1.4 to 1.7 engine swap

[arekpol]

Hi,

I found a 340 with a perfect rust free body but the engine and transmition is is dead. I was wondering if it's easy to swap the 1.7 engine and transmition from my 340? Are the engine mounts the same or there has to be some modifications done? What else should I swap from the old one to make it work?

Arek.

[340GLT]

Engine mounts are different!!! The best bet is to swap everything from the prop forward engine wise renix etc. And then if you think the transmission is shot too swap the gearbox and final drive!!
Cheers Adam

[5lab]

its unlikely both the engine and transmission would go together - what clues are there as to death?

yes though, you could do the swap

[arekpol]

I was told that the transmition is dead by the owner.

Arek.

[antiekeradio]

ah well, might be that it's all OK with a few small fixes after all.

if engine/box turn out to be shot after all, be assured that is IS possible to swap.

as said, you need to transplant quite a lot of 1700 specific parts.
the renix is certainly one of them, it's very specific for the 1.7 !!!!
(1.4 looks exactly the same.. but look at the numbers)

Greetings Wouter

[arekpol]

Sounds like a lot of work , but nothing me, my brother-in-law, and few beers can't handle

[classicswede]

With all the parts to hand you should have it all together over a weekend.
Let us know how you get on.

Dai

[huskyracer]

I did basicaly this swap in mine. it is no problem realy as long as you have the 1.7 belhousing and mounts. the renix is diffarent but I think the 1.4 one will run the car, just not that well ! as Dai said, if you have both cars, the swap can be done easily in a weekend. Good luck!

[antiekeradio]

as I said (didn't say it for nothing...), the B172K has a very specific renix unit.

the engine _might_ run, but not even remotely drivable.

some explanation:

B172K is designed to run quite lean on partial load. the ignition is really retarded at idle. upwards, it advances quite steeply (more than 1.4)

as a result, renix from 1.4 would always have ignition times that are way off desired, wich (certainly in combo with lean mixture!) might lead to severe engine damage (burnt valves, hole in piston etc)

[classicswede]

It could be very usfull for me to see the two ignition curves together and see if it would be suitable for my LPG 1.7 as I need more advance low down and less high up.


Dai

[huskyracer]

renix from 1.4 on a 1.7 gives very retarded ignition timing, which 'shouldnt' cause damage, as said it will run the car but not well, I put this in just in case the 1.4 unit has to be used to prove/eliminate a problem, not to suggest its use to drive the car around. the 1.7 uses a lot of ignition advance to ovecome the poor combustion chamber shape caused by the flat head/bowl in piston design which has an excessively large surface area which means a slower 'burn' time, using a 1.7 renix on a 1.4 could as you say cause major internal damage as the timing would be way too advanced causing pinking/detonation which will destroy the pistons in very short order. hope that clears this up a bit

[classicswede]

That makes sense, was just a thought but will not work. It would maybe work the other way. 1.7 renix on an LPG 1.4 but idealy want remapping.


Dai

[antiekeradio]

retarded timing is bad as well.

spark comes too late, then the mixture starts burning -but way too slowly-, keeps on burning until exhaust valve opens.

it will not give instant destruction as might happen with too advanced ignition, but still its a killer.

[huskyracer]

Agreed, retarded ignition can damage an engine, but as said, i would use the wrong renix ONLY to test. also, you would notice things like the exhaust manifold glowing red hot and the fact that the car would have about ten horsepower long before you broke somthing. Boosted engines are a whole new ball game though.......

[antiekeradio]

yep, agreed to that!

testing will be OK. perhaps even some nice afterburn bangs