LRP ZR 28/30 roto start alignment?

[AeroFinn]

Gents,


The rotostart axle hole of the F4.6V1 engine is located in the top-left corner of the engine backplate when viewed from behind, enabling perfect alignment of the rotostart axle. See picture.

Here’s the thing: I’m planning to swap the stock engine for an LRP ZR.28 or ZR.32 engine. On this engine, the rotostart hole is located on the left side of the backplate, but not in the top-left corner — it’s positioned more vertically in the middle of the backplate.

My question is: will I run into problems starting the engine since the rotostart axle won’t have a straight path past the shock towers and other components, unlike with the stock setup?

What do you think?

 

[Vinni]

I finck you can rotate the Lrp rotobackplate ? It must deffo line up coz it’s the no1 choice for savages go on YouTube check the guys that run that system my Lrp savage is pullstart but I’m 99% shure it won’t be a problem there was 1 guy called nitro talk with Todd who add the problem yor wurryd about n he removed i bit of plastic wi a dremmal ? 👍

 

[ohsnap]

I abandoned efforts to put an LRP into a first gen Savage due to that alignment issue.
IIRC, there was more than just plastic in the way (I may be wrong here), but I seem to recall that there was a metal crossbar (or something else significant) in the way.

Your roto-start doesn't need a completely straight shot, but I couldn't figure out how to get a good angle to use the LRP's roto-start backplate.

You can fit the LRP arrangement into a Savage X, but their proprietary roto-start backplate (at least ones that I've been able to find) only has the connection point on the middle edge and you need one with it in the corner for the first gen bulkhead to work. Like the one on the right.

 

[AeroFinn]

Thanks Ohsnap and Vinni,

So wrapping up: either you go for the pullstart or skip the LRP option? I just happen to have an unrun LRP (Nosram) RS 30 that would be a nice engine for the truck. Especially as the stock F4.6v1 has next to no pinch.

Or, is there anyone that has succesfully mounted the HPI roto backplate (as shown in the picture sent by Ohsnap) in conjunction with the LRP oneway bearing arrangement?

P.S. I've never tried the pullstart. Maybe it's just fine? I've heard some stories about pullstart mechanism failures but I dunno.. Any advice if it turns out I need to go the pullstart route? I'm a new to the nitro trucks scene anyway.

 

[ohsnap]

Or, is there anyone that has succesfully mounted the HPI roto backplate (as shown in the picture sent by Ohsnap) in conjunction with the LRP oneway bearing arrangement?

You can't - The LRP engines backplate has a different bolt pattern than most other big blocks.
The holes that the screws thread into are further apart than HPI's (something like 31mm vs 27mm).
That's why I previously mentioned LRP's "proprietary roto-start backplate".

I've also never tried their pull-start (I'm lazy and swap out pulls for Roto's), but it's worth a try if you want to use the LRP in your Savage. There are some people who prefer pulls to Roto's, I'm just not one of them.

You can mount a roto-start LRP engine in a Savage equipped with Savage X bulkheads/shock tower, but I could not figure how to get one to work in a Savage with the first gen bulkhead.
I went so far as to replace a first gen bulkhead with a Savage X bulkhead/differential/shock tower arrangement in one older Savage to permit Roto-start access (different engine than the LRP - but same access issue).

If I were you...
Installing the LRP with the pull-start is your cheapest (and easiest) option.
Buying a Savage X roller and installing the LRP (with their Roto-start) is another one.
Buying a different engine and reusing your current Roto is another.

Installing complete Savage X bulkheads/differentials/shock towers, is also a straightforward option.
Installing Savage X bulkheads/shock towers and trying to reuse your current differential and pinion isn't so straightforward as there are shimming and tolerance issues to address.

Hope this helps.

 

[frogeyeman]

Gents,


The rotostart axle hole of the F4.6V1 engine is located in the top-left corner of the engine backplate when viewed from behind, enabling perfect alignment of the rotostart axle. See picture.

Here’s the thing: I’m planning to swap the stock engine for an LRP ZR.28 or ZR.32 engine. On this engine, the rotostart hole is located on the left side of the backplate, but not in the top-left corner — it’s positioned more vertically in the middle of the backplate.

My question is: will I run into problems starting the engine since the rotostart axle won’t have a straight path past the shock towers and other components, unlike with the stock setup?

What do you think?

With the standard Savage you will need the offset roto start. I have been through the process and only the offset one works. I do not like pull start and all my three Savages run roto..