63 Bullnose Rally Project

[modernbeat]

And I forgot to mention. We've been on the XP list for some time and bought the tuning manual. Since this was our first go-around with a two stroke we hadn't heard too many of the wrong things.

[simo96]

You can then see the flow data for each of the carbs.

Chris Partingtons engine is a large stroked unit with reed valves and Sonett 2 carbs (xp shaft, plate and chokes). He also has the inlet lifted to put mixture direct into the cylinder at BDC to improve the transfer. You can only do this with the reed's though.
Dave Barrow found the reed block helped the engine retain more mid range (probably stopping the inlet charge going back through the carbs with large inlet duration).

I am not a big fan of increasing the cc's of engines unless they have enough breathing to cope with it. You just end up with a big narrow lump of power at the max rev range the engines breathing can cope with.

[V4_guy]

The tires are a little tall, but they are one of the few aggressive tires that will fit on the stock rims and under the stock fenders, and as a bonus, they were period correct to the 1970 target year. The tire is the Mickey Thompson Mini Mag. It was developed in the early years of Baja racing to run on the front of VW Rail jobs. We were afraid it wouldn't have enough forward bite and we'd have to hand groove it. But it's been adequate so far. We haven't punctured any of them nor have we knocked one off the bead. But they don't bite like a modern rally tire.
http://www.mickeythompsontires.com/off- ... em=MiniMag

Yeah, the options for 4 inch rims seem very limited but those look like some good tires. The reason I ask is because I'm planning on rallycrossing my '72 96 so I'm exploring my wheel/tire options. For the time being I'm planning on running 4.5 inch soccerballs with some 185 series snow tires, not ideal but about the best I can do for now. Okay, I'm done threadjacking.

[modernbeat]

Unless you plan on building a custom gearbox, I'd run shorter tires. Remember that a significant part of this build is just to have a period, fun, rally car. It wasn't built to be a champion. If it was we'd be building a circa '85 car instead of a '63 built as if it were 1970.

We've got a box that uses parts from three different models. The HD case was from one car, the actual 4-speed guts came from another, and the very low (numerically high) final drive and freewheel parts came from an early 2-stroke 96. This required swapping the steering column and shifter parts, adding an additional trans mount, a custom clutch cable and more.

In my experience, rallycross doesn't require a lot of ground clearance or a rally suspension that will soak up jumps. We hosted a rallycross on our shop property a few weeks ago and two near-stock Mitsubishi Evo Xs and a new MX5 all did very well.

You might consider getting custom 14" wheels made so some of the smaller tires will work without being too tall.

[Crazyswede]

here is one crazy idea for you: USA rally rules state that you can run any engine in a car as long as it was made by the same car company. So for instance you could put a twin turbo audi engine in a vw golf and it would be legal. so I say we find a wrecked Saabaru and put the full drivetrain into a Saab 96

[simo96]

I would look to the works rallycross cars, they ran smaller 4 stud pattern wider wheels. Best bet is either the hard to find sport hubs or make adaptors. Just dont look too long at the supercharger or the later turbo version, you might want one!

John ran a 6:35 spec 1 box with LSD in his car and loved it. For the odd long straight where you ran nearly out of revs it made up for it on the twisty stuff. This gives you a very low first, probably ideal for a highly tuned stroker, but I found a bit too low in the v4. I prefer a spec 2 set with 6:35 or 7:38 in a v4.

[V4_guy]

Unless you plan on building a custom gearbox, I'd run shorter tires. Remember that a significant part of this build is just to have a period, fun, rally car. It wasn't built to be a champion. If it was we'd be building a circa '85 car instead of a '63 built as if it were 1970.

We've got a box that uses parts from three different models. The HD case was from one car, the actual 4-speed guts came from another, and the very low (numerically high) final drive and freewheel parts came from an early 2-stroke 96. This required swapping the steering column and shifter parts, adding an additional trans mount, a custom clutch cable and more.

In my experience, rallycross doesn't require a lot of ground clearance or a rally suspension that will soak up jumps. We hosted a rallycross on our shop property a few weeks ago and two near-stock Mitsubishi Evo Xs and a new MX5 all did very well.

You might consider getting custom 14" wheels made so some of the smaller tires will work without being too tall.

I'll be running a stock gearbox, I'm not building my car to be a champion either, I just want to have fun and use my 96 for its intended purpose which is being driven hard and having some fun in the dirt while still being able to be a daily driver. If I were to go with custom wheels I'd want to get some of the stock 4 inch steelies widened to 5 or 5.5 inches to give me a good choice of wheels.

Again, I don't mean to jack this thread, I just really love what you guys have done with your rally car and I'm also way into 96s (I know most of the guys here are into 99/900s, not that there's anything wrong with that!). Check out my project thread here.

[Crazyswede]

USA rally cross is much different than Euro Rally cross...for those over the pond reading this thread. The USA version is just a cone course laid out in a field or parking lot. Helmets are required but no roll cages. Speeds rarely get over 35 mph and roll overs are very rare.

That said...rally crosses in the USA will break more cars than a full on rally is. The short courses encourage hard acceleration often with the wheel cranked to the lock position. CV joints like to explode, its hard on the transmissions, and even rally tires wear faster under these conditions.

[simo96]

OK we have Auto Solo which is our version, I think. Its a bit quicker than autotesting on a more open course.

[allessence]

Hey, just found this thread.. I just sold my Monte Carlo 850 and after looking at all of my old NOS GT850 parts have decided not to sell it but to rehab it.

I love that you guys are rallying the old Snubber..

I have looked into getting pistons for my GT engine.. did you guys end up finding a good source or did Bud Clark all ready have in mind what you guys wanted to get done.

Crazyswede: When I threatened to put an Audi AWD into Rosie I got so much hell thrown at me I decided to leave her as she is.

Now, I do have an extra 96 GT850 Shell that might handle an AWD swapt in.. To bad i love the 2 strokes the best.

Also, I have been looking at getting a Yamaha GP1300R 03-04 engine to stick into a snubber instead of a SAAB motor.

This engine has 84mmX76mm piston/stroke..

Read more: Yamaha GP1300R Muscle PWC And SR230 Sport Boat - Popular Mechanics

Naked, unabashed speed. That's what sells 2-seater muscle PWCs. Scooting around on a machine that makes you the absolute lord of the lagoon translates into personal watercraft market share. Last year, Yamaha's GP1200R WaveRunner was at the top of the PWC heap, outselling all the other muscle craft. Those 3- and 4-seater PWCs may be all right for family fun, but hop on Yamaha's new 3-cylinder, 2-stroke GP1300R sizzler, with room for you and one terrified passenger, and you'll leave your family on the dock while you get a well-deserved adrenaline rush.

With a water-shredding 165 hp, the new GP1300R is touted as the most powerful and fastest production PWC on the planet. We intend to put that claim to the test down the road in a big-dog PWC shootout. What is certain, however, is that the new boat trumps last year's 1200 water warrior in every category. First of all, it's faster, by about a mile or two on top end. Yamaha claims 65 mph. In our ride, however, we saw only low 60s because our beast had thrown a plug wire.

The GP1300R is also quicker. Yamaha's engineers clocked the 50-yard elapsed time at 4.19 seconds for the 1300 versus 4.67 seconds for the 1200.

Sorry for the Hijack..

[Crazyswede]

Hey, just found this thread.. I just sold my Monte Carlo 850 and after looking at all of my old NOS GT850 parts have decided not to sell it but to rehab it.

I love that you guys are rallying the old Snubber..

I have looked into getting pistons for my GT engine.. did you guys end up finding a good source or did Bud Clark all ready have in mind what you guys wanted to get done.

Crazyswede: When I threatened to put an Audi AWD into Rosie I got so much hell thrown at me I decided to leave her as she is.

All the more reason to do so

Now, I do have an extra 96 GT850 Shell that might handle an AWD swapt in.. To bad i love the 2 strokes the best.

Also, I have been looking at getting a Yamaha GP1300R 03-04 engine to stick into a snubber instead of a SAAB motor.

This engine has 84mmX76mm piston/stroke..

Read more: Yamaha GP1300R Muscle PWC And SR230 Sport Boat - Popular Mechanics

Naked, unabashed speed. That's what sells 2-seater muscle PWCs. Scooting around on a machine that makes you the absolute lord of the lagoon translates into personal watercraft market share. Last year, Yamaha's GP1200R WaveRunner was at the top of the PWC heap, outselling all the other muscle craft. Those 3- and 4-seater PWCs may be all right for family fun, but hop on Yamaha's new 3-cylinder, 2-stroke GP1300R sizzler, with room for you and one terrified passenger, and you'll leave your family on the dock while you get a well-deserved adrenaline rush.

With a water-shredding 165 hp, the new GP1300R is touted as the most powerful and fastest production PWC on the planet. We intend to put that claim to the test down the road in a big-dog PWC shootout. What is certain, however, is that the new boat trumps last year's 1200 water warrior in every category. First of all, it's faster, by about a mile or two on top end. Yamaha claims 65 mph. In our ride, however, we saw only low 60s because our beast had thrown a plug wire.

The GP1300R is also quicker. Yamaha's engineers clocked the 50-yard elapsed time at 4.19 seconds for the 1300 versus 4.67 seconds for the 1200.

Sorry for the Hijack..

.

[allessence]

Well, now that SAAB has up and evaporated.. I'm thinking it was best I didn't cut up an SPG.. Better collector interest's..

Same with the GT850 I'm gonna restore.. But the extra chassis, Hummmmm..

[simo96]

Venola did some pistons, but I think they are all flat top items. You need to make sure with ones you get are for teh correct crank as they did some for the stroker conversion that have a slightly lower crown and longer skirts. They also need to have big clearances in a high tuned engine, I have been told to run between .015-.018mm!!
I have had a set made over here in the UK using a Lamberetta forging, they are 71.5mm with a dome top, std size pins and two 1.2mm chrome rings. They are alot lighter than the std items and they cost about £90 each. To be honest this forging would suit a 16mm pin better and that would reduce weight even more. Peter can make them from 70mm to 75mm flat, domed how ever you want them.

[Geoff]

Also, I have been looking at getting a Yamaha GP1300R 03-04 engine to stick into a snubber instead of a SAAB motor.

AWESOME! That would be SO much fun!
What would you use for a gearbox?

[allessence]

I'd stick with a stOck Saab . Maybe a 4.88 r&p .

I have 3, 5:14 gear boxes but with the better power of the 1300cc I might be able to even get away with 4.67. Have to see if I can find a motor for decent money.