now be a 316i with a 2.5 litre engine, but it's still a 316i.
Re: engine swap legalities
Posted: Tue Jan 13, 2015 2:19 pm
by Brianmoooore
Problem of proving engine age only occurs if you fit an engine such as an M20, that was fitted as standard in another E30. If you go for an engine such as jmc330i's M44, a M42 in a touring, or a M5x then these are all tested to the pre cat. limits, even if both engine and E30 are post 08/1991
Re: engine swap legalities
Posted: Tue Jan 13, 2015 5:32 pm
by HairyScreech
^^ How so? Is there a non-standard to car loop hole I am not aware of?
Re: engine swap legalities
Posted: Tue Jan 13, 2015 5:52 pm
by jmc330i
If the combination of car and engine was not offered by the manufacture, so E30 with 24v or V8 conversion, E30 touring with M42 or M44 etc etc, then the emission test is to be carried out to the pre-cat limits as long as the car was first used before Aug 1995.
Vehicles first used between Aug '95 and Aug 2002 have slightly different rules.
http://www.motinfo.gov.uk/htdocs/m4s07000309.htm
That's how my '93 touring with '99 M44 engine is MOTd with a pre-cat test

I won't say it was easy trying to teach the tester his job though

Re: engine swap legalities
Posted: Tue Jan 13, 2015 6:11 pm
by maxfield
That flow chart is from the MOT manual, so as above it should be tested pre-cat. And make your MOT tester aware of this. There's that many laws that change all the time.
Re: engine swap legalities
Posted: Tue Jan 13, 2015 7:03 pm
by Brianmoooore
Lines three and four of note 2 can be used to advantage if necessary.
Re: engine swap legalities
Posted: Tue Jan 13, 2015 7:29 pm
by stew72
Brianmoooore wrote:
Lines three and four of note 2 can be used to advantage if necessary.
Good point although I'd expect most mot testers to take this route if they can't find the engine details in 30 seconds