Oh Brian, wash your mouth out!! ha ha
El Stiemo, how does this strike you?
My finnie with the 450V8 should be rego'd and on the road in the next month. I originally had a 302W ford motor, but to get it sitting nice and low, you have to change the steering = major work.
Just in Brisbane Australia here we have many V8 conversions going on - my 450, a finnie sedan changed to a 2 door convertible with a 500, another sedan with a 500, one with a 302W and one with a lexus 4.0. So we have all learnt a lot!
Go to my photobucket page for a look at what I did - I think if you go to my profile it is there. I went extreme with the trans tunnel transplant - no need to do that, but you will have to make some room for the flex disc. Anyway, here are some pointers:
- An M117 would be the best motor as they are lighter alloy rather than cast iron, so handling is better. They come in 380, 420, 500 and 560. Injection systems could be K Jet or KE Jet - KE needs a bit more wiring.
- you need engine arms from the M116 3.5 (or maybe US 4.5?) V8 and the motor will bolt right up to the standard mounts. need V8 mounts.
- exhaust manifolds from a 3.5 fit well
- the biggest problem with the V8 conversion is the diff ratio. The finny diff has to go, and you need to find the lowest numerical ratio diff you can from W108/9. At least one from a 3.5/4.5 (say 3.69 from memory), but best would be a 2.88 from a 6.3 - but this will set you back some $$$. These options give you 4 wheel disc brakes - so you need to remove the valve in the master cylinder that retains pressure for hte finny drum brakes (not a big job).
- Tail shaft will need to be modifed to join the trans to the diff
- Upgrade the front brakes to V8 units. The vented ones from a W108 3.5/4.5 work well. vented from 6.3 is great. Beware that you may need to change stub axles - I just grabbed the whole front subframe from a W108 and bolted it in.
- Ideally beef up the radiator. I used a W108 unit with the finny sides soldered on so it could bolt into the panel. May need some light metal massaging to move it forward a bit. No room for the oil cooler, so if you plam on towing, will need to consider aftermarket unit mounted underneath somewhere.
- speedo - depends on what motor you use. 450 can use a custom made hybrid cable with the trans end as per W108 and speedo end as per finny. W126 motors (M117) have an electronic speedo, so you would need custom gauges or a box from an instrument specialist that can convert pulses into a spinning cable.
- need to rig up a throttle linkage - see a 108 with a V8 in it. Or cut the bit on the firewall out of the W126 and transplant it.
Anyway, I have to get going but you get the idea. Not too hard, but all the work adds up. This is a good exercise for me actually, as I am just tossing up what to do now with my coupe that just arrived from the paint shop. I was going to stick with the standard 250 motor, but the paint came out so well that it almost seems a shame to underpower it with the 250. So I need to do some thinking as to if all the extra work and cost is worth it. I am wondering if there is even a more modern MB motor to put in?? Any ideas others? M103/4 6 cyl? M113 V8?? How big is my budget and how much time do I want to spend on it??!!
A 6 cyl engine from the period is much easier though. Gee if you were in oz I could hook you up with plenty of engines very cheap, from 220's to 300's. I had a 280S motor from a W108 in my red finny and it went well. Just needed some wiring, speedo cable and shortened tail shaft. I ended up bolting in the W108 rear end so the diff ratio was more highway froendly too. M110's also go well, but you need to massage the trans tunnel again.
If you need more info in a hurry, then email me as I only log on here from time to time.