Cutting an engine mount

[Lessen]

I'm still deciding on what engine to buy for my TMaxx and at the same time I've been very happy with the RB that I purchased for my buggy. Even though I've only idled two tanks through my new .21 I'm very pleased that it has ran consistantly. So basically, I'm considering putting an RB .28 in my TMaxx upgrade build. Problem is... the RB .28's that I'm looking at don't fit my FLM engine mount. The width (side to side) for the mount screws is fine but the width of the block right below the ears is 1.5mm too wide for my mount. Now I've seen plenty of 2 piece engine mounts, my buggy is 2 piece and my funny car is 2 piece. So I wondering what everybody's take is on having a 2 piece mount for a .28 size engine. I've sort of succomed to the idea that I want power power power so I'm considering spending more on an engine that I originally planned. I like the idea of the RB RT28. It's a 7 port engine vs. the ST28 which is 3 port. At any rate, both of these engines are too wide for the mount.

So..

Do you guys think if I cut the engine mount into 2 pieces that It will support either of these engines well enough?

 

[beason]

if the screw holes line up but the block wont fit in between the uprights, i dont see where cutting it in half will help. if you can fit the block in there then the screw holes will be 1.5mm too wide.i would say trim the mount down on the inside just enough to fit the mill in between the uprights. pics would help though.. good luck!

 

[Lessen]

yeah, I hear ya. The inside of the uprights is already a mere 1mm thick. I really don't feel confident in grinding that down much. Maybe I should just shop for a different engine mount...

 

[olds97_lss]

I was under the belief that the higher the port count, the higher the RPM range of the engine. The lower the port count, the higher the torque of the engine...

Regardless, seems a bit of a waste in a t-maxx, but since it's your money, I'd like to see vids when your done!

 

[Lessen]

I was under the belief that the higher the port count, the higher the RPM range of the engine. The lower the port count, the higher the torque of the engine...

Regardless, seems a bit of a waste in a t-maxx, but since it's your money, I'd like to see vids when your done!

Yes yes. I'm running 1/8 scale diffs so the overall ratio is great for bottom end get up and go but I'd like to get an engine that can product a few more thousand RPM's so I get a relatively decent top speed even if I gear it low. I'm not necessarily looking for a fast truck, but a truck that has badA acceleration and only a fair top speed. I'd be happy with 30 mph to be honest.

*edit*

so I got the idea of checking those dimensions on my RB S3... they are the same so I took the S3 out of my buggy and attempted to mount it to my TMaxx mount. It doesn't fit but it wouldn't take as much work as I thought so I should be able to shoehorn it in there. Thanks Blake!

*edit*

Ouch, putting a rotostart on that 7 port will be expeeeeensive. I think the 3 port might be ok after all... heh

 

[Lessen]

ahhhh. This is just gonna be a PITA if I try to mod this mount. The 3 port .28 with roto start is even wider than the 7 port truggy version. If I'm gonna stick with RB engines I think I'd be better off making my own mount.

 

[Lessen]

I got to looking at this again and I'm pretty confident that cutting the mount may work. I'm looking at the specs on the RB engines and the width of the crankcase below the mounting tabs is 32.5mm. The mouting hole width center to center is 37.5mm. So that's a 5 mm difference and 2.5 mm difference per side. So the mount just needs to have no more than 2.5mm of material from the inside of of the mount to the center of the screw hole. It's a for/aft adjustable mount and the screw has a little bit of lateral play in it's slot in the mount so the lateral variable is anywhere from 2.5-3.5mm. So cutting the mount should work just fine for a truggy engine with dimensions like that. So now I just need to decide what powerplant. I guess I'm just writing this to convince myself that it fits

 

[HeartBreak]

Lessen, have you checked out the engine mounts from the GS Storm? They fit the bigger blocks, and are 2 piece. I think you can probably score a set on ebay for fairly cheap.

Here's a set, screws and all, for $12.
http://cgi.ebay.com/GS-Racing-Engin...rol_Parts_Accessories?_trksid=p3286.m20.l1116

 

[Lessen]

Thanks for the link bro but unfortunately that won't work. I've looked into other mounts and I came to the conclusion that I either need to make the one I have work or have one custom made. The reason is not how the engine mounts to the mount itself, but how the mount secures to the chassis. At any rate I have to do one of the two because I've finally taken the plunge and bought an engine that won't fit the mount I have.

I think this pic will better explain the issue.

 

[Racer 1966]

I've got BIG hammer, we can MAKE it fit!

 

[GrudgE]

Ah so I see said the blind man to his deaf wife as there crippled children ran up the stairs. You are talking about splitting the mount between uprights then you have all the play you need since all other holes are adjustable. That should work once the engine is mounted it should be pretty solid.

 

[Lessen]

Have you considered a picco .26 maxx they have a Tmax mount for it. A guy that goes to our LHS has a Tmax with the picco and its sick.

Honestly, nope.

I never intended to power this with anything other than a standard big block mill of at least .28 displacement. I have an RB ST28 on the way.

 

[HeartBreak]

Splitting the mount should work, but I would wait until the engine arrives before you whip out the dremel.

 

[Lessen]

Splitting the mount should work, but I would wait until the engine arrives before you whip out the dremel.

Oh yeah, no doubt. Hopefully it fits, but if not there is always plan B.

 

[qaart]

hey i fitted a .28 engine in a rustler you should be able to do some thiang to get it to fit