I’ve owned my car for going on 2 years, many parts updated. When I received the car, I rolled over 100K miles. I don’t know the history of the engine, but she runs strong. I’ve been considering an SU triple carb conversion from my dual Strombergs. I’ve found a used complete kit and wondered what thoughts are if in my situation? Would you consider converting?

 

If you have the kit already, do the swap. Back in the 70's, after wrecking my '69 E, I found a '66 car with a blown engine so we put the 69 motor in it and transferred the triple carbs from the '66 onto it. Ran like a charm.

 

Hi Smonop,
I have heard from many E-Type owners that 3 carbs is the way to go. I feel the same way.
In the past I have had a 68 OTS with triple webers. It felt fast and it looked great.
I now have a 68 FHC that I am restoring with some upgrades to improve drivability and reliability. I an installing an SU three carb set up. However, I also had the head replaced with an XJ6 head that has bigger valves to go with the carbs. You don't have to replace the head to benefit from the trip carbs. I did it because since the engine was being rebuilt, might as well.....
I have a 67 OTS that of course has the triple carb set up from factory, and it does seem to have more pep than the 68 had with the double strongbergs. If for no other reason, the engine compartment looks great with the three carbs. This is the type of modification that will not take away from the value of the car. In fact, it may increase its desirability. Just make sure to keep the original cabs and manifold for the next owner in case they want to return the car to the original spec.
Good luck.
Bill.

 

Great advice! I will keep the group posted, appreciate it!

 

Just remember that the 2 strombergs Vs 3 SUs wasn't the only difference between UK and USA spec cars. The UK spec had a 9:1 compression engine Vs 8:1 for USA spec, timing and advance/retard mechanisms were different, emission controls, etc. Still worth going for the conversion though, and maybe then making the other changes as you go. Webers can be great, but many report difficulties setting them up/keeping them in tune, as well as idling nicely, and it's probably not worth it unless you're going for different spec cams etc.

 

Thank you for the additional info. I’m going to pursue SU carbs. I’ve read about what you have pointed out regarding Weber set up, tuning, etc.

 

The full kit for 3 SU carbs, will include every thing you need, with the performance improvement coming from the Triple (twin-port-balanced) manifold not the extra carb. When the two ZSs are at 3/4s throttle, the 3 SUs will be at 1/2 throttle or less. You will need to source the pre-smog vacuum advance distributor yourself. (a Pertronix D171618 High performance distributor and matching #45011 coil will be fine)

Some improvements you can make:
1. Do some port work between the new manifold and the Cylinder Head using a intake gasket to show you where the mismatches are, they can be significant. Also trim final intake gasket so it does not intrude in to gas path.
2. If you are going to overhaul cylinder head, use a core from XJ6 S3, they have the larger intake valve.
3.The K&N filter flows better than Jag stock.
The combination of pre-smog ignition and carburation will definitely be felt in seat of the pants driving, and you will get the classic look for an E-type.
Rgds
David

 

Great advice David, thank you!