My 122S

[Rick269]

Just thought I'd share some pics of my 122S. It's a '66 model and is fitted with a mild B20 (2.1L), 'D' cam, ceramic coated headers. Standard 4-speed manual. Currently a B20B head and 8.5:1 CR.
Recently, I have fitted an alternator from a Mazda 929. It's internally regulated and rated at 65 amp. Much better than the 30A Marchal! At the same time I upgraded to a electronic thermo fan in front of the radiator controlled by a temp sender from a Nissan Pulsar.
Also, I have gone the whole way with the ignition system and fitted a Megajolt Lite computer, using standard Ford EDIS components. It wasn't hard to install and transformed the car in terms of driveability, economy and performance. All up, it cost me less than $150AU. http://www.autosportlabs.net/MJLJ_V4...allation_guide
Future mods include fitting my supercharger and fuel injection system using the Delco 808 computer.
The dilemma I now face is that I also have a fully worked over B20E head to go on but if I want to fit my supercharger the CR will be too high, meaning I will have to get lower compression pistons, take material from the chamber or get a decompression plate. Any suggestions?

[Burdekin]

Hi Rick, very nice looking amazon you have. One suggestion is a F head, lower CR but apparently the pick for tuning. I think they were only sold in US and Ireland but maybe some of the more experienced guys could correct me. I use to live in Roxby Downs, can't remember seeing too many old Volvos in SA, must be a real head turner.

[Rick269]

I've read the B20F head is similar to the E but is nearly 5mm greater in height, resulting in the lower compression. But the E head I have is so nice and cost a lot to work over that I really want to use it.
Yes, the car does get a lot of looks and positive comments. Most people don't know what it is.

[Alf ista]

Lovely car Rick. Welcome to the forum!
Hugh.

[Derek UK]

Nice car, nice mods. Your current head/cr is fine for your supercharger. What do you think the cr is of your reworked head? The only way to get the cr down is to take more material out of the combustion chamber. Perhaps a bit more around the valve pockets or cutting the edge of the flat, squish area back. Some people put a notch in it opposite the plug but I don't know if that gives better numbers. Having a tight squish area is vital so thick gaskets and "shorter" pistons are a step backwords. Pistons need to come up very close to flush with the top face of the block. Skimming the top of the block to acheive this often done. The gasket effectively makes the gap that keeps the pistons from hitting the head.
John Parker did the initial work for his supercharger kit by just bolting it onto a well used 1800ES which gave about a 50% power increase with a pretty high cr. Developing your supercharger installation using your current engine and head sounds like a good idea to me. The D cam might even be a bit to racy for it. Your "nice" head can sit on the shelf for a while or you might consider selling it to add money to the supercharger kitty...........

[Tail]

Very nice car, love it

[Rick269]

Thanks, guys. Derek, I think the worked head will bump the compression up to 10:1. I'd really like to fit the supercharger but I think I'd better give the bottom end a freshen up before fitting it. So for now I'll fit the worked 'E' head and fuel inject it. Then I'll search for and F head while I'm enjoying N/A. I think 150hp shouldn't be out of the question which will be the limit of my clutch and I don't want the project to snowball out of control cost wise. I'm having a bit of trouble finding the bridges that hold the injectors in on the E head. They are not really common here. If anyone can point me in the right direction, it would be greatly appreciated.

[asneddon]

If you have gone to 2.1L (B21 pistons on an 8 bolt?), then you should be able to take quite a bit of metal out of your worked E heads combustion chamber. It sounds like you know what you are doing, so I wont point out the obvious ways of doing this.

[Rick269]

Ok, so is it normal when going to 2.1L that the compression will be lowered when using the standard B20B head? Or maybe I have low compression pistons already.
I didn't build the engine but the specs I got with it on a plaque are as follows:
Capacity: 2.1L
Cam: D
IGN: 22°. Fully Adv: 34°
Comp Ratio: 8.5:1
Octane: 91 RON
Int: 0.014 Exh: 0.014

From what I know, a standard B20B is between 8.7-9.5:1 depending on year?
To me the valve clearances look too tight as well, but I have kept them like this.
Also, to me 22° seems like a lot of initial advance but it ran well with the distributor at these settings and that's what I used as a baseline for my ignition map with the Megajolt. It could obviously be tuned better on a dyno though but at the moment it doesn't ping at all and will pull over 6000 in 4th.

[Derek UK]

Pistons are all the same. CR is set by how much is skimmed off the head for the B20E and B20F. It's possible to measure the height on the car with the valve cover off, at least, accurate enough to tell which one you have. B20E is 85.5mm and B20F is 87.0mm. This equates to 10.5 and 8.7:1 cr respectively. Assuming you have the latter and the 8.5 cr is correct it'll be due to the clean up around the valves or the bore increase. Valve clearances should be 16-18 thou for both valves with the D cam.
Ignition is best set after the basic set up. If you have no pinking that sounds good, you might even be able to go up another degree or so but max ignition advance is about right, again maybe 36º might be OK. The engine will be running at this over about 3500rpm so too much can burn holes in your pistons.
I believe that ignition timing with supercharging can be a bit of a nightmare.............