63 Bullnose Rally Project

[63stroker]

Hello. My name is Jeff from Dallas and I'm building this late 63 stroker for an upcoming stage rally in Paris Texas. This is my first Saab, my first two stroke , and my first Rally. The goal is to build the car to Rally America Specs for Historic Class and finish all stages.





The car is bone stock and complete. It was running ( weakly) when I got it and the brakes were bad. So far, I've pulled the head to make sure a piston wasn't bad, removed the expansion chamber, exhaust and muffler, removed the rear axle and all the brakes.



I've replaced all the axle bushings, rear wheel bearings, wheel cylinders and shoes and KYB shocks. I know I should use a 95 axle, Bilsteins shocks and upgrade to discs but those upgrades will have to wait until they make themselves available or until I'm limited by my equipment and not by my skills.
I plan on making it run and drive first and get my cage started so I can get my log book in plenty of time.



I'm really hoping I can get some input from others who have built a stroker 96 and tell me about the pitfalls I should avoid and perhaps some driving tips from those that have raced a bullnose.



In the meantime, I'll keep posting my progress along with questions as I get deeper into this. I really like the forum and although most of you are 99 and 900 guys, I hope this 58 horsepower wonder isn't a buzz kill to the board.

[Crazyswede]

Thats a very ambitious project....Good luck. And I'd be very surprised if it has 58 hp....you are more likely down in the 30 - 40 hp range. An excellent source for help is Bruce Turk who lives in NY.

Also, do you know how to drive a 2 stroke? Other then the obvious part about revving the piss out of the engine you will need to avoid prolonged engine braking as they tend to not get much lube when you are not on the power. They also tend to run great right up to the point where they dont. As in the problem with the 2 strokes is they give little or no warning that there is a problem. Still if you build the car well and learn how to eek out the performance you can have a blast.

here is a video I took from the passenger seat of Bruce's car at Rally New York when we were running as course opening car.

http://video.google.com/videoplay?docid ... 2362961228

[63stroker]

Thanks for the advice and the video. It looks like it was a blast! I'd like to see how the battery cutoff was engineered. I've also got to have a cutoff inside the car as well.
I've heard of Bruce Turk and I think I've seen him posting on the Vsaab forum. So far Chip Lamb has been my main source. He's provided me with a new 2" exhaust and some of my brake and suspension parts.
Right now, you're right...30-40hp on a good day but I hope squeeze 58 hp by the time I'm done. A GT crank would really help me on my way.

[Crazyswede]

http://www.youtube.com/watch?v=1lJQzrWprQE here is some more incentive

[max]

Thats a very ambitious project....Good luck. And I'd be very surprised if it has 58 hp....you are more likely down in the 30 - 40 hp range. An excellent source for help is Bruce Turk who lives in NY.

Also, do you know how to drive a 2 stroke? Other then the obvious part about revving the piss out of the engine you will need to avoid prolonged engine braking as they tend to not get much lube when you are not on the power. They also tend to run great right up to the point where they dont. As in the problem with the 2 strokes is they give little or no warning that there is a problem. Still if you build the car well and learn how to eek out the performance you can have a blast.

here is a video I took from the passenger seat of Bruce's car at Rally New York when we were running as course opening car.

http://video.google.com/videoplay?docid ... 2362961228

Wow that things sounds pretty cool inside actually... much different than from the outside.


I like how Seth is just so humongous inside it that he can only film through the green sun strip.

[Crazyswede]

I am quite big inside one of those things actually though I do fit. I was trying to stabilize the camera so at times I was holding it against the roof for support. Your arms get pretty tired after holding a camera up high like that for 10 minutes.

[Geoff]

Awesome! Good luck with the project! I don't have any stroker experience but as Erik Carlsson always says, "You kan never lift!"

Chip should be a good source for parts. Bruce should be a good source for rally-stroker related things since he has a stroker rally car (the only active one in the US?). In reality it isn't a full rally car as it doesn't have the complete cage, but he uses it as a course opening car for rallies and goes quite fast! All he would really need is a complete cage for competition.

We'll all do our best at encouraging you and giving you general rally prep tips (some things should cross over between 99s and 96es). My school of thought on first rally cars is to focus on reliability, safety, and suspension. You should probably re-wire the car using high quality wires and connectors (DNFing an event that cost you over $1000 because of old wiring isn't much fun). All of the rules regarding safety make for a pretty safe car so follow those. Over-build your skidplate. Focus on suspension work so your car turns when you want it to, goes straight when you want it to, and keeps it's suspension components from breaking. I think 96 front shocks are somewhat interchangeable with 99 front shocks (?). If that is true you can find some used shocks and have them re-valved for rallying (shocks with stock valving seem to get over used and break). There is a thread on SAABCentral with a listing of shocks that should be interchangeable (size-wise) with 99 front shocks
http://www.saabcentral.com/forums/showthread.php?t=89699&page=2
You might be able to find some in a junkyard and then send them to Bilstein for a rebuild with custom valving.

[formulasaab]

Hi Jeff,
Great to see someone playing with the stroker!

I road race a couple cars with Saab 2 stroke power, so I've really gained an appreciation for these little motors.

As far as keeping the engine happy goes...

I've found the most vitally important thing is to make sure that the combustion temperatures are correct. This keeps you from holing a piston. Keep an eye on the cylinder temps with an exhaust gas temperature sensor and gauge.



If you really want to get jazzy, use three!

Otherwise, keep it cool with a modern copper core radiator. Toss whatever was originally in there and get the most efficient copper core radiator you can fit in the space. Add an electric fan to it and get rid of the fan/shaft mounted to the cylinder head.

[Sean Tennis]

My first rally car was a Monte Carlo 850, I still get folks asking me to bring it out again... I have a "lot" of 2-stroke SAABs and many years of experience with them.

First off to get 50-60 hp one will need a GT crank, do not over advance the ignition timing, as compression ratio goes up the timing needs to be retarded. A higher compression head is needed, either by milling the head you have now or getting a GT 850 head-depends on the compression ratio you're after and reliability, usually a good mid range power engine is better then "the ultimate engine". you will have to get larger main jet and carrier-or drill the 3 holes in the carrier larger. I would recommend new pistons and rings, the ones in the engine are of unknown life/condition and running the engine hard will show flaws very quickly with very negative results...

Tuning the engine isn't that tough, if you use an EGT (exhaust gas temperture) gauge jet the carb for 1100-1150 degress f, aluminium melts at 1200 f, if you get things right you can keep your right foot to the floor for longer then your brain will want to let you on a twisty dirt road...Just don't advance that ignition timing....

Stock suspension on the SAAB 850 will be very good with some uprated shocks. New suspension bushings is a must in my opinion as the car will be "tight", I recommend stock rubber nothing firmer. If the front shocks are very stiff you should install aditional supports to the top outer shock mount that run straight up to the inner fender housing (bolted in to place)-this will keep the upper shock pin from flexing too much and cracking the inner wheel housing. One could plate the front "A" arms, it will help on rougher events-Paris TX is sand, plating not needed for this event IMO. The rear axle trailing arms that run from the body backwards to the axle should also have a plate welded on them so they become a box rather then the "U" shape they are from the factory, same thoughts for Paris TX.

The clutch will need an uprated pressure plate as the stock one for the 38hp motor in the car is weak and will cause clutch slip. Order a unit for a VW 1500 transporter, it is of multiple finger design and is the same unit the factory used for racing, if you have trouble locating one I can help...Clutch lining should be okay, if you reline the disc there are options, don't go to grippy there isn't much need.

Do you have the factory recommended porting specs for this engine? With factory recommendations power will be from 3,000-,6000rpm but really usable from about 3,800-5,600rpm, more revving above this will be with power actually falling off...

Do you have the recommended porting specs for this engine?

What transmission will you be using?

Are you relining the brake shoes? What linings? New hoses or make aeroquip type metal braided hoses, also check the steel lines near the throttle/brake pedal (inside car floorboard), moisture from the ones shoes drips here and can weaken the lines, repair or replace if needed, I know your in TX buts still it's worth a look.

Exhaust plays a huge role in the power of a 2-stroke, is it just 2" or is the front muffler modified or an expansion chamber?

Get the right temp range spark plugs and learn to read them, not just color but heat range...

When SAAB or Erik said, "you could never let up", they did not mean the throttle, they meant you have to keep going, one can not relax or slow down always on attack mode!!!

[99Super]

63Stroker;

All this talk of EGT reminds me, I still have a Digitron DT32-K laying around from my Kart racing days. It's a combination Tach/EGT sensor. I was thinking of using it on one of my 99 Projects (Megasquirt can us an EGT signal..), but I'll never get to it. I'd make you a good deal on it!


john

[63stroker]

Thanks for all the advice. I knew this was the place to come to!

Geoff.....I know Bilsteins are the way to go. I'll check into the interchange between 99 and 96 shocks.

Formulasaab.....I did not know that you tuned two strokes by EGT. Great advice. Can I drill and tap my cast iron exhaust manifold or do I need to have bungs welded in?

Sean...Tons of great information. You're a wealth of knowledge.
I have the factory specs for porting but if I'm reading it correctly, I enlarge the top side and add material on the bottom side? It sounds like this may be the thing to have a pro do.

Where's a good source for Pistons and rings?
and GT cranks?

I'll be using the stock 3 speed unless I find a four speed and column soon. I'm worried mostly about those rubber inner gwebo joints. Are they reliable or do I need spares?

I've bought new (not kits) wheel cylinders and shoes and hardware for all four corners. I'll pick up some steel braided lines and double check the hard lines.
Master cylinder has been rebuilt.

Today I dropped the radiator off to be recored with a 4 row copper unit.

I'll install an electric fan if I have to but I'd really prefer to run that cool overhead fan shaft as stock. I've rebuilt mine and think it's honestly one of the most charming things I've ever seen on a automobile.

I've got all new water hoses and a water pump kit on the way from Sweden.

I should install the rear axle assembly ( all new stock bushings ) and brakes on Sunday ....then I'll start on the front.

[Crazyswede]

Are you going to convert over to disc brakes up front? Bruce Turks car has the drums but it could really use the discs. You only get about one good stop out of the drums every couple of minutes as they heat up very fast.

[Sean Tennis]

Sean...Tons of great information. You're a wealth of knowledge.
I have the factory specs for porting but if I'm reading it correctly, I enlarge the top side and add material on the bottom side? It sounds like this may be the thing to have a pro do.

**No adding of metal-just enlarging** **Grind intakes lower-this allows the intake to open sooner and close later. Exhuast are ground higher allowing them to open sooner and close later, transfer ports are ground higher (hard to get at-might want to find someone with a mill to reach in...) allowing to open sooner and close later. Basically what is being done is the port hole is enlarged, this gives more open timing which allows the gases more time to move on to their next location, like changing to a longer duration cam in a 4 stroke engine. Widening of the ports helps to, kind of like larger valves in a 4 stroke.

Where's a good source for Pistons and rings?

***Chip @ west of Sweden or Niklas @ http://www.classicsaabracing.com/ the later is a very good source...

and GT cranks?

***You will need to have one built if you have a set of full circle weights, either source (Chip or Niklas) may be able to help locate the weights.

I'll be using the stock 3 speed unless I find a four speed and column soon. I'm worried mostly about those rubber inner gwebo joints. Are they reliable or do I need spares?

****The joints are fine, stock units have to used in FIA historic racing, Niklas has some alternate material units available, I've never used these so have no input on them. Also keep the smaller tires 155, larger units take away the power an accelleration!

I've bought new (not kits) wheel cylinders and shoes and hardware for all four corners. I'll pick up some steel braided lines and double check the hard lines.
Master cylinder has been rebuilt.

***I would get the front shoes relined with competition linings, they will work well if you do, very grabby and heat resistant, (there is a person near me that could help you-let me know) the stock units will over heat and fade very quickly-make sure to torque the drum assembly to factory specs otherwise it will shear the key!

Today I dropped the radiator off to be recored with a 4 row copper unit.

I'll install an electric fan if I have to but I'd really prefer to run that cool overhead fan shaft as stock. I've rebuilt mine and think it's honestly one of the most charming things I've ever seen on a automobile.

****the cars will run hot, (surprisingly many new cars actually run very hot 240 f) it is typical to see 200-210 f on the early SAAB cars, proper engine tuning will have a large effect on engine temp, which will have an effect on engine life...

[63stroker]

Okay....last Sunday finished the rear axle assembly. Installed new bushings ( stock), bearings, wheel cylinders, brake springs, shoes, and new shocks.




E brake cables were greased and in good shape.

I've got braided brake lines and limiting straps on the way.
and I just picked up my new 4 row copper core radiator

I've got a question about rims. I've read that the stock 96 wheels tend to bend at the center. Yikes! So I'd like to get something stronger but still be true to form to my late 1960's / early 1970's theme for historic class. No alloy soccer balls, cromodora, etc. I've heard Sonnet steel wheels are stronger and an inch wider but what years am I looking for?

Next is front suspension.

[Sean Tennis]

The Sonett rims are from 68-69 and early 70, pretty tough to find now days.

You should be fine with stock rims, use the early units with the rise around the bolt holes.

Yes the rims can bend at the centers, actually the rims/wheels crack around the lug nuts, (I've had Sonett rims do this autocrossing) however that is usually from track racing were the tire sticks more to the surface as increase loads at the wheel center.

The stock rims can also be reinforced in the center, SAAB use to sell a kit for this, basically it put a sliver of metal on 2 sides of the wheel bolts on the outside of the rim running from center of rim towards outer edge, about 1" long which would strengthen the wheel at the stress points.

As far as I know the factory 2-stroke rally cars ran stock wheels, and that was at a time when a rally was several thousand miles long and the car had 2 spares at most...