6 replies to this topic

[Dodds1990]

a member on here has recomened i ask about information on how to convert an spi engine to a carb engine as it is something im looking in to doing.

can anyone give me up to date information on how to do this and be able to give me a list of all the parts i will need to do this conversion

thank you  

[cal844]

Hiya fella 😁

I'm sure from previous threads you'll need:

An electronic dizzy(with vacuum advance)
Inlet manifold and carb (ideal time to fit a stage one kit)
Mechanical fuel pump and new lines

You can plumb the fuel overflow from the carb to the fuel return pipe.

Someone will be along soon to correct us 😂

[Dodds1990]

no doubt they will I'm definitely thinking about doing it tho

[dyshipfakta]

You will also need an mot station with a dodgy gas analyser

[wile e coyote]

If you search there'll be lots of detailed results on the topic...  - but take note of warning above re MOT the job has been done many times but there is the theoretical issue.....

 

It's been a while since I did this but....above is about right for starters - you'll need a new inlet manifold with a vac take off for your brake servo - the MG metro inlet is about the best OE one...

 

I like using OE parts wherever possible -  the electronic dizzy on the spi one is "dumb"a 59DM4 (rare)  or  65DM4 (pop up on ebay regularly)  but your coil will be fine..

 

My memory may be faulty here - but I don't think the spi cam has the lobe to drive a mechanical fuel pump - so I used a facet cube type (nothing fancy only 3-4 psi needed)  with a regulator - you've already got an inertia switch in the spi loom (ended up swapping the cam to a 266)....

[cal844]

If you search there'll be lots of detailed results on the topic...  - but take note of warning above re MOT the job has been done many times but there is the theoretical issue.....
 
It's been a while since I did this but....above is about right for starters - you'll need a new inlet manifold with a vac take off for your brake servo - the MG metro inlet is about the best OE one...
 
I like using OE parts wherever possible -  the electronic dizzy on the spi one is "dumb"a 59DM4 (rare)  or  65DM4 (pop up on ebay regularly)  but your coil will be fine..
 
My memory may be faulty here - but I don't think the spi cam has the lobe to drive a mechanical fuel pump - so I used a facet cube type (nothing fancy only 3-4 psi needed)  with a regulator - you've already got an inertia switch in the spi loom (ended up swapping the cam to a 266)....

65DM4 is factory original for the last of the carb cars

[Retroman]

You will also need an mot station with a dodgy gas analyser

Or a good friendly mot man...ways and means

You may as well go the whole hog and dump the exhaust cat too, as they do nothing for power.

The spi cam will have the fuel pump lobe for a mechanical pump.

As above the MG manifold and HIF44 carb takes some beating, just make sure the carb is not too used.