Now, I'd like to ask what are some sensible engine modifications to do to improve performance? I've got a B20 head I could rebuild and I wouldn't mind installing a racier cam. I've heard a lot of different opinions about different parts and I'm confused as to what to go with, especially with the cams.

What should I do with the head alone so I don't have to pull the motor?

I've heard one of the first things to do is to get a steel exhaust manifold, is there any truth to that?

 

By steel exhaust manifold do you mean a tubular steel header like this?

http://www.ipdusa.com/products/7011/108024-exhaust-header-ceramic-coated-fi-weber

If so, it looks like you have the dual down pipe exhaust manifold on your engine which is probably as good as it gets unless you have a full race engine. I suggest sticking with the existing manifold.

Do you have air filters for the carburettors? If not, you should get some. Driving around without air filters is a sure path to a long term decrease in engine performance due to accelerated piston / ring / cylinder wear.

There is probably not a lot you can do by modifying just the head. It all needs to be matched up (longer duration / high lift cams need to be tied to modifications to the valves, ports and fuel system to support increased air flow). If the increased air flow is associated with higher engine speeds then you need to start spending money on the engine block. This would include decking the block to set and match the clearance between the pistons and the head so that you have a proper quench zone in the cylinder. If you are pushing higher engine speeds you might need to consider different pistons, engine balancing ...... Modifying a B20 to make significantly more horsepower gets really, really, really expensive.

If the head is coming off for some reason, do a valve job to clean up the seats and valves. You could consider having the valve seats cut with multiple angles which might result in some small flow improvement and should be minimal additional cost. The valve guides could be replaced with new bronze valve guides and if you can find somebody who knows what they are doing, they could be shaped to reduce the flow restriction. If the engine is original and Finland has made the move to unleaded gas (I would expect so), have a machine shop install inserts on the exhaust valve seats to improve durability. Unless you make the move to a higher lift camshaft, larger valves or a camshaft that increases the engine speed, resist the urge to install double valve springs. They just increase parasitic losses in the engine. Also, unless you know what you are doing, resist the urge to modify the intake and exhaust ports. The exhaust ports on the B20 may not be great; but, just grinding out more is probably going to make things worse.

When the head is off, you should pull the lifters and examine them. Check for spalling on the contact surface with the camshaft. Volvo camshafts and lifters are notorious for wear at the lifter / cam interface. If there is spalling, both the lifters and the camshaft should be sent to the garbage bin! There are replacement performance lifter / pushrod kits offered by a bunch of different vendors which you can put in with your new camshaft. At that point, whether you go with a stock replacement or a different cam is your choice. I have no advice on alternate camshafts (experimenting with different cams gets expensive and time consuming, I prefer to drive my car!).

Its easier to do things that restore performance and perhaps improve reliability. Not so easy to increase performance. The low cost way to improve performance with a Volvo would be to sell the 144 and buy a used turbo Volvo 850!

 

Thank you very much for your in-depth reply!

I have air filters for them, yes, but for the first 300 miles or so I drove without it because the carbs needed to be adjusted (and the throttle linkages rebalanced and the exhaust manifold bolts retightened constantly) so it was more convenient without it on but once they calmed down I have put it back on.

I'm not interested in higher revs, I want it to stay together for longer trips! I'd be happy to improve the flow in and out of the engine and if there is some torque to be found that's always a plus

I'm making a new head since I forgot to change the valve stem seals off the engine and as a result it consumes some more oil than would be desirable. So that I can get to work daily I'm doing the changing on a separate B20 head. I thought this is a good opportunity to do some other head work as well as I don't have to go through the inconvenience of not having a method of transport while I work on the engine.

Why are bronze valve guides better than original ones?

Would it be wise to have some material shaved off the bottom of the head for more compression? I can only find 1.4 mm head gaskets and B20B original has 0.8 if I'm correct. If I shave the head will it change the combustion chamber unfavourably?

We have indeed made the move to unleaded gas but we have some additives in it that reduce knocking instead of using lead.

I inspected the lifters and the cam when I built the engine and there was no uneven wear. I also had a more experienced Volvo guy with me to speed things up building the engine and he was amazed at the condition of the camshaft and confirmed my opinion of the lifters.

In any case, the most important thing here for me is to learn about old-school simple engines, what to do and what to not do (such as forget to change stem seals) not so much to make a 450 bhp 2100cc overbore turbo race car

I do hope I remembered to answer to everything that was on my mind! I'll be reading your post multiple times to be sure to remember everything and I'll be back soon with more questions

Thank you again
Oskari

 

My recollection is that the original guides were some kind of iron or similar material. The advantage of the bronze material is that it is similar to a bearing material and appears to retain an oil film better than the original material. Not a performance advantage; but a durability advantage. The guides were not that expensive and if they are original its a good idea to do them if the head is off and you are working on the valves.

The lead (TEL) in the gasoline acted as a surface treatment for the valve seats which inhibited wear. Shortly after TEL was removed from gasoline formulations, auto manufactures changed the valve seat material to deal with the accelerated seat wear caused by the removal of TEL from the gasoline. Having a machine shop install inserts in the exhaust valve seats is the equivalent to using similar hard wearing seat material that modern engine manufacturers use. Nothing to do with dealing with detonation.

Shaving the head slightly probably won't alter the shape of the combustion chamber significantly; however, I would be cautious about raising the CR by shaving the head. If you are considering that path, first make sure that the piston to cylinder deck height is correct. This sets the quench band clearance in the cylinder. The B20 is somewhat prone to detonation and a correct quench band goes a long way to suppressing detonation. You would then need to cc your heads and with the correct deck height, you could calculate your clearance volume and your theoretical compression ratio. Then you can make a decision as to whether you want to change your CR. Sometimes an engine will tolerate a higher static CR if it has a longer duration camshaft. However, you would have to discuss that with somebody who has some direct experience. KG Trimning makes and sells performance camshafts for B20s. You might be able to get them to give you some guidance on appropriate CRs to go with their various camshafts (my recollection is that they are not cheap, at least compared to a stock Volvo camshaft).

As a cheap experiment, you might want to try putting in a Volvo D grind camshaft. The D grind comes out of the B20E engine. The combination of the D grind, 2 mm larger intake valves and a 10.5 (claimed) CR gives the E engine a claimed 12 hp increase over the B20B. Changing out the valves to larger diameter gets kind of expensive so I would skip that part. If you are going to replace valves, you are getting serious and need to discuss the work with someone who has a good reputation getting positive modifications out of the engine (again, that usually means $$$). The only reason I offered up the D grind is that they are available at a pretty low cost (around $100 in North America).

Cometic has a huge range of different thickness head gaskets for the B20 starting at .027 " / .68 mm. I don't know whether that is the compressed size or just the thickness in the package. Really expensive for a head gasket; but, if you need one at least they have them available.

As a suggestion, check out the pushrod performance forum on Swedespeed. You will get better advise on modifying the B20 for performance than I can give. I am closer to the stick to stock than the performance side!

Good luck with it and don't break the bank!

 

Sorry, I forgot to reply!

I read your post and took all the advice.
Had the head done by a reputable machining shop according to instructions.
Got a 0.8mm head gasket from Skandix which I'll install later this week, yay!
Also on Friday I'll order a pointless distributor with corresponding coil

Meanwhile I've done about 500-600 km with the new head and 2mm head gasket and everything's working well.

 

If by pointless distributor you mean the 123 distributor, do a little research on the Volvo forums. There seems to be a mixed response to how well the 123 works with the Volvo B engines (issues with MAP and engine speed advance curves). I have no direct experience with the 123 distributor so I can't comment directly.

If by pointless you just mean something like a Pertronix module, then there should be no problem. The Pertronix should work just fine with the stock coil.

 

I wrote about the 123 on a B20B. The problem is that the engine is set up for vacuum retard, and the 123 is set up for vacuum advance. When you put the two together you get a really screwed up car. I talked to 123 and they insisted that vacuum retard was a US-only thing which is simply not true. It's all B20Bs worldwide.

When I say "the engine is set up for vacuum retard", that means the vacuum port on the manifold is on the engine side of the throttle flap, so high vacuum at idle. The high vacuum retards the timing. Then when you punch the throttle the vacuum drops and the timing pops forward.

Vacuum advance works just the opposite. The port is on the air cleaner side of the flap, so at idle there is no vacuum. When you punch the throttle the vacuum level jumps up and advances the timing.

When you mix the two, punching the throttle causes the timing to retard which is exactly the opposite of what you want.

I ended up swapping ports around to connect the 123 distributor to a before-the-throttle-flap port. I don't know if it can be done on all models, but was possible on the B20E without having to drill and tap a hole.

123 was completely uninterested in acknowledging the issue, let alone fix it. Very disappointing.

 

I wrote about the 123 on a B20B.

That is an interesting story you wrote, never heard about that before. I acctually don't understand why people are so enthusiast about the 123. It is very expensive, about $420 in the Netherlands, and I did not notice much diffence with my old fashion Bosch system. One of the main arguments you allways hear is that you not have to check the contact points, well that not what you can call a big job! I still have a 123 ignation on my Citroen DS, I'll check how the vacuum hose has been connected today!

Best regards,

Mathieu.

 

One of the feature that the 123 offers is a set of contacts to trigger the fuel injection. That makes it pretty much the only replacement option for the distributor on a B20E or other Bosch D-jet injected car. That's why I went with it.

One possible reason you don't hear about this very much might be because the vast majority of these cars have been modified from their factory configuration. How many cars do you see that still have the original SU or Solex carbs as opposed to a webber replacement? It's just a guess, but I'll bet the webber has a correct vacuum port (it probably has multiple for max flexibility), so people just pick the port that seems to work best, and move on.

I've made a real point to keep my car as original as possible, so it still has the D-jet injection which is fully functional. The 123 distributor is of course a notable exception to the originality goal, but it's also why I bumped into this.

 

I've ran this engine with a B18 distributor because I didn't have a vacuum retard distributor at the time. I have both ports on my SU's, the other carb has the port after the flap and the other has it before the flap Then again I found the car runs best with the advance completely disabled

 

Head bolt cracked, hell of a job to get it out of the block as it snapped inside the hole in the block :facepalm:

Anyone know if it's possible to get an R-Sport cluster for a reasonable price? There's one on eBay currently but it's going for 800 dollars.

 

If the cluster is in nice shape and everything works, $800 is probably in the correct price range. Scabby looking ones that looked like they had been stored on a shelf outside in a shed for 20 years were going for around $400 when I was looking a couple of years ago. I decided I could do better by making up my own cluster which allowed me to use a GPS speedometer - eliminated problems with final drive and tire size changes.

Shame about the broken head bolt. Its a hassle; but, fixable.

 

Thanks for the answer!

Anyone got a spare "hub cap holder"? You know, the thingies that hook under the rim and have a hole for the screw for the hub cap I have only 3 of them

 

Guess what I've got coming in the mail...

Christmas came early this year :biggrinsanta:

Anyone got an electric diagram for the cluster?

 

Nice!!

 

Thanks!

So anyone know how to wire that thing

 

OE instructions can be found here:
http://sekokupu.pp.fi/volvo/lisavarusteet/montGT.pdf

 

Try davebarton.com. He sells a lot of electrical stuff for older Volvos. He has new gauge faces for the Rally clusters and he might have the wiring diagrams for them. There is another company around (can't remember the name) that specializes in refurbishment of the rally clusters; but, they may be reluctant to part with what they view as proprietary information.

Just for fun, the stock senders on the Volvo may or may not work with the rally cluster. Some of the clusters came with unique senders. There is a good discussion of that problem here:

http://forums.turbobricks.com/showthread.php?t=301665

If you need to find an odd ball sender for fuel or water, egauges.com is a good place to start looking.

 

Thanks guys! I'll have a look-see and report back once it's actually here. I was hoping it'd arrive by this weekend so I'd get a chance to tinker with it, but instead I've been tearing an engine apart to send a block to my machinist

 

Even the voltage regulator works!

 

Even the voltage regulator works!

How long before your engine is back together so you can test the tacho, etc?

 

Getting pistons mid next week, then delivering them to the machinist and after that a couple of weekends to put the engine in shape and in the car I suppose

 

Incredibly buggy video for some reason but speedometer works I tried the same RPM on the old speedometer, which was about 10% too optimistic, and it showed a bit over 40 km/h so looking good!

 

Everything else works on the dash except water temp gauge, it does react to switching the ignition on so I suspect I need a new sensor

 

The sensor is easy to test. I'm sure someone on here can post up a plot of what the stock sensor resistance should read vs. temperature. You can do this with a Ohmmeter, thermometer, and water from the sink. If you haven't filled the block with coolant then the hard work is already done!

Otherwise, you can buy a cheap potentiometer (a few USD?) to test if the gauge responds to different resistance values. I don't know off hand, but I don't think rigging up an impromptu simulation should be difficult. Or, you might already have one. The rheostat on your center console that dims the lights (if you have one, my 164 does but I don't know 140's) is just a potentiometer. You can measure the rheostat's resistance to see if it falls in the range of a functioning temp sensor and just use that.

Nice job on the engine!

 

Do you have the correct sensor for the water temperature? The 5 gauge rally clusters came with a unique temperature sensor, VDO part # 323-801-001-033N. The 4 gauge clusters like yours may also require a unique sensor. The part # should be stamped on the side of the sensor. The above VDO part has a resistance that varies from about 250 ohms cold to 20 ohms (gauge pegged in the hot zone). With a 250 ohm potentiometer or a 20, 100 and 220 ohm resistor you could test to see if you get movement on the gauge

 

I'll take a look at that next week, thanks for the tips!

Now my problem is that everything works perfectly except for one of the bolts that attach the oil pan to the block leaks oil. I'd get it if it leaked oil from the seam or to under the bolt, but it leaks on from the (how do I explain this) upper part... it leaks on the block, it seeps slowly from between the block and the screw. The seal between oil pan and block seems fine and doesn't seem to be the problem

 

Everything's been groovy for 3 months now! I've had time to do small maintenance work that's been waiting in queue after all the engine restoring etc... After rebuilding the engine the mileage went from 21 mpg to almost 30 in variable terrain

 

Vacuum retard was a mostly ineffective smog device for a time. When working on a car with one of those distributors, I just leave the hose disconnected and cap the manifold port. They run better that way.

Early B18 distributors used on low-compression engines had vacuum advance, but I don't think any U.S. market B20 did. The high-compression B18 version as used in the 123GT had only centrifugal advance. Vacuum advance was used on at least some B20s in Sweden I had such a distributor at one time).