Engine Conversion - B200E to B21A

[OppositeLock]

I know it sounds crazy but hear me out...

The timing belt snapped in my B200E the other day and we all know what happens when that goes. So now I have a Volvo branded boat anchor in the front of my little 360.

A mate of mine has given me '79 240 wagon which had a reco B21A engine installed less than 10,000 kays ago before it was ran into and written off. (I would really like to go bigger and turbo'd but I cant find any nor do I have the time for that sort of project at the moment)

So... Can I make this work? Can I strip down the B21A to a long block and bolt on the Manifolds from the B200E?

[Ride_on]

It will probably work, but like the turbo conversion you need the 360 oil pump, sump, water pump.

The main difficulty you have is the ignition system, I don't imagine the B21A will be compatible with your 360 Renix system, you could swap over the flywheel perhaps, but it won't match the engine and isn't adjustable, B21A has different compression ratio and camshaft. Best if you can transfer the 240 ignition (points?).

I guess you want to keep the 360 injection, I think it should be ok, you may have to plug some holes in the head (360 carb has water heated manifold) with core plugs and maybe unplug some (for thermal time switch. actually might be a bolt..threaded). I don't really know what the B21A head is like, just assuming it like the B200K.

[OppositeLock]

Yeah I knew about the sump and pumps.

But your right, the ignition is my concern and these are the questions I hope to get answered.

[volvosneverdie]

Yeah I knew about the sump and pumps.

But your right, the ignition is my concern and these are the questions I hope to get answered.

Megasquirt if youve got the ££££.

Programable managment=winz

[classicswede]

The conversion is quite easy tbh.

All the parts will bolt onto teh B21a engine from the B200e. The exact water set up on B21's changed from year to year but not to complicated to blank off the manifold heater connections.

You can bolt the 360 dizzy in place of the B21 item. I would personaly look at changing the cam for the bit of extra power but you do not have to.

[Fuse]

I would probably install the B21 ignition and install this to get rid of the points:

http://www.pertronix.com/prod/ig/ignitor/default.aspx

I installed the same conversion kit for my father's 240 with B23A and it's an excellent system. Very easy to install (just replace points with the sensor plate, install the magnetic sleeve on to the rotor shaft and route the wires to the coil) and doesn't require any maintainance after that.

Or you could find a later 240 ignition system which is hall-sensor based also and doesn't have points.

[OppositeLock]

The conversion is quite easy tbh.

All the parts will bolt onto teh B21a engine from the B200e. The exact water set up on B21's changed from year to year but not to complicated to blank off the manifold heater connections.

You can bolt the 360 dizzy in place of the B21 item. I would personaly look at changing the cam for the bit of extra power but you do not have to.

Shweeet, Thats what I wanted to hear. The B21 will be out soon and striped down to a block and head. When I get the B200 out, the sump, oil pump, water pump, flywheel, dizy, inlet manifold will get bolted on to the B21 and dropped back in.

Have I missed anything? Im about to start ordering gastkets and whatnot.

[Ride_on]

The conversion is quite easy tbh.
You can bolt the 360 dizzy in place of the B21 item.

Why would he want to do that? Surely the B21A will not work with the Renix computerised ignition with no points in the 360 dizzy, and timing wouldn't be right anyway if you swapped over the flywheel. Aren't they the same dizzy anyway just with points in the older one? Its not like the 940 cam end dizzy.

[OppositeLock]

Lets just think about this logically for just a minute and explain why this WONT work.

The common parts are the Head, Cam, Block and Crank. So I'm told by a handful of blokes that work/worked for Volvo say that they are almost exactly the same. They didn't redesign any of these parts between these models. The cam is my maybe, but still the firing order hasn't changed.

So im back to my original question. What is stopping me from bolting all the late model EFI setup on to this long block?

[Chris_C]

If it was the same, it'd have the same engine code. There are a load of different heads for redblocks, all have the same bolt patterns and port sizes, but they vary enough that the ignition timing should be different. Same with the cam, pistons and whatever else. The only way to find out is to look at the individual part numbers, VADIS, or find someone that knows (and you trust to actually know, rather than guess)

Yes, it'll run on modern ignition. The question isn't whether that is the case, most of the people on here could take a megane renix set up and fit it to a 1.7 300 (look at the amount of valvers on bike carbs with the 1.7 or even 1.4 renix ), but whether you'll be making more or less power doing so and how to get something that runs well consistantly

[OppositeLock]

Should be different? I don’t buy it, why would they change? I can think of quite a few engines that started there life as carburetted system and as time progressed EFI was introduced to the later models on the same long block essentially. The last one of these I did was a 202 from and early Holden and take all the related EFI bits from a later model doing basically what I'm trying to do now.

So much for thinking somebody had done something similar and it was gonna be an easy answer.

[volvodspec]

firing order and ignition mapping is like comparing fire with water, 2 completely different things.

yes, all redblocks share the same big piece of red-colored cast iron with only the differences in the piston bores (excluding the different crankshaft bearings); yet if you look closer into it there are countless variables for a redblock setup.

the thing with Renix is that it will only work 100% if the entire factory spec setup is used; who knows, you might find a setup that works even better than the factory made it to, or; like in most cases a setup where everything doesn't perform to factory standards (even if you might see an improvement on the factory spec)

performence simply depends on the correct ammount of mixture in the right ratio, compressed to the right ratio and with the spark at the correct time to get an optimal combustion.

it is not said that your old Renix won't work with the B21 parts, it's just that the mapping isn't designed for that engine's characteristics. this could mean that with a spark at the wrong time, you can get risk of detonating or an ignition that is retarted too much so you'll miss power. you can have the best mixture, compression ratio etc etc etc, if the spark isn't exactly at the right moment at the right height of the piston, it's all worth nothing. so in the end why would you put so much effort in the first 2 pieces of the formula and guess with the most important one?

my advice on any similar setup is to get a mappable ignition system and adjust it to you setup, Renix is brilliant on the stock setups what the mappings are designed for (V300 alone has 14 completely different Renix mappings!!!), but for tuning or hybriding engines the options are quite limited; does LH2.2/2.4 include a mappable ignition by any chance?

[Chris_C]

so in the end why would you put so much effort in the first 2 pieces of the formula and guess with the most important one?

This is what I was trying to say, but failing!

LH can be fiddled with, theres a chap on Tbricks selling Eproms.

[Ride_on]

Just to be clear EFI (Electronic Fuel Injection) is nothing to do with ignition, the injection system should be fine. It just delivers fuel according to air input, with some cold start stuff, it also has adjustable mixture.

Anyway, the other problem with ignition is too much advance will damage the engine. The high compression 360s tend to use quite high advances to make the most of the compression so the wrong renix could damage the engine. The B21A has different compression (to any 360) and a different cam. The simplest thing is just to stick with the B21A ignition setup which will have adjustable timing, albeit not as smooth as sensor+computer timed and needing points maintenance. It will be dead simple, you just have to mount the coil and run a wire from the points.

The 940 LH2.4/EZK has a knock sensor so if you fit that it may be ok aswell, but again need the right flywheel.

Having said that I have just looked up the B21A 240 ignition and it does have a particularly high advance at 15deg, so a B200K high compression renix might match it (assuming the vacuum advance profile isn't vastly different, don't know much about that), thinking a 414A Renix.

[classicswede]

The conversion is quite easy tbh.
You can bolt the 360 dizzy in place of the B21 item.

Why would he want to do that? Surely the B21A will not work with the Renix computerised ignition with no points in the 360 dizzy, and timing wouldn't be right anyway if you swapped over the flywheel. Aren't they the same dizzy anyway just with points in the older one? Its not like the 940 cam end dizzy.

The dizzy is quite differnt between the 240 and 360. The 360 dizzy takes a smaller rotor arm along with many other differences.

The B21A engine should work resonably with the renix ignition. I know with 240's I have swapped B200's with B21's and performance is very good and the set up works very well. I know the renix ingnition is not the same but even so the mapping will not be drasticaly out.

The best ignition system to use the dizzy and module from a K jectronic 240. No points and non of the renix problems.