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Fri Jan 29, 2021 12:07 pm

I have the opportunity to buy a pretty sweet sand rail, everything but the engine. At first I was thinking putting in a 1915 vw, but a coworker thought it might be better to go a different route. I figure to build a higher hp vw would run me in the 2k - 3k range and its still aircooled, so I think this route would be better and I'd get more hp. We've been talking about a corvair swap, ecotec, and quad 4's. Personally, I was leaning toward the quad 4 due to 180hp (high output)and I can get them near me for around 500. My main concern is that I put together an accurate list of To Do's/part list to see if the whole job will fit my budget.

If I were to go the Quad 4 route:
1. The engine
2. The engine adapter to the 3 rib bus trans
3. Exhaust
4. ECM (which I believe would need to be simplified?)
5. Radiator and associated hoses
6. Engine mounts

Am I missing anything? Also, if anyone knows of another forum/website that has info on simplifying an ecm that would help greatly. I've searched quite a bit and haven't found much.

Fri Jan 29, 2021 3:28 pm

Look into Subaru..... 200-225 HP "stock".... Carbureted version... KEP has adapters in stock...

Dale

Fri Jan 29, 2021 4:45 pm

Bigger HP water pumper engines come with a weight penalty. What is the intended use?

Fri Jan 29, 2021 6:15 pm

I run a Honda 3.5 V6 in my Thing. And I’m also putting together another rail that I picked up. Putting an Acura 3.2 Type S in that one. The engines are cheap. I also recently pinned out a harness and ECU for a buddy. The harness and computer were about $120.00 at the junk yard. Took some time to do the harness but we saved him a grand. Power to weight is pretty impressive with these engines. Just a thought.

Fri Jan 29, 2021 9:15 pm

Intended use is for a 90” wheelbase two seater sand rail. I’m concerned with weight as it will be on the sand dunes 80% of the time so I don’t want to be at a constant wheelie (rear engine) or struggling to float on the sand. I didn’t realize subie engines were a feasible option, I’ll research a bit. I have a coworker with a 3.5 Honda in a funko four seater, but he advised it’d be a bad idea for my buggy.

Which non turbo subie engines are popular for sand rails? A quad 4 is around 320-340lbs, so I’d prefer to not go much heavier.

Fri Jan 29, 2021 9:53 pm

If going watercooled, Subaru or Ecotec. They are the most common water cooled motors for a buggy. Both supported very well because a lot of guys use them in the desert. Because of the additional weight, don’t forget stronger torsions and better shocks. VWs are light, but water cooled motors have a lot of advantages.

Sat Jan 30, 2021 7:44 am

My rail has a Ford V6 naturally aspirated water cooled engine in it. I love it but yeah, it's heavy. I had the engine and KEP adapter and then acquired a rail with no engine. I mounted the radiator high up on the back so it can catch some airflow while traveling. I tried it mounted down in front of the engine but the fans ran continuously there. Now the fans kick in and shut back off after a minute or so.

Be sure to add some engine mounts for the heavier engine . Don't rely on just bolting it to the VW trany. You'll probably have to beef up the suspension too. My engine makes a lot more power than my trany will handle so I have to baby it. Eventually, I'll build a stronger trany but that's all stuff to think about and plan for when swapping to a more powerful engine.

One of the best parts, is the sound. My engine has headers but they're short so it has a lot of rumble at an idle. When I pull up to a traffic light, people expect to hear the VW putt putt but instead they hear the rumble of a V engine. I love it!

Sun Feb 07, 2021 10:46 pm

I would like to try a Toyota 1NZ-FE like in my Scion XB, its only 1.5L and it only makes 108hp but it is very light, it weighs 190lbs. you would need the Toyota computer to work the VVT though. You can buy them cheap at about $600 or less.

eQ

Mon Feb 08, 2021 9:11 pm

I had a 2275 in my rail for 8 years worked fine but they are pricey to build parts aint cheap.I finally decided to sell it to do an ecotec swap but got a deal on a j35 for 1500 for engine,adapter and ecu ready to run.Needed exhaust and a clutch to complete plus the normal other stuff for efi and water(fuel system and radiator) Not bad radiator was 250 for a cherokeee alm one with fans.

So far i love it power is instant and it added about 150 pounds over the vw overall.But for a smaller car like yours might want to consider an ecotec they are a lil heavier than a vw but not a whole lot and its a common engine.Honda k24 is also a good one too but a lil pricier.

Fri Feb 12, 2021 7:17 am

i always thought rotary was a good idea, light weight and able to turn alot of rpms. but the popularity if the rx7's was limited to start with and im sure its also getting harder and harder to find a donor ... although i do have an rx8 out in the yard, hmmmm

Fri Feb 12, 2021 4:58 pm

If you have driven a Rotory you already know that they have no torque. If you are into sand drags and rooster tails at full song then go for it. From trail riding and powering up a hill I think you will be disappointed.

Fri Feb 12, 2021 6:29 pm

oprn wrote: If you have driven a Rotory you already know that they have no torque. If you are into sand drags and rooster tails at full song then go for it. From trail riding and powering up a hill I think you will be disappointed.

i actually did have an 86 gslse and it had plenty of torque, wasn't hard to get it sideways at all. ive heard several ppl say that and wondered if they ever owned one. and if a 1600 vw has enough torque to push a rail... well, ill just say that about the only way to get less torque than the 1600 would be to use a briggs & straton.

Fri Feb 12, 2021 9:53 pm

If you had a 1600cc VW with less torque than a 1300cc rotory you had a very very sick VW engine indeed! I have driven Mazdas from the RX2 right through to the RX7 and there is nothing there at the bottom end on any of them. Wind them up and it's a different story but bottom end torque? Sorry!

Sat Feb 13, 2021 7:31 am

I recently went through this same thought process. I have a lot of experience with being high horsepower engines, all of these four cylinders we’re new territory for me.

I have driven my buddies healthy 1776 with a single Webber And it was pretty much perfect for a stock-ish suspension Baja. I was surprised but I wouldn’t rule out air cooled if you can get it done affordably.

When I started looking for my Manx, I looked at Subaru, Ecotec, and rotaries. the rotary is just so much more difficult than the other two I scratched it off the list. It also doesn’t really have a good power band with the available transmission gear ratios. The Subarus are also another level of complexity that I didn’t want to mess with, The exhaust is goofy, And the motors aren’t really compact Like an eco-tech. The eco-tech also has a tremendous amount of aftermarket support in comparison, at least from my perspective.

Only negative I see with the eco-tech, is the difficulty of locating a radiator compared to the Subi

Sat Feb 13, 2021 8:41 am

I went to the Mint 400 back in 1978 if I recall right and there was a Class 1 with a evinrude 150 Hp 2 stroke V6, only problem he had was he kept breaking one of the plugs on the skid plate. it was mounted in a inverse V layout. found a pit crew with a torch and cut a hole in it. I don't think the trans held up he didn't finish the race. a real distinctive sound with straight pipes.

Sat Feb 13, 2021 7:13 pm

im not saying the rotary has a lot of torque, im saying it has enough to break tires loose and make a 3200 +/-? car scoot pretty good, alot better than any stock beetle. and if a stock 1600 can move a rail along good id imagine a rotary would too. but i haven't owned a rail with one , yet.
i think the rx's never made it because 1 ppl forget they burn oil and ppp are to lazy to maintain something like that. and 2 ppl wanted to drive them like a normal 4 stroke, and there not the same. you gotta drive it like its a 2 stroke

Sat Feb 13, 2021 9:36 pm

I used my Ford V6 because I had one in the shop with the Kennedy adapter already on it. Big money savings. I bought a custom radiator and mounted it on upper back just peeking over the top so it can catch some airflow.

Sun Feb 14, 2021 6:08 am

richardcraineum wrote: im not saying the rotary has a lot of torque, im saying it has enough to break tires loose and make a 3200 +/-? car scoot pretty good, alot better than any stock beetle. and if a stock 1600 can move a rail along good id imagine a rotary would too. but i haven't owned a rail with one , yet.
i think the rx's never made it because 1 ppl forget they burn oil and ppp are to lazy to maintain something like that. and 2 ppl wanted to drive them like a normal 4 stroke, and there not the same. you gotta drive it like its a 2 stroke
Now all that I can agree with! The problem that I envision with a rotary is driving along and coming to a place where you need the power. Now like a two stroke you have to get the revs up by grabbing a lower gear before you can tackle the sand pit/mud hole/hill whatever it is. With stock gearing in the lower two and tall tires for off road clearance the only way is to buzz it up and slip the clutch or dump the clutch and let the tires do the slipping. With a stock VW engine you just roll the throttle on, it has that low end torque.

The torque curve on the rotary is way up the rpm scale. My driving impression was that it was a dinky 4 banger below 4K, felt like a 6 cylinder by 6K and you would sware you had a V8 by 8K! The torque is huge for it's size but it's at the very top end.

My mechanic Buddy who worked at a Mazda dealer in the RX8 days said that is one of the reasons that Mazda pulled the car from the lots and sent them back to Japan. People that bought them wanted "jack rabbit" starts off the lights like the big displacement American iron and the car was too heavy and high geared to do that. He said that seldom a week went by without an RX8 coming in with the clutch destroyed for replacement on warranty.

Sun Feb 14, 2021 4:11 pm

I don't know much about rotary engines except that one was once used for a motorcycle and it was a serious pain to work on. "Normal engines" can be built for more bottom range power, mid range, etc. The exhaust, cam, intake system, ignition, etc. can all be chosen or modified for the specific range that you're looking for.

Plus, there are things you can do to an engine that will increase it's power over the whole range. On my V6, I added a four inch tall spacer between the carb and the manifold to give the mixture some "run" before it entered the manifold and spread out. The difference was very noticeable. Instant free low end horsepower with no loss on top that I could notice and faster throttle response. I have no trouble powering up steep hills without hitting higher rpms and can still run down the interstate at 100+.

Sun Feb 14, 2021 5:33 pm

i bet a street rail with a built, boosted rotary would be a blast. i swear i read ( years ago ) that if you changed out the stock apex seals they'd turn close to 20k rpm? i dunno though...
but they dont have hardly any moving parts in them so maybe?