Chassis modding question

[Greywolf74]

I'm trying to fit a .26 engine on a buggy that was designed for a .21 and it appears I'm gonna have to do some modding to get it to fit. (Yes I know its like putting a corvette engine in Honda civic but I have a buggy with no engine and an extra engine laying around so it seemed like a fun thing to do even though I know it will probably spin the tires right off of it lol) So in order to get this engine to fit I'm either going to have to remove one brake pad and disk from the rear side of the center diff, or cut a small rectangular hole in the chassis. The hole is because when the .26 engine is mounted on the engine blocks the crankcase is fine but the backplate sticks down about a 1/4 inch lower than the engine mounts. So the hole would basically be for the bottom of the back plate to sit in and lower the engine down. I currently have spacers mounted on top of the engine mounts to raise the engine up high enough so the back plate doesn't touch the chassis. I thought that would work until I tried to put it on there and now the flywheel is hitting the rear brake pad.

So the question becomes would you mod it to just run one break pad in the rear or would you cut a small rectangular whole in the chassis for the bottom of the backplate to sit in? If you would cut a hole in the chassis is a dremel capable of cutting 1/8 inch aluminum? If so what kind of bit would I need to buy for my dremel to do that?

P.S. I dont want to have to bump start it so changing the backplate is out.

 

[robmob]

I would cut the chassis.

This is the setup I use to cut anything.

http://www.amazon.com/Dremel-EZ406-...LRVA/ref=sr_1_4?ie=UTF8&qid=1314115241&sr=8-4

 

[Greywolf74]

well the hole that I would need to cut only needs to be as wide and as thick as the backplate so something like 3.5in X .5 in ? that cutting wheel would work for the 3.5in sides but not the .5 in sides. What do you propose for that?

 

[mayrider]

draw out the rectangle you need to cut. cut both long side with the dremel should be only .25 or so left, if to much make a pass down the middle then you should be able to break out whats left or use small coping saw to cut them out and finish cleaning up with dremel with a deburring bit.

 

[Krawlin]

Do you actually have to cut a hole completely through the chassis or could it be machined (like how most higher end buggies have an area of the chassis right below the engine machined out to let the engine sit really low)? If you have to actually cut a hole all the way through the chassis to get this engine to sit in the car then I think you need to go another route. Personally I wouldn't want any part of the engine backplate level with the bottom of the chassis, or even exposed with a hole below it, where it could get banged up/damaged/hung up.

I know you said you don't want to bump start it but I am going to be that guy that recommends bump start anyway. I used to use pull start and roto-start and all of that junk, and honestly I got really sick of replacing OWB's and yanking on the pull start handle and air leaks around the shaft going into the engine and dead batteries on my roto-start unit. Then I got the bright idea to switch to bump start and I haven't looked back. If you can afford it, just get some high mAh rated LiPos to run in a starter box and it'll last for quite a few bashing/racing outings before needing a recharge. You set up everything just once, and then all you have to do is throw the car on the box, put the glow ignitor on the plug and push down. And IMO a starter box is no more clumsy than carrying a cordless drill or hand held roto-start unit, and you arm will never be tired from using a bump box like it will from using a pull start. And if your engine is worn out or has a bad tune, a pull start will really frustrate you, and a rotostart will kill a OWB fairly quick, but the bump box makes life really easy since you don't have to put much effort into it at all and no one way bearings to deal with.


I'm just saying that you should seriously consider switching to a bump start setup. About 4 or 5 fried OWB's or pull start units later, it will have already paid for the starter box (about $60 for a good OFNA box, I use an OFNA Chrome Top with twin 550's and running 4S LiPo in it). From a performance standpoint, and convenience, in my opinion you can't beat a bump start setup.

 

[Greywolf74]

The back plate doesn't hang below the chassis I just had to cut the hole all the way through the chassis because it almost hangs lower than the chassis.

Bump start is out. The area that my friends and I bash at is remote. you have to walk about a mile to get to it. I have a losi roto starter and some 6cell packs for it which fit in my already loaded down backpack. A bump start does not fit in my back pack. I appreciate what you are trying to say about the bumpstart but its just not an option for me plus I already had the engine laying around not being used. The kit is old and not worth buying a new engine for.

I already have the hole cut and the engine mounted and so far all is well. Still have some diff maintainance to do before I can take her out for a spin though

 

[Snook Man]

Looks like you are good to go…

Another option for future reference:
Since you are not using a starter box, you can shim the engine up to clear the backplate and then used a smaller diameter flywheel to clear the brake components.

Been there done that with a few .28 and .30’s on the buggys.

 

[Greywolf74]

Looks like you are good to go…

Another option for future reference:
Since you are not using a starter box, you can shim the engine up to clear the backplate and then used a smaller diameter flywheel to clear the brake components.

Been there done that with a few .28 and .30’s on the buggys.

I'm still somewhat new to the hobby only been in it for about a year...I didnt realize that they made flywheels in various sizes...most of the ones I've seen so far are roughly the same size...good to know though for future reference.