Saab Vintage 2 Stroke - Tuning Two Stroke

[@anderszettergren4302]

A long time ago I had an experimental ignition distributor from Saab. My father worked in Saab's competition department. Three switch tips and three ignition coils. Water could be flushed over the engine and distributor without problems. Unfortunately I sold everything. But the car, Saab 96 1962, went like a bullet in the night. About 160-170 km/h between Trollhättan and Goetenbourg at the old road 45.

[@donneysaab]

Yes, they love independent coils. Sounds like you had a lot of fun with yours.

[@terrysmith7076]

I've wanted a two stroke Saab since 1972 when I rode in my first Saab. Too Cool Thxs for sharing.

[@roverchap]

MZ two-stroke motorcycle pistons have three rings - the ES250/2 (243cc). These make about 17.5 bhp. The bikes were built 1967-73 but replacement pistons are still available.

[@crusiethmaximuss]

Such a rad tiny engine!!!

[@abbaby555]

Interesting engine, reminds me of a snow mobile engine.

[@amelierenoncule]

Most interesting, mon ami !

[@patfilice]

That’s cool

[@alext8828]

Do the 2 stroke motors use expansion chambers in the exhaust? I saw an interesting video on that. I think it was from Driving 4 Answers. Excellent channel IMO.

[@donneysaab]

Yes they do. The chamber is often called a front muffler even though the muffler had a chamber built into it.

[@alext8828]

@@donneysaab Is that necessary if the motor uses reeds?

[@donneysaab]

Reed valves, add low in power that these engines desperately need however, when we race at Bonneville, we want to end power only so the reed valve becomes a restriction. So far our Racing at Bonneville we do not want them, but obviously Had so still been making these cars I’m sure they would’ve changed the technology and added the reed valve or more porting to make the engine more efficient.

[@e1gr3co]

2:25 what kind of technology is used to fill up the chamber with aluminium?

[@donneysaab]

Simply lay in weld a little at a time

[@jr6874]

Hey what oil do you run in these two strokes do you run full synthetic do you get more life out of the engines

[@mateuszm3905]

What do you think about reed valve (also known as intake reed; membrans)? Did you trying build an engine with it? In Europe (mainly Germany) owners of Wartburgs 311/312/353 do that, but I have not seen how it works. Theoretically it;s provide to better loading of gas-fuel mixture. Honestly I'm waiting for a long time for concept reed valves in old's generations of 2 stroke engine (like Saabs, Wartburgs, IFAs etc) or just conversation about this, in my opinion, interesting idea. Nice work Mr. Tom! Greetings from Poland! PS. Take my English with a pinch of salt please ;)

[@donneysaab]

Mateusz M Yes some people are running reed valves in these engines. XP Extreme Power in Sweden sells them. With a read valve you can run your intake at 100% and whenever there is a pressure difference the reed valve allows flow of fuel into the lower chamber. Whenever the pressure is higher it closes the reed valve as you mention. Thx.

[@alext8828]

Yes! Reed valves. I'd forgotten all about them. Very good.

[@dquinn8755]

I have an old mid 60's 2 stroke Saab was my granddad's and I want to get it out and get it running. Have any tips for me?! Been sitting probably 35-40 years but was parked only due to fuel pump issue supposedly. Decent mechanical knowledge but only ever messed with 4 stroke stuff.

[@donneysaab]

I would pull out the spark plugs and squirt some oil down the holes and run the starter with the plugs out a few times. While you have the plugs out check and see if you have spark. Then pull the top off the carburetor and clean out the bowl and blow things as best you can. supply some fuel with a separate pump and 2 gallon fuel can (or whatever works for you). Once you get fuel into the bowl, choke it & crank it over and I bet it will fire off (if you have spark!)

[@dquinn8755]

@@donneysaab thank you! That was pretty much my plan but I wasn't sure if there would be more involved that I wasn't thinking of. My only other concern is the alt/water pump combo. If I get it running and want to drive it around is that common to just keep on working or would it be bad from sitting so long?

[@donneysaab]

dquinn 87 run it!

[@whalesong999]

Hope your experience went O.K. with the make-run. After sitting for so long, rusted, dry main bearings might be an issue as it was with so many other engines with roller/ball bearings on long storage.

[@jasperprudon]

Did you make it run again i am really curious. Hahaha

[@ckryses3962]

I loved your work, knowledge about Saab... How i can follow you?? On fb or insta?? Prob one day i will visit you and wanna take my Saab to Dr. Donney !!

[@Eelco440Turbo]

Hi Tom, What's the difference between a stock 850 head and a gt head. I've bought a 93F with a 850 GT engine and bought it with a rattle at the front cilinder. Today ive noticed the head number is 709483 wich refers to a standard 850cc head. I cant read the block number yet, but it has oil injection and a triple carb. When i did a compression test i came at about 90 psi on all cilinders, wich isn't good for a GT engine either. Thanks from the Netherlands! Eelco

[@donneysaab]

Reading the block number should start with 716. Unless someone used a long block injected motor yours has to be a GT block as no standard bullnose blocks had injection.

[@donneysaab]

www.tomdonneymotors.com/wp-content/uploads/2015/02/Two-Stroke-Engine-ID-Chart-2-11-15.txt

[@Eelco440Turbo]

Thanks Tom, it's a 716503. But isn't it strange they used a single carb 850cc cilinderhead on this engine instead of a GT head. Or isn't there any difference in those heads?

[@donneysaab]

Eelco van Knippenberg not really. The GT head is hard to source so very common to use a standard head and mill it down to gain back GT head compression. Also some like lower compression head to prevent detonation and run lower grade fuel as these required higher octane @98.

[@gmmza03]

Tom do you have any cars for sale? Old 93 or 96

[@donneysaab]

Maybe. [e-mail]

[@markveits6300]

DOS and a what, 2400 dial up> i can hook you up!

[@yetzbiker4995]

two strokes car without power valves, like my bike. magic

[@barenekid9695]

Yamaha or Sea Doo Jet ski..... 2 stroke 3 cyl were rated at 130 -150 hp... Box stock.

[@donneysaab]

Indeed. But not in 1950! These are old designs and the trick is to make more with less.

[@CZ350tuner]

3:08: Not true at all!! Many companies still make aftermarket 3 ring pistons for the following high compression high torque 2 stroke motorcycles such as Babetta, Italjet, Jawa, CZ & Yedzi: ASSO Werke (Italy) RAM (India) HM (Hungary) CZ (Czech Republic)

[@donneysaab]

Thanks. Odd u mention odd obscure brands never head of an USA. I talked to Wiseco pistons about making some 3 ring pistons. They laughed at me and said “no way”. No modern 2 strokes use 3 rings they said. But thanks anyway.

[@misters2837]

Yeah in fact "most" high hp Snowmobile engines that I have seen are Two Ring...and there are some that are using a single ring...with today's metallurgy and close tolerances its not necessary. (Most people think pistons are "round" too!)