Alfa Sud 1600cc race engine specs

[PSk]

Okay Genius asked me if I wouldn't mind posting the specifications of the engine I used to race ... so I thought, well, I do not race anymore so why not ...

This engine was built in 3 stages (the first was nearly standard with a simple bit of blue printing and porting ... a great little strong engine, the second stage was about a 170hp engine that was not very reliable and we learned absolutely heaps about these engines during this phase, and the last stage was a 200hp extremely strong and reliable engine ... that I only killed because I missed a gear causing the crank to crack and later break).

• Okay the engine was actually 1598cc and this was made by using a 1500cc crank and a 1700cc block. Originally we just bored the 1500cc block, but this proved problematic as the block walls flexed and eventually cracked. We cut the block in half (after it cracked) and the walls were less than 1mm thick on one side ... thus a poor casting ... and also was costing us hp. Thus we bought an Alfa 33 1700cc short block.
  I would not recommend boring a 1500cc block ... Alfa 33 1700cc engines are cheap enough. (If you are going to play with serious mods, the cost of an Alfa 33 engine/block is small change compared to the rest of it ).
• We then had slipper pistons made by Cosworth. Very slow delivery ...
• We used the Alfa 33 conrods (which are slightly thicker than the 1500cc rods). The rods were shot penned and obviously balanced, with brand new rod bolts installed.
• The crankshaft was also renitrided, balanced and also straightened (the nitriding I think bent it).
• We made a new flywheel (er, Randell Edgel did) for a Titon twin plate clutch to mate to a Ford straight cut gearbox. This flywheel was miles lighter than the normal Sud one and the clutch miles better for racing than the undersized little Sud one.
• The oil pump drive was modified so that it only turned the distributer.
• The rear casting of the engine was modified and the oil filter housing cut off and a fitting for an oil line welded on in its place. This allowed the engine to be moved further back in the sportscar that I built and more room for my feet.
• A tiny sump was made with a curved windage plate. The sump had a trough in the middle that had 2 mesh fittings sucking the oil out of the sump.
• The nose end of the crankshaft had a new tooth belt pulley added for a dry sump oil pump that sat on top of the block in the middle.
• I also installed a tooth belt pulley for the water pump ... because and this is a serious warning for all high revving Sud owners, the V belt pulley broke at 8-9000rpm and took a cam belt off and bent all 4 valves, etc. Thus I made a toothed belt drive system that drove the water pump directly from the crank and also slowed the water pump down a far bit. Note: We removed the alternator and just charged the battery the night before a race meeting.
• The head faces of the block were machined to increase the compression ratio to 12.5:1 ... the block was also o-ringed (this probably was unnecessary ?)

I think that completes the block work. Note we ran the dished pistons (with cutouts for the valves). If I built another engine I would use the later Alfa 33 heads and the flat pistons because the pistons would be even lighter ...

To be continued ...
Pete

[PSk]

Okay now we look at the really expensive part, the heads.

We had had heaps of trouble running race cams that Alfa Romeo supplied (with the 170hp engine). These cams were still the split type. I must say it was very frustrating dealing with Alfa Romeo and trying to buy these cams ... we ended up getting cams we really did not know anything about. Again I would not recommend stuffing around with them ... just get the Cosworth cam grinds specifications and then choose a cam grind. As many, many Ford engines use these cams and many, many people know about them it is heaps easier.

Anyway runnig high lift split cams just fncks the buckets. The top face concaves and thus the bucket grows and machines the aluminium camshaft housing ... until you have a knocking noice and a buggered housing. I was not the only to have this problem ... and imagine that these camshaft housing are a fairly rare item, especially in NZ

Note we were running 12.5mm lift and big duration ... which I cannot remember.

Thus modifications as follows:

• Head and inlet manifold massively ported. Inlets ported to suit 45mm Delorto downdraught carbs. All unnecessary holes, etc. were plugged.
• As big as possible stainless steel valves were installed, along with new seats (obviously) and new guides. Randell Edgel does a really nice trick with his valve guides ... which I would like to reproduce for my 1750's engine, even though it will be standard. Anyway he makes them with a step so they cannot sink into the head. Hope it was not a secret .
• Camshafts were MADE, yep I found a small engineering business somewhere in Auckland and gave him the split cams and told him to make new blanks (I would get them ground). The big difference with these cams is that we drilled the cam from end to end and thus supplied oil directly to the cam lobes (via tiny holes in the non-lift side of the lobe). Randell and I were concerned that maybe the followers were not getting enough new and thus cooled oil ...
  Note the cams were not of split lobe design but normal wide lobes.
• New buckets were made to have the shims under the buckets like normal overhead cam engines.
• Camshaft housings were modified (I did the engineering drawings for this ... as I used to be an design draughtsman, and thus had access to AutoCAD) and brass sleaves installed for the buckets to run in. These sleaves were as long as possible to support the buckets. The standard design is weak in this area and allows the buckets to come out to far ... again with high lift cams. These brass sleaves went right down to the top of the head surface and thus were clamped in place when the cam housings were bolted on to the head. They had an oil drain hole ...
• Cosworth double valve springs were installed ... you will have to ask Randell about what rating ... but never had a problem or valve bounce.

I think that is the major work. Ofcourse there are many other little things we had to do, like modifying the throttle cross shaft to work with the narrower block, etc.

I also made up 4 into 1 extractors to Randell's specs. and these had very short primaries and were a challenge. Unlike in a Sud engine bay though, I was able to run them forward and they collected infront of the engine ... just infront of the end of the crank. Lots of heat sheilds, etc. ... and exhaust wrapping.

Anyway this engine came on cam at 5000rpm and was still making power at 9000rpm. Had great pulling power below cam and really just got angrier when on cam and pulled real hard. The best engine I have ever driven ... by far! I used to rev it to about 8500rpm all race day long and it never missed a beat. Sometimes when pushed I would use 9000rpm ... but my pockets were not completely endless

I used to check the valve clearances all the time and they never altered ... even after the missed gear instance where the engine revved right off the end of my rev counter (thus way past 10000rpm). For some reason the rev limiter did not work ????

We really should have pulled the engine and stripped it, but as we could not find any thing wrong with everything we could check ... we stupidly went to the next race meeting. I think it was the third race that day when it let go ... and it just destroyed itself. There was not a valve straight, bucket, or cam undamaged. The crank broke between number 1 and 2 ... and broke the front main bearing cap. Real sad ... and I decided not to fix her after a $8000 estimate, and retired from racing and went to Uni. instead.

Over the years I had spent a fortune rebuilding Sud engines, it is a shame that this engine never ran again, because we finally got it right.

I seriously reckon with Carello rods, later heads and thus flat pistons that 210hp is achievable at 10000rpm. I'm not sure whether it would be possible or even advantageous to run 50mm carbs (or fuel injection) but these engines are much better for making power than the Alfa Nord engines. The only thing against them is they are heavy. The block weighs way too much ... but is bloody strong.

Good luck to all that take on the challenge.
Pete
ps: I also have to say that Randell Edgel who did a lot of the work on my engine(s) personally does the most beautiful work. The machining was to extremely high tolerances and just beautiful. In the end I wanted BIG power, and while we had a lot problems over the years we finally got it right. Considering this was the first full race Sud engine he had ever built, and myself ... you have to expect to pop a few in the learning process.

I used to put my engine together, Randell did most of the specification and machining work.

[PSk]

I have some old photos so will scan ...

Pete

[genius]

I don't know what to say...I'm gobsmacked !!...

I think I may be paying a visit to Edgel Motorsport when the planning stage is over (although my 1800cc 8V may be a bit tame compared to this little lot !!.

[PSk]

Yes it was fun ... .

Right, here is the Alfa Sud I used to race. This car never had the 200hp version of the engine. Only the first 2 versions. Thanks to the development issues with the 170hp engine it is probably known as an unreliable car ... but the problems were really caused by us learning ... and also I made the extractors for this engine with way to large primaries, thus we had a flat spot (big) which made the power come in very suddenly and the car very hard to drive.

This Sud when everything worked was fast though ... and with the 200hp motor would have been a rocket ... inbetween gearbox rebuilds .

[PSk]

Cylinder head pictures showing the brass sleaves:

[87Sprint]

wow - thanks heaps for sharing that! Ive heard allot but racing boxers in terms of power output but never anything indepth as to what sort or work or route is taken - its all very interesting! My mechanic here in adelaide seems to do allot of race engines of all sorts and he had a 1600 boxer however the route taken was to stroke the 1500 block - although it didnt have a dry sump setup he said it was around 170hp. its a pitty our cars are getting older and as a concequence all this sort of stuff is becoming more and more of a black art! - wouldnt it be great to see a article in a car mag about this sort of stuff now! Still i suppose only someone who loves alfas can justify $10,000 for something that puts out less power than most standard imports

[PSk]

As you will see we put this engine in the front of a rear wheel drive sportscar ... to do this we cast our own bellhousing, etc. The advantage of this engine was that we had learnt heaps and were pretty sure we finally knew how to keep one from exploding (and we were proved right) and it is very low, and thus the car had a low CoG:

[PSk]

Genius,

Those are the carbs, aircleaners and manifolds I am talking about ... if you are interested.

Pete

[PSk]

Quote:

Originally Posted by 87Sprint wow - thanks heaps for sharing that! Ive heard allot but racing boxers in terms of power output but never anything indepth as to what sort or work or route is taken - its all very interesting! My mechanic here in adelaide seems to do allot of race engines of all sorts and he had a 1600 boxer however the route taken was to stroke the 1500 block - although it didnt have a dry sump setup he said it was around 170hp.

[PSk]

One thing I forgot to mention about the engine was that we ran motorcycle piston rings. The top ring was like less than 1mm thick ...

Pete