JAE12 Riggers With .12/.15 Car/Truck Engines

I am starting this thread to see if anyone is running a JAE12 (or an small hydro) with a .12 or .15 car/truck engine? I am not looking for Nova .12 or OS .18 hydros, there is plenty of info about those on this site. I know when the JAE was originally released it was "drop your car engine in and go".

If you have a hydro powered by a .12/.15 non-marine engine, please post it here.

What engine?

What prop?

What troubles, if any, did you run in to?

What speeds are you getting?

Thanks,

Chris

Well in theory my Nova 12 is a car engine. Cost twice as much as the marine version. The heavy hitters are going 80-90 with them I believe.

I think the biggest issue is probably the slide carb linkage vs barrel. Then just prop accordingly and you shouldn't have a problem. Keep the tub light weight to help and remove some of the cooling fins.

Kevin Krogness said:

Well in theory my Nova 12 is a car engine. Cost twice as much as the marine version. The heavy hitters are going 80-90 with them I believe.

I think the biggest issue is probably the slide carb linkage vs barrel. Then just prop accordingly and you shouldn't have a problem. Keep the tub light weight to help and remove some of the cooling fins.

Click to expand...

I concur

We have run the black bodied PICO .12 in the JAE 12. Used a black K&B carb and it ran really well.

David

Chris,

We have run: Sirio, Nova Rossi, O.S., & Picco engines in our

12 hydros and they all seem to run quite well once you get use

to the characteristics of the car engines. I think the little hydros

Run best with a 37 to 38 mm propeller diameter. You want to be

careful and not load these motors with too much pitch, the speed

seems to be in the RPM of the pipe and engine combination. We

have also found out with a lot of testing that they like a little bigger

carb than what most car guys run.

Have Fun,

Mark Sholund

Here is a solution to the slide carb

.12 I have been testing going to try to get more heat an keep the fuel rich

Great idea Chuck! Really well thought out my friend!

Joe

Chuck,

Nice set up, but the carb is too small.

Try something in the .270" to .300" range

I think you will be surprised.

12 motors love fuel, if you can give it to them?

Ken,

Use a real motor like the one in the middle.

What are you saving the Nova Rossi 12 for?

Start breaking it in, summer is short.

Have Fun,

Mark Sholund

I have been racing .12 boats for 8yrs now. My Boats run OK.... nothing really special. I Have used a OS CVR.12 its a side exhaust engine very middle of the road car engine.... as a beginner i got the boat to run mid to upper 40's. I then went to a nova car 3ngine i got off ebay.... some 5 port with an "M" on the side .... later found out wa a very good engine for this application.... boat would do upper 50's-very low 60's. i have had probably 3 of the 5port water cooled nova engines.... only 1 was new the other where bought used.... all the novas including the car nova all run about the same for me. I have seen 2 .12 hydros that where faster than 70 mph. 1 was glenn quarles boat at hobart last yr. and the other was gary preusse at flint michigan.... gary went 76mph... i did average of 58.666mph.... this was my heat race boat as i would run it every day. so guess what i am saying is just build it and run it will get better as time goes on.... if you get her going and then for no reason the boat just wont work.... seams like your chasing a needle trying to make it go..... STOP!!! check your bearings real good its critical.

good luck

ohhh yeah now there are i think less than a handful with these boats over 80mph if you see one you are a lucky person they are incredible to see.

my edit is:

if ya have a slide carb you can get a rotary i would guess to replace it also

prop 1440 backcut detonguned and barr cut and then pitched up lol... most of the time this is just a guess with some pliers on the pitched up part.

Mark, that's a rb engine, where can I get a carb. I looked for a rotory carb and came up empty. It seemed like it was a weird size. I'll have to measure it again

It's rb v12, best I can tell the neck is 9mm. I'll look around for something big from the car guys

I don't recall the size of the 12 carbs but I believe you can get a nova rotary from Ron Shaw for 45$ bit spendy but it's hard to find a Orlic considering he isn't making them anymore.

This rb has an off size neck. The whole purpose of my project is cheap. There are a bunch of guys running 12 riggers with car motors. I got this one for 60 bucks

Duratrax tora 12 an .18R knockoffs of OS MAX

parts interchange got 2 to tinker with off ebay made an offer 60.00 for 2 delivery free.casing looks different but the milling an guts or the same . not the fastest motor but cheap to tinker with to try portting ann timing ideas with.

This is a .12 i have been using an testing

here is what I did years ago: NR .15 with Os carb.,,,,boat was fast turning a mod prather 215

Hopefully I will have a couple of JAE12s on the water by the end of this month. It is nice to read about everyone's experience with these little boats. What is a common/average heat racing speed with these?

My local club I believe is around 50-55 with a couple above 60